Noise Reduction vs RAW

[papasan]

I just read in the Magic Lantern Guide for Canon EOS 30D that noise reduction

is not apply in RAW format. I'm a bit surprised, I understand that functions

like WB and exposure are not being processed in RAW format, but Noise

reduction I would have assumed would be carried out if the camera - like the

30D - has noise reduction functions. Did I missunderstand the MLG, or is it

completely useless to turn Noise reduction function on for long exposures when

shooting RAW images?

[pavel_olavich]

Michael, exposure is not being processed in a raw file? Where did you get that myth? Not true.

 

I think NR is not used with the 30D unless you turn it on and/or the exposure is very long...forget how long.

[PuppyDigs]

"Magic Lantern Guide" pretty much sums up the problem here.

[pavel_olavich]

"Satan comes as an angel of light, to deceive....." from the Bible...I paraphrase, and I digress.

[papasan]

Puppy Face wrote: Magic Lantern Guide" pretty much sums up the problem here.

 

What do you mean by that? and do you know whether Noise Reduction works when shooting in RAW?

 

Thanks

[adzy]

I think Michel is talking about the long exposure noise reduction, which is indeed done to the RAW file.

 

Michel, are you ?

 

Azi

[adzy]

Michel, sorry, should have read your post before replying.

 

Yes, the noise reduction feature (if enabled), is run on the RAW file.

 

Azi

[PuppyDigs]

Michael I was making a sarcastic remark about the accuracy of information in Magic Lantern

Guides. They have a reputation of being less than helpful...

[papasan]

azi

 

thanks for your input. It does seem logical that NR would apply to RAW files.

 

Puppy Face

 

Thanks. The Magic Lantern is the only guide available for the 30D at this time. I can't say I learn much from it, but then again I haven't learn much from Canon's manual either...

 

Regards

[KenPapai]

Noise Reduction is applicable to any images shot with a digital camera.

 

As far as Photoshop goes there are better tools, plugins, that do NR better than PS does -- whether you are in ACR (Adobe Camera Raw) or using the Reduce Noise filter in CS2.

 

This is often amply covered in the Digital Darkroom forum anyway.

 

And, as far as turning on the built-in NR in the 30D, I would say go for it. Try it both ways. See what produces the most attractive images. It's digital so the only thing it costs you is your time testing this.

 

The Magic Lantern Guides are aimed at beginners (to photography and to SLRs).

[awindsor]

The noise reduction in the 30D is actually a dark frame subtraction. It is not like post processing noise reduction with noise ninja, noiseware, or neatimage. The long exposure noise reduction really does not address random "noise" at all. It removes dark current due to sensor heating and eliminates (crudely) hot pixels. The advantage is that the in camera noise reduction does not reduce fine detail. All of the post processing noise reduction algorithms do. With Long Exposure NR on there is a second exposure of the same length as the first taken immediately after but with the shutter closed. This frame is then subtracted from the first frame.

 

As far as I know this is the approach taken to noise reduction in every Canon camera prior to the 5D. With the 5D I am not sure what happens. It does not lock up after an exposure like the 30D.