Hi Paul,Does the 43 or 35 & 28 digitar lens a bit greyish with shifts over 15mm on 160 or 260 back?blue skies or green grass will get a bit greyish near the edges.
I own both the 35 and 28, and use them all of the time on my IQ260.
I would say that the 35mm works well on the 260 in terms of handling color cast up to about 15mm of shift. After that, you do start to get a decrease in the situation of the blue channel, which is much more intense in vertical orientation. Cross talk does become a concern earlier on as well, especially when you have edges with white subjects, like a wall.
The 28mm is another great lens, considering how wide it is and the fact that it is full symmetrical. However, the issues above become much more apparent. The blue channel starts to be effected from shift at 12mm and 8mm of shift depending if you are in a horizontal or vertical orientation. With additional layers in post, you can shift the lens up to 14mm or 11mm (depending on orientation) and recover the blues. However, after this, the blue channel is completely lost. Cross talk can be seen without any shift on lighter white surfaces at the far edge of the image.
Recently, I was able to test both lenses on the IQ3 100 and the IQ4 150. On the IQ3 100, I would say neither lens is useable. Maybe the 35mm would be okay without any shift, but the 28mm did not respond well at all.
On the IQ4 150, both work better then they do on the IQ260. The 35mm has almost no lens cast all the way to the edge of the IQ. Tiling did appear at an extreme shift though. Also, the light fall off correction in post without using the center filter produced significantly less noise in the corners, even with extreme shifts, then what I was expecting. I would still plan on using the center filter, but having the ability to shoot without it, if need be, would be a nice plus.
The 28mm on the IQ4 150 works very well too, however there was a decent amount of noticeable lens cast. Still not as much as on the IQ260, but enough to see when the picture comes in. On extreme shift, I would say the CF is needed and advisable to use without any shifts.
I also did not notice any cross talk with either lens on the IQ4 150, but I also used them in horizontal orientation.