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05-16-2010, 10:23 AM   #1
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Help with K7 & K10 and Sigma 300mm/2.8

First of all I want to give kodo's to Pentax"s C.R.I.S camera repair. I sent the K7 in last wednesday and received it back this friday. Auto exposure adjust, AF adjust, SR adjust and cleaned and checked to manufacture specs. ( supposedly ) fingers crossed.

I am posting a couple photos as examlpes to show the difference with the two cameras. I know this isn't the best test and examples but its a start. I forgot to change the settings for RAW as PEF and Elements 7 doesn't recognize PEF so I shoot DNG. This is why I am posting jeps straight from the camera. I shoot RAW+.
What I need help with is suggestion to do this proper



When I was out in the field and looking at the photos in the LCD I was discouraged and thought they didn't fix the camera at all but getting the camera back and looking at them on the computer I think its all good.
The K10D at suggested setting adds a bit of contrast and sharpness so I did manipulate the photos from the K7 just a tad to compensate.
I also adjusted exposure and darkend.

Okay now, unmanipulated photos.

I did change the ISO to compensate shutter speed. The K7 is @ 200 and K10 @ 100.

Tell me what I'm doing wrong and what you think of the comparison please.

Last edited by OrenMc; 05-16-2010 at 11:57 AM.
05-16-2010, 11:14 AM   #2
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The K 10 picture looks a bit underexposed while the K 7 picture is slightly overexposed.
There could be a very simple explanation to this.
Have you checked which exposure metering mode you were using? Have you tried using center spot metering on both bodies?
The two cameras have different metering systems, and the K 10 is known to have a tendency to underexpose a little. With the K 10 I freguently used exposure correction, nearly always to increase the exposure. The K 7 metering system seems to do a somewhat better job.
05-16-2010, 11:54 AM   #3
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I agree in the difference of exposure, thats the reason I darkend the the sample form the K7 in the first images.
I used AV mode which I normally do and works fine most of the time. The K7 I believe meters much better and the colors are better because of it also.

My main concern was, is the sharpness there? I believe it is although the overexposure from the K7 didn't help. I know I answered my own question there but would like thoughts from others also.

I should know better but you can never really go by what the LCD displays. But I was discourage like I said and kept using the K10 the rest of the day because I didn't want to miss any shots. Turned out I din't get any real keepers anyway so I should have spent the day focused more on testing since I just got the camera back from C.R.I.S.

I need to do some testing at lower shutter speeds to check the SR since I think that was most of the culprit before.

Thanks for the comments PePe!
05-16-2010, 12:37 PM   #4
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I am using the same combo, works pretty well.
The only issue I had was some BF with my copy of the lens. Shot quite a lot of test shots and eventually got it fixed with the built-in AF adjustment of the K 7.
This was lens-related as none of my other lenses needed any corrections.


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