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Old Aug 27, 2006, 7:39 PM   #31
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Darren and Roy-

Thanks for posting some excellent photos.

MT/Sarah
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Old Aug 27, 2006, 8:31 PM   #32
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Thank you. Praise from here is always welcomed - as too are comments/critique.



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Old Sep 10, 2006, 12:00 PM   #33
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Sorry to bump this thread, but here goes ... BUMP



The waterlily above I have had made up to A3 by Jessops and it is still as sharp as 6x4 and A4. Why do we need 10Mp?



On the flash topic, this may be obvious, but I think the problem with the diffuser on the flash is caused by the pre-flash. If it does a pre-flash, then with the diffuser on, the lvel will be too low, so the flash compensates with a higher output, thus over-exposing. Therefore a Sto-Fen diffuser is around +1.0 stop of light.



I may be right or I may be in cloud cuckoo land with this.



Comments welcome.





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Old Sep 10, 2006, 12:28 PM   #34
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that's something to consider.. never crossed my mind. thanks darren. i'll ck it out.
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Old Sep 10, 2006, 1:14 PM   #35
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Darren, you mean the built in diffuser?

I noticed that, when you pull the diffuser down, the lights by 28 and 105 starts blinking. So my guess is that the flash "knows" that the diffuser is down. (But maybe it does not do anything with that information.)

Richard.






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Old Sep 10, 2006, 2:59 PM   #36
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Ritro wrote:
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Darren, you mean the built in diffuser?

I noticed that, when you pull the diffuser down, the lights by 28 and 105 starts blinking. So my guess is that the flash "knows" that the diffuser is down. (But maybe it does not do anything with that information.)

Richard.





Sorry, meant the Sto-fen diffuser.

But yes I would guess there is a sensor to let the flash know that the wide-angled diffusser is down (I never use this, always the Sto-Fen).

Roy - Look forward, as always, to your results. By the way, the high speed flash seems to work fine on my cam, but only about halfway through the apertures. At the smaller aperatures the pics are underexposed.





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Old Sep 10, 2006, 4:11 PM   #37
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i've worked everything out. if with the difusser on it's preflashing, then i can't see it doing so..

can you see yours, preflash?? or is it to fast to see??

roy
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Old Sep 10, 2006, 4:37 PM   #38
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I must admit I have never seen the pre-flash working. I have even checked the box and LCD several times to esure I have the right gun. I can only assume it is a very short flash of light.



Like I say, it is only a theory due to the +1.0 stop over-exposure that seems to happen when using the sto-fen diffuser.



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Old Oct 24, 2006, 10:56 PM   #39
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Hello.

I have a few questions and this seems a good thread to coattail them on to.

I own a DL, Sigma EF-500 DG Super and a Sto-Fen Omni-Flash. I took what seemed to be reasonably good (flash) photos a few months ago at a company function but ended up with lots of blown out highlights at a recent family event. I'm hoping to get some comments here in order to help me determine what's going on.

First off, from this thread, it sounds as though, uncompensated, the Sto-Fen willresult inover-exposure. It seems I once discovered this, forgot about itbut then just re-proved it. Has anyone changed their position on this, or is it still the popular belief that exposure compensation should be applied when using this diffuser?

What does your EXIF data show when you shoot external flash photos? My EXIF data ends up containing the same shutter speed and aperture data that lights up when I partially depress the shutter. I'm recording a lot of 1/45 sec @ f4.0 (AUTO PICT & P - I'll get f8.0 when I set it on Av priority, but I'll still see 1/45 sec), and I'm having a hard time believing that after pre-flash these are the actual programmed values. I just now bumped up the ISO from 200 to 1600, and while I finally record different values (perhaps only by virtue of switching to shutter priority), I have two images with _identical_ tags, but the non-Sto-Fen image is exposed much better than the Sto-Fen counterpart. I'm somewhat convinced that my flash EXIF data doesn't depict the actual firing parameters. Should it? Does yours?

Does anyone know exactly how P-TTL works? Does the camera evaluate pre-flash results and tweak Tv and/or Av values before the shutter fires, or does the camera simply squelch the intensity of the flash? If the latter, then maybe the EXIF values I see really are the firing conditions. I just have a hard time believing it.

Has anyone come acrosssignal characteristicdata on the hot-shoe contacts?

Finally, I remember a lengthy thread about two months ago on various flash units and Pentax DSLRs, but I can't find it. I'd be grateful if someone would post a link.

Thanks in advance for your time.

Regards,

Corey





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