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Pentax Accessory Reviews » Flash Equipment » Flashes (Genuine Pentax)


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10 28,022 Tue December 31, 2019
Recommended By Average Price Average User Rating
80% of reviewers $407.71 8.10


The Pentax AF 540FGZ II flash is successor to the original AF 540 FGZ. It features full weather-sealing thanks to built-in weather sealed (known as an "AW" design).

Launch price: $629.

This is the most powerful flash in the Pentax line-up with a maximum guide number of 54. The flash is compatible with all Pentax SLR and DSLR cameras (except the auto 110 series), but flash automation is not available with older film cameras and also not with M and K lenses. The flash has a zooming flash head and a built-in wide-angle diffuser. The flash head zooms automatically with AF lenses and can also be set manually.

The LED light on the front can be used to create a catch light and also serves as video light and AF assist light.

Distance and zoom head information on the LCD display adapts to the camera format in use (only with AF lenses): 645D, 24x36, APS-C, or Q.

Announced optional accessories: TR Power Pack 3

Flash namePENTAX AF 540FGZ II
Guide Number (meters ISO 100)54 at max zoom position (58mm APS-C)
Flash controlP-TTL auto, Manual (9 power settings), Multi, Wireless P-TTL, Wireless Manual
Flash synchronizationLeading curtain, Trailing curtain, High speed, Slow speed, Contrast control
Control modesMaster, Control, Slave
Flash exposure comp.-4 to +2 EV /1/3 EV or 1/2 EV steps)
Flash range0.8 to 8m (35mm lens at f/5.6 on APS-C, ISO 100
Flash coverage (APS-C)16mm lens, 13mm with pull-out wide-angle panel
Flash coverage (645D)30mm lens, 25mm with pull-out wide-angle panel
Zoom head settings (APS-C)13 mm*, 16 mm, 19 mm, 24 mm, 34 mm, 48 mm, 58 mm
Zoom head settings (645D)25 mm*, 30 mm, 35 mm, 43 mm, 62 mm, 87 mm, 105 mm
 * The shortest setting is activated by pulling out the wide-angle panel
Rotating flash headTilt and swivel
Flash duration1/20,000s to 1/1,200
Modeling lightYes
Autofocus spotbeamYes, white beam. Requires firmware update with some cameras
Video lightYes
ConnectionsHot shoe
Hot shoe pins5 (incl. ground)
Batteries4 x AA: Alkaline (LR6), Ni-MH rechargeable, Lithium (FR6)
Recycling time (fresh batteries)Alkaline: 5 s, Ni-MH: 3 s, Lithium: 5 s
Dimensions (W x H x D)76 x 113 x 108mm
Weight350g (without batteries)
In productionYes

Dedicated camera functionsActual availability depends on the camera, exposure mode and flash settings
Set synch speed when flash is chargedYes
Flash ready signal in view finderYes
Flash confirmation in viewfinderYes
Set aperture (Programmed flash)Yes
In Production: Buy the PENTAX AF 540FGZ II
In-Depth Review: Read our PENTAX AF 540FGZ II in-depth review!
Price History:

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Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-10 of 10
Loyal Site Supporter

Registered: September, 2017
Location: Medellín
Posts: 1,284
Review Date: December 31, 2019 I can recommend this item: Yes | Price: $400.00 | Rating: 8 

Pros: WR, recycle time, LED.
Cons: No bounce card, F5P or power pack connector, laser AF assist.

Bought two units new, both failed, one beyond repair, the other is up and running. Bought a third one used here on the forum. So far no more problems. They lack a lot of connectivity and power options, but do the job.
Forum Member

Registered: March, 2008
Posts: 85
Review Date: August 11, 2017 I can recommend this item: Yes | Price: $450.00 | Rating: 9 

Pros: Solid built
Cons: No red AF spot beam

I have this to replace 2 AF540FGZ.
The good:
Solid construction, much better hot shoe mount, WR.
Smaller size and faster recycle time.
Video light

The bad:
No red AF spot beam - Using white light for focusing is very glaring for people in the dark.
No bounce card - going into the menu for secondary light is slower.
No socket for HV battery pack - I had one for the AF540FGZ.

Still I bought it mainly for the WR and 3 sec recycle time.
Senior Member

Registered: August, 2007
Location: Los Angeles
Posts: 233

1 user found this helpful
Review Date: February 28, 2017 I can recommend this item: Yes | Price: None indicated | Rating: 9 

Pros: Relatively Small, Powerful, Easy to Use
Cons: No "A" Setting, Bounce Flash Card, Pricy, maybe a bit weaker than the old AF540

This is really a great flash. I've used the old AF360fgz and the old AF540fgz, as well as the Sigma EF530 and many old auto flashes. This one is the easiest to use by far.

It is the same size as the AF360 (first version), so it is much smaller than the old AF540. The whole unit feels quality. It doesn't have those stupid battery door problems that plague other Pentax flashes. Cycle time is very quick because you rarely use the full power of the flash. The head is pretty much infinitely adjustable. The LED light is handy for video and sometimes just to get a bit of light. The foot is metal and slides in easily, much better than older flashes. With this flash, you no longer get that high pitched "nuclear reactor charging" whine you do with older flashes.

P-TTL of course, is not always super reliable, and I miss having an auto flash setting (which the old models had). Also the little bounce card is missing on the new 360 and 540. The card was really useful for quick macro work. I also feel this flash is slightly weaker than the old 540 but maybe that is because the zoom only goes to 58mm on APS-C.

All in all, it is a great flash, if a bit pricy.

Responses to earlier critical reviews:

I am very used to the Pentax flash menu system, so all the functions work great. Yes, it doesn't have a radio, but you know this going in. It does wireless through the flash.

HSS works well and that is really the main reason for buying a expensive modern flash no?

I used 2300mah Rechargeables and they worked great. I stopped at 100 flashes, but it was still going strong.
New Member

Registered: November, 2014
Posts: 3

1 user found this helpful
Review Date: September 6, 2016 I can recommend this item: No | Price: $360.00 | Rating: 4 

Pros: ?
Cons: price, picky functionality, dumb

The only reason I bought this flash is to use the rear curtain sync. It seems that functionality doesn't work on manual mode. In comparison, my Nikon D80 worked with _any_ flash for rear curtain sync.

I'm utterly disappointed. The modes are confusing, it's pricey; there is no radio sync option.
If you don't need HSS or the barely ever working rear curtain sync, just by a few Yongnuo YN 560 IV - you'll get 4 for the price of a single Pentax unit.
Inactive Account

Registered: April, 2015
Location: Niagara Falls
Posts: 14
Review Date: July 2, 2016 I can recommend this item: No | Price: None indicated | Rating: 3 

Pros: GN
Cons: inconsistant exposures

So I'm totally unimpressed with this flash thus far. Bought it when I bought my 645z and first shot was grossly overexposed. Next one was better, one after that was hot, no consistency. Spoke to some people who thought it might be a compatibility issue with the z.... fast forward a year, bought a K-1, slapped it on the body, same issue. No consistency in the exposures.

I'm going to send it in to service to see if I got a bum flash, hopefully that will be the cause.

I'd love some feedback from other owners that have tried on either of the two bodies I own.

I'll re-review once I get it back from service.


Veteran Member

Registered: October, 2012
Location: Colorado
Posts: 1,433

1 user found this helpful
Review Date: January 3, 2016 I can recommend this item: Yes | Price: $354.00 | Rating: 10 

Pros: Build quality, high-speed sync, features, power, weather sealed
Cons: Drains batteries, first copy melted the Fresnel, too many settings

Hands-down, this is the best flash I've ever used. For me, the mot useful part of it is triggering my on-camera flash at 1/16th power and having this flash off-body providing the majority of the illumination. That makes this an ideal flash for off-body work with minimal frontal fill to cancel harsh shadows. That said, it too k me a few minutes to figure out how to do that because the flash has so dang many features that it's hard to figure out what they all do.

The flash is VERY powerful and bright. I accidentally had the flash in corner of my eye when it went off during a shoot and I that eye only had flash residual in it for a minute or two. So do not look into this flash when it goes off nor should you touch the Fresnel and the flash puts off a LOT of heat.

The flash also tears through batteries like Cookie Monster through the Keebler factory. I put in four, fully-charged, 2,400 MaH AAs and they was getting the low-battery warning after ten flashes. That may have as much to do with the batteries' age as the flash, or it may have been draining them too quickly. The batteries were too hot to touch when I took them out, which is not uncommon with my most powerful flashes. Just be aware of that ahead of time.

Overall, this is a really tremendous piece of gear and if you need a lot of light with a lot of features and weather sealing, this is a flash that can't be beat.
Loyal Site Supporter

Registered: September, 2009
Location: Phoenix, AZ
Posts: 6,477

4 users found this helpful
Review Date: May 5, 2015 I can recommend this item: Yes | Price: $420.00 | Rating: 10 

Pros: Relatively small, clear feature set and operation
Cons: Price

I have had the AF360FGZ for several years and have used it frequently. When the the AF 540FGZ II arrived I was amazed to find that it is a bit smaller than the AF360 although it is slightly heavier. The AF560FGZII is a solid feeling performer. So far, I have mainly used it with PTTL and it has been spot on every time. The bounce/swivel helps create soft, interesting lighting for portraits even when the flash is on the camera. I am very pleased with the flash. The price a a little higher than I would like but it is worth it for the extra features and weather proofing in a small package. I also always like to have Pentax products if possible. Here is a photo of the two flash guns to show relative sized.
Loyal Site Supporter

Registered: September, 2011
Location: Nelson B.C.
Posts: 3,763

4 users found this helpful
Review Date: February 28, 2015 I can recommend this item: Yes | Price: $400.00 | Rating: 10 

Pros: Build, size, Pttl consistency, LED light, hotshoe mechanism
Cons: No saving of settings across power cycle.

I purchased it specifically for weather resistance. We have had little rain since I got it

Shooting with the K3 there have been very few instances where the pttl has exposed poorly. I have taken lots of shots of my dogs indoors and the results have been consistently good, either bounce or straight on. Outdoors typically I have a flash extender similar to the better beamer and it has worked well, but too few occasions to have a sound opinion. One instance it was wet, early morning and I got better results manually, mostly due to hot spots on the water drops. A tough metering environment. I usually under expose and push in post to avoid the bright reflections.

The size is surprisingly nice. Battery and recycle is about the same as anything else I've shot; most of the time if I'm shooting continuous shots I'm at less than full power. I use rechargeable eneloops and I don't remember when I changed them last.

I like the manual on off switch, it is positive and instantaneous. In some conditions I will switch off the flash, user mode1 to take some shots in the bright light, them walk a ways, flash on, X mode to get something in the bushes.

The controls are good. I would like a mode saving, since power cycling resets to default all the settings. The power saving works very well. Half button press and it's on, it becomes an extension to the body. The yongnuo I shot with would not awaken until an exposure was taken.

To adjust the power, Set button, thumb dial, then Set button. To set to manual, Mode button once, then adjust the power. HSS, Sync button four times. Off-on and it is back to pttl 0.0.

A few other small things that I like, the vertical angle locks at horizontal. A previous flash unit would sag to the macro angle with the flash extender installed. The LED light is bright, I've used it a few times for locking focus in the dark, as well as a flashlight. It supposedly can replace the green focus adjust light on the body but I have yet to use it that way successfully. That is one setting I wish would carry over power cycles.

I have yet to try the slave modes. I use them for macro shooting.

I like the hot shoe mechanism. It is loose and sloppy, very easy to get on and off the body, but once on it clamps tight and secure.

Those are my impressions so far. Definitely nothing in the design or operation that annoys. The Metz AF50 is a great flash, tough and reliable, but it ended up being left on the desk because of the somewhat obtuse interface. The yongnuos needed a shoe lace to prevent sagging, although I must say that for the money they are excellent. The Pentax is becoming part of my standard gear when I go for walks.

A year from now when I have used it in all seasons and weather my opinion will be more valuable.
Site Supporter

Registered: October, 2006
Location: North Face of Mount Shasta
Posts: 120
Review Date: February 16, 2015 I can recommend this item: Yes | Price: None indicated | Rating: 9 

Pros: Solid Build, Compact, LED Catchlight, Ease of Use
Cons: Expensive

No doubt the best flash ever from Pentax. The learning curve is small, the menu system is well organized and easy to access settings.
The flash performed as well as anything I've ever used in P-TTL. On my K-3, flash photos both direct and indirect were well exposed and pleasing to the eye. The catch light is a very nice side benefit.
I was also surprised at the compact form ... actually smaller than my AF360. The build is professional and communicates quality throughout.
My only complaint about this product is the current price ... hopefully we will see it come down where it belongs in the near future. I really want one on a permanent basis.
Senior Member

Registered: January, 2014
Location: viking country
Posts: 276

2 users found this helpful
Review Date: November 1, 2014 I can recommend this item: Yes | Price: $470.00 | Rating: 9 

Pros: powerful, weathersealed, swivels in all directions, led light, size
Cons: pricey

I'm surprised this flash isn't reviewed, it has been on the market for quite some time and it is really a very competent flash. It has every feature that you are likely to use as an amateur, the pentax system lacks a few things for studio use but you can't blame the flash for that.

Most of the time this flash is used with a cable and a softbox for daylight shooting, thats also the reason I went for the more powerful one. Overpowering the sun is a full time job. At the time I bought this I was choosing between this and the metz 52, but weather sealing wss the deal breaker, I fish alot and do alot of other things outdoor, so I needed it. I've not had reason to regret my choice a single time. The construction is sturdy yet compact and it's got that air of quality to it. Sure it stings in the wallet to give $400 for a flash when the metz is down to $250 at the moment, but at the same time you do get real quality.

On the photo course me and two others are in charge of we went through flash techniques last time and we had Pentax, Canon, Nikon, Metz and Yongnuo flashes represented, the pentax was the center of attention, people commented on how small it was, the quality feel of it, a consensus was reached that of all flashes there, the pentax was without doubt the mose well made.

I guess in the end it boils down to, do you need weather sealing and the power this flash dishes out go for it, if not then there are cheaper versions available
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