20D: HORRIBLE BANDING CAUSED BY FLASH
/forum/topic/151171/2

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Sam Bennett
Registered: Sep 26, 2004
Total Posts: 4731
Country: United States

JVasek wrote:
I also repeated this with the 10D just in case again no banding.


Very interesting - thanks again, Jan.



hqmhqm
Registered: Aug 28, 2004
Total Posts: 203
Country: United States

Are you taking RAW images? This could be a problem with the software being used to convert to JPEG. Those "bands" look like some sort of conversion error, I know I have gotten errors using the DPP software that came with my 20D, which caused bad artifacts in RAW conversion.



Sam Bennett
Registered: Sep 26, 2004
Total Posts: 4731
Country: United States

hqmhqm wrote:
Are you taking RAW images? This could be a problem with the software being used to convert to JPEG. Those "bands" look like some sort of conversion error, I know I have gotten errors using the DPP software that came with my 20D, which caused bad artifacts in RAW conversion.


It occurs with in-camera JPEGs and across all RAW-to-JPEG conversion software.



ChrisMoon
Registered: May 06, 2004
Total Posts: 73
Country: United States

I have called canon a couple times today. The first guy said that he has had a few people with this problem and canon was able to fix it, and thesecond guy said that no one has heard of this problem. Im starting to lean tward getting my money back on the 20D and then keep using my 10D until I hear that canon has fixed the issue. (By the way, my 10D does not have the same problem...)



craig360
Registered: Sep 19, 2003
Total Posts: 368
Country: United States

Here is an example of my banding. This was with NO flash, 100 2.8 at ISO 1600. Converted to BW so the banding really showed up when I did that. Sorry it is so big but it was the only way I thought you could really see the banding.



This image is copyrighted by the owner




ekrz
Registered: Oct 17, 2004
Total Posts: 55
Country: Netherlands

Craig, can you share more exif info on the picture ? Sam got banding @1600 ISO when using the 50/1.4 lens in combination with AI Servo. What was your lens / settings ?



SCOR
Registered: Jan 18, 2003
Total Posts: 2015
Country: United States

When will you ever shoot long exposures with the internal flash? Is this really a deal breaker for people?

I can see the AI Servo being a much bigger issue.

How many have that problem? Is it limited to long exposures? If so, who uses AI Servo on a long exposure?

thanks



craig360
Registered: Sep 19, 2003
Total Posts: 368
Country: United States

Here is the full Exif

File: _MG_1025.JPG
File size: 2,998KB
Camera Model: Canon EOS 20D
Camera serial number: 0320111961
Firmware: Firmware 1.0.5
Owner: unknown
Date/Time: 2004:10:29 04:34:05
Shutter speed: 1/60 sec
Aperture: 2.8
Exposure mode: Av
Flash: Off
Metering mode: Evaluative
Drive mode: Continuous: frame 1
ISO: 1600
Lens: 100mm
Focal length: 100mm
AF mode: One-shot AF
Image size: 3504 x 2336
Rotation: none
Image quality: Fine
White balance: Auto
Saturation: Low
Sharpness: Normal
Contrast: Low
Picture Effect: Normal
Tone: Normal
Custom Functions:
CFn 1: SET button function when shooting: Change parameters
CFn 2: Long exposure noise reduction: On
CFn 4: Shutter release: AF; AE button: AF lock, no AE lock
CFn 5: AF-assist beam/Flash firing: Only ext. flash emits/Fires
CFn 8: ISO expansion: On
CFn 9: Bracket sequence: 0, -, +, Auto cancel: Disable
CFn 11: Menu button return position: Top
CFn 13: AF point selection: Multi-controller direct
CFn 16: Safety shift in AV or Tv: Enable
CFn 18: Add original decision data: on



Sam Bennett
Registered: Sep 26, 2004
Total Posts: 4731
Country: United States

Interesting Craig, thanks. This isn't totally surprising. I think that AI Servo just increases the chance of seeing the problem greatly - even when using AI Servo on the same kind of shot, you'll only see it about 50-75% of the time. I think this is becaue the lens motor has to be engaged at a particular moment when you release the shutter. I could see quick One Shot shooting resulting in it as well if there's no lag between focusing and then taking the photo - but since most of us focus, pause to frame, then take the photo, I think it's just less evident.

And if SCOR hasn't noticed already - No, the AI Servo problem is not limited to long exposures or ISO. I've seen it on normal shutterspeeds down to ISO 400.



ekrz
Registered: Oct 17, 2004
Total Posts: 55
Country: Netherlands

Craig, thanks. Given the subject you shot I had not expected AI Servo to be used.

Well is does leave us with a problem....
The banding is there and the predictability of it occurring varies apparently from close to 100% in the setup Sam advised us to test with, to 50% in the 50/1.4 plus AI Servo setup, to incidental banding as seen in Craig's sample. Now we can continue to try and get as much banding photo's with full exif, post processing story, shooting conditions, battery status etc, but that would be a long way to go. This was tried with the 1.04 firmware upgrade lockup situation where we all posted what type of CF card was in our camera to perform the upgrade. In the end it turned out to be something completely different (specific lens on camera during uppgrade).

Sounds like a having conversation with Canon experts on the subject would be the logical next step. Honestly, I can hardly believe they are unaware of the problem.

Anyone here that has contacts with Canon beyond normal customer techsupport and willing to discuss it with them ?
Any Canon person on the forum that can let us know if this is being worked ?



varela
Registered: Nov 26, 2004
Total Posts: 4
Country: Portugal

Hello,

i have the same banding problems. itīs my second 20d body and i will return this too. i donīt understand the problem.

the examples: 100 iso /13 s- 100% crop -normal and levels pushed

i read a lot of critiques of 20d and none mentioned the banding problem. i donīt understand.


This image is copyrighted by the owner
http://www.4youphoto.com/IMG_1559_1.jpg">



amirm
Registered: Nov 02, 2003
Total Posts: 1373
Country: United States

Are you saying these are 13 second exposures? If so, I don't think there are that many people using digital cameras at long exposures like this.

You may want to apply some noise reduction and see what that does.



varela
Registered: Nov 26, 2004
Total Posts: 4
Country: Portugal

after this, for long exposures i still use film, not my 20D. fuji velvia and a good scan for now is the solution.

i will send my 20d back and wait for the solution.





RDKirk
Registered: Apr 11, 2004
Total Posts: 8477
Country: United States

They may be aware of the problem, but in many instances, the discussion goes, "What percentage of users will be affected by this?" and the answer to that question dictates whether they'll solve it in this release.



Willem W
Registered: Dec 29, 2002
Total Posts: 133
Country: Netherlands

"Are you saying these are 13 second exposures? If so, I don't think there are that many people using digital cameras at long exposures like this."

Amir, why do you think that? I've seen lots of long exposure samples on the net, made quite a few myself too with my D60. Thank heaven I never encountered this type of horrible banding and for me it absolutely is a reason not to buy a 20D.



varela
Registered: Nov 26, 2004
Total Posts: 4
Country: Portugal

Never buy the first car model or the first dslr model. wait one year until all the problems be solved.

BUT a read only good things about 20d that i made the mistake of buying one. I should wait for users reviews...F_ _ _!



varela
Registered: Nov 26, 2004
Total Posts: 4
Country: Portugal

More banding problems:

http://forums.dpreview.com/forums/read.asp?forum=1019&message=11229400



stevei
Registered: Feb 20, 2004
Total Posts: 949
Country: United Kingdom

Without the flash, you shouldn't be getting banding with normal long exposures. Look at Phil Askey's 30 second test shot on this page:
http://www.dpreview.com/reviews/canoneos20d/page21.asp

I've opened that image in Photoshop and pushed the levels up quite drastically, and no banding.

Steve



Tony C
Registered: Jan 22, 2002
Total Posts: 154
Country: United Kingdom

stevei wrote:
Without the flash, you shouldn't be getting banding with normal long exposures. Look at Phil Askey's 30 second test shot on this page:
http://www.dpreview.com/reviews/canoneos20d/page21.asp

I've opened that image in Photoshop and pushed the levels up quite drastically, and no banding.

Steve


Could it possibly be lens related, or CF card/microdrive related?



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