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03-06-2007, 08:19 PM   #1
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Lens Question

I use a Sigma DC 18-125mm 1:3.5-5.6 lens on my K10D. I just noticed in Pentax Photo Browser the lens name is listed as Pentax-F 28-80 (3.5-4.5). A few things are displayed in red text... Focal length 18mm, shutter speed 1/50sec, and the shooting date as well.

I surmise the focal length is listed in red because the 18mm is out of range of the focal length the camera thinks its using. I'm not sure of the other stuff.

Also will this misinterpretation of the lens used affect IQ in any way?


03-06-2007, 08:46 PM   #2
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I actually found an answer to one of my questions. I should have looked at my Photo Browser manual in the first place. It says that if your information changes from one image to the next while advancing frames (for example you change your zoom from 50mm to 18mm, it will appear in red. The same will apply if your shutter speed changes, aperture, etc.

I'm still unsure of the lens data though.
03-06-2007, 09:24 PM   #3
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The lens data: Ah, that's an old confusing thing. The simple answer is that Sigma failed to mimic the Pentax way to make up the in-lens electronics. Or it is the Pentax software that screws it up. I wonder what lens data that would be reported in Adobe Camera Raw?
For now I think you'll just have to learn what the software reports and interpret it yourself to the actual situation. Just take a few test pictures at different focal lengths and see what the software thinks about it.
03-06-2007, 10:05 PM   #4
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Sounds good Jonas. I tried to look up the lens info in Adobe Bridge... it had everything listed but the lens data.

By what you're saying, it seems this it just a software issue anyway. As long as there's no miscommunication between lens and body, that's fine with me.

Thanks for your help... again!

03-06-2007, 10:35 PM   #5
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Sigma does not have access to the inlens electronics of the big camera companies it makes lenses for.

So they have to go buy lenses, disassemble/reverse engineer to try to figure out which wire is which. So thats why pentax may not read the focal length properly.

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