High ISO Noise Reduction

[jrsforums]

Probably could have asked this in the 1D/5D forums, but it "hit my radar" via the 50D announcement.

My question....is High ISO NR applied to only the JPEG file or is NR also applied (other than a tag for DPP) to the RAW file?

I searched as best I could but the search engine is not real good for multiple terms. The DPR 40D review, when comparing in-camera jpeg to DPP/ACR processing seems to "alude" to the RAW not having it applied, but is not explicit.

If High ISO NR is not applied to the RAW files, why would there be a reduction in FPS when using it (assuming RAW only images being created)

Thanks....JOHN

[Martin_Doudoroff]

I would be flabbergasted if the RAW data was being touched.

[Jerry Skrocki]

It is applied to Jpeg files in camera, Raw files are not affected in camera.
Canon explains the technology in depth here:

Canon Digital Learning Center - High ISO Noise Reduction

[jrsforums]

Thanks, Jerry

Martin, I would have been surprised also....but could not find anything where it was discussed.

Seems as if this, probably significant, Canon development, as well as Highlight Tone Priority, are not much worth for those who primarily use RAW (non-DPP).....oh well

John

[Felix01]

Originally Posted by jrsforums

If High ISO NR is not applied to the RAW files, why would there be a reduction in FPS when using it (assuming RAW only images being created)

Depends upon the RAW processing software you're using. Jerry's link to the Canon Learning Center gives a good overview of the differences (even though one of the picture sets is mislabeled).

[Noel_Carboni]

My take on the high ISO NR in the 40D is that it's surprisingly good, visually, but if you're looking to capture fine color detail a lot of it can be lost. Simply stated, it is very aggressive in removing color noise, so much so that it can affect the subject colors.

I've done some Raw + JPEG shooting and comparisons, and I've found that careful conversion and post-processing of a raw file can most often yield an image that looks as good as or better than a JPEG shot at high ISO with the NR turned on.

Think of the high ISO NR much along the lines of JPEG shooting itself... A big time saver for making acceptable images.

If High ISO NR is not applied to the RAW files, why would there be a reduction in FPS when using it (assuming RAW only images being created)

There is ALWAYS a JPEG created, even when shooting in pure Raw mode. The JPEG embedded by a 40D in every single .cr2 file is a quite good quality 1936 x 1288 pixel "preview". To that image the NR is applied. These embedded JPEGs are quite good enough to use for many purposes not requiring the full resolution of the camera.

It will be interesting to see what size the embedded 50D JPEG previews are.

-Noel

[jrsforums]

Thanks, Noel

John

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