K20D banding?

wlachan · 03-13-2008, 02:09 AM

Okay, this is going to be embrassing as I have just purchased a whole set of 40D from B&H, everything are perfect, except... um... banding? After a brief search, banding at iso3200 seems common for 40D. It has been almost 2 years since Pentax managed to fix it with the last *istDS firmware, and I have been spoiled by banding free high iso shots even if I had to push the limit in ACR. I can tolerate quite a bit of noise but banding is something different and cannot be removed afterward. It is a hardware thing and all my very old banding shots went straight to trash. So my question is, before I decide what to do with the Canon, I would like to know if any K20D owners ever experienced banding at any iso. My typical habit is to shoot first (up to iso1600 without flash) then fix later in ACR, and often mean pushing the darker areas quite a bit. My *istDS has been doing well without giving me banding whatsoever, and if Pentax did indeed address this issue with the K20D, I might give it a shot. I am tired of the ongoing exchange or repair which has never been trustworthy (any manufacturers), so any actual user experience would be much welcome.

*falconeye* · 03-13-2008, 07:24 AM

Ok, judge for yourself.

The attached image is a 100% crop from the region which most shows something which resembles a banding.

It is K20D, a 1/4 s dark shot at ISO 6400 w/o noise reduction in camera or RAW processing, then pushed by 3 EV to ISO 51200 in PS (noise or banding didn't get clipped away!).

You clearly see the noise ... if you don't see banding than there is no banding.

I added a 12.5% crop of the entire sensor height at ISO 51200 as well so you see how small the banding artifacts really are. They are clearly much smaller than ordinary noise. I also added the ISO 6400 image of the dark to make it obvious that I pushed the noise as much as I could!

What does a 40D crop look like at ISO 51200, w/o any noise reduction?

*benjikan* · 03-13-2008, 07:32 AM

Originally Posted by wlachan

Okay, this is going to be embrassing as I have just purchased a whole set of 40D from B&H, everything are perfect, except... um... banding? After a brief search, banding at iso3200 seems common for 40D. It has been almost 2 years since Pentax managed to fix it with the last *istDS firmware, and I have been spoiled by banding free high iso shots even if I had to push the limit in ACR. I can tolerate quite a bit of noise but banding is something different and cannot be removed afterward. It is a hardware thing and all my very old banding shots went straight to trash. So my question is, before I decide what to do with the Canon, I would like to know if any K20D owners ever experienced banding at any iso. My typical habit is to shoot first (up to iso1600 without flash) then fix later in ACR, and often mean pushing the darker areas quite a bit. My *istDS has been doing well without giving me banding whatsoever, and if Pentax did indeed address this issue with the K20D, I might give it a shot. I am tired of the ongoing exchange or repair which has never been trustworthy (any manufacturers), so any actual user experience would be much welcome.

I have had absolutely no banding issues with my K20D's. But, I only shoot from 100-400 iso in most cases.

Ben

jeffkrol · 03-13-2008, 07:41 AM

Originally Posted by wlachan

Okay, this is going to be embrassing as I have just purchased a whole set of 40D from B&H, everything are perfect, except... um... banding? After a brief search, banding at iso3200 seems common for 40D. It has been almost 2 years since Pentax managed to fix it with the last *istDS firmware, and I have been spoiled by banding free high iso shots even if I had to push the limit in ACR. I can tolerate quite a bit of noise but banding is something different and cannot be removed afterward. It is a hardware thing and all my very old banding shots went straight to trash. So my question is, before I decide what to do with the Canon, I would like to know if any K20D owners ever experienced banding at any iso. My typical habit is to shoot first (up to iso1600 without flash) then fix later in ACR, and often mean pushing the darker areas quite a bit. My *istDS has been doing well without giving me banding whatsoever, and if Pentax did indeed address this issue with the K20D, I might give it a shot. I am tired of the ongoing exchange or repair which has never been trustworthy (any manufacturers), so any actual user experience would be much welcome.

The banding at 3200 jumped out to me here. It's not much but it's there (I think

)
Pretty clean lower iso's though and not real fair to judge without the RAW files..
A K20D high ISO test [3 imgs]: Pentax SLR Talk Forum: Digital Photography Review
As a side note my D was pretty "pattern free" until it got a sensor swap... now I get HPN at high iso's

So my opinion: hit or miss for any camera/brand unfortunately....

egordon99 · 03-13-2008, 07:53 AM

I find my 40D shots up to 1600 pretty good regarding noise (and don't see much/any banding), but I do see some funky noise stuff going on at 3200, but once I downsize somewhat, it doesn't look too bad. I use ACR and sometimes add some NR during the RAW conversion.

Regardless, high ISO is much better on the 40D than the K10D. It does seem that Pentax has made some great strides in this department with the K20D. Too bad they didn't do much with the autofocus. My 40D smokes my Pentax K10D in that department, and I don't think the K20D was improved enough to catch up with it. Let's see what the K30D holds!

wlachan · 03-13-2008, 07:55 AM

Thanks falconeye for the pics. I can see the banding noise but then it is 51200. What I am really interested in is iso1600 because it is the highest that I use but often enough that it matters. I have searched a bit more and managed to find some other 40D full size pics which are free of banding even at 3200. So jeffkrol is quite correct, it is hit or miss. I am just a bit surprised that after all these years, they still haven't addressed it. Shopping has never been so little fun.

wlachan · 03-13-2008, 08:02 AM

Originally Posted by egordon99

Regardless, high ISO is much better on the 40D than the K10D. It does seem that Pentax has made some great strides in this department with the K20D. Too bad they didn't do much with the autofocus. My 40D smokes my Pentax K10D in that department, and I don't think the K20D was improved enough to catch up with it. Let's see what the K30D holds!

That is the only reason I chose 40D, even though I will be keeping my Pentax lenses which are too sweet to let go. But let's don't go there, not in this thread anyway. I am still trying to get used to those fat Canon lenses. Maybe my hands are a little small.

davemdsn · 03-13-2008, 08:53 AM

I have shot up to 3200 and didn't see any banding. At 1600 I barely saw any noise at all on screen and none in a 11x14 print.

codiac2600 · 03-13-2008, 09:00 AM

there is no banding up to ISO 5000.

At ISO 6400 if you look on a really really really bad shot and are zoomed out it looks like banding but when you zoom in it's just random pattern noise that our eyes interpret in a regualr pattern. Probably the refresh rate of the monitor tricking us.

jeffkrol · 03-13-2008, 12:36 PM

Originally Posted by codiac2600

there is no banding up to ISO 5000.

At ISO 6400 if you look on a really really really bad shot and are zoomed out it looks like banding but when you zoom in it's just random pattern noise that our eyes interpret in a regualr pattern. Probably the refresh rate of the monitor tricking us.

Not to argue but unless the op had a bad camera, there is banding w THIS image at iso 3200:
Dissected to prove it.....Red channel shows it best......
A K20D high ISO test [3 imgs]: Pentax SLR Talk Forum: Digital Photography Review

The "bad" photo.........

robgo2 · 03-13-2008, 03:55 PM

Originally Posted by egordon99

I find my 40D shots up to 1600 pretty good regarding noise (and don't see much/any banding), but I do see some funky noise stuff going on at 3200, but once I downsize somewhat, it doesn't look too bad. I use ACR and sometimes add some NR during the RAW conversion.

Regardless, high ISO is much better on the 40D than the K10D. It does seem that Pentax has made some great strides in this department with the K20D. Too bad they didn't do much with the autofocus. My 40D smokes my Pentax K10D in that department, and I don't think the K20D was improved enough to catch up with it. Let's see what the K30D holds!

But many users are reporting that in actual practice, focusing with the K20D is considerably better than with the K10D. Now that the camera has been released, it is time to stop repeating the uninformed complaints about "poor" focusing that were made before it was released.

Rob

codiac2600 · 03-13-2008, 03:56 PM

Originally Posted by jeffkrol

Not to argue but unless the op had a bad camera, there is banding w THIS image at iso 3200:
Dissected to prove it.....Red channel shows it best......

So you're proof is a bad shot that has the all colours but red removed? Noise is typically on the Blue channel anyway...

I've got tons of stuff at 3200 and have never seen this anomaly myself. I guess if you put a magnet to things you can get that as well as pulling the noise channel from the image.

jeffkrol · 03-13-2008, 05:41 PM

Originally Posted by codiac2600

So you're proof is a bad shot that has the all colours but red removed? Noise is typically on the Blue channel anyway...

I've got tons of stuff at 3200 and have never seen this anomaly myself. I guess if you put a magnet to things you can get that as well as pulling the noise channel from the image.

I'm sorry, I didn't say it was an issue, only that it can be there....and proved it was.
When the OP posted these shots it only too a fraction of a second for my wee little brain to see it on my CRT. Wouldn't have even checked out the severity if I didn't notice it right off the bat.
You should see (and BTW: how a lot was found) how bad SOME of the k10D files were...

*falconeye* · 03-13-2008, 06:14 PM

I think my earlier post said it all already.

Banding? Yes, but by far outweighted by random noise to be invisible at a 100% crop. If you downsample a lot you can make the banding noise somewhat more visible because it is less reduced than randon noise.

To really study the effect, you have to go to 1/4s @ ISO 51200. At ISO 6400 already, the effect is almost gone already.

For all practical considerations banding can be considered to be a non-issue with the K20D.