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Old Aug 27, 2007, 3:19 PM   #1
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Hi,

I just purchased a bounce/swivel flash from digital concept for my pentax k100D.

It's advertised as p-ttl, but any way I try shooting it overexpose ( if direct ), or underexpose ( if shot upward and diffused ).

I know I can shoot in manual, but I don't see the point in having a p-ttl to do everything manual. I even tried a Canon flash of a relative, and on my camera it exposed well.

Is it a defective flash, do I do something wrong, or it's just a bad product I shouldn't have bought?

In case, do u recommend getting a pentax original, or a sigma would be ok?

Thanks
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Old Aug 27, 2007, 3:38 PM   #2
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Although it is advertised as P-TTL, do the instructions say P-TTL or just TTL.



I remember when I was looking for a flash, Jessops had a Digital compatable flash in the Pentax flavour for around £60. I asked to see it, told the assisstant I had the DL2 and needed P-TTL. He assured me that this flash was fully compatable with all Pentax dSLR's.



Checked the instructions, and it was TTL only, so was ok up to the DS.



I didn't buy that flash and told the assisstant he should learn a bit more about cameras!



Dal
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Old Aug 27, 2007, 4:56 PM   #3
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this is MY!!! peeve with pentax. no TTL.
it's also why i'll keep the DS

roy
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Old Aug 27, 2007, 5:06 PM   #4
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Hi Lando,

As Dal said, it's possible that your gun is only TTL compatible. Does it preflash? -- you should be able to see a flash in the viewfinder just before it blacks out to take the exposure. If you don't see this preflash, then it probably isn't P-TTL compatible. Only the D, DS, and DS2 nhave the necessary sensor in the camera to be compatible with TTL guns.

A lot of the dedicated flashes do, however have thyristor exposure control mode, where you set the ISO and aperture on the camera, and the flash alone controls the exposure. This is usually called Auto Mode or Auto Thyristor Mode, and it can work well if you're not shooting at vastly varying distances from your subject, or need to use significantly different apertures for DOF concerns.

I often use my AF 280T and even my fully P-TTL AF 540FGZ in Auto mode with my K10 as I have at least one relative who is a constant blinker with P-TTL flashes.

IMO, though it's nice to have a through the lens metered flash, and some of the features are very nice (like high and slow speed synch, rear curtain synch, and wireless remote capabilities), Auto thyristor flashes are really all that's usually needed for most users' external flash needs, and you never have the compatibility problems if Pentax decides to further tweek its P-TTL protocols.

Scott
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Old Aug 27, 2007, 6:19 PM   #5
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Thanks guys.

The flash has written pttl also in the instructions, and it's not so cheap being 114$.

On the dpreview forum someone said it's pttl, but i can't find the thread anymore.

Anyway I'll send it back to seller and try a new one, I paid for pttl I don't want to work in auto.


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Old Aug 28, 2007, 2:40 AM   #6
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Unfortunately, at $114, this is very cheap for a P-TTL flash.



We are held to ransome as only the new flashes do this.





Dal
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Old Aug 28, 2007, 7:48 AM   #7
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Is it the same flash like this one? (Soligor DG420Z):

https://secure.soligor.com/index.php?id=5&backPID=75&L=1&tt_produ cts=6704&L=1

This one supports PTTL. But: since it is achieved in reverse-engeneering process, you never know how good they did it.

The flashes sold as Soligor and Digital Concepts
have been herereported as working okay with the Pentax dSLRs.But these simple flashes do not offer high-speed snyc or wireless P-TTL (Sigma DG500Super has HSS mode).


I own AF540FGZ. I can tell you that in bouncing mode or with some Lumiquest bouncer it sometimes underexpose as well. But directly itlights the subject perfectly (without overexpose). But I rarely use it directly – almost never.


Underexpose in bouncing is not a big deal, since you easily fix it with compensation or in software lately. You can still get excellent pictures even if they are a little underexposed (better then overexposed).




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Old Aug 28, 2007, 8:10 AM   #8
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Never thought of the reverse-engineering.



If so, that could be the problem, as the Sigma flashes were like that that. I bought mine for my DL2 and had to have it re-chipped for the K10D (would have needed it re-chipped for the K100D as well).



This is why the Sigma is cheaper than the Pentax equivalent - in my case £150 for the Sigma and £299 for the Pentax. Sending the Flash back to Sigma for a few weeks free of charge for re-chipping was no real hardship.



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Old Aug 28, 2007, 8:36 AM   #9
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It looks like Digital concepts or Soligorisproduced informer Pentacon/Practica companyfrom easternGermany:

http://www.praktica.de/cms/index.php?id=9&tx_prdatasheetflash_pi1[showUid]=3&cHash=51c16e10e6


You can get it very cheap in Germany, for like 90Euros. I dont know how good is it, as I said I use AF540FGZ...



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