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06-14-2009, 08:27 AM   #16
pbo
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I think what he's trying to say is that his K10D's results are different from K20D's results at the totally same settings. So, he HAS to use a slower shutter speed on K20D, all other parameters held constant, to achieve same results as he had on K10D. Which is kinda weird, because same settings should give about same results, on any camera and any lens

06-14-2009, 08:29 AM   #17
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A shorter way of saying it is, he isn't complaining about metering; he's complaining because two cameras don't produce same results at same settings - and the difference is quite noticeable.
06-14-2009, 08:42 AM   #18
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QuoteOriginally posted by pcfranchina Quote
I agree but think 1/15 is too slow of a shutter speed to get me the better shot.
So raise the ISO. If I'm interpreting what I'm seeing properly, yes, there is a fraction of a stop difference in how ISO is interpreted between the two cameras, but nothing to get upset about - just raise ISO by a fraction of a stop and you'll get the shutter speed you want.
06-14-2009, 09:43 AM   #19
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I'm still at a loss to know what you're after.

First was "why is my K20D underexposing?" - this is only an issue when metering on an auto mode (Av, Tv, etc) since M mode overrides metering, but I'm not sure there really is a problem with your K20D's metering given the example.

Second was "why is my K20D exposure less bright for the same settings compared with my K10D?" - best described with another example saved as JPEG with no PP. I'm assuming the above example was done on an auto mode that selected Tv 1/15 on your K20D and something a little faster on your K10D (?).

06-14-2009, 09:49 AM   #20
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Even if you're shooting RAW and you haven't tweaked any of the default settings on either of these two cameras, there will be a difference between the two. You are talking about two different cameras, with different programming and different sensors (CMOS vs CCD).

I would compare it to two pairs of glasses with the same exact prescription but different kinds of polycarbonate on different frames. The prescription is just one aspect in this complex equation.
06-14-2009, 10:38 AM   #21
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QuoteOriginally posted by pbo Quote
A shorter way of saying it is, he isn't complaining about metering; he's complaining because two cameras don't produce same results at same settings - and the difference is quite noticeable.
It took me a bit to figure it out, but I think pbo is right. According to the OP:
  • Same subject
  • Same light (presumably)
  • Same lens
  • Same aperture
  • Same shutter speed
  • Same ISO
  • Different body
  • Different results
So the problem is not one of metering. Possible causes:
  • Inaccurate shutter on one or both cameras
  • Inaccurate aperture control on one or both cameras
  • Difference in sensor response between cameras
Question: Does this problem exist with any other lens? How about full manual using the aperture ring?

Steve

BTW...1/15s, f2.8 at ISO 400 for an interior shot of dark wood cabinets does not seem unreasonable. I just took a short tour in my kitchen (medium oak cabinets with white walls/counters) and got a reading of 1/20s, f/2.8 at ISO 400 with natural daylight from multiple windows.

Last edited by stevebrot; 06-14-2009 at 10:46 AM.
06-14-2009, 11:31 AM   #22
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Let's review shall we?
QuoteOriginally posted by pcfranchina Quote
I am shocked to see how my new K20D underexposes everything. Shots that I can normally get with my K10 or K100 come out dark and unusable with my new K20D. .... I'm really disappointed and shocked people find this acceptable.
So we then pointed out that no, your shot wasn't unexposed; the camera was actually doing a good job protecting your highlights. This is normal.

QuoteOriginally posted by pcfranchina Quote
I agree but think 1/15 is too slow of a shutter speed to get me the better shot.
Maybe, but now we're on the second page of posts, and you still haven't told us how much difference in exposure settings there were between the two cameras.

You also stripped out the EXIF data from the pictures you posted, so we can't see any of your cameras' exposure and parameter settings.

You are asking for advice but not giving nearly enough information to solicit a reasonable opinion. This could all go a lot faster if you would just post the jpegs from each camera with EXIF data, and then we could give you some definitive advice.
06-14-2009, 12:52 PM   #23
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QuoteOriginally posted by jimby Quote
So we then pointed out that no, your shot wasn't unexposed; the camera was actually doing a good job protecting your highlights. This is normal.
Tell me how is the camera doing that if the ISO, aperture and shutter speed are locked by the user ? And they are the same on two cameras ?

From my knowledge the camera is "doing a good job protecting the higlights" only by changing the ISO or/and the aperture or/and the shutter speed - and here is not the case.

If these 3 elements are locked, camera cannot do anything - maybe just use it's hdri function (post process in the camera after the picture is taken).

06-14-2009, 01:13 PM   #24
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And is the extended dynamic range function ON on the K20D?
06-14-2009, 01:24 PM   #25
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I'm a new upgrader to the K20 as well. I also find that spot metering is a specialized metering mode that will give all kinds of varied responses in an image which you showed. I only use centerweighted or sector. You might try both of these to see which you prefer.

I find that my K20 generally exposes 1/3 stop under as well and adjust the EV to plus 1/3 stop. I'm not sure why you consider that problem.

Do you have your camera on Dynamic Range or not. I initially didn't understand what that label was telling me and had DR on for most of my early shots even though many advise not to use it because of additional noise.

Also, which Custom Function, from the center button of the Fn menu have you chosen. I have mine on Natural. There's so many different settings on that camera, might be difficult to troubleshoot it on this forum. Perhaps you should do a default reset to see if it makes a difference.

As to whats been said before, the K20 with its CMOS sensor is not the same as the K10 which i still have. But i welcome many of the changes to the K20 and its all i use now.

Last edited by philbaum; 06-14-2009 at 05:45 PM.
06-14-2009, 01:34 PM   #26
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The obvious answer is that your K10 exposure (picture) sucks and the K20 is perfect. So, whats the complaint?

Are you saying if you took the k10D at 1/60 it would have given a similar result to the k20? (with all other settings similar)
06-14-2009, 02:05 PM   #27
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- Few days ago I was charting AF on my quirky Tamron 28-75 on K20. Because I wanted uniform conditions I used natural light and manual exposure. It turned out that manual exposure was a bad idea, clouds passing by randomly ruining some shots taken in 15 minutes. After that I light up few cold bulbs (?) of 6400K and was better. Maybe was your case too. Try again using artificial light only and CW mettering.
06-14-2009, 02:21 PM   #28
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Original Poster
Thanks PBO. You understood what I meant.

Same Lens
Same F-Stop
Same ISO
Same Shutter Speed
In my opinion should produce the same or better result with the new lens.
06-14-2009, 02:24 PM   #29
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Sure. Same exposure should result with the same settings given K20D's dRange mode is off and lighting is the same. No such thing as a 'better result' though.

I've tested my K20D against my K10D with the same settings: spot on exposures between both of them - in auto and in manual modes.
06-14-2009, 02:32 PM   #30
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QuoteOriginally posted by pcfranchina Quote
In my opinion should produce the same or better result with the new lens.
You didn't used the same lens in both tests ? I think you should repeat the test with the same lens...and as somebody else suggested, with an artificial light source.

If the result is not the same, I think the sensor in one of the camera has a different sensibility (e.g. ISO 400 is not really ISO 400 in that camera). Or the shutter speed isn't dead on in one of the camera. Am I missing some other reason ?
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