[bkpix]

Hi all,

I've been shooting with a K-7 since buying it a few months ago and have been quite happy.

In making large prints (16x24) recently, though, I've begun to notice a consistent vertical interference pattern running through most images shot at 400 and above. The effect is most pronounced along horizontal or diagonal edges, though it sometimes actually overwhelms a near-vertical edge with interference.

I can sometimes get rid of it with aggressive noise reduction in LR3, but at the expense of overall detail in the image.

I have gone back and checked and can't find any instance of this in photos from my K20D.

Any ideas what it is? How to fix it?


Here's a 100 percent crop photo from this afternoon, shot at ISO 800, high-ISO noise reduction on high, no noise reduction in LR. In a 16x24 print the interference pattern is quite objectionable.

Thanks for any help.

[blende8]

This is most probably either a faulty SD card or an interference from a mobile phone or something like that.

[dlacouture]

Someone on a french forum recently had such a problem...

The camera went for a complete sensor change...

[bkpix]

dlacouture:

Merci!

That post you pointed out on the French forum described the problem exactly and in detail. That tale had a happy ending. Fortunately my K-7 is new and under warranty; it will be making a trip back to Pentax very soon.

I appreciate the suggestions about the SD card and the nearby telephone, but really don't believe they are factors here.

Guess I'll be shooting with the K20D for a while again.

Bob

[bkpix]

Shipped the body off to Pentax this morning for warranty repair. Will update the thread when it returns.