Canon 40D posterization? - DPChallenge Forums

Canon EF 70-200mm f/2.8L IS USM II

11/19/2007 10:24:01 AM · #1

I've been getting some disappointing results with my 40D in situations where I would expect much better image quality. Check out this crop:

See all that nasty pixelization? It shouldn't be there. That shot was taken in RAW at ISO 200, f/3.5, 1/60, with my Tamron 28-75 on a sturdy Bogen tripod with cable release! Is anybody else getting strange results like this?

PhotoDave

Canon EOS-5D Mark II

11/19/2007 10:31:49 AM · #2

Is that a 100% crop? Ive noticed a little something like that with mine but not that bad I dont think... Some picks Ive taken lately with my 17-40 have sucked and Ive finally figured out why but thats a problem with the lens not the camera as my XTi kit lens is out performing it ATM... :(

-dave

FireBird

11/19/2007 10:40:32 AM · #3

Whoa! Is that the full frame? That's horrible. Can you post the full EXIF with this image? Was this in 12 or 14 bit raw mode? Or JPG?
That baby needs to go back to Canon.
Seems I remember there is a extremely compressed RAW mode available on newer Canons. Maybe you have slipped into this mode by mistake.

Canon EF 28-135mm f/3.5-5.6 IS USM

11/19/2007 10:40:46 AM · #4

That's not full frame (not a 100% crop, but probably close). It was a full 14-bit RAW file. I don't have the file with me to post full EXIF right now, but the problem isn't exactly subtle. :-(

Message edited by author 2007-11-19 10:45:27.

Kari48

Google Pixel 8

11/19/2007 10:50:03 AM · #5

WOW, I've taken a few thousand shots with my 40D and never have seen anything like that.

Mike_Adams

Canon EOS-40D

Canon EF 70-200mm f/2.8L IS USM

11/19/2007 10:54:27 AM · #6

Wow I haven't anything event remotely like that so far. My guess is you are shoot a great deal more than I, but everything that I have taken has been extremely sharp or my fault. Since you are really really good I am gonna go with the camera has an issue or has moved into some settings that are messed up. Since you are shooting in RAW clearly you are either in one of the custom set ups or are in one of the advanced zones so seeing what those settings are would help a great deal. Well lets start working to narrow done I have never used the 40d with a cable release. I doubt that could be an issue, WAIIIIIT did you cover the viewfinder when you took this shot?? If you are using the cable release and you didn't cover the viewfinder I could see this happening. They gave a lengthy warning on that if you were going to use delay or release.

CHECK THAT. If there was nothing covering the viewfinder I bet that is it.

pix-al

Tamron AF 28-300mm f/3.5-6.3 XR Di LD Aspherical IF for Canon

11/19/2007 10:55:48 AM · #7

That is obviously a converted file excerpt - What are you using to convert to JPG? Could it be settings within your conversion software.

Quite often I am dissapointed with some results when viewed as RAW (Blocky gradients etc), but once converted and PS'd, they are perfectly fine!

Message edited by author 2007-11-19 10:58:01.

pix-al

Tamron AF 28-300mm f/3.5-6.3 XR Di LD Aspherical IF for Canon

11/19/2007 10:57:44 AM · #8

Originally posted by Mike_Adams:

CHECK THAT. If there was nothing covering the viewfinder I bet that is it.

???

On a very long exposure shot, OK, but on a shot at 1/60th second, I would be very surprised if that was the cause?

Simms

Canon EOS-5D Mark II

Canon EF 24-70mm f/2.8L USM

11/19/2007 10:58:12 AM · #9

any others scalvert or just this one?? thats dreadful. send it straight back to canon matey!

Message edited by author 2007-11-19 10:58:19.

eamurdock

Pentax KP

Pentax FA 77mm f/1.8 Limited AF

11/19/2007 11:00:58 AM · #10

It looks like you don't have any anti-aliasing... since you're shooting raw the filtering would (I think) be done by your raw converter - perhaps you have anti-aliasing turned off?

hankk

Sigma 24-70mm f/2.8 EX Aspherical DF for Canon

11/19/2007 11:14:11 AM · #11

How does the 20D do in similar lighting?

ISO 200, f/3.5, 1/60? must not have been a bright day. Did you bring the exposure up in PP?

PHOTOKID

11/19/2007 11:16:41 AM · #12

I am looking at mine at this moment and do not have any issues other than them being to sharp for a Raw file out of the camera. Off to find out how to check to see if there is in camer sharpening dont on the 40d....

Strikeslip

Canon EF 100-400mm f/4.5-5.6L IS

11/19/2007 11:25:04 AM · #13

I get 'grainy banding' sometimes, and don't expect it. It feels like it's coming from the sensor. I'll try to find an example.

Canon EF 17-40mm f/4.0L USM

11/19/2007 11:50:28 AM · #14

I've seen this posterization on many files, and I don't think it's the camera settings. I've checked and re-checked them carefully. It's not the RAW converter, either. I get similar results in Photoshop CS3, iPhoto, Aperture, and Canon's DPP software (I'm not exactly new to RAW). I'll have to set up a side-by-side test with the 20D and see what happens. I was just wondering if others had run into the same issue.

david_c

Canon EOS-7D

11/19/2007 12:23:30 PM · #15

That's mighty disappointing, for real. I'd be interested to know if others are experiencing this phenomenon...I've had my eye on the 40D as my first foray into the world of DSLR. I've gotta know if this is the Digic III, or an isolated sensor malfunction.

scalvert, have you tried to reproduce this with a different lens?

Prof_Fate

11/19/2007 12:54:59 PM · #16

Underexposure and pushing it it what it appears, or some really nasty plug-in effects, or a seriously zoomed/cropped file, or a bad RAW conversion, or a level 1 JPG (serious compression issues)

Was that a RAW file (10mp) or an sRAW file (2mp)?

Bear_Music

Samsung Galaxy S24, S24+, S24 Ultra

Sony 24-70mm f/4 Vario-Tessar T* FE OSS

11/19/2007 01:02:02 PM · #17

I agree that's not an acceptable result, but frankly I don't care; I just want her phone number :-) Tell me she's available?

R.

Mr_Pants

SiPix Blink

11/19/2007 01:14:25 PM · #18

Originally posted by Prof_Fate:

Was that a RAW file (10mp) or an sRAW file (2mp)?

I've seen other people run into problems when they've not spotted the little 's' in front of the RAW icon on the camera's status screen. To me, this looks as though it's a picture that's at something like 400%. As the good Prof asks, are you in sRAW by mistake?

Probably not, I'd guess, but I had to ask anyway.

Message edited by author 2007-11-19 13:15:17.

Canon RF 24-70mm f/2.8 L IS

11/19/2007 01:40:57 PM · #19

Originally posted by Mr_Pants:

To me, this looks as though it's a picture that's at something like 400%. As the good Prof asks, are you in sRAW by mistake?

The sample image might very well be enlarged (I just grabbed an already-cropped image I had handy). However, I've compared original RAW files next to 20D RAW files at the same scale, and the problem is readily apparent.

The camera has NEVER been set to sRAW (I don't see the point of that format). The format is displayed on the LCD panel and listed in the EXIF. It's plain old RAW, and would be really hard to accidentally switch to sRAW. FWIW, all firmware and software is up to date.

Originally posted by david_c:

...have you tried to reproduce this with a different lens?

I haven't looked at which shots were from which lenses, but that Tamron is my most-used lens. It's been through 3 other cameras besides the 40D and probably 100,000+ shots, so I know what to expect from it.

kirbic

Canon EOS R5

11/19/2007 01:42:26 PM · #20

Originally posted by Prof_Fate:

Was that a RAW file (10mp) or an sRAW file (2mp)?

That was my first thought, given that it really is pixelization.

Samsung Galaxy S24, S24+, S24 Ultra

11/19/2007 01:50:36 PM · #21

I'll take some test shots when I get home and post 100% crops and full EXIF data.

Bear_Music

Sony 24-70mm f/4 Vario-Tessar T* FE OSS

11/19/2007 02:06:48 PM · #22

Originally posted by scalvert:

The camera has NEVER been set to sRAW (I don't see the point of that format).

It gives the benefits of RAW processing (exposure comp available, WB can be changed, for example) but the write speeds and small file size of JPG; you can shoot extended bursts when doing sports, and you can also cram a LOT of images on CF cards if you need to.

R.

11/20/2007 12:10:54 AM · #23

Well, now that I WANT to show the difference I can't seem to get a decent example. It turns out that the earlier example I posted WAS enlarged. I dug through some old stuff to find a couple with the same lens, similar settings and exposure situation. These are 100% crops with identical RAW conversion settings (basically default) in Photoshop CS3-

40D:

14-bit RAW, Adobe RGB
ISO 250
1/250
f/2.8
75mm
Tripod, cable release, subject still

20D:

12-bit RAW, Adobe RGB
ISO 400
1/400
f/4.0
1/400
Handheld, subject moving

They don't look all THAT different, but what's getting me is that the 40D shot doesn't appear to be sharp anywhere (I always try to focus on the eye), and there isn't as much fine detail. Granted, the 20D shot had a faster shutter speed and was stopped down a notch, but I would expect 14-bit, 2 more megapixels and lower ISO to result in less noise and more fine detail. Maybe I'm just seeing things. :-(

mpeters

Canon EF 50mm f/1.8 II

11/20/2007 12:26:16 AM · #24

Shannon-- FWIW I find my Tamron/20D combo to be fairly soft, similar to what you originally posted when it is set at 28 or 75mm, even stopped down to 4.5- 5.6. Here is an example I posted from an old thread speculating that my Tamron was having focus issues. My 70-200 f4 at 70mm/f4 shows much sharper focus. In the middle of the zoom range, the Tamron goes back to its old tack sharp self.

Here is my example. Tripod mounted, f5.6 I think, and about 28mm. [thumb]506230[/thumb]