Feature Comparison

Feature Charts

Major Features

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 Automatic zoom only; no manual zoom control.
⁸ Requires 5050DXR/PX digital flash module for P-TTL functionality
⁹ Full or ¹⁄₁₆ when used with separate FTM5000 manual focus module.
¹⁰ Auto mode available with separate FTA5000 auto focus module.
¹¹ Manual zoom only, to 35mm, 50mm, or 85mm.
¹² Missing the typical 28mm and 70mm zoom stops
¹³ Also available under many other different brands and names. Some models may not be P-TTL compatible.

Other Features

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.

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.

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).

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.

Secondary Reflector

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.

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. This can be very significant: there's typically a 3× effective gain in power from 24mm to 85mm.

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 the guide number table 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.

The Sigma EF-530DG ST has the opposite deficiency: the zoom is motorized, but only automatically adjusts itself based on the information from the camera. You can't change the zoom manually if you want a wider or narrower beam.

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, but due to a bug in the current firmware, it can't do HSS in master/controller mode. There are currently no known plans for an updated firmware to fix this issue.

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.

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 controller¹. 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.

The Metz 58 AF-1 also has this limitation due to a bug in the current firmware. There are currently no known plans for an updated firmware to fix this issue. It works in HSS mode as a slave, however.

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.

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, but it also gives increased flexibility, since it adds a couple of stops to the range and because many Pentax camera bodies can work in ⅓-stop increments.

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.)

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 (the FTM5000) 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.

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. Zoom information isn't automatically communicated and must be set manually. Also, many people find it annoying that the flash will reset to P-TTL mode whenever resuming from auto-off (while the Metz 58 AF-1 stays where you left it).

Somewhat oddly, when a Pentax flash is in auto mode and the camera is in P or Tv (shutter priority) mode, the camera gets (and sets itself to) the appropriate aperture based on directions from the flash. (Including automatically doing the right thing for different ISO settings.) The Metz 58 AF-1, by contrast, works the other way around: the flash automatically reads the current aperture and ISO information from the camera (which works in all program modes).

Promaster offers a separate module (the FTA5000) for its 5000-series flashes which makes them work in auto mode.

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.

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.

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. This is more important with film where there's no other easy way to get instant feedback, but can still be useful in the digital era. The entry-level models from each manufacturer are missing this feature, but most middle and higher-end models all have it.

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.

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.

Unfortunately, this feature does not work in wireless P-TTL mode.

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.

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.

Camera Format Conversion

The angle 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 numbers that match 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 (electronic or mechanical) require mental conversion.

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.

Note that the ST version of the Sigma EF-530DG lacks a manual zoom mode entirely.

P5 Sync Port

The Pentax AF540FGZ has a P5 Sync Port. This is similar in concept to the old standard X Sync (or PC Sync — that's Prontor/Compur) port, but not compatible. Unlike the X Sync cable, this provides full Pentax-specific communication just as if the flash were mounted on the hot shoe directly.

No Pentax dSLRs have the corresponding port on that side, so you need Pentax's "Hot Shoe Adapter F". And, for any flash which doesn't have the port, you can use the "Off-Camera Shoe Adapter F" to provide one. In either case, you'll need Extension Cord F5P, which comes in short (1m) and long (3m) varieties.

More Information

Next, compare flash power or look at flash details. Or, go back to the overview.