[vagabond79]

Hey all,

I bought a K10d about a month ago and I have noticed that when I zoom in on a slightly overexposed area of a photo (in camera raw) there are these "little red lines". You can see what I'm talking about in this link:

http://img33.imageshack.us/img33/5963/pixelsd.jpg

Is this normal for overexposed areas of a picture? Is there anyway to fix it or avoid it?

Also, if I were to sharpen this photo the lines would become drastically more visible.

Thank you in advance for any advice you can give me.

Jon

Welcome Jon.
Don't overexpose, sometimes the solution is in the question.

You could also check your saturation settings in the camera.

[Ash]

Those faint red checks over the pants? They don't look all that sinister.

This is a low quality JPEG of the shot - is it evident on the original at 100%?
It's not normal for the camera to add detail that's not there.

[shadeless]

this is definitely not normal. did you buy the camera used or new ?

i would return it or send it in for repair if possible.

[vagabond79]

To answer a couple questions -

Yes, the red checks are there on the high quality RAW image.

I bought the camera as a refurb but it is still under warranty. I showed the issue to the Pentax support folks and they think it's a problem with the sensor and I should send it for repair. I guess that's the route I'll take.

[RBellavance]

This looks a lot like "maze artifacts", and that it a demosaicing problem (i.e. it originates from the RAW converter).

References:

• Moiré: Digital Imaging: Glossary: Learn: Digital Photography Review
• Maze artifacts in raw files from Nikon | Super Soft Cafe

Google "maze artifacts" for more.

Maybe it is exacerbated by the overexposure... Can you try another RAW converter ? Does the Pentax Photo Lab software show the same thing ? What about Lightroom or RAWTherapee ?

[vagabond79]

RBellavance - thanks for your reply.

It does look a lot like the maze artifacts you mentioned. However, I am seeing the issue in Camera Raw, Pentax Laboratory, and Raw Therapee (cool free program btw!). I am noticing that all the areas I am having issues with ARE in fact overexposed. Someone else I spoke to said that some color pixel distortion in overexposed areas is not uncommon. I've also noticed that if I try to recover those areas with the recovery slider in Camera Raw it just makes the lines more noticeable. It's honestly better to just let them be washed out than try to bring detail back that is distorted.

[Canada_Rockies]

I do not have this problem with my k10. Send it in for repair. Here is a 100% crop of a loon where the breast is overexposed. Cropped in LR 2.5 for display here. As you can see, my k10 does not produce those artifacts in what is, for image analysis, the same picture. There is a slight reddish tinge to the breast here, but it is not evident in the RAW image. I had to pump the red channel to bring out the eyes in the loons.