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01-09-2015, 07:29 PM   #1
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My Pentax K5 and K7 don't "pre-flash". Pls help

I noticed last night that both my Pentax K5 and K7 won't "pre-flash" (using on-board flash and external P-TTL flash unit). I shoot mostly by available light so I did not bother to check my cameras' P-TTL until last night. Please advise what could have happened and if it is possible to bring back the "pre-flash". If not, does it mean that my cameras are now plain TTL, and no longer P-TTL? The photos appear well-exposed though. Your comments or assistance will be greatly appreciated. Thanks.

01-09-2015, 07:37 PM   #2
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The K-5 and K-7 doesn't have "plain" TTL.

Which flash do you use and how have you set the flash up? Some units have an "auto" setting where they will use their own light sensor (no pre-flash) to determine exposure. Usually the exposure comes out great, if not better than P-TTL in this "Auto" mode
01-09-2015, 07:38 PM   #3
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The pre-flash is typically not visible to the naked eye for most people. TTL is not an option on newer bodies since the *ist series.
01-09-2015, 07:41 PM   #4
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I believe the flash must be set to P-TTL auto. And it doesn't work with manual lenses. Some people cannot even detect the pre-flash -- the delay between it and real flash is very short.

01-09-2015, 08:12 PM   #5
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Thank you all. My external flash unit is the Sigma ST 530 and it is set to P-TTL. I asked about the "pre-flash" because I read somewhere here that it sometimes causes the subjects to close their eyes and this is captured when the main flash fires. I have never encountered this though. Still confused. I hope my cameras are functioning as they should (flash- wise). Any suggestion how I can be centain about this?
01-09-2015, 08:19 PM   #6
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If the exposure it's good why worry?
01-09-2015, 08:24 PM   #7
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If the exposure is good it is probably working. The pre-flash for the P-TTL is not like the red-eye preflash which is impossible to miss, it is in fact very easy to miss.
01-09-2015, 08:24 PM   #8
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The red-eye reduction pre-flash is quite visible (obviously or else it wouldn't have any effect on the subject's eyes). If red-eye reduction is turned off then it is hard to notice the P-TTL pre-flash.

01-09-2015, 08:40 PM   #9
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Thanks again for the additional comments. I read somewhere that the "pre-flash" could scare away birds when photographing them with flash, so that by the time the photo is taken the bird is almost outside the frame. Also, that it will make a slave flash fire prematurely. If this is true with P-TTL, I might get an Automatic flash unit and set my cameras accordingly.
01-09-2015, 09:08 PM   #10
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Slave flashes that don't understand pttl can flash prematurely as you stated.
01-09-2015, 09:46 PM - 1 Like   #11
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The best way to see the preflash is to use the 2 second delay drive mode. The preflash fires, then the 2 second delay, then the main flash.
01-10-2015, 02:38 AM   #12
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QuoteOriginally posted by Just1MoreDave Quote
The best way to see the preflash is to use the 2 second delay drive mode. The preflash fires, then the 2 second delay, then the main flash.
Thanks a lot for the tip. Will give it a try. Cheers.
01-10-2015, 04:30 AM   #13
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Simple test:
If you can see the flash through the optical viewfinder,,it must be the pTTL pre-flash.
During the time the main flash fires, the mirror is up and flashing cannot be seen through the viewfinder.

As this works perfectly with my *istDS and K200D, I guess it will work with your bodies, too.
01-10-2015, 08:22 PM   #14
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QuoteOriginally posted by Just1MoreDave Quote
The best way to see the preflash is to use the 2 second delay drive mode. The preflash fires, then the 2 second delay, then the main flash.
I tried the 2-second set up as you suggested and saw 2 very distinct flashes of about the same intensity. The first looks like the "red eye reduction" flash.
Any comment?
01-14-2015, 09:52 AM   #15
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I have been using the K3 with a AF-540FGZ Flash. I noticed I don't see a pre flash using the PTTL mode and TTl does not come up at all when selecting modes. Is this possibly the same situation even though I am using a K3? I hear the K5 has a lot more problems with flash.

Is the double flash so fast we I can't see it like described above? 2 Second delay?

Thanks
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