Pentax P-TTL Hot Shoe Flash Comparison

The Expanded P-TTL Guide Website

When I started work on this guide, I had no idea how detailed it would become. It has certainly grown beyond the single "unit of knowledge" the Knol web site is intended to support. In addition to becoming unwieldy, it's hard to keep everything organized.Therefore, I've created an expanded version of this guide, which you can find at <http://pttl.mattdm.org/>. I still intend for this Knol page to be useful, and am thinking about ways to best use it — but for now, the new page is best. Future large expansions to the guide (including some interactive tools) will be at the expanded guide site. I will probably trim back some of the information here to make it less overwhelming and more of an overview. It will be interesting to see how this comes out as Knol itself progresses out of the beta phase.

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Overview of Options

P-TTL is Pentax's preflash-based through-the-lens flash metering system. It's used by all current and recent Pentax and Samsung digital SLR cameras to automatically obtain correct exposure for both camera-mounted flashes and wireless slave units. If you're interested in buying a Pentax-compatible flash, there are a lot of options to choose from. This article provides a comprehensive look at the different flash models available and explains in detail how they differ from one another.

There are currently three hot shoe flashes made by Pentax which work with the P-TTL flash metering system, plus four from Metz, one from Sigma in two variations, seven from Promaster, and one made by Sakar and marketed under many different names.

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Official Pentax Models

Pentax currently makes three hot shoe flash models:

• AF200FG — a basic model with no advanced features; offers a little over three times the power of the built-in flash on the K10D or K2000/K-m, and about double that on the K20D or K200D. In the US, this flash is bundled in a kit with the K2000.
  
• AF360FGZ — a much nicer flash available at a good price. Many advanced features; the most notable lack is a swivel head for bouncing from the ceiling in portrait orientation.
  
• AF540FGZ — Pentax's top of the line model. Big and powerful, with the ability to connect an external power source for faster refresh times.

Pentax also makes a P-TTL ring flash for close-up work, the AF160FC. This is worth mentioning as part of the Pentax system, but since it's a specialty item it isn't covered in this article.

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Samsung Rebadged Models

Samsung sells the AF360FGZ and the AF540FGZ as the SEF-36PZF and SEF-54PFZ. These do not appear to be currently available in the US, but are presumed to be functionally identical to their Pentax twins.

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Metz

German flash maker Metz historically used a system of interchangeable modules to provide compatibility with various camera systems. They still make many models that use that system, including one hot shoe flash which works with P-TTL, but they now have three dedicated P-TTL flashes as well:

• Mecablitz 36 AF-4 — an entry-level flash with a few more tricks than the Pentax AF200FG and flash power about like the AF360FGZ. The Pentax version of this flash is very new and does not appear to be available yet in the US.
  
• Mecablitz 48 AF-1 — effectively a small upgrade from Pentax's AF360FGZ, with about 50% more power, a tilt/swivel head, and equivalent advanced functionality (plus a few unique features). Oddly, while the 48 AF-1 can function as an off-camera wireless slave it cannot act as a camera-mounted controller for other slaves.
  
• Mecablitz 54 MZ-4i — this older model requires the SCA 3702 adapter module with firmware M2 or later. With that module, the 54 MZ-4i has features roughly equivalent to the 58 AF-1, but slightly less flash power. It also can't do Pentax's P-TTL wireless, but can act as part of Metz's own wireless auto flash system.
  
• Mecablitz 58 AF-1 — another completely-dedicated model, with more power and the longest list of features of any Pentax-compatible flash.

Additionally, there are two module-based Pentax-compatible models not covered here: the 45 CL-4 and the top-of-the-line 76 MZ-5. These are "hammerhead"-style flashes, designed to mount on a flash bracket and connect via a cable (included with the 76 MZ-5 but not the 45 CL-4) to the shoe-mounted SCA 3702 adapter.

Metz also makes a P-TTL ring flash, the Mecablitz 15 MS-1, which operates as a wireless P-TTL slave (which would allow an on-camera controller to also control additional slaves).

The 48 AF-1 and 58 AF-1 modules feature a USB port for in-the-field firmware upgrades. The 36 AF-4 may need to be sent for factory service for compatibility upgrades to match future Pentax cameras. The 54 MZ-4i is upgradable via factory updates to the SCA module.

While Metz flashes are more expensive than their Pentax counterparts in the US, the reverse is often true in Europe.

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Sigma

Sigma makes two almost-identical flash units:

• EF-530 DG ST — relatively inexpensive, but powerful and capable.
  
• EF-530 DG Super — adds wireless P-TTL, high-speed sync, better manual control, and a few more features.
  

Sigma's older EF 500 DG models are basically the same with about 10% less power. The older flashes flashes may need to be sent to Sigma for a free firmware upgrade for compatibility with current Pentax camera bodies, and the current Sigma flashes may need the same for future cameras.

Sigma makes a macro ring flash as well, the EM-140 DG, which can act as a wireless P-TTL controller.

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Promaster

Promaster makes a series of P-TTL compatible flashes, and also has a module-based line. The module-based models require the 5050DXR/PX digital flash module.

• 5250DX — a very simple module-based model with a tilt head and non-zooming reflector.
• 5550DX — still basic, but this module-based flash adds a tilt and swivel head.
  
• 5750DX — a more powerful module-based flash with a non-motorized zoom and a secondary reflector.
  

• 7200EDF — a basic P-TTL-dedicated model with a bit more power.
• 7400EDF — this P-TTL-dedicated model adds a motorized zoom (and a power increase).
  
• 7500EDF — and this P-TTL adds yet more power, a swivel head, and a secondary reflector.

As with the Sigma flashes, firmware upgrades must be performed at the factory.

And Promaster also has a macro ring flash, the MacroLume TTL Digital. This is module-based, and uses the same modules as the 5000-series flashes. Promaster informs me that modules and flash units shipped from the warehouse after August 2008 have the proper codes to communicate with current Pentax dSLRs but that earlier copies may need to be sent in for an update.

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Sakar, Under Many Names

There's also a "generic make" flash made by Sakar and sold as the Sakar / Digital Concepts 952AF/PEN, Soligor DG-420 Z, Dörr DAF-42, and perhaps other names. The Vivitar DF400MZ and  Praktica Exakta DPZ 38AF look similar but claim slightly smaller guide numbers. Given anecdotal reports that the Sakar / Digital Concepts model is somewhat underpowered, it's entirely possible that they are just being more honest — and in fact, some empirical testing indicates that the guide number is even lower than that.

Newer versions of this flash have P-TTL support, but older versions do not. I am not aware of a good way to tell which it will be without testing, and I don't think an upgrade is available. The Praktica / Exacta 38AF models are quite certainly all too old, and it seems likely that the Vivitar-branded models (which appeared more recently) are all the new design. Soligor has confirmed that their model uses P-TTL.

Either way, they don't have high-speed sync or work as P-TTL optical wireless slaves.

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Feature Comparison

Feature Charts

Major Features

Make	Model	Tilt/Swivel	Zoom¹	Wireless	HSS	2nd Sync	Manual	Auto	2nd Flash
Pentax	AF200FG	No	None				Full only
	AF360FGZ	Tilt Only	85mm	✓	✓	✓	6 steps	✓²
	AF540FGZ	Both	85mm	✓	✓	✓	7 steps	✓²
Metz	36 AF-4	Tilt Only	85mm³			✓	None
	48 AF-1	Both	105mm	✓⁴	✓	✓	8 steps
	54 MZ-4i⁵	Both	105mm		✓	✓	25 steps	✓	⁶
	58 AF-1	Both	105mm	✓	✓	✓	25 steps	✓	✓
Sigma	EF-530 DG ST	Both	105mm				Full or ¹⁄₁₆
	EF-530 DG Super	Both	105mm	✓	✓	✓	7 steps
Promaster	5250DX⁷	Tilt Only	None				None⁸	⁹
	5550DX⁷	Both	None				None⁸	⁹
	5750DX⁷	Both	85mm¹⁰				None⁸	⁹	✓
	7200EDF	Tilt Only	None				None
	7400EDF	Tilt Only	105mm¹¹				None
	7500EDF	Both	105mm			✓	7 steps		✓
Sakar¹²	952AF/PEN¹²	Both	85mm			✓	5 steps

¹ Expressed as 35mm EFL.
² Only with camera in M mode.
³ Manual zoom only. Zoom range begins at 28mm and skips the typical 70mm zoom stop.
⁴ As wireless P-TTL slave only — not as controller.
⁵ Requires SCA 3702 adapter for P-TTL functionality.
⁶ Does not work in P-TTL mode even with SCA 3702 module.
⁷ Requires 5050DXR/PX digital flash module for P-TTL functionality
⁸ Full or ¹⁄₁₆ when used with separate FTM5000 manual focus module.
⁹ Auto mode available with separate FTA5000 auto focus module.
¹⁰ Manual zoom only, to 35mm, 50mm, or 85mm.
¹¹ Missing the typical 28mm and 70mm zoom stops
¹² Also available under many other different brands and names. Some models may not be P-TTL compatible.

Other Features

Make	Model	Custom Auto-Off	Contrast Control	Modeling Light	Strobe Mode	Flash Bracketing	Spot Beam	Beep Option	Format Conversion	Extended Zoom
Pentax	AF200FG
	AF360FGZ		✓	✓			✓		✓
	AF540FGZ	✓¹	✓	✓			✓		✓
Metz	36 AF-4
	48 AF-1	✓	✓	✓		✓	✓		✓	✓
	54 MZ-4i²	✓	✓	✓	✓	✓	✓	✓	✓	✓
	58 AF-1	✓	✓	✓	✓	✓	✓	✓	✓	✓
Sigma	EF-530 DG ST		✓
	EF-530 DG Super		✓	✓	✓
Promaster	5250DX
	5550DX
	5750DX
	7200EDF
	7400EDF
	7500EDF			✓	✓
Sakar³	952AF/PEN³

¹ Only enabled or disabled.
² Requires SCA 3702 adapter for many of these functions.
² Also available under many other different brands and names. Some models may not be P-TTL compatible.

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Feature Discussion

Tilt/Swivel

A flash which simply sits in the hot shoe pointing forward offers little more than what one gets with a built-in flash. In fact, since the Pentax AF200FGZ does not work as an optical wireless P-TTL controller, it is actually a step back in features from the built-in flash on most recent Pentax camera bodies. All other models covered here can tilt upwards, enabling ceiling-bounced flash for indirect, even lighting. All except the Metz 36 AF-4 can also tilt downwards for more even coverage of close subjects (-10° for Pentax models, -7° for the others). Most have click stops at 0°, 45°, 60°, 75°, and 90°, but the Sigma model only clicks into place straight forwards and straight up.

Many of the flashes also have a swivel feature, which is vital when using ceiling-bounced flash with the camera in portrait orientation. Of course, if your primary use of the flash is off-camera, this is unnecessary.

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Wide-Angle Diffuser

All models but the Promaster flashes and the Metz 36 AF-4 have a built-in wide-angle diffuser which pops out and flips down over the flash head. Most Promaster units include a push-on diffuser in the package. These diffusers are not designed to soften light but simply to disperse it for use with wider-angle lenses. This is necessary at real focal lengths (on current Pentax dSLRs) below 16mm for the zoom models and below about 19mm for the fixed reflector models. Although the exact claimed numbers vary, using the diffuser should provide coverage down to approximately 13mm (again, real focal length).

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Bounce Cards

The Pentax FGZ zoom models, Metz 48 AF-1 and 58 AF-1 models, and Sakar flash all have a built-in bounce card next to the pop-out diffuser. This can be used to bounce a small portion of light forward to provide catchlights in the eyes of your subjects.

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Secondary Reflectors

The Metz 54 MZ-4i, Metz 58 AF-1, and Promaster 5750DX and 7500EDF additionally have a secondary forward-facing reflector to which some of the flash power can be directed. This can provide more forward-directed light than a bounce card in order to fill in shadows. There is a separate flash bulb, but power comes from the same source, so main flash power is reduced by about 15%.

The secondary flash on the Metz 58 AF-1 has a guide number of 15 and covers a 35mm field of view (35mm equivalent focal length). It can be used at half or quarter power via a menu option and works with P-TTL bounce flash.

The 54 MZ-4i's flash has a guide number of 10, and can be cut in half by physically changing a filter. Unfortunately, the secondary reflector on the 54 MZ-4i does not work in P-TTL mode — non-P-TTL auto must be used instead. The 58 AF-1 does not have this limitation.

The Promaster 7500EDF's secondary reflector is somewhat less powerful, with a guide number of about 6.4 at a much tighter angle of view of 50mm.

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Zoom

Flash light is only useful when it's actually included in the photograph. Therefore, more advanced flashes feature motorized zoom reflectors which automatically narrow at greater focal lengths. This directs more of the flash power directly into the field of view. All auto-zoom flashes listed here begin at 24mm in 35mm terms, but Pentax and Sakar stop at 85mm while the rest go to 105mm. See below for details on how this affects flash power at higher focal lengths.

Note that the Promaster 7400EDF is missing the typical 28mm and 70mm zoom steps.

The Promaster 5750DX has a zoom reflector, but it isn't motorized or automatic. Instead, it can be set manually to 35mm, 50mm, or 85mm. The Metz 36 AF-4 also has a manual zoom reflector; it can be set manually to 28mm, 35mm, 50mm, or 85mm.

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Wireless

Pentax's P-TTL system includes the ability to control flashes remotely, not just as dumb slaves but with coordinated exposure information. There are two required components: a master or control flash and at least one off-camera slave flash. The built-in flash on every K-series Pentax dSLR except the K100D/K100D Super can act as a master/control flash — even on the low-end K-m/K2000. (This is an amazing feature unique to Pentax at the low end. Nikon's i-TTL wireless system is more advanced, but is not available on their low-end cameras or their low-end flashes.)

Pentax's AF200FG is unfortunately not able to act as part of a wireless P-TTL setup, which, in combination with its lack of a tilt head makes it largely useless. If Pentax were to add this feature to a future version, the flash would move from being merely basic to being an entry-level to the whole system and would remain useful as secondary lights for intermediate users.

Both the Pentax AF360FGZ and AF540FGZ can act as both controller and slave units.

The Metz 48 AF-1 can act as a slave, but not as a controller. The 58 AF-1 can do both.

The 54MZ-4i can't participate in Pentax's system but with a separate module from Metz can have similar functionality in combination with other Metz flashes in non-P-TTL auto mode — either other 54MZ-4i flashes or more powerful models, or with the 28 CS-2 slave unit (which seems a bit pricey in the US but is interestingly reasonable in Europe).

Sigma's Super version can act as both slave or controller; the ST version can't do either. Be aware that in low light when using a built-in flash as a controller, a EF-530 DG Super slave may be triggered erroneously by the camera's autofocus assist strobe — a problem Pentax and Metz don't share.

The Sigma EF-530 DG Super, the Promaster 7500EDF and the Sakar flash can be used as dumb slaves (simply flashing in response to another flash), but this requires another non-P-TTL flash on-camera, because otherwise they will be triggered before the exposure by the P-TTL preflash. Promaster also makes a slave module for the 5000-series flashes. This has the same limitation.

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High-Speed Sync

This allows one to use the flash in combination with shutter speeds faster than the camera's sync speed, which in current Pentax models is 1/180th of a second. At shutter speeds exceeding that, there's never actually any time when the entire sensor is exposed at once: there's just a fast-travelling slit between the front and rear shutters. HSS works by creating many very fast pulses rather than one bright flash, so the tradeoff is reduced power. This isn't necessary (in fact, quite the contrary) for freezing motion — for that, you need to look at the actual flash duration (which is generally much, much shorter than the shutter speed).

The Pentax AF360FGZ and AF540FGZ can do this, as can the Metz 48 AF-1 and 58 AF-1 models and the Sigma Super variant. Sigma calls it FP flash (for focal plane) instead of HSS.

The Metz 54 MZ-4i has the ability to do HSS with some systems, but not currently with Pentax and the SCA-3702 module.

Note that HSS can be used in combination with wireless P-TTL, but not when using the camera's on-board flash as the controller. This may simply be a software limitation due to user interface design — wireless flash mode and high-speed sync mode are separate choices one may select from the various flash modes, rather than being independent switches.

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Rear-Curtain Sync

Rear-curtain sync (also called second- or trailing-curtain sync) is the ability to time the flash pulse to just before the shutter closes rather than when it opens. This is usually used in combination with a longer exposure to gather ambient light while using the flash to freeze a main subject. With first-curtain slow sync, any motion trails captured by the ambient exposure appear to lead backwards from frozen subject. Rear-curtain makes it look right, but the downside is that it's much harder to get the timing right.

Again, the Pentax AF360FGZ and AF540FGZ can do this, as can all Metz models and the Sigma Super variant. Additionally, the Promaster 7500EDF and Sakar flashes can too.

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Flash Output Compensation in P-TTL Mode

The Pentax flash control system lets you set a flash compensation value on the camera body which is cumulative with any value set on the flash itself. (Having two independent settings is most important when using multiple flashes for a scene.)

With the exception of the AF200FG (which only offers Auto, -0.5, or -1), the Pentax and Sigma flashes allow compensation from -3 to +1 in half-stop increments.

The Metz flashes allow EV -3 to EV +3 in third-stop increments, except for the 36 AF-4, which has no independent compensation control.

The Promaster and Sakar flashes don't have separate on-flash settings (but are still affected by the camera's setting for flash EV compensation.)

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Manual Power Control

Most models allow one to turn off P-TTL mode and simply control the flash manually. This is done by setting the flash to output at a certain fraction of its full power, normally ¹⁄₁, ½, ¼, ⅛, etc.

Metz is the clear winner here, with the top models having 25 settings all the way down to ¹⁄₂₅₆ power in third-stop increments, and even the 48 AF-1 has 8 steps down to ¹⁄₁₂₈.

The top-of-the-line Pentax AF540FGZ, Sigma EF-530 DG Super, and Promaster 7500EDF flashes each have 7 steps to ¹⁄₆₄, followed by the Pentax AF360FGZ at 6 steps to ¹⁄₃₂ and the Sakar flash at 5 steps to ¹⁄₁₆.

Of course, since the AF360FGZ has about half the power of the AF540FGZ, ¹⁄₃₂ of the former is about the same power as ¹⁄₆₄ of the latter.

The Sigma EF-530 DG ST allows only full or ¹⁄₁₆ power, and the Pentax AF200FG can only be manually fired at full power. The Metz 5000-series flashes can be equipped with a separate module which enables manual flash at full or ¹⁄₁₆ power. The Metz 36 AF-4 and Promaster 7200EDF and 7400EDF models to have no manual mode at all.

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Other Flash Modes

This article is only concerned with P-TTL operation. However, older camera bodies do not support this, and it is sometimes desirable to have the flash choose the appropriate power  level itself.

Regular TTL

P-TTL works by sending a small flash pulse at much less than full power. Light bounced back to the camera from this preflash is used to compute the amount of power required for the real flash, which follows nearly instantaneously. Old-style TTL worked by measuring light reflected off of the film, or from the sensor in early Pentax models. Apparently this was problematic when used with modern sensor coatings, so this mode is no longer available in current camera bodies — a discussion for another article.

The Pentax, Metz, and Sigma models all automatically revert to regular TTL on camera bodies where that is available but P-TTL is not. The Promaster flashes don't support regular TTL and will fire at full power. It is unclear how Sakar flashes behave in this situation and it may depend on the specific version.

It's important to keep in mind that this is strictly a backwards-compatibility feature. The old-style TTL requires an additional light sensor in the camera body, and that's unlikely to come back.

Auto

It would sometimes be convenient for the flash to be able to choose the appropriate power level automatically itself. P-TTL isn't available with manual-focus lenses which lack electronic communication with the camera body, and it handles some scenes (particularly when there are reflective surfaces in the shot) erratically.

This is sometimes called "auto thyristor", and requires a sensor on the flash, which most models do not have — only the Pentax AF360FGZ and AF540FGZ, and the Metz 58 AF-1. The Metz 54 MZ-4i has an auto sensor in the Pentax-specific module and can also use the auto-only standard SCA 301 module.

Auto mode on the Pentax flashes is clearly intended for older camera bodies only. Although the manual does not make this clear, auto mode only works when the camera is set to M. The Metz 58 AF-1, by contrast, works in all program modes — and also automatically reads the current aperture and ISO information from the camera.

Promaster offers a separate module for its 5000-series flashes which makes them work in auto mode.

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Customizable Auto-Off

All of the flashes turn off automatically after a few minutes of inactivity, and can be turned back on by lightly pressing the camera's shutter button. This auto-off feature can be disabled on the Pentax AF540FGZ, and on the Metz flashes (except the AF 36-4) either disabled or changed between a 1 minute or 10 minute delay.

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Contrast Control Sync

This is a Pentax flash system feature where a cable-connected flash fires in combination with the camera's built-in flash. The built-in flash provides one third of the required light and the off-camera flash provides the rest. Pentax and Metz supports this on their more advanced models, and Sigma on both models. This mode does not appear to be meaningful when using wireless P-TTL. In any case, setting flash-based exposure compensation can be used instead, for models which support that.

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Modeling Light Option

A modeling light mode causes the flash to strobe for a brief time, temporarily providing the effect of a constant light. This allows one to directly see where shadows will fall before taking a photograph. The entry-level models from each manufacturer are missing this feature, but the middle and higher-end models all have it.

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Stroboscopic Mode

The Metz MZ 54-4i and AF 58-1, the Sigma EF-530 DG Super, and the Promaster 7500EDF can produce multiple visible flashes per exposure to produce a multiple-stop-motion effect in one image. These multiple flashes must be at lower than full power.

The Metz flashes can fire up to 50 flashes at speeds ranging from 1hz to 50hz at a maximum of ¼ power. The Sigma flash can fire up to 90 flashes at a frequency from 1hz to 100hz, with the limits changing depending on the power level selected (again, at maximum ¼  power). The Promaster can fire up to 10 flashes at seven choices of frequency ranging from 1hz to 100hz, at ¹⁄₁₆ power only.

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Automatic Flash Bracketing

The Metz flashes (except the AF 36 AF-4) have an auto-bracketing feature where three consecutive shots are taken, the first with no exposure compensation, the next with negative compensation, and finally with positive compensation. The correction value can be up to 3EV each direction, in ⅓ stop increments.

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Auto-Focus Assist / Spot Beam

All flashes except the Pentax AF200FG include a focus-assist beam which replaces the horrible subject-startling strobe effect Pentax built-in flashes use to provide AF assist. Additionally, Pentax and most Metz models provide a mode where the AF assist light is enabled but the flash doesn't fire.

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Beep Function

The higher-end Metz flashes can be made to beep when the flash is ready, on correct exposure, and on errors. Metz flashes are unusually quiet while recharging, and without the familiar high-pitched whine of a flash that isn't ready yet, it's nice to have an alternative indicator.

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Camera Format Conversion

The area of coverage provided by a zoom flash is conventionally referred to in 35mm full-frame terms. The Pentax and Metz zoom flashes can instead display real APS-C focal lengths. (I'm not yet sure about the Metz AF 36-4, as I haven't even seen images of that model's user interface.)

Of course, the other flashes actually zoom to the correct angle of view for APS-C lenses, but their displays require mental conversion.

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Extended Zoom Mode

Metz auto-zoom flashes have a unique feature: they can be set so they use one zoom step wider than strictly required to cover the field of view of the current lens focal length. This provides a more diffuse light with more reflections bounced from out-of-frame — nice, when you don't need all the focused power anyway. Of course, you can do this manually on the AF 36-4, or on any flash in manual-zoom mode, but then you must remember to keep up as focal length changes.

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Comparing Flash Power

The relative power of these flashes can be confusing to compare because the manufacturers don't list their flash power specs by luminosity, only via guide numbers. And to make things worse, product overview web pages tend to present only a random sampling of different focal lengths at which they've measured the GN, so more complete correlation takes some digging. And there's not an industry of rigorous third-party testing for flashes, so we have to take them at their word.

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Guide Numbers

The guide number gives the (nominal) number of meters away a subject can be to be lit at that focal length and ISO, at f/1. Divide by aperture to get effective distance stopped down to the realm of real lenses — that is, the Metz 48 AF-1 is listed as providing full lighting at about 3.6 meters away at f/8. (That's approximately 12 feet, for those of us accustomed to the Imperial system.)

This really ought to be tested by someone with access to all of the flash units and a flash meter to give a perfect answer, but this is what I can do with the publicly-stated data. With some scouring of manuals and official web sites, I put together the following list of manufacturer-claimed guide numbers (in meters) for ISO 100 at various 35mm-equivalent focal lengths. Remember to divide by 1.5 to get real focal lengths for Pentax's current APS-C dSLR bodies. The list is ordered by guide number at 50mm, with the Sakar unit placed at its estimated position.

Guide Numbers in Meters		Wide¹	24mm	28mm	35mm	50mm	70mm	85mm	105mm
Pentax	K10D/K2000	✗	✗	11	✗	✗	✗	✗	✗
Pentax	K20D/K200D	✗	✗	13	✗	✗	✗	✗	✗
Pentax	AF200FG	15	✗	20	✗	✗	✗	✗	✗
Promaster	5250DX	✗	✗	24	✗	✗	✗	✗	✗
Metz	36 AF-4	✗	✗	20	24	30	✗	36	✗
Pentax	AF360FGZ	14	21	22	25	30	33	36	✗
Promaster	5550DX	✗	✗	30	✗	✗	✗	✗	✗
Promaster	7200EDF	20	✗	30	✗	✗	✗	✗	✗
Sakar	952AF/PEN	?	?	?	?	?	?	42	✗
Promaster	7400EDF	13	20	✗	27	30	✗	34	37
Promaster	7500EDF	14	23	26	30	34	38	40	42
Metz	48 AF-1	21	24	26	29	35	38	43	48
Promaster	5750DX	24	✗	✗	32	36	✗	40	✗
Sigma	EF-530 DG²	?	28	29	31	40	45	48	53
Metz	54 MZ-4i	22	28	31	34	40	44	46	54
Metz	58 AF-1	25	29	31	35	42	46	52	58
Pentax	AF540FGZ	21	32	35	39	45	50	54	✗

¹ with built-in or included wide-angle diffuser.
² both Super and ST models.
✗ indicates that this flash does not have this zoom step.

If we assume the numbers are truthful, or at least that all the brands all lying equally, then this may be somewhat useful.

I'm working on a graphical chart presenting this data, but my current attempt is basically just a meaningless jumble of rainbow lines. Ideally a scripted form would allow one to display just a few selected options to compare, but Google Knol doesn't currently allow that.

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Relative Power

The power in terms of light output is proportional to the square of the guide number. However, a simple comparison in this way isn't necessarily the most useful in practice. Generally the relative power of each flash is mostly consistent across the zoom range, but depending on how the flash is to be typically used, different factors may be more important. So, it's helpful to look at the data in a number of different ways.

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Focused Power

Since the guide number at the narrowest reflector zoom setting is the biggest, flash makers like to focus on it, usually working it into product names.

The Metz, Sigma, and Promaster flashes have a reflector which can focus the burst more tightly than the Pentax and Sakar flashes — they go to 105mm (35mm full-frame), whereas the Pentax and Sakar models have zoom reflectors which stop at 85mm. (The zoom reflectors move in discrete steps rather than being continuous, so there's no particular benefit at until you go above the final step.) So, on a current 1.5×-crop Pentax dSLR, if you're at a (real) focal length of 70mm or above, the relative list looks like this, normalized to the Pentax  AF360FGZ.

• Metz 58 AF-1 = 2.6×
• Pentax AF540FGZ = 2.2×
• Metz MZ-4i = 2.2×
• Sigma EF-530 DG = 2.1×
• Metz 48 AF-1 = 1.8×
• Promaster 7500EDF = 1.4×
• Sakar 952AF/PEN, et al = 1.4×
• Promaster 5750DX = 1.2×
• Promaster 7400EDF = 1.0×
• Promaster 5550DX = 1.0×
• Pentax AF360FGZ = 1.0× (Of course.)
• Metz 36 AF-4 = 1.0×
• Promaster 7200EDF = 0.72×
• Promaster 5250DX = 0.46×
  
• Pentax AF200FG = 0.31×
• K20D/K200D built-in = 0.13×
• K100D/K10D/K2000/K-m built-in = 0.09×

The number for Sakar is based on their single published figure: their claimed power at maximum zoom of 85mm. Anecdotal reports suggest that the flash is actually less powerful than this in practice. Therefore, I don't recommend putting much faith in it without further information.

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Normal Power

The narrow beam guide number is interesting, but are only relevant at higher focal lengths. This list represents the middle of the zoom range — a field of view which covers the "normal lens" range of 50mm equivalent focal length — that is, about 35mm on a current Pentax dSLR.

• Pentax AF540FGZ = 2.2×
• Metz 58 AF-1 = 2.0×
• Metz MZ-4i = 1.8×
• Sigma EF-530 DG = 1.8×
• Promaster 5750 = 1.4×
• Metz 48 AF-1 = 1.4×
• Promaster 7500EDF = 1.3×
• Promaster 7400EDF = 1.0×
• Promaster 7200EDF = 1.0×
• Promaster 5550DX = 1.0×
• Pentax AF360FGZ = 1.0× (Of course.)
• Metz 36 AF-4 = 1.0×
• Promaster 5250DX = 0.66×
• Pentax AF200FG = 0.44×
• K20D/K200D built-in = 0.19×
• K100D/K10D/K2000/K-m built-in = 0.13×

Since there is no data from Sakar, the 952AF/PEN can't be included in this list.

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Wide-Angle Power

The relative power level of each flash at different zoom levels is relatively consistent: the 50mm chart above is so close to the ones for 35mm, 70mm, and 85mm that there's no point in graphing them separately. The only exceptions are at the narrowest zoom position as detailed above, and at the widest setting.

The fixed-reflector flashes are set at a 28mm coverage angle (35mm equivalent), and can't go wider than that without a diffuser, while all of the zoom flashes except the Metz 36 AF-4 go to 24mm. At higher focal lengths, the inability to produce a more focused beam severely penalizes the fixed-reflector packages. This is particularly unfair to the tiltable-reflector Promaster flashes, because it is common to use a non-zoomed setting when using bounced light — so this value may be your typical use case.

Here are the fixed-reflector flashes, normalized to the Pentax AF360FGZ set to 28mm:

• Promaster 7200EDF = 1.9×
• Promaster 5550DX = 1.9×
• Promaster 5250DX = 1.2×
• Pentax AF200FG = 0.83×
• K20D/K200D built-in = 0.35×
• K100D/K10D/K2000/K-m built-in = 0.25×

Note the oddity with the Promaster figures — the 7200EDF does not zoom but Promaster claims a GN of 100' at its fixed 28mm coverage, the same as the 7400EDF zoomed to 50mm. E-mail from Promaster confirms that the 7200EDF does indeed have a more powerful strobe to compensate for its lack of zoom. In fact, by the manufacturer-stated numbers, at 28mm it is more powerful than all but the most expensive offerings from other companies.

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Flash Burst Profiles

Another practical approach is to look at the total area each flash could cover at any zoom setting. That is, consider the flash to be fixed in one place and examine the possible places a single subject could stand and be appropriately lit. This takes into account both flash reflector zoom angles and the raw power needed to reach into the distance.

The following flash burst profile images use the actual correct angles for zoom settings. The shape and proportion of the profile remains the same regardless of aperture and ISO, but of course becomes smaller. And obviously light doesn't really work like this: the hard-edged cutoffs are a fiction — but a convenient one.

As Sakar does not provide complete guide number data, no flash burst profile is available.

Relative Potential Flash Coverage

This concept can be boiled down to a single number by measuring the total potential area of flash coverage. The following list shows this area relative to that covered by the Pentax AF360FGZ.

Keep in mind several things when looking at these numbers. First, the data is entirely based on manufacturer-stated numbers which may be faulty in multiple ways: the guide number could be overstated, and the angle of coverage at a given zoom position could be not completely adequate. Second, this particular number is not a measure of raw flash power. It's a partial indicator of the versatility which a certain amount of power can give you in combination with the zoom reflector of a particular flash.

• Pentax AF540FGZ = 2.3×
• Metz 58 AF-1 = 2.2×
• Metz 54 MZ-4i = 2.0×
• Sigma EF-530 DG = 1.9×
• Metz 48 AF-1 = 1.5×
• Promaster 7500EDF = 1.3×
• Promaster 5750DX = 1.1×
  
• Pentax AF360FGZ = 1.0× (Of course.)
• Promaster 7400EDF = 1.0×
• Promaster 7200EDF = 0.93×
• Promaster 5550DX = 0.93×
• Metz 36 AF-4 = 0.88×
• Promaster 5250DX = 0.60×
• Pentax AF200FG = 0.41×
• K20D/K200D built-in = 0.18×
• K100D/K10D/K2000 built-in = 0.13×

Again, since Sakar does not provide complete guide number data, their flash cannot be included in this comparison.

If you need more power than this in a single flash, the non-hot-shoe mount Metz flashes which can use the Pentax P-TTL SCA module come in at 1.7× for the 45 CL-4 (with a much higher guide number at 35mm than any of the above), and an impressive 3.9× for the 76 MZ-5.

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Flash Duration & Recharge Times

Flash Duration

The normal style of strobe flash (including all those listed here) varies light output by reducing the duration of the flash pulse. Flash duration is important for two reasons. First, a pulse longer than the time the shutter is completely open is partially wasted. The camera's shutter sync speed (¹⁄₁₈₀th of a second, for current Pentax dSLRs) is the absolute limit for this, but if the flash pulse can't keep up with even slower shutter speeds underexposure will result. Second, when using a flash as the primary light source, shutter speed is irrelevant for purposes of freezing motion, and only flash duration matters.

A flash pulse is a curve, not a straight on-off thing. This makes measuring flash duration tricky, and so it's done in a tricky way. The standard normally used is the T.5 time, which is the time in which the light output is at least half of the brightest level. This number isn't particularly helpful for any practical use, but can serve as a standard for comparing between different models.

Another measurement is the T.1 time: time in which the light output is above 10% of the peak. This comes much closer to representing the meaningful duration of light output. A rule of thumb is that T.1 duration is approximately three times the T.5 time, but there's no absolute correlation.

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Pentax, Sigma, Promaster, Sakar

Pentax provides no duration information for the AF200FG, but for lists the T.5 time for both the AF360FGZ and the AF540FGZ as approximately ¹⁄₁₂₀₀ seconds at full power and ¹⁄₂₀,₀₀₀ seconds at minimum power. Unfortunately, Pentax customer service was unable to provide more detailed information on request. It's a bit odd that the same numbers are repeated for both flashes, since not only does full power vary greatly between them but also minimum power is ¹⁄₃₂ of full in one case and ¹⁄₆₄ in the other. We can estimate that the T.1 time is about ¹⁄₄₀₀ seconds at full power and that stopping power goes down to about ¹⁄₆₀₀₀, but it doesn't seem safe to extrapolate too much from these numbers.

Sigma simply states that the flash duration for full-power firing is about ¹⁄₇₀₀ seconds. No details are provided, but it seems safe to assume that this is the standard T.5 measurement, which would put the T.1 speed at around ¹/₂₃₃ seconds — give or take. My request for more details as declined — "I spoke with our corporate office regarding this issue and unfortunately we cannot provide you with privileged information to you as it is not available at this time. We apologize for the inconvenience."

Promaster claims a duration range of ¹⁄₁₀₀₀ to ¹⁄₃₀,₀₀₀ seconds, and Sakar says ¹⁄₁₀₀₀ to ¹⁄₂₀,₀₀₀ seconds. Again it seems unwise to extrapolate much from this beyond the guess that this refers to T.5 time.

There are reports that the Sakar 952AF/PEN underexposes when a full charge is needed; this may be a symptom of a too-long flash duration at maximum power.

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Metz — Useful Data!

Metz does not provide T.5 times at all, but instead gives full tables of T.1 durations at each power level stop. The tables are not identified as such, but Metz customer service confirms that this is the measurement method used. This is excellent news, since T.1 is the actually-useful number. The ranges given are as follows:

• 48 AF-1: from ¹⁄₁₂₅ seconds at full power to ¹⁄₂₅,₀₀₀ seconds at ¹⁄₁₂₈ power
• 54 MZ-4i: from ¹⁄₂₀₀ seconds at full power to ¹⁄₂₆,₀₀₀ seconds at ¹⁄₂₅₆ power
• 58 AF-1: from ¹⁄₁₂₅ seconds at full power to ¹⁄₃₃,₀₀₀ seconds at ¹⁄₂₅₆ power

The reduced-power numbers are significantly faster than anything available from the other manufacturers. This is partly because Metz's flashes allow several stops more latitude in reducing flash power than the competition.

At the other end of the scale, though, there is a concern that the flash duration of the 48 AF-1 and 58 AF-1 at full power exceeds the ¹⁄₁₈₀ second sync speed. Metz technical support confirms that when full flash is necessary, the shutter speed must be kept below the listed duration. However, it should be noted that Metz is the only maker to give solid numbers on this at all, so I would be careful about holding this against them unless we can get better real data from anyone else. Also, when the flash is used as the primary light source, my K10D in P mode prefers to set the shutter speed to ¹⁄₆₀ with any P-TTL flash, well within the safe range.

Metz does not provide a detailed chart of flash duration for the 36 AF-4, probably because without manual control that information would be of little use. The duration is listed as ¹⁄₅₀₀ to ¹⁄₃₀,₀₀₀ seconds, and Metz technical support confirms that this is indeed the T.1 number — the tech even tested in the lab to double check at my request. (The T.5 duration is about ¹⁄₁₀₀₀.)

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Semi-Practical Duration Chart

The T.1 timing data can be used in combination with guide number information to calculate the maximum distance at which one can freeze motion to a given duration. The following chart is for ISO 100 at f/2.8. Multiply the distance by √2 in order to increase ISO or aperture by one stop or conversely divide to go the other direction. It assumes maximum zoom.

Again, please remember that this is based on manufacturer-published data rather than on actual measurements. There's really not going to be any useful way to calculate this without careful hands-on testing.

The ✖ indicates a very rough approximation of the range and duration of the Pentax AF540FGZ at minimum power based on the given T.5 number. (The AF360FGZ estimate is about a tenth of a meter less, and therefore basically in the same approximate range.) This is really just an educated guess, and I only include it at all because Pentax-branded equipment is obviously of particular interest.

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Recycle Time

Make	Model	Alkaline	Ni-MH	Lithium	Power Pack
Pentax	AF200FG	4	4	4	✗
	AF360FGZ	6	6	6	✗
	AF540FGZ	6	6	6	4.5
Metz	48 AF-1	3.5	3.5	3.5	✗
	54 MZ-4i	6	5	?	?
	58 AF-1	5	5	?	2.5
Sigma	EF-530 DG¹	6	4	?	✗
Promaster	5250DX	10	?	?	✗
	5550DX	10	?	?	✗
	5750DX	10	?	?	✗
	7200EDF	10	?	?	✗
	7400EDF	10	?	?	✗
	7500EDF	10	?	?	✗
Sakar	952AF/PEN	9	?	?	✗

¹ both Super and ST models.

Keep in mind that these numbers represent the worst case: time to recover from a full discharge. A more powerful flash will need a smaller portion of full charge for a given level of light and will be correspondingly faster in practical use. On the other hand, recharge times will increase as the battery drains.

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Physical Qualities

Size and Weight

Size and Shape

Although all flash makers list the height, width, and thickness of their flash units in the manuals, the fact that flashes are not actually cubical makes these numbers not particularly useful on their own. All of the flashes bulge in different directions, and there's different degrees of narrowing near the base. The Metz 48 AF-1 is nominally smaller than the Sigma EF530-DG, but it's fatter, so it doesn't necessarily take up less space in practice. Plus, some companies seem to give the dimensions in the tilted-forward configuration, and others with the flash straight up.

The important thing is: only the very basic Pentax AF200FG is really small. The Pentax AF360FGZ and Metz AF 36 AF-4 might qualify as compact, but the others range from large (Metz 48 AF-1) to quite large (Pentax AF540FGZ, Metz 58 AF-1).

Weight

This list shows weight with four NiMH rechargeable batteries. The manuals list the weight without, but since they all use the same batteries and since a flash without power isn't much good, this is more useful. The values also include any required modules.

• Pentax AF200FG: 300g
• Metz 36 AF-4: 315g
• Promaster 5250DX: 330g
• Promaster 5550DX: 360g
  
• Promaster 5750DX: 360g
  
• Promaster 7200EDF: 365g
• Pentax AF360FGZ: 380g
• Sakar 952AF/PEN: 380g
• Promaster 7400EDF: 395g
• Sigma EF-530 DG ST: 415g
• Sigma EF-530 DG Super: 445g
• Metz 48 AF-1:450g¹
  
• Metz 58 AF-1: 465g
• Promaster 7500EDF: 490g
• Pentax AF540FGZ: 490g
• Metz 54 MZ-4i: 550g²
  

¹ The higher weight published in the manual is in error.
² This is with the Pentax-specific SCA 3702 module. With the generic SCA 301 module, total weight is about 20g less.

These flashes can be broken into several groups in terms of flash power for the weight. All six Promaster models and the Metz 36 AF-4 produce about the same flash coverage per gram as the Pentax AF360, with the Promaster 5250DX trailing behind a bit. The AF200FG covers considerably less — about half. The Metz 48 AF-1 and Metz 54 MZ-4i weigh noticably more than the AF360FGZ, but do produce a little more light for the weight. And the Metz 58 AF-1, the Pentax AF540FGZ, and the Sigma flashes do much better — not quite twice the light per gram.
As the chart shows, though, especially when batteries are considered, there's not really a huge range in the entire chart.

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Build Quality

Unfortunately, I don't have the funding to experiment with dropping flashes from heights onto hard surfaces. However, I will make a few surface-level comments. All of these flashes are made of plastic, and even the Pentax-brand modules seem like it, especially when put next to a solidly-built camera like the K20D. The Metz flashes subjectively feel the most solid to me, but this may very well be mostly because of the type of plastic used for the outer casing. The Sigma and Promaster flashes seem a little more flimsy than the Pentax or Metz ones (especially when moving the tilt/swivel heads), but not so as they'll fall right apart or anything.

There have been some complaints about the Pentax flashes getting their zoom reflectors stuck and needing to be sent in for service. Research on the web indicates that this is unfortunately common with zoom reflector flashes of all brands (including those from other camera manufacturers), and I don't think Pentax is particularly bad in this regard.

There are also several reports of the hot shoe locking pin getting stuck with Pentax flashes. Sigma and Metz also use this locking pin, and I've seen no equivalent complaints, but it may just be due to a smaller sample size. I certainly found the Pentax locking lever the easiest to use. Metz's more solid feel also carries through here, with the Sigma and Promaster units feeling a bit more klunky to get on to the shoe.

Sakar is primarily known for making cheap plastic trinkets like keychain digital cameras and MP3 players. Looking for an exception from their power zoom flash seems unwise.

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User Interface

The basic flashes, of course, have a very basic user interface. The Pentax AF200FG, for example, has an a power switch, a dial for exposure compensation (or manual mode), and test button. Or the Metz 36 AF-4: there's a power switch and a couple of lights, and the zoom setting is changed by just physically moving the reflector. The Promaster 5750DX doesn't have many controls, but does have a old-school mechanically-operating exposure calculator built in.

When you get to the advanced models, there's a lot more possibilities, so the user interface is much more important. As with the interface of camera bodies, this is highly subjective and one person's favorite feature can be another's pet annoyance.

Pentax addresses the problem directly: lots of buttons, switches, and dials. Most only do one thing, and the buttons with multiple features are next to a slider switch which acts as a function shift. There's not really much to complain about.

The interface on the Metz 48 AF-1 and 58 AF-1 is likely to provoke the most strongly divided reactions. Rather than having dedicated buttons for each feature as the Pentax flashes do, Metz uses a menu system.This means you never have to remember how to get to a certain feature, because they're all accessed the same way. And, this is why Metz is able to cram in so many little nice touches — they don't need to add a new button for each one. On the other hand, this means making several button presses for most operations. My main complaint is that on the 48 AF-1 the parameter menu is activated by pressing two buttons simultaneously, and it can't be done easily with one hand. The 58 AF-1 works a little more elegantly.

The Sigma EF-530DG Super suffers from having the same basic interface as the ST model but more features to control. I had to keep going back to the manual whenever I wanted to do something I hadn't done before, and even operations like setting an EV compensation value are more arcane than they should be. This isn't helped by the way Sigma uses different terminology than Pentax — for example, the HSS mode is indicated by the letters "FP". I'm sure that one could get used to this after not very long, but if you use certain flash features only occasionally this may be a real concern.

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Flash Accessories

Included Accessories

Diffusers

The Promaster flashes don't have a built-in wide-angle diffuser, but the 5750DX and all the 7000-series models include a push-on plastic diffuser in the package.

Case

A soft carrying case is included with all Pentax and Sigma models and with the Metz MZ 54-4i and 58 AF-1

Table Stand

The Pentax AF540FGZ, Metz 58 AF-1, Sigma EF-530 DG (both ST and Super), and Promaster 7500EDF models all come with a flat plastic stand to hold the flash on a table or other flat surface for off-camera operation. This is worth mentioning because a stand is incredibly useful for the wireless P-TTL-capable models which don't include it (the Pentax AF360FGZ and Metz 48 AF-1), and getting one separately is more pricey than it should be — see below.

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Optional Unit-Specific Accessories

Diffusers

Metz makes a couple of flash diffusers designed for their flash units. The Bounce Diffuser 54-23 is a soft, velcro-mounted bounce diffuser that is described as matching all three of the flash units mentioned here and would probably fit on anything. There's also a plastic clip-on diffuser, Mecabounce 58-90 for the 48 AF-1 and 58 AF-1 models and Mecabounce 44-90 for the 54 MZ-4i.

Sigma also makes a bounce reflector designed for their flashes, but which would probably fit on anything of a similar size.

Of course, there are many third-party diffusers like the famous Sto-Fen Omni-Bounce which will fit any of these flashes. However, the 48 AF-1 manual mentions that it automatically detects when the Mecabounce 58-90 is attached and displays a wider focal length automatically — that probably doesn't work with third-party diffusers.

Modular System

Since the Metz 54 MZ-4i is based on the SCA system of interchangeable modules, it has a whole little universe of add-on possibilities. This would make particular sense if you use multiple camera systems (e.g. also Canon or Nikon) or if you have some of the other SCA-capable Metz flashes.

Promaster's 5000 series is also based on a (different) modular system.

External Power Packs

The Pentax AF540FGZ's recharge time can be improved with the TR Power Pack III, which uses six C-cell batteries.

And the Metz 58 AF-1 and Metz 54 MZ-4i can both use Metz's NiMH-based Power Pack P76. They require different power cables, though.

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Optional Generic Accessories

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Documentation and Support

Quality of Documentation

Metz, Pentax, and Promaster all make their product manuals readily-available on their websites. Sigma has manuals for the older EF-500 DG models but not the current lineup — however, on request they did e-mail me a scanned copy, as did Sakar.

Metz deserves a commendation for publishing the most useful timing data, and providing first-rate documentation in general, both clearly written and clearly translated into English. The 36 AF-4 manual suffers from an attempt to document Canon, Nikon, Olympus, Pentax, and Sony variants all at once. Theoretically this model, which Metz touts as having "likeably easy operation" is simple enough that the documentation isn't really necessary. The 54 MZ-4i is much more complex, though, and its manual suffers the same problem, made worse by the fact that you have to also have the SCA 3702 manual on hand for cross-reference, and even worse by being somewhat out of date. The Pentax-dedicated 48 AF-1 and 58 AF-1 models, though, get current and Pentax-specific manuals.

The Pentax manuals are also good and (unlike those of the other brands) feature many illustrations and diagrams. However, some features are inadequately explained, while other pages seem a waste of paper — like the one with 28 pictures of the LCD panel's zoom indicator showing all the possible numbers.

Sigma's manual is passable, but short on detail, and sometimes comically translated from Japanese. ("The furrow of the subject will therefore be exposed behind the subject,creating a more natural effect.") I also found it the most necessary manual, because the EF-530 DG Super packs a lot of functionality into an arcane user interface and I had to keep referring to it in order to remind myself how to do things.

Promaster produces short English-only manuals  which are light light on detail. That's probably okay for the light-on-features models, and even the 7500EDF is straightforward enough that the manual won't be needed terribly often.

The Sakar 952AF/PEN manual is a single sheet of paper with fine print. It's not badly written but is extremely light on specific details — Sakar is the only flash maker to not provide guide number data.

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E-Mail Support Responsiveness

In the course of research for this article, I contacted all five flash makers with a variety of questions. Pentax, Metz, Sigma, and Promaster were all reasonably prompt and helpful.

Pentax tech support is reasonably good, but be aware that they will refuse to answer any questions about camera compatibility with third-party flashes — fair enough. Also, several of my requests for more detail have been met with the explanation that Pentax Japan has not provided the wanted information to Pentax USA. I actually contacted Pentax Japan directly too, but that didn't help either.

The Metz technical support advisor was particularly accommodating, even performing additional testing with an oscilloscope when the data I asked for wasn't immediately available. 

Sigma response time seems to vary — some questions were answered right away, and others have yet to get a response.

Queries to Promaster's "Flash Expert" via their web site are met with an automatic e-mail promising a response within 72 hours, and indeed, replies usually came back well before that. These were very helpful for basic questions, but Promaster was unable to provide technical information beyond that listed in the manual.

Sakar sent me a PDF copy of the 952AF/PEN manual on request (about a week later) but has not yet responded to my other questions. None of the other companies selling differently-labeled versions of this flash have responded to my queries.

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Further Information

Jens Roesner has a page full of information about the Pentax flash system. Some of it is slightly dated, but even those portions are useful for historical perspective.

Bojidar Dimitrov's Pentax K-Mount Page contains a section on flashes. This only covers Pentax-made equipment and focuses on history over current products.

On Actually Using a P-TTL Flash

This article is concerned with comparing the available P-TTL options. For information on actually making the most of P-TTL, take a look at OK1000's introductory guide to P-TTL  and (particularly if you are having exposure problems) the P-TTL flash guide from Pentax User UK.

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Acknowledgments / License

Thanks to the members of photo.net and pentaxforums.com for suggestions, corrections, and clarifications.

Except otherwise specified below, the contents of this site (including all the tables, charts, and graphics) are © 2008 Matthew Miller and released under the Creative Commons Attribution-Share Alike 3.0 License.

If you copy content from this site, please include my name and the URL of the expanded version of this guide <http://pttl.mattdm.org/> as part of the required attribution, properly hyperlinked where possible, as specified by the license. That's basically my payment.

Pentax flash images provided by Pentax and used with permission. Metz flash and power pack images provided by Metz and used with permission. Sigma flash images provided by Sigma and used with permission.

Graphs and charts, including the flash burst profile images, are © 2008 Matthew Miller and released under the same Creative Commons Attribution-Share Alike 3.0 License as the rest of this document.