abqnmusa wrote:
I used to see the same type of banding with the 5D (original) and 40D when the image was underexposed too much and pulled back from a RAW file. I think that is normal for all digital SLR's when underexposed too much.
Daan B wrote:
Did you happen to try that software for the 5D2 banding/criss cross pattern noise as well?
Yes, I tried it on a sample crop from the intrent. Worked well on that. Run it in to passes, one vertical and one horizontal. Don't have access to a 5D2 myself. I have mentioned this a couple of times, but there is so much NOISE in the forum these days, so nobody seems to have picked it up.
You should give it a try, there is a free 15 days trial
alundeb wrote:
Yes, I tried it on a sample crop from the intrent. Worked well on that. Run it in to passes, one vertical and one horizontal. Don't have access to a 5D2 myself. I have mentioned this a couple of times, but there is so much NOISE in the forum these days, so nobody seems to have picked it up.
You should give it a try, there is a free 15 days trial
My new 7D makes a thunk sound from the mirror/shutter when taking a picture. I take this is normal? My XSi makes a clack sound like a normal SLR camera which is a huge difference than the 7D.
Not strictly true, Daan - I've pulled banding out of D700 files without much trouble at all, and Nikon's own D3S examples (the Sea Eagle) showed really obvious banding at normal exposure/processing settings and "only" 640 ISO, viewed at 100%.
garycoleman wrote:
I just wanted to my sure nothing is wrong.
My new 7D makes a thunk sound from the mirror/shutter when taking a picture. I take this is normal? My XSi makes a clack sound like a normal SLR camera which is a huge difference than the 7D.
Mine is fairly quiet, no "thunk" sound. If you got it locally, I would check it against another 7D.
ejmartin wrote:
I'll be curious if the effect goes in the direction 20D=5D2<40D<50D<7D. A fixed tolerance for CFA misalignment should cause an effect that varies as roughly the square of the pixel spacing -- on a big pixel, a misalignment yields a leakage of R or B into green that is from a much smaller area relative to the area of the pixel.
It may also be possible to do a least-squares fit of the color charts to see if the effect can be nulled out by subtracting a proportion of R from one G subarray, and another proportion of B from the other G. That is, the hope would be that a fixed proportion (G2+a2 R) and (G1+ a1 B), or the other way around, would get the green channels to match on all patches. The coefficients a1 and a2 would be fit by least squares to minimize the G1-G2 difference across the image. If that works, it would be pretty strong evidence that the issue is the CFA and manufacturing tolerances. It would also suggest a slightly more effective workaround....Show more →
one thing I can say is that most patches with either of my 7Ds had the std deviation of G1 and G2 differing by very roughly 10-20% or so while the patches from the 20D,50D,5D2 never show more than a few percent difference between the std dev for G1 and G2 (I forget but I think 3% was about the max); that difference is very clear between my two 7D copies and all the previous canon bodies I have had (and it appears to be the case for the others I had used or borrowed as well although I dont have strict test shots from those ones)
having downloaded and played with the RAW, I'd agree that the sky is overexposed, but the forergound (where the banding lives) is three plus stops underexposed.
ejmartin wrote:
It would be worth checking if the non-grey patches were close to clipping; that could drive the sensor non-linear and cause the chromatic features that are seen.
the white patch on the 50D chart was very close to clipping in G1 and G2
the white patch on the 5D2 chart was high but not as close to clipping, same for 20D
none of the other patches were remotely close to clipping
keithreeder wrote:
Nobody is denying that this banding exists, but - seriously Stoffer - yours is another perfect example of why it is unlikely to be an issue in the real world for most of us: a 100% crop(?) of an image underexposed by God knows how many stops and then dragged back up at conversion?
Apart from playing with it, that file was only ever destined for the Recycle Bin so it doesn't represent real world usage.
I doubt that any other APS-C camera file would respond particularly well to that kind of treatment either: they might not show the banding, but they'd probably be just as unusable......Show more →
although i haven't taken such a photo, it might show up if you shot a wedding under natural lighting, that could make banding show up with the 5D2, either you blew the white shirt or the darker parts of a tux would pick up some banding unless you crushed the detail away to solid black.
anyway not the end of the world but it does reduce the effective DR, certainly with black and white film you could do a lot better
the mazing stuff seems to be a bit more universally annoying since it leaves nasty mazing with ACR, at least as it is now, and even with DPP it does add patterned speckling and a bit of extra noise compared to other canon bodies
brainiac wrote:
But let's pray we are allowed to install a manual focus screen.
oh man that would be awful to have FF and be stuck with those electronic doodads instead of proper focusing screens, let us hope they consider the 5D3 to be more 1D4 class than 7D class....
having downloaded and played with the RAW, I'd agree that the sky is overexposed, but the forergound (where the banding lives) is three plus stops underexposed.
keithreeder wrote:
having downloaded and played with the RAW, I'd agree that the sky is overexposed, but the forergound (where the banding lives) is three plus stops underexposed.
Sorry, I should have posted a resize of the original photo so you could all see the nature of the test shot.
It is close to a worst case scenario that nobody in their right mind would attemp to take for a real photo, but it most certainly pushed the camera to - and beyond - its limits. Besides the banding the 7D was actually able to retreive a decent amount for detail in the underexposure foreground IMO, so not all is bad news.
