[Guest]

Hi,



There is a rumour about 7d's low iso noise performance. Especially pictures includes blue sky or out of focus areas of the pictures shows this problem. Is this really a problem (see samples, images are not clear), or is this normal for a digital slr? I discovered some pictures taken with 450d or d300s have same unclear areas.



I would be very glad if you share your ideas, otherwise I may throw my 7D out of window



PS. sorry for my bad English.



all photos 100 ISO



http://photozone.smugmug.com/photos/7774...FeGQ-O.jpg

http://img683.imageshack.us/img683/1088/1680.jpg

http://img697.imageshack.us/img697/1656/5390.jpg

http://img594.imageshack.us/img594/1696/img4728crop.jpg

[Guest]

That's normal, and gets worse the smaller the sensor is. It's called 'pixel-peeper noise'<img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' /> Smaller pixel bins have relatively more noise from quantum effects, electrical noise, and measurement errors. These factors (noise) remain (very roughly) constant while the signal gets smaller in smaller bins.



-Lars

[Guest]

Thank you very much Lars,



I know that is pixel peeping <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' /> but people around me says that is a big problem, even you cannot process image in PS. they say 40D, 50D or 500D have better image quality. maybe turning off auto lighting optimizer will reduce the problem. People expects a lot from a crop sensor I think.

[miro]

I can share my experiance with my two bodies. Since I shoot landscapes all my images are taken bellow ISO 400. 90% @ISO 100. Sotware used for RAW conversion ACR 4.5

1. 400D – difficult to tell you. Since this was my first dSLR body I accept that this is normal behavior. I’ll use this camera as base line to compare to 50D.

2. 50d – noticeable better high ISO performance. Shadows has more noise but I was positively surprised how many highlight details I can recover with ACR 4.5.



My conclusion is.

Both camera offers equal low light performance but they requires different handling





This is not scientific test. I share my experience in developing my images from both cameras.

For scientific review go to photozone Canon 7d review or Dxo website.



Greetings,

Miro



PS PS don´t throw your 7d. My experience is that the bets images are coming from old cameras. Why?



People get used to equipment. They know their limit.

They have good post processing skills.

[Guest]

[quote name='karakuss' date='08 July 2010 - 12:04 PM' timestamp='1278587099' post='898']

Thank you very much Lars,



I know that is pixel peeping <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' /> but people around me says that is a big problem, even you cannot process image in PS. they say 40D, 50D or 500D have better image quality. maybe turning off auto lighting optimizer will reduce the problem. People expects a lot from a crop sensor I think.

[/quote]



Hi,



Auto Lighting Optimizer will definitely show up noise! You should turn that feature off, and check that there are no other settings on your camera that could be causing problems.



I'm guessing also that you shoot JPEG - If you shoot RAW, you'll get much better image quality and you can disable/enable most of the camera settings when you process your image on the computer. Shooting JPEG alone is always going to cause problems in PP which you could avoid by shooting RAW.

[tale]

Hey,



I do not own a 7D, but as the pixel pitch of this camera is very small (= many pixels for an APS-C sensor) I could imagine that this is normal for this camera model. But, don't obsess about it, this type of noise is invisible in a print, even a largeish one! Enjoy the camera and take many great photographs with it.



Manuel



[quote name='karakuss' date='08 July 2010 - 11:28 AM' timestamp='1278584897' post='896']

Hi,



There is a rumour about 7d's low iso noise performance. Especially pictures includes blue sky or out of focus areas of the pictures shows this problem. Is this really a problem (see samples, images are not clear), or is this normal for a digital slr? I discovered some pictures taken with 450d or d300s have same unclear areas.



I would be very glad if you share your ideas, otherwise I may throw my 7D out of window



PS. sorry for my bad English.



all photos 100 ISO



http://photozone.smugmug.com/photos/7774...FeGQ-O.jpg

http://img683.imageshack.us/img683/1088/1680.jpg

http://img697.imageshack.us/img697/1656/5390.jpg

http://img594.imageshack.us/img594/1696/img4728crop.jpg

[/quote]

[Guest]

Thank you all for your answers.



@pinhole, I always shoot RAW+sJPG but I will turn the Auto light optimizer off.



Again thanks a lot..

[Guest]

[quote name='tale' date='08 July 2010 - 02:05 PM' timestamp='1278590745' post='901']

Hey,



I do not own a 7D, but as the pixel pitch of this camera is very small (= many pixels for an APS-C sensor) I could imagine that this is normal for this camera model. But, don't obsess about it, this type of noise is invisible in a print, even a largeish one! Enjoy the camera and take many great photographs with it.



Manuel

[/quote]



I did see that kind of noise show up in print, but that was only when I printed a 3MP JPEG from a compact camera at 60x80 cm.



-Lars

[tale]

Well, large-ish meant something like 20x30cm oder 30x40cm. But 60x80 from a 3MP Jpeg is... hm, let's call it large ;-)



[quote name='larsrc' date='08 July 2010 - 04:00 PM' timestamp='1278601253' post='908']

I did see that kind of noise show up in print, but that was only when I printed a 3MP JPEG from a compact camera at 60x80 cm.



-Lars

[/quote]

[Guest]

[quote name='tale' date='08 July 2010 - 05:05 PM' timestamp='1278601554' post='910']

Well, large-ish meant something like 20x30cm oder 30x40cm. But 60x80 from a 3MP Jpeg is... hm, let's call it large ;-)

[/quote]



Kinda puts the whole 15MP vs. 18MP discussion into perspective, doesn't it? I did use Genuine Fractals for the enlargement, but it came out surprisingly nice. The noise is not noticable since one cannot get really close to where I've hung it. Someday, just for kicks, I'll have to blow something from my 350D up to 2x3 meters



-Lars