[cbope]

Hi All

I bought my K-5 from an electronics store here in Finland a bit over 10 days ago, which I immediately took with me on a trip to the US. Having just returned with almost 600 shots on the ticker, I downloaded all my images to my computer last night and started to go through them. I noticed what may be a sensor stain. It's an L-shaped blur that appears only in some shots, I noticed it first in shots where there is blue sky at the area where the stain is. It is stronger in some shots more than others and in some images it is not visible at all.

According to EXIF data, my body was made 7.25.2011. I thought this body was new enough to be free of stains. Can someone confirm if this date falls within the stained batch?

I will upload a couple samples as soon as I can.

[cbope]

Ok, here are a couple photos, look in the upper left area of each image, the artifact is in the same location. Is this a sensor stain?

IMGP0156 | Flickr - Photo Sharing!
IMGP0141 | Flickr - Photo Sharing!

[altopiet]

That seems like a dirty sensor, get a rocket blower and it should come out if you give it a few blows.

[pxpaulx]

That is dust, definitely 100% not stains. Probably a small piece of string-y lint (like a carpet fiber or something thin of that nature).

[topace]

That does not look like the K-5 specific sensor stain problem (string of pearls), but rather a normal sensor stain from a speck of dust or dirt that fell onto the filter in front of your sensor. Get a dust blower, set your camera to the "Sensor cleaning" mode, hold it with the lens mount facing downwards, and blow some air towards the sensor through the lens mount. Then turn the camera off, which closes your shutter, and remount the lens. Be careful not to get the dust blower in the way of the shutter closing.

To see if the stain is still there, set your camera to the Aperture Priority (AV) Mode, set aperture to the highest (most closed) setting, focus to infinity, point at a white surface and shoot, maybe moving the lens around a little during the exposure so that no details are captured, but not so much that any non-white gets into the image. I usually shoot my wardrobe door. The narrow aperture is to better show stains, the white surface, defocus and movement is to get rid off all details that could be mistaken for stains. The blue sky is also good at showing stains, which you no doubt noticed.

[cbope]

Thanks everyone for your suggestions, I will try blowing the dust from the sensor. This is my first DSLR, so this is new to me. My first thought was a sensor stain, since this has been a problem with K-5's.

[sterretje]

Yours is not what is considered "the stain"

example by eigelb

http://img703.imageshack.us/img703/49/69345632.jpg

or this clearer one by Gimbal

https://www.pentaxforums.com/forums/attachments/pentax-k-5-forum/77440d129148...ilter-dots.jpg

[causey]

Learn to change lenses quickly, to avoid dust getting on the sensor. If that bit of dirt is "welded" to your sensor, the blower won't remove it, and you might need to resort to other methods. (DustAid works for me.) But prevention is better than any medicine.

[paulh]

All good advice. I would also learn how to use the clone tool (or healing brush, clone brush, etc) in your image editor to easily remove the dust spots on your photos.

[aleonx3]

Yes, it looks like some speck of dirt or dust to me which will likely be cleared with a blower. As many have suggested, be careful when changing lens... such as not in wide-open windy area, and try to keep the time when the sensor is exposed as short as possible while keeping the lens mount pointing toward the ground before mounting the lens.