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02-03-2009, 04:53 PM - 1 Like   #1
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Digital Concepts flash 918AF reviewed and tested

Well, I was trying everywhere, including this site, to find some review or info on this new Digital Concepts flash, no luck. So I figured that the only way to learn more about this flash is to buy one. I am no pro and I do not need all the special features, but my old relic Pentax 200s that I was so far using with my K100D just did not have enough reach and working in the Av or manual modes only was not just very convenient. So here it goes:

I bought the flash off ebay for $79 US, $95 including shipping to Canada. The flash itself has the Digital Concepts logo on the front and the model inscription “918AF/PEN SPEEDLITE” on the back. There is NO ‘made by’ or even ‘made in’ inscription anywhere on the flash. However, if you look at the bottom of the packaging box, there is Sakar International Inc. and Made in China printed there. Similarly, at the bottom of the one page (11” x 17”) manual, there is a reference for the technical support to be found at Sakar – unfortunately, no such flash model there.

As pointed out by ‘mattdm’ when I inquired about this flash few weeks ago, the DC 918AF looks nearly identical to the Tumax DSL 880AFZ. In fact the looks, the controls and the manual (all the wording, pictures and specs) are identical except two things, 1) the 918AF has GN of 38 m vs. GN of 32 on 880AFZ and 2) the 918AF has both bounce AND swivel, the 880AFZ has bounce only. So if you want a full description and specs of the 918AF, look at this link with the above mentioned corrections http://www.icorpandtumax.com/uploadfiles/file_470c455cb34aa.pdf .
I think that with today’s global/integrated economy you never know who’s product you are buying, there might be one obscure manufacturer who makes the product, and then half a dozen companies put their brand name logo on it …

Now the facts and observations:
The DC 918AF seems to be built reasonably sturdy, the zoom head clicks nicely into the four zoom positions and the bounce and swivel positions are solid as well without any free play. The 28-35-50-85 zoom positions refer to a full frame camera, so with the Pentax D series 1.5 factor sensors it means actually 18.7-23.3-33.3-56.7 mm lens coverage. The flash comes with an optional diffuser lens that is supposed to widen the coverage to 24 mm or 16 mm on the DSLR Pentax. BTW the diffuser lens cuts the flash power by almost two stops, no effect on correct exposure of thou. I have experimented with the flash coverage at different camera lens focal length and flash zoom head settings and the flash coverage was as expected. If you set the zoom head at 85 (56.7) and the camera lens around 50 mm or less, you start seeing some darkening at the top of the frame. The GN of 38 m @100 ISO puts the 918AF slightly above the Pentax own AF360FGZ. To put it into a perspective, the 918AF will give you a respectable reach up to 27 m at 800 ISO setting and 4.0 aperture lens.

Now the most important thing – how the flash works and communicates with camera? I think very well. Generally, the 918AF gives you the same features including the P-TTL as the built in flash, plus couple more. The 918AF has an on the flash switch for the rear curtain sync and the camera correctly sets itself to a maximum 1/90 sync speed or less (with the front curtain sync setting the camera goes automatically to 1/180 speed or less). The second extra feature is the low light infrared beam (AF illumination) – great thing. Basically when you push the shutter release half way, the IR beam lights up until camera locks its focus, then it goes automatically off. You can shoot/focus with it in a complete darkness and I tried a distance up to 9 meters. In a low light the camera can focus much faster that it would without the AF illumination.

You can set the four flash modes (auto normal, auto red eye reduction, manual normal and manual red eye reduction) in full auto mode camera setting, but it looks like the flash fires some fill in light in auto mode even if there is a sufficient ambient light present. In every other than auto camera mode you have just the manual normal and manual red eye reduction settings available, same as with the built in flash. Note that the built in flash never pops up in auto mode by itself if the 918AF is attached. The flash exposure compensation works as well, but I found that the P-TTL exposure control works so good that I most probably will never need it.

As mentioned, the exposure control with this flash is just amazing. I have tried every possible camera mode, Auto, Program, Av, Tv, all combinations of apperture setting and shutter speed, low ambient light, lots of ambient light, no light, and the exposures were CONSISTENTLY perfect or near perfect. The only time I noticed about 0.5 stop underexposure was with the standard Pentax 18-55 DA lens at the maximum 55 focal length setting. However, when using my favorite Pentax FA 28-80 lens, the exposure was correct at any focal length. I tried as well my Tamron LD 70-300 and exposures were great at any focal length.

One thing that impressed me was the accuracy of a short distance (near macro) flash and the daylight fill in flash. I usually get an overexposure with the built in flash or with my old Pentax 200s in these situations, not so with this baby. I never tried things like slave or wireless flash so I cannot comment on that. Not sure if this flash would go to a high speed sync in a bright daylight, probably not. Forgot to mention that this flash comes with a nicely fitting protective pouch and a reflective plate accessory that would be probably good for a macro photography.

So, to summarize, on a scale 1 to 10, I would give the 918AF flash a 9. If you have to have all the bells and whistles and this nice LCD of the AF360/540FGZ’s plus the Pentax brand name, go for it. If you just need a reasonably powerful flash that you can attach to your camera, forget about any settings AND have always a correct exposure, then get the DC 918AF for a fraction of the price.

Lumir

02-03-2009, 08:32 PM   #2
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Cool — thanks for the report. Glad to hear that this thing works so well with exposure accuracy.

QuoteOriginally posted by luma Quote
The GN of 38 m @100 ISO puts the 918AF slightly above the Pentax own AF360FGZ. To put it into a perspective, the 918AF will give you a respectable reach up to 27 m at 800 ISO setting and 4.0 aperture lens.
Several reports on the 958AF indicate that it doesn't quite live up to the stated guide number. Does it seem like in your testing that this one is really putting out the light it says it can?
02-04-2009, 06:48 AM   #3
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Thanks for posting your review. I think a lot of us were waiting for someone to try one of these. Good info.
02-04-2009, 08:17 AM   #4
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QuoteOriginally posted by mattdm Quote
Several reports on the 958AF indicate that it doesn't quite live up to the stated guide number. Does it seem like in your testing that this one is really putting out the light it says it can?
Honestly, I did not test/measure the reach (GN number), but I will.

02-04-2009, 12:24 PM   #5
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How do the controls look on the back of the flash? Since there is no LCD screen but is there a slider or something? Does it have a manual mode?

And does it have any sync outlets or any type of outlets, such as for a external power pack or such?
02-04-2009, 12:42 PM   #6
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Thanks for the review! Nice to see there's a good cheap PTTL unit out there. Can you do me a favor? How are the manual controls on the flash? Easy to adjust power?
02-04-2009, 02:12 PM   #7
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QuoteOriginally posted by luma Quote
The second extra feature is the low light infrared beam (AF illumination) – great thing. Basically when you push the shutter release half way, the IR beam lights up until camera locks its focus, then it goes automatically off. You can shoot/focus with it in a complete darkness and I tried a distance up to 9 meters. In a low light the camera can focus much faster that it would without the AF illumination.
With my Pentax flash unit, I can turn off the flash itself and use the assist beam only (in SB mode). Can you do that with this flash?
02-04-2009, 06:03 PM   #8
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QuoteOriginally posted by Marcus Quote
How do the controls look on the back of the flash? Since there is no LCD screen but is there a slider or something? Does it have a manual mode?

And does it have any sync outlets or any type of outlets, such as for a external power pack or such?
The only "control" on the back of the flash is a 3-position switch: OFF, ON with front curtain sync and ON with rear curtain sync. No it doesn't have manual mode.
Other than that, you can make only the on camera settings, same that you have available for the build in flash.

02-04-2009, 06:20 PM   #9
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QuoteOriginally posted by asdf Quote
With my Pentax flash unit, I can turn off the flash itself and use the assist beam only (in SB mode). Can you do that with this flash?
NO, just tried it out. The AF illumination works only when the flash is turned on and then if you push the the shutter release button all the way, the flash fires.
02-04-2009, 06:29 PM   #10
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QuoteOriginally posted by mattdm Quote
Several reports on the 958AF indicate that it doesn't quite live up to the stated guide number. Does it seem like in your testing that this one is really putting out the light it says it can?
Well, tried it in my living room, shooting from corner to corner, distance 9 meters. This room is all wood including ceiling, so no reflective surface. At 200 ISO and Av mode on camera, I start seeing a some darkening at 5.6 aperture, that would correspond to 4.0 aperture @ 100 ISO. So 9 x 4 = 36 GN. Maybe not quite 38 as stated, but fairly close.
02-04-2009, 06:50 PM   #11
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QuoteOriginally posted by deuces Quote
Thanks for the review! Nice to see there's a good cheap PTTL unit out there. Can you do me a favor? How are the manual controls on the flash? Easy to adjust power?
There are no manual controls on the flash and to be honest, I do not mind as long as exposure is correct - and it is, pretty much at any distance including less than three feet. You can still adjust the power on camera, the K100d has flash exposure compensation in range from +1 to -2 steps. This feature works with this flash.
02-04-2009, 07:24 PM   #12
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QuoteOriginally posted by luma Quote
Well, tried it in my living room, shooting from corner to corner, distance 9 meters. This room is all wood including ceiling, so no reflective surface. At 200 ISO and Av mode on camera, I start seeing a some darkening at 5.6 aperture, that would correspond to 4.0 aperture @ 100 ISO. So 9 x 4 = 36 GN. Maybe not quite 38 as stated, but fairly close.
Within the margin of error for the experiment, surely. Thanks for trying it out.

If you're still in the experimenting mood, can you try it at the different zoom settings? One major annoyance from my making-a-flash-guide point of view is that they only publish the number for the narrowest zoom.
02-05-2009, 01:54 AM   #13
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QuoteOriginally posted by luma Quote
NO, just tried it out. The AF illumination works only when the flash is turned on and then if you push the the shutter release button all the way, the flash fires.
Too bad. Thanks for checking. It would be great if there was a cheap flash unit with an AF assist beam and the ability to turn off the flash or even a cheaper unit with just an AF assist beam. Although, it's not so bad: usually, if there is a need for an AF assist beam, you probably want to use the flash anyway. Also, anything is an improvement when compared to the extremely irritating pulsating flashes the built-in flash makes to assist AF.
02-05-2009, 08:48 AM   #14
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QuoteOriginally posted by mattdm Quote
If you're still in the experimenting mood, can you try it at the different zoom settings? One major annoyance from my making-a-flash-guide point of view is that they only publish the number for the narrowest zoom.
Seems like going from 85 mm zoom head seting to 28 mm will cut the flash power/reach by one stop (making comparison from the histograms)... does it make sense?
Another thing that I found, I stated earlier that at 85mm zoom head there is some darkening on top with 50 mm focal lentght. Well, if I lift the head up a bit(~5 to 10 degree), I can go to 40 mm focal length and still have a full coverage ...
02-05-2009, 10:21 AM   #15
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Thanks, really great info.

So we have one significant negative. Without manual controls, it makes it pretty much useless for off camera radio triggered flash.

Really wondering about HSS and wireless. If it could do wireless commander for PTTL, it'll be a hell of a cheap way to do off camera HSS.
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