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7D's bad mid-to-high ISO performance

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Charlie Jin

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After I wrote http://forums.dpreview.com/forums/read.asp?forum=1019&message=33480040
and read the replies, I tried some tests and compared with the high ISO shots
that I took with Pentax K10D a month ago.

With 7D, I tested from ISO 100, and white dots/pixels in dark area begin to
appear from ISO 400, when viewed 100%. From ISO 800, the white pixels in
the dark area are apparent, and at ISO 1600, it becomes unacceptable
(when viewed in 100%). It looks like this is quite normal behavior in Canon
or Canon 7D. Some people suggested workaround methods, but I don't think that

they are reasonable. I would get the right hardware first of all, rather than fixing
the images after images using software.

I investigated my old pictures that were taken using Pentax K10D in ISO 800 or

1600, they don't have a single white pixel in dark area at all, however I may increase
the sharpness. I don't know much about Canon system. This is my first time
to use it. I didn't know that it is this bad...

--
cj
 
ACR doesn't do that as much, otoh it tends to show mazing in smoother areas, especially of certain colors
Charlie Jin said:
After I wrote http://forums.dpreview.com/forums/read.asp?forum=1019&message=33480040
and read the replies, I tried some tests and compared with the high ISO shots
that I took with Pentax K10D a month ago.

With 7D, I tested from ISO 100, and white dots/pixels in dark area begin to
appear from ISO 400, when viewed 100%. From ISO 800, the white pixels in
the dark area are apparent, and at ISO 1600, it becomes unacceptable
(when viewed in 100%). It looks like this is quite normal behavior in Canon
or Canon 7D. Some people suggested workaround methods, but I don't think that

they are reasonable. I would get the right hardware first of all, rather than fixing
the images after images using software.

I investigated my old pictures that were taken using Pentax K10D in ISO 800 or

1600, they don't have a single white pixel in dark area at all, however I may increase
the sharpness. I don't know much about Canon system. This is my first time
to use it. I didn't know that it is this bad...

--
cj
Click to expand...
 
Hmmm. I have yet to see that. I just took several shots at 3200 and do not see this in my dark areas.
Charlie Jin said:
After I wrote http://forums.dpreview.com/forums/read.asp?forum=1019&message=33480040
and read the replies, I tried some tests and compared with the high ISO shots
that I took with Pentax K10D a month ago.

With 7D, I tested from ISO 100, and white dots/pixels in dark area begin to
appear from ISO 400, when viewed 100%. From ISO 800, the white pixels in
the dark area are apparent, and at ISO 1600, it becomes unacceptable
(when viewed in 100%). It looks like this is quite normal behavior in Canon
or Canon 7D. Some people suggested workaround methods, but I don't think that

they are reasonable. I would get the right hardware first of all, rather than fixing
the images after images using software.

I investigated my old pictures that were taken using Pentax K10D in ISO 800 or

1600, they don't have a single white pixel in dark area at all, however I may increase
the sharpness. I don't know much about Canon system. This is my first time
to use it. I didn't know that it is this bad...

--
cj
Click to expand...
 
I haven't done anything in DPP. The image is directly the screen captuire of
the DPP preview window just after it imported the RAW file.

I don't think that white dots/pixels are the artifact of noise-reduction.
In fact, when I maximize the luminance noise reduction to 20, the white
dots disappeared. So, actually, the disappearance of the white dots is the
artifact of noise reduction, isn't it ? Besides, we cannot apply this kind of
software tricks to the every image created by the wrong hardware.
Well, I don't have time to do so, first of all.
GeorgeML said:
The white dots are a noise-reduction artifact.

Adjusting the NR settings and using better NR software might help get rid of them.
Click to expand...
--
cj
 
I shot with ISO 6400 with 7D RAW and don't see the dandruff stuff.

I used Lightroom (beta) to process my photos.

Depends on what software you use. DPP shows this artifact.

DXOMark shows the K10D sensor still has a long way to go before they match current Nikon and Canon offerings. Although 7D is not yet reviewed on DXOMark, my previous 400D shows lots of dandruff stuff. You can compare K10D against 400D on DXOMark. and the huge advantage of 400D at high ISO is rather apparent.
 
I also processed with LightRoom 2.5, and it also shows the white dots/pixels.
The number of white dots/pixels are reduced comparing with DPP. But the image
from LR 2.5 is much less brighter than the DPP's. So, after the adjustment of
brightness, it's just similar.

And as a few people already indicated, this looks like a normal behavior of 7D.
I don't know about DXO mark, but I can only talk about the shots that I
myself took in reality - I see LOTS of white dots at ISO 1600, viewed
in 100% (taken by Canon 7D). No single white dots at ISO 1600 from
the images taken by Pentax K10D.
photo nuts said:
I shot with ISO 6400 with 7D RAW and don't see the dandruff stuff.

I used Lightroom (beta) to process my photos.

Depends on what software you use. DPP shows this artifact.

DXOMark shows the K10D sensor still has a long way to go before they match current Nikon and Canon offerings. Although 7D is not yet reviewed on DXOMark, my previous 400D shows lots of dandruff stuff. You can compare K10D against 400D on DXOMark. and the huge advantage of 400D at high ISO is rather apparent.
Click to expand...
--
cj
 
Charlie Jin said:
...but I can only talk about the shots that I
myself took in reality - I see LOTS of white dots at ISO 1600, viewed
in 100% (taken by Canon 7D).
Click to expand...
Strange 'cos I don't see white dots (100% view) from my 7D ISO 1600 to 6400 test images.
Charlie Jin said:
I also processed with LightRoom 2.5, and it also shows the white dots/pixels.
The number of white dots/pixels are reduced comparing with DPP. But the image
from LR 2.5 is much less brighter than the DPP's. So, after the adjustment of
brightness, it's just similar.
Click to expand...
I suspect you have a poor copy. Looks like Canon's QC for the 7D hasn't been too good so far. There are also copies with severe banding problems. Mine has excellent sensor quality but the AF calibration is way off. Anyway, it's at the service center now for AF calibration. :)

Warning: poor copies typically come in batches.
 
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