540FGZ underexposure

**Ash** · 03-09-2008, 02:09 AM

If you're referring to the above photos, they're on an Adobe RGB calibrated iMac 20" TFT monitor, and I've shot the pictures on Adobe RGB, judging exposure by the histogram, not just on their appearance on the screen. Either way, on FEC 0, none of my flashed shots with the AF 540 were exposed enough IMO...

Fritz · 03-09-2008, 09:07 AM

I don't mean to hijack this thread, but I've been having similar issues with my Sigma 530 super. It always appears to be underexposed by a full stop. Trying any other settings other then bumping the EV to +1.0 (in camera or on flash) doesn't seem to help. This is using my DA kit lens and the DA 50-200mm. I noticed however that when I put on an "A" lens, that the exposures come out perfect with no EV adjustments. I have a SMC A 50 f2.0, and my Vivitar series 1 105mm f2.5 that I've tried this on, and the results always come out perfect. And my DA lenses always come out underexposed by a stop. Anyone have a good explanation for this? Thanks!

**Lowell Goudge** · 03-09-2008, 10:03 AM

as I noted earlier, my impression was that when you bumped the compensation, the shots were washed out.

Were these shot in RAW or JPEG? If JPEG you might try reducing the contrast a little, so that you can have less difference between highlights and dark areas.

**Ash** · 03-09-2008, 01:02 PM

These were shot in RAW (Bright mode - if that makes any difference) with Contrast at +1, Saturation at +1 and Sharpness at +2, then no PP to convert to JPEG in its natural form. When contrast is taken down to -1, I get even duller pictures and a flattened histogram in comparison.

Perhaps our monitors project the pictures differently - even when I turn up my monitor's contrast and brightness to near max, I still see all the details in my compensated shots, and the histogram records no pixels as clipped highlights. Lowell, do the shots from your uncompensated flash have pixels on the top half of your histogram? Would colourspace have anything to do with this? Do most people use sRGB as default? Perhaps I should set up a poll on this...

Fritz, with your A lenses, are you shooting in Av mode on the A setting? Are you using a K10D or K100D, and do you have a replacement viewfinder screen? What have other EF 530 users experienced?

Fritz · 03-09-2008, 01:22 PM

Originally posted by Ash

Fritz, with your A lenses, are you shooting in Av mode on the A setting? Are you using a K10D or K100D, and do you have a replacement viewfinder screen? What have other EF 530 users experienced?

I use the A setting on the lens, and any other setting other then Manual, and the metering appears to be accurate. P, Tv, Av, even auto pict. It just appears to work as it should, and very consistently.

I'm using a K100d with a split prism screen (k10 screen from china). I have no other metering issues. As far as I can tell the metering hasn't changed from the factory issued screen to this one. I suppose I could swap the original screen back in and see if that makes the difference.

From what I have read the one stop underexposure is fairly common. I just find it interesting that the two A lenses I have tried meter the PTLL flash correctly, but not my DA lenses.

**Lowell Goudge** · 03-09-2008, 04:10 PM

Originally posted by Ash

These were shot in RAW (Bright mode - if that makes any difference) with Contrast at +1, Saturation at +1 and Sharpness at +2, then no PP to convert to JPEG in its natural form. When contrast is taken down to -1, I get even duller pictures and a flattened histogram in comparison.

Perhaps our monitors project the pictures differently - even when I turn up my monitor's contrast and brightness to near max, I still see all the details in my compensated shots, and the histogram records no pixels as clipped highlights. Lowell, do the shots from your uncompensated flash have pixels on the top half of your histogram? Would colourspace have anything to do with this? Do most people use sRGB as default? Perhaps I should set up a poll on this...

Fritz, with your A lenses, are you shooting in Av mode on the A setting? Are you using a K10D or K100D, and do you have a replacement viewfinder screen? What have other EF 530 users experienced?

I shoot in sRGB, and generally not in bright mode but normal mode. also I shoot almost exclusively JPEG resolution is no issue with making 11 x 17 prints from either *istD or K10D in jpeg.

I adjust contrast, as I have commented on many posts, as a function of lighting at the time.

Note also that I use my *istD for TTL flash on K mount lenses, and the K10D for P-TTL flash on KA and KA-J lenses

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03-09-2008, 02:09 AM	#16
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920 Original Poster	If you're referring to the above photos, they're on an Adobe RGB calibrated iMac 20" TFT monitor, and I've shot the pictures on Adobe RGB, judging exposure by the histogram, not just on their appearance on the screen. Either way, on FEC 0, none of my flashed shots with the AF 540 were exposed enough IMO...

03-09-2008, 09:07 AM	#17
Fritz Veteran Member Join Date: Jun 2007 Location: Tillamook, OR Posts: 1,222	I don't mean to hijack this thread, but I've been having similar issues with my Sigma 530 super. It always appears to be underexposed by a full stop. Trying any other settings other then bumping the EV to +1.0 (in camera or on flash) doesn't seem to help. This is using my DA kit lens and the DA 50-200mm. I noticed however that when I put on an "A" lens, that the exposures come out perfect with no EV adjustments. I have a SMC A 50 f2.0, and my Vivitar series 1 105mm f2.5 that I've tried this on, and the results always come out perfect. And my DA lenses always come out underexposed by a stop. Anyone have a good explanation for this? Thanks!

03-09-2008, 10:03 AM	#18
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	as I noted earlier, my impression was that when you bumped the compensation, the shots were washed out. Were these shot in RAW or JPEG? If JPEG you might try reducing the contrast a little, so that you can have less difference between highlights and dark areas.

03-09-2008, 01:02 PM	#19
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920 Original Poster	These were shot in RAW (Bright mode - if that makes any difference) with Contrast at +1, Saturation at +1 and Sharpness at +2, then no PP to convert to JPEG in its natural form. When contrast is taken down to -1, I get even duller pictures and a flattened histogram in comparison. Perhaps our monitors project the pictures differently - even when I turn up my monitor's contrast and brightness to near max, I still see all the details in my compensated shots, and the histogram records no pixels as clipped highlights. Lowell, do the shots from your uncompensated flash have pixels on the top half of your histogram? Would colourspace have anything to do with this? Do most people use sRGB as default? Perhaps I should set up a poll on this... Fritz, with your A lenses, are you shooting in Av mode on the A setting? Are you using a K10D or K100D, and do you have a replacement viewfinder screen? What have other EF 530 users experienced?

03-09-2008, 01:22 PM	#20
Fritz Veteran Member Join Date: Jun 2007 Location: Tillamook, OR Posts: 1,222	Originally posted by Ash Fritz, with your A lenses, are you shooting in Av mode on the A setting? Are you using a K10D or K100D, and do you have a replacement viewfinder screen? What have other EF 530 users experienced? I use the A setting on the lens, and any other setting other then Manual, and the metering appears to be accurate. P, Tv, Av, even auto pict. It just appears to work as it should, and very consistently. I'm using a K100d with a split prism screen (k10 screen from china). I have no other metering issues. As far as I can tell the metering hasn't changed from the factory issued screen to this one. I suppose I could swap the original screen back in and see if that makes the difference. From what I have read the one stop underexposure is fairly common. I just find it interesting that the two A lenses I have tried meter the PTLL flash correctly, but not my DA lenses.

03-09-2008, 04:10 PM	#21
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	Originally posted by Ash These were shot in RAW (Bright mode - if that makes any difference) with Contrast at +1, Saturation at +1 and Sharpness at +2, then no PP to convert to JPEG in its natural form. When contrast is taken down to -1, I get even duller pictures and a flattened histogram in comparison. Perhaps our monitors project the pictures differently - even when I turn up my monitor's contrast and brightness to near max, I still see all the details in my compensated shots, and the histogram records no pixels as clipped highlights. Lowell, do the shots from your uncompensated flash have pixels on the top half of your histogram? Would colourspace have anything to do with this? Do most people use sRGB as default? Perhaps I should set up a poll on this... Fritz, with your A lenses, are you shooting in Av mode on the A setting? Are you using a K10D or K100D, and do you have a replacement viewfinder screen? What have other EF 530 users experienced? I shoot in sRGB, and generally not in bright mode but normal mode. also I shoot almost exclusively JPEG resolution is no issue with making 11 x 17 prints from either istD or K10D in jpeg. I adjust contrast, as I have commented on many posts, as a function of lighting at the time. Note also that I use my istD for TTL flash on K mount lenses, and the K10D for P-TTL flash on KA and KA-J lenses