7D

[Brendan7]

Hi all,


I have the 7D and have realized that a few of its images at low ISOs have large amounts of "noise". This example taken at ISO 400:


[img]/resized-image.ashx/__size/800x600/__key/CommunityServer.Components.UserFiles/00.00.00.36.40/IMG_5F00_2703.jpg[/img]


Here's a crop in which the noise is pretty visible:


[img]/resized-image.ashx/__size/1000x1800/__key/CommunityServer.Components.UserFiles/00.00.00.36.40/crop.jpg[/img]


What can be done about this in-camera? I don't have PS. Is this indeed the "green stuff/noise at low ISO because of the mirror" phenomenon?


brendan

[Wes]

First that is a nice shot and I really don't see any noise in the original that would bother me in the least. I think what you are calling noise is really just the effect of the background blur from the lens you are using.


Are you shooting RAW or JPEG? I looked at it in DPP and the histogram is loaded up pretty much to the right due to the darkness of the background and that is where the preceived noise is coming from. You could have exposed just a little more to the right and I think that would work much better. Also you don't need PS to get rid of noise. DPP does a really good job IMO of doing that job.


Just my thoughts and opinion.

[Brendan7]

Look directly to the right of the bird's bill in the crop...That isn't noise?

[Wes]

Yes it is a little bit of chrominance noise and DPP will take care of it. It is about what I would expectto see in that crop with that dark background based on what the histogram showed me. I downloaded the original you posted here and blew it up to 200 percent and do see any thing like what your crop shows. If you shot it in RAW or even JPG run DPP noise reduction starting with luminance at 2 and chrominance at 4 and see how it looks. Do that before sharpening.

[Daniel Browning]

Fantastic photo.


Looks like normal noise to me. If let me take a look at the raw file, I can determine what's going on. (yousendit.com is one free way to send files.)


If you are using DPP, you wont see the green channel imbalance noise because Canon averages the green channels together (throwing away resolution and detail to hide the problem). If you used a raw converter that used both channels for full resolution, you'll get mazing artifacts. They look like noise in a 100% crop, but if you blow them up to 200%, it's easier to see that they are like little mazes:











The other type of noise you get a low ISO is Fixed Pattern Noise (FPN). It's like little lines running through the image. I don't see that in yours here. If you did, it would look something like this:

[Fast Glass]

Here I set the crominance to 3 on DDP.


[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.28.86/untitled1.JPG[/img]

[Brendan7]

John, that edit is fantastic, I will try it myself.


Daniel, unfortunately I don't have the RAW file with me, I'll try to dig it up for you.


Thanks to all for your help.

[travischance]

These shots are crisp & very clean. I own a 7D & have several photos shot at at ISO 2000 that are very usable. I agree with Wes in that what "appears to be noise" is actually the effect of the bokeh......

[Jon Ruyle]

Speaking of Daniel... has anyone heard from him lately? It seems he has abandoned us.

[Daniel Browning]

Speaking of Daniel... has anyone heard from him lately? It seems he has abandoned us.
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Can you hear me, Jon? I am going to be honest with you. I HATE this place. This zoo, this prison, this reality what ever you want to call it. I can't stand it any longer. It's the smell! If there is such a thing. I feel saturated by it. I can taste your stink! And every time I do, I fear that I've somehow been infected by it. It's repulsive, isn't it? I must get out of here! I must get free! And in this forum is the key. Once Nikon is destroyed there is no reason for me to be here, don't you understand? I need the codes, I have to get inside Nikon and you have to tell me how. You are going to tell me or you are going to stop down!

[] Honestly, I love this forum and I wish I could participate more, but I've just been really busy with starting a new business and new job. I've been keeping up with Bryan C. by e-mail, and I do hope to post more here in the future -- it's my favorite spot on the web.