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05-29-2009, 07:14 AM   #1
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DSLR Flash Inquiry

Hi there!

Some quick background:
I'm new to this forum, but not new to photography.
I've been shooting professionally for over twenty years.
My medium format cameras were Pentax 645's.
I went digital first to Nikon, then switched to Canon, and am now considering making the switch and going over to Pentax (based upon my good experiences with their medium format cameras).
I mainly shoot weddings, events and portraits.

Now that I've given you some background, what I'm looking for is straightforward feedback on how Pentax's flash system works.
My real-world experiences were that Nikon's iTTL worked pretty well for me, and Canon's eTTL-2 works well most of the time, but I constantly have to ride the flash exposure compensation (especially on a wedding) and find that it under-exposes most of the time.

What information can you give me regarding the accuracy of the system, and whether or not it's easy to work with?



05-29-2009, 07:33 AM   #2
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I do not use flash that often, but when I do, I've found exposure to be 99% of the time "correct". I must admit I've encountered very few situations where the exposure was totally off. Such situations most always were related to close range photography (less than 3 ft)

Interesting though, I've found that when using wireless p-ttl (with my K20D and AF540FGZ flash unit, the exposure is always right. I've even used p-ttl flash with one 540, one 360 and one 500 (this one in slave + manual exposure) and the whole array worked very nice.
05-29-2009, 07:39 AM   #3
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My quick response is that you would probably find it comparable to Canon's eTTL-2. With bounce it usually works like a charm but with direct flash and trickier reflective subjects including white dresses/dark backgrounds it will likely tend towards underexposure. Pentax digital-SLR segmented metering trends towards underexposure anyway, preferring to protect highlights.

Quite a few Pentaxians eschew P-TTL for various reasons and go with full manual or old-school thyristor auto-flash. As often as not though these reasons are value-related because they don't want to pony up for $300 flashguns...or their planning on using dumb radio triggers anyway so diving into P-TTL is again sort of a waste.

As far as being easy to work with, I don't have any serious problems with it...but if you're professional and shooting weddings/events you may have higher standards in that area than I do. Hopefully you'll get some more 'pro' responses to your questions.
05-29-2009, 01:17 PM   #4

I am one of the aforementioned eschewers...

I am one of the folks that Andrew mentions... And I am one of very few... so please take this with a grain of salt. Weighing it against all the positive stuff.
"Quite a few Pentaxians eschew P-TTL for various reasons and go with full manual or old-school thyristor auto-flash. As often as not though these reasons are value-related because they don't want to pony up for $300 flashguns"

For me it is the weakest link in the pentax chain. And the only thing that I am consistently frustrated with. My experience is that the exposures vary too much... I am not a pro, so my use of flash is limited entirely to birthday parties and family events. After two years, I will never use the Pentax again in those situations. In the last two weeks I had my 4 year olds last day of school and my 7 year olds birthday party. A fast 2.8 28-75 zoom and bounced flash. I can count the keepers on two hands. My wife and her 5 year old sony p&s was way more successful. From now on I will be using my Fuji F30 for those events.

Actually my 7 year old daughter shot better shots than me with her sony P200 I am happy she did so well... And sad I failed.

But there will be a lot of folks who will post after me saying they never miss with their Pttl flash. So take my failure with a grain of salt and a shot of tequila. I do!

-EDIT- I just realized you are a pro and will be shooting weddings. Disregard my silly post as you will be using professional flash set ups. I just use a single flash pointed at the ceiling and hopin' for the best.

Last edited by Igilligan; 05-29-2009 at 01:41 PM.
05-29-2009, 01:24 PM   #5
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I am not too happy with the pttl performance myself. I use manual flash usually instead.

and I think that is disappointing, the flash does a pre flash and measures ttl so how can it in some cases be 3 whole stops off!

yes in fact u can set +2 exp on the flash and +1 on the camera and I have been in a situation where that was not eanough, had to go manual to get the proper lighting.

the system works fine on straight on flash, then if you bounce it, it tends to be 1 stop off, and if its wireless and bounced, then it can be even more.

I get a feeling the old ttl system worked better....
05-29-2009, 01:32 PM   #6
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Hi Bill
Welcome to the forum.
I'm not pro either, and have not compared Canon or Nikon's systems, but can say Pentax's P-TTL is reasonably accurate - giving me well exposed images almost all the time (despite it being Pentax's 'weakness' according to many users).

My experience has led me to starting the FEC on +0.7 (on the body) for primary lighting from the flash, which usually provides me with adequate exposure in most cases, then ride it either up or down half a stop on the flash unit whilst on the job to either augment or tone down the flash effect as needed.

For fill flash, I'm between FEC -1.0 and -0.3, and this usually works (if it's not too bright where I'm shooting (bear in mind Pentax's sync speed of 1/180)
06-01-2009, 06:22 AM   #7
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Thanks for all the responses.

From what I've seen and heard, no manufacturer is making a 'fool proof' TTL flash system these days.

In the film days, the sensor would read reflectance off the film itself. And that varied, depending upon emulsion (slide/negative/brand) so testing was needed and then you were generally OK. Keep in mind you had quite a bit of leeway +/- for film and were generally giving film a +1 stop over-exposure for good skin tones (in the wedding/portrait business).

Digital, on the other hand, has such a narrow exposure latitude that it's critical to get good exposure and difficult at times.

Just shot a wedding on Saturday, and using my Canon setup, got pretty good results with the Flash Exposure Lock, taking a spot reading off the face of the subjects and locking it in. This needs to be dialed in, too. I was +1 on the flash to get results that I did not have to adjust in post. That worked well for formal shots but for candids, it's more tricky to do.

I guess that's one of the reasons that we shoot so heavy with digital these days compared to film...most of your shots end up being 'retakes' in an attempt to get a better looking shot than the first one.

I'm waiting to check out Pentax's new DSLR and hopefully get a chance to play with it (and it's flash system) thoroughly.
06-01-2009, 08:27 AM   #8
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Pipes, I think your conclusion is probably accurate. The problem is that with digital, blown highlights are so unattractive that manufacturers often bias the metering to avoid this at the expense of the rest of the image. On the positive side it's relatively easy to bring up the shadows a bit digitally.

I'm hoping that maybe the new 77-segment metering in the K-7 might improve P-TTL metering a bit--perhaps with the smaller segments Pentax can be a little more agressive and allow small highlights.

I don't think Pentax has anything quite like the FE-L you mention Canon has. I've sometimes wished for something like that. I've also wished that the flash might tell you (record in EXIF) the level of P-TTL or Auto output so that you could then dial that into manual if you wanted.


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