[Ivan Glisin]

The normal filter was actually swapped for an IR filter. Its an IR only camera.

That may explain the problem: the new filter may have irregularities in it (structural or mechanical after cutting and polishing) and light passing through it may show those irregularities, especially POLARIZED light. Have you used polarizing filter? Under some circumstances the sky can be polarized as well showing the same pattern. If the pattern does not show under regular light (like indoors) then it is definitely a filter.

I have participated in several experiments (using lasers or other sources of polarized light) testing structural integrity, stress and load distribution, weak points, etc, and under polarized light most types of glass and plexiglas are showing very similar patterns you are seeing.

[d.bradley]

My vote goes to optics as well...it looks like almost a moire-type pattern. Question: Does this only happen at certain apertures?

[jshurak]

That may explain the problem: the new filter may have irregularities in it (structural or mechanical after cutting and polishing) and light passing through it may show those irregularities, especially POLARIZED light. Have you used polarizing filter? Under some circumstances the sky can be polarized as well showing the same pattern. If the pattern does not show under regular light (like indoors) then it is definitely a filter.

I have participated in several experiments (using lasers or other sources of polarized light) testing structural integrity, stress and load distribution, weak points, etc, and under polarized light most types of glass and plexiglas are showing very similar patterns you are seeing.

My vote goes to optics as well...it looks like almost a moire-type pattern. Question: Does this only happen at certain apertures?

Ok, so I'm going to have to do a number of experiments.

I can emulate the issue and throw a polarizer on there and see if that helps.

d.bradley, I'm not sure. I will keep note

Definitely looks like a smear pattern to me as well.

[Ivan Glisin]

Ok, so I'm going to have to do a number of experiments.

Just take pictures of a blank evenly illuminated white (or near white) wall with and without polarizer and see what happens.

[Arpe]

Does it have the latest firmware? I think you need it, or a recent one anyway, to be compatible with SDHC cards.

[jshurak]

I went out yesterday and no avail. I'm going to try to clean the sensor later. Luckily the person that modded the camera has offered to take a look at it. I've also noticed that the patterns are more prevalent towards the right side of the frame. I hope its something as simple as a smeared sensor. Although, the pattern is so uniform that I have my doubts.

Thank you all for your help

[Donald]

Moiré. Just above and also to right of little hut is observable 'swirling' moiré. This can be caused by any overlapping pattern. Your new filter glass may have some pattern, unobservable to you, perhaps from cutting, polishing, optical, metal or other film coating. I've read also that Bayer filter sensors exhibit moiré under some circumstances, but don't remember what those were. Perhaps the new sensor glass affects this.