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01-28-2008, 11:40 PM   #61
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Just bump up the flash comp...

Pentax P-TTL is easily fooled by bright spots as was said here before. Just check your LCD periodically and dial up flash exposure compensation to .07 in the flash mode menu, that's actually where I leave mine, and then if I need more or less exposure, just dial in + or - exposure compensation.

01-29-2008, 12:21 AM   #62
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QuoteOriginally posted by proudtoshootpentax Quote
Pentax P-TTL is easily fooled by bright spots as was said here before.
OK seriously, how do people make these generalizations? The Pentax P-TTL is not easily fooled by "bright spots" and I can prove it. The attached shot was taken in a dark room with a flashlight pointing directly into the camera lens. You don't get much brighter spots than that, yet the image is pretty well exposed considering there were no lights on in the room, so all light came from the P-TTL metering of the flash. If the P-TTL was easily fooled by bright spots, this picture should be very underexposed.
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01-29-2008, 12:53 AM   #63
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Hey now!

QuoteOriginally posted by PentaxPoke Quote
OK seriously, how do people make these generalizations? The Pentax P-TTL is not easily fooled by "bright spots" and I can prove it. The attached shot was taken in a dark room with a flashlight pointing directly at the camera. You don't get much brighter spots than that, yet the image is pretty well exposed considering there were no lights on in the room, so all light came from the P-TTL metering of the flash. If the P-TTL was easily fooled by bright spots, this picture should be very underexposed.
I'm not trying to pick a fight! I've just found that I need about .07 EC at least under most indoor conditions to get an exposure I'm happy with. The fact that the camera compensates for bright spots means it's smart. You can't recover blown data, but you can rescue a shot that's a little dark.
My method is to leave the over exposure warning on, and shoot to the point that just the very tips of the highlights are blown. This seems to require the least amount of post processing to get images I'm happy with in the end. It's all about taste. Personally, I think the above example is a little dark... but that's just my opinion.
As for the flashlight, once again, your camera's smart enough to tell between the preflash and a light that's already there. The dangerous bright spots come from reflected flash.
01-29-2008, 01:06 AM   #64
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QuoteOriginally posted by proudtoshootpentax Quote
As for the flashlight, once again, your camera's smart enough to tell between the preflash and a light that's already there. The dangerous bright spots come from reflected flash.
Would you like to see a result of shooting in a dark room directly at a mirror? That is pre-flash metering off of itself. Same result. I disagree that P-TTL is easily fooled by bright spots. I have found it to be very robust.

01-29-2008, 01:12 AM   #65
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agreed

QuoteOriginally posted by PentaxPoke Quote
Would you like to see a result of shooting in a dark room directly at a mirror? That is pre-flash metering off of itself. Same result. I disagree that P-TTL is easily fooled by bright spots. I have found it to be very robust.
I guess 'easily fooled' is a bad choice of words, the meter usually returns consistent results... but there are times when flash and/or exposure compensation are needed. That's why they're there. Personally, I think pictures from a K10D or A k100D are a little underexposed when used in fully auto mode with no correction. It's not a problem though, because it does it in a consistent manner, and as I said, I think this is just to play it safe, and not clip highlights.
01-29-2008, 01:33 AM   #66
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Here's a casual shot I took a few days ago. I was using Pentax AF 360 FGZ flash on P-TTL.

I had deleted the original, which was really underexposed, but with +0.7 E/V it looks OK now.

With the dark wood panelling filling half the picture , logically, it should have been over-exposed, but there was the spot of bright flash reflected from the Flat screen TV.
Pardon the smudge on the TV screen - my little toddlers!

01-29-2008, 06:51 AM   #67
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QuoteOriginally posted by kittykat46 Quote
Here's a casual shot I took a few days ago. I was using Pentax AF 360 FGZ flash on P-TTL.

I had deleted the original, which was really underexposed, but with +0.7 E/V it looks OK now.

With the dark wood panelling filling half the picture , logically, it should have been over-exposed, but there was the spot of bright flash reflected from the Flat screen TV.
Pardon the smudge on the TV screen - my little toddlers!

Seems to depend on placement in the metering zones.
See this: If I shift to the left so mirror is not dead center thngs get better. This is w/ an old D.
Keep speculars out of the center...I've seen this w/ lamps ect...
At the edges it may just think it's a sunset/sunrise
02-13-2008, 09:26 PM   #68
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Just when I thought I had it figured out...

I was trying to do a test for using the top of a Pringle container box to set the AWB (ie a cheap man's version of the expodisk) when I stumbled back on my exposure issue!

I was just shooting picutes of the bed in my guest bedroom as a means to test the accuracy of using the semi-clear lid to set the custom WB feature. I noticed the pic seemed a little underexposed. Base on what we had talked about earlier, I used the OK button and saw that the ISO was selecting 200 eventhough I had it set to AUTO ISO ( I doubled check that under the Fn button). Also, the flash icon was blinking.

Again, why wouldn't the light meter select a higher ISO so as I wouldn't need to use the flash?!?! Really frustrating b/c the "logic' of the processor simply confuses the heck out of me. I was shooting in P mode, but I also tried it in Apperture priority and it behaved the same way...

Do they not look under exposed? How about the one at ISO 100 and ISO 200 having very similar exposures at the same speed 1/45s and apperture f4.0?? Shouldn't they be very different exposure?

I posted the pics in flicr.com:
exposure test - a photoset on Flickr

02-14-2008, 12:10 AM   #69
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What is the auto ISO range set to on your camera? If you don't know, if you press the fn button and then ISO you will see on the right side a green bar. Is the bar just covering 100 and 200, or does it go all the way from 100-1600?
02-14-2008, 06:06 AM   #70
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I think you can set the flash to ONLY pop-up when you ask it to. I think it's something like "Flash - Manual" (as opposed to "Flash - Auto") I thought this would only apply to the Green mode, but maybe you can have it auto-decide-to-use-the-flash in P as well.

Did the flash actually fire when you did the two shots at ISO100 and ISO200? If so, they would look the same because the P-TTL flash determines how much power to output for proper exposure, based on the f-stop and ISO, so it would just need to use twice as much power for ISO100 than for ISO200.
02-14-2008, 01:11 PM   #71
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a) auto ISO 100-1600 (checked before, during and after)

b) did not use flash

The flash symbol was flashing. Not sure why the camera would recommend using the flash instead of increasing the ISO...
02-14-2008, 03:52 PM   #72
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QuoteOriginally posted by jjfdvm72 Quote
a) auto ISO 100-1600 (checked before, during and after)

b) did not use flash

The flash symbol was flashing. Not sure why the camera would recommend using the flash instead of increasing the ISO...
Per IM, I really think there is a problem with the camera now. You may try reinstalling the v1.3 firmware first before getting service. You camera is not at all behaving as it should in Auto ISO.
02-24-2008, 06:28 PM   #73
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Here are some sample pics that I took with my AF360fgz and k10d. Kit lens. 10 feet or so from my model. In my test shots, I varied the "zoom" and that was all. To me all these photos seem to be underexposed. I took the camera to Wolfs today and they couldn't help me get the right metering
Picture 006 on Flickr - Photo Sharing!
Picture 005 on Flickr - Photo Sharing!
Picture 004 on Flickr - Photo Sharing!

Last edited by mi2nc; 02-24-2008 at 06:29 PM. Reason: make pics show up
02-24-2008, 10:46 PM   #74
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Does it appear to underexpose as well with the built-in flash?
02-25-2008, 12:43 AM   #75
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QuoteOriginally posted by mi2nc Quote
Here are some sample pics that I took with my AF360fgz and k10d. Kit lens. 10 feet or so from my model. In my test shots, I varied the "zoom" and that was all. To me all these photos seem to be underexposed. I took the camera to Wolfs today and they couldn't help me get the right metering
Picture 006 on Flickr - Photo Sharing!
Picture 005 on Flickr - Photo Sharing!
Picture 004 on Flickr - Photo Sharing!
Am I correct in taking the sofa's colour is somewhat dark brown ?

If so, the P-TTL exposure is actually "reading" the scene correctly.
The exposure system normally attempts to expose the overall scene to an average gray. In a scene with a mixture of light/ dark objects, a darker object like the sofa should appear somewhat underexposed.

You can always make the scene brighter by putting in +E/V compensation, but the result would be a light toned subject e.g. a person sitting on the sofa would then be overexposed.
Unless the person has darker skin, in which case +E/V would be the correct procedure.

If you sit a person or some other object (preferably lighter colour) on the sofa and focus on that, you can see more clearly the accuracy of the exposure.
You may likely find that the subject itself is correctly exposed.

Now, I have family members who range from very fair to quite dark skin. How do you expose everyone correctly when they all sit together ? I Never found a solution, just accept the average gray exposure.
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