Steve Balcombe
Forum Pro
I refer the honourable gentleman to my earlier post:
http://forums.dpreview.com/forums/read.asp?forum=1019&message=33984651
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Is that amount of "snow-like" noise normal for 7D? Sample images inside
- Thread starter Grummbeerbauer
- Start date
http://forums.dpreview.com/forums/read.asp?forum=1019&message=33984651
Grummbeerbauer
Well-known member
I find it interesting that so many people are having this issue (or in this case non-issue?). Maybe their monitor settings are far from optimal or maybe the white specs look to much like dust sitting on the screen that is lit from the side.
Thank you for reassuring me that I don't have to send back that 7D sample of mine.
Absolutely... isn't pixel-peeping "lens cap on" pictures the most important aspect of photography?
Did you use a tripod or was this test handheld. A 1 second exposure, I think, hand held may be you problem. The electrons appear to be very unstable in your second shot.
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http://www.pbase.com/lannyg
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http://www.pbase.com/lannyg
To all the people out there who see nothing but black....please check your monitors.
I definitely see the red and white specs. That said, my lowly opinion is that considering you're shooting "nothing", you should expect to see this as the poor sensor is trying to make sense of "nothing" and that's what you get.
I know you're going to extremes to make a point here but how about taking a shot of a black bear in the woods at midnight and seeing if you get any red blobs and white specs then? If not, I'd say you're good to go.
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I am as ignorant as ever, and wiser than I've ever been.
I definitely see the red and white specs. That said, my lowly opinion is that considering you're shooting "nothing", you should expect to see this as the poor sensor is trying to make sense of "nothing" and that's what you get.
I know you're going to extremes to make a point here but how about taking a shot of a black bear in the woods at midnight and seeing if you get any red blobs and white specs then? If not, I'd say you're good to go.
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I am as ignorant as ever, and wiser than I've ever been.
If you can see that, then you're monitor has its black point set horribly improperly (which virtually all of them do out of the box). See here:
http://www.normankoren.com/makingfineprints1A.html#gammachart
That said, the red and blue speckles (I enhanced your images in PS to make the noise visible) are normal. The white specks are impulse noise and DPP does nothing useful to get rid of it. ACR/LR get rid of it easily.
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Lee Jay
(see profile for equipment)
http://www.normankoren.com/makingfineprints1A.html#gammachart
That said, the red and blue speckles (I enhanced your images in PS to make the noise visible) are normal. The white specks are impulse noise and DPP does nothing useful to get rid of it. ACR/LR get rid of it easily.
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Lee Jay
(see profile for equipment)
Steve Balcombe
Forum Pro
I'm using a calibrated monitor - not a professional one, but good enough.
I didn't say the noise was easy to see, but it's there.
See here:
I'd never compared this before, but I've just re-processed my file in ACR and there's a huge difference just as you say. I rarely use DPP, I only fired it up today so that I could process my shot the same way as the OP's.
BTW, how low can you see the A bar? It should be visible at 2.2, invisible by 1.9. I'll bet you can see it way, way below 1.9.
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Lee Jay
(see profile for equipment)
sparkey2
Veteran Member
On my Dell 24" I don't see anything but a few hot pixels when viewed at a sharp angle. On my wife's Mac I do see both the croma and luma noise present. However, I have the black point set very deep on my monitor and as she has her's set very bright and light for Facebook and email use only.
So I suggest you consider a monitor calibration effort first then drop $4.00 and print a large test image of your black frame image and you may be surprised to see that it looks different. Some how better!
So I suggest you consider a monitor calibration effort first then drop $4.00 and print a large test image of your black frame image and you may be surprised to see that it looks different. Some how better!
Gotcha. Seen it years ago. Gamma 2.2 and my black point extinguishes at 1.9 on the chart like it should.
I should have explained that I can see the spots if I strain like crazy when I stare at the screen with a darkened room. Under normal circumstances they aren't "there" (read significant). As I said, OP should just ignore it as in the histogram in photoshop, it's obvious the bulk of the stuff is in the lower five levels where it isn't a huge deal. To me it might be if there was something important but some people don't see it and it shouldn't be a problem in print.
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I am as ignorant as ever, and wiser than I've ever been.
I should have explained that I can see the spots if I strain like crazy when I stare at the screen with a darkened room. Under normal circumstances they aren't "there" (read significant). As I said, OP should just ignore it as in the histogram in photoshop, it's obvious the bulk of the stuff is in the lower five levels where it isn't a huge deal. To me it might be if there was something important but some people don't see it and it shouldn't be a problem in print.
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I am as ignorant as ever, and wiser than I've ever been.
I seen it right away when OP posted it. I just did not respond because I do not know enough about this. I get the same thing at high ISO in the shadows.
The white specs are a result of sharpening I was told. The red specs again I was told not to worry about. I sent my 7D in for focus issues and I also mentioned the white and red specs and Canon stated they calibrated the sensor. I still get it. I have stopped worrying about this a long time ago.
The white specs are a result of sharpening I was told. The red specs again I was told not to worry about. I sent my 7D in for focus issues and I also mentioned the white and red specs and Canon stated they calibrated the sensor. I still get it. I have stopped worrying about this a long time ago.
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Eugene Powers
Guest
Ok after I zoomed in I still only see few red spots but mostly 99.9% black frame.
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Eugene
The only time a smaller sensor with the same pixel count is superior to a larger sensor (aka higher pixel density) is when you are focal-length limited.
Lee Jay
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Eugene
The only time a smaller sensor with the same pixel count is superior to a larger sensor (aka higher pixel density) is when you are focal-length limited.
Lee Jay
ToniVC
Well-known member
You are right! In my case this was the cause that made me not notice the noise. I was thinking it was just dust on the screen. After a close inspection and doing some scroll up and down I see the "dust" is moving
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http://www.flickr.com/photos/tonivc/
bronxbombers
Forum Pro
i can see it, more on the second one, but i'm not sure that is all that unusual
how long were the exposures?
bronxbombers
Forum Pro
it's there but they are pretty dark dots and don't jump out at you unless you turn the brightness up really high
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Eugene Powers
Guest
You mean pixel peeping at its worst? I can't believe I got suckered to stare at black screen for a few minutes.
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Eugene
The only time a smaller sensor with the same pixel count is superior to a larger sensor (aka higher pixel density) is when you are focal-length limited.
Lee Jay
HotspurJr
Leading Member
I use Aperture, not lightroom. The two programs are very similar. That being said, the build-in NR in Aperture is a weakness of the program, but that doesn't matter to me since I just use dFine, which is fantastic.
Grummbeerbauer
Well-known member
While I admittedly sometimes have a nasty pixel peeping tendency, in this case I would not speak of pixel peeping, as this noise is visible when viewing images full-screen (i.e., not zoomed in) on a (properly set-up) 24" monitor.
Grummbeerbauer
Well-known member
It really seems to depend on monitor settings or individual perception whether people see this effect or not. I posted the same two images to a German forum, the reactions were about the same, 50% see the noise (but most of them say its okay for a 7D and also when compared to competing models), 50% don't see it.
I doubt that I have very unusual monitor settings, I neither turn brightness very high, nor do I fiddle with gamma settings etc. Actually, my monitor at work is shiny new and I never touched any of the settings, and I see the noise very clearly here. Maybe different people's eyes have different dynamic range in the shadows? ;-) Although I would not call these bright white specs shadows.
Anyway, the people that see the effect and have a 7D for comparison say its absolutely normal. Since I really love everything else about the camera and consciously decided against a 5D Mk. II in favor for overall operating and AF performance and features, I will keep it. And I will look for better RAW processing software. Any info when the Lightroom 3 Beta will expire?
I don't remember the exact values, but it was definitely below 1sec, I believe around 1/10sec.
Grummbeerbauer
Well-known member
It isn't black. Believe me. When viewed on any of my monitors (home and office, I still have to try it on my laptop), it is clearly visible even at normal viewing distance, and from ISO 3200 on it is apparent even when looking at "normal" images (not the "inside of lens cap" ones that I used to better illustrate the effect and have a simple test setup for people with a 7D to reproduce so that I can find out for myself whether my 7D is faulty or not), and even when not viewing at 100% magnification but at full screen size.
No one is trying to pull your leg here, for sure.
Grummbeerbauer
Well-known member
I understand your point (and you mine, which is not always to be expected in internet forums
). But it is not only a theoretical problem. As I wrote somewhere (I believe in my initial post in this thread), the snow is also apparent in real world images, like those I made at a local christmas market (and NO, we didn't have ANY snow at that time ).Well, since I am more sensitive to the problem than some of the folks here I think I have to invest in a better RAW converter and maybe some add-on noise reduction software.
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