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02-02-2019, 09:55 AM   #16
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Don't forget when using a flash your dealing with two separate exposures. 1st being your ambient light the 2nd being your flash exposure. What affects your flash lighting is power and distance. If the power is full then the distance will affect how much light the subject receives. Bounce flash, distance and color one is bouncing off of can affect it. So if your exposures are too dark then you compensate by moving your flash lighting closer. adjusting your ambient light settings or adjusting how your using your flash lighting.

02-02-2019, 04:29 PM - 1 Like   #17
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It's still hard to be sure, from what the OP has written so far, whether this is a case of equipment failure or user error / lack of experience ....

To help rule out the latter, why not grab a copy of my Flash Guide "Supplement" PDF? This contains a section dedicated to automated flash control considerations with P-TTL.
02-02-2019, 07:18 PM   #18
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QuoteOriginally posted by pschlute Quote
Aperture ring set to "A"


It is. Thatís what I meant. Sorry it wasnít stated that way but I always control aperture through the camera.


02-02-2019, 07:19 PM   #19
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QuoteOriginally posted by RedBoomer Quote
Try setting ur camera in manual and flash in pttl. Say 1/200, f4, iso 200. The camera then let's the flash make the exposure. I find when the camera is in Av and flash pttl then there are two mechanisms trying to make the correct exposure and often it isn't right. I have k1ii and 540 flash as well. Good luck with it


Yeah. Or X-Sync? Itís just the first time Iíve had a problem shooting with flash in Av mode. Always seemed to be reliable in the past, with the appropriate FEC set as I alluded to above.




02-02-2019, 07:20 PM   #20
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QuoteOriginally posted by Not a Number Quote
I've seen software fixes get "broken" again in subsequent releases. The fix isn't sufficiently documented and gets taken out in an update. Or you different teams working on releases and the base release one team is working off of doesn't get a fix the other team adds. It happens all the time in software development.


Okay. Though that should mean others are experiencing it too. It should be a pretty frequent occurrence in real use, so it would be a problem to many. Is this the case?


02-02-2019, 07:21 PM   #21
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QuoteOriginally posted by derekkite Quote
Are you in X mode? Iirc the k3 would set the iso to 800 if i wasn't in X mode.


Not sure why that would be. ISO should be independent of other settings.


02-02-2019, 07:22 PM   #22
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QuoteOriginally posted by Oldbayrunner Quote
Don't forget when using a flash your dealing with two separate exposures. 1st being your ambient light the 2nd being your flash exposure. What affects your flash lighting is power and distance. If the power is full then the distance will affect how much light the subject receives. Bounce flash, distance and color one is bouncing off of can affect it. So if your exposures are too dark then you compensate by moving your flash lighting closer. adjusting your ambient light settings or adjusting how your using your flash lighting.


Yep. Iím aware of that. I like using fill flash a lot and have done so in the past without any problems in Av mode. The flash is close to the subject and ceiling like I stated before.


02-02-2019, 07:23 PM   #23
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QuoteOriginally posted by mcgregni Quote
It's still hard to be sure, from what the OP has written so far, whether this is a case of equipment failure or user error / lack of experience ....

To help rule out the latter, why not grab a copy of my Flash Guide "Supplement" PDF? This contains a section dedicated to automated flash control considerations with P-TTL.


Thanks for your suggestion, though Iíve done this kind of work for many years now. No problem with all previous 8 Pentax dSLRs.




02-03-2019, 04:29 AM   #24
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The problem is though, you're made references to the green button, ISOs and modes that suggest you don't really have a firm grip on things ... That's the impression conveyed. So you allow the question to keep hanging about whether there is an auto-ISO or mode behavior difference on the K1 that you are not aware of, that behaves differently from your previous cameras

Until you say conclusively that you are shooting with specific fixed settings, within the distance / environment limites as detailed in my flash guide supplement, and show a test image to portray the scene as the metering sensors read it, then there will be no conclusion to this. You will be left with the option of taking the camera back and trying to prove a fault for a repair or replacement.
02-03-2019, 04:35 AM   #25
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Underexposed images with bounce flash on K-1 II

Iíll have to change the title of this thread. Iíve just worked out that my FGZ-540 refuses to fire for the exposure. It only flashes for metering but thatís it. Test flash button fires the flash fine. I donít understand why it doesnít fire the second time (for the exposure when the shutter is open).





So I go and get my other flashgun. The Sigma EF-500 DG Super. It has worked fine as a P-TTL flash on my previous cameras. On this K-1 it is firing only for the exposure (no metering pre-flash) and always at full power.





Now what? Is it the two flashes or something else? I used the FGZ-540 successfully the week before. Didnít test the Sigma prior to today though. Canít tell if the Sigma is compatible or not but I canít see why not. Any guesses as to the problem here?
02-03-2019, 04:41 AM   #26
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QuoteOriginally posted by mcgregni Quote
The problem is though, you're made references to the green button, ISOs and modes that suggest you don't really have a firm grip on things ... That's the impression conveyed. So you allow the question to keep hanging about whether there is an auto-ISO or mode behavior difference on the K1 that you are not aware of, that behaves differently from your previous cameras

Until you say conclusively that you are shooting with specific fixed settings, within the distance / environment limites as detailed in my flash guide supplement, and show a test image to portray the scene as the metering sensors read it, then there will be no conclusion to this. You will be left with the option of taking the camera back and trying to prove a fault for a repair or replacement.
I’ll reiterate, I know what I’m doing here, you can give me the benefit of the doubt on that.

Settings should be visible on the EXIF data of the attached images if desired.
All images pretty much f/5.6 with ISO 200 in low lighting (artificial) and zero EC for both camera and flash in Av mode. Subjects are close (1st image, about 50cm with bounce ceiling flash 1.5m away for both scenarios) and moderately far (2nd image, about 2.5m with front flash for both scenarios).

These are the typical situations where flash should adequately light the subjects without any trouble in P-TTL mode.

Last edited by Ash; 02-03-2019 at 05:03 AM.
02-03-2019, 06:02 AM   #27
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QuoteOriginally posted by Ash Quote
Settings should be visible on the EXIF data of the attached images if desired
EXIF is stripped on these images.

If the AF540 is firing a pre-flash but not main flash make sure it is not set to Wireless "Controller" mode. The flash on off button should be firmly in the on position, not at the halfway Wireless position. What does the panel say the mode is ?

i don't know if your Sigma is compatible with the K1. it is quite an old model so possibly not. If it should be compatible and is also not working then perhaps the fault lies with the K1 hotshoe/electronics.

Can you find another Pentax flash to test on your K1

Last edited by pschlute; 02-03-2019 at 06:15 AM.
02-03-2019, 06:21 AM   #28
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QuoteOriginally posted by Ash Quote
All images pretty much f/5.6 with ISO 200 in low lighting (artificial) and zero EC for both camera and flash in Av mode.
Maybe not too much help in it, but I just tested my K-1 (original) with a Metz 58 AF-1 (w/updated FW) with the settings you describe above, flash in P-TTL mode, bounced off the roof. All the exposures were spot on. The in-camera lightmeter says 1.5-2 seconds without flash, with flash I get 1/60th.
02-03-2019, 07:23 AM   #29
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I apologise if this presents a red herring, but I mentioned inconsistent P-TTL flash metering with the FGZ-540 to a Ricoh Pentax rep at a recent trade show. The specific issue here was occasional random over-exposure (especially with daylight fill).

He indicated that the firmware in the FGZ-540II is better in this regard. But Iíve not got hold of one to try it yet. Are you using the older flash model too?
02-03-2019, 01:27 PM   #30
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QuoteOriginally posted by Ash Quote
I’ll reiterate, I know what I’m doing here, you can give me the benefit of the doubt on that.
But you must appreciate that you had to understand you were not necessarily conveying that impression ....

The only way to test P-TTL working, by isolating the flash exposure from all other possible influences, is to set M camera mode, set a fixed ISO, a fixed aperture, and a fixed shutter speed, and report exactly what these are. These settings should be such that they completely eliminate all ambient exposure. We still don't have this assurance from your tests so far, as they have been in Av mode with who knows what Flash Sync mode setting, and what ambient exposure level is mixed in there.

I do of course accept that you appear to be dealing with some sort of flash contact or communication issue through the hotshoe, but that's still not absolutely proven by your reporting so far.


The other good thing to try is to use M flash mode on your flashes (again of course with every camera settings fixed to eliminate ambient light), in order to check if your flashes are syncing correctly. You can assess the flash exposure level on a series of shots in M mode as you progressively increase the power, say from 1/32th through to 1/2. At least this would prove whether its a flash contact issue, or if its likely to reside in software, ie the camera is not telling the flash what to output properly in P-TTL mode.
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