5d3: NR/Abberation Correction affect on RAW files

[xthebillx]

Hello!

I'm curious to know whether or not the various noise reduction/abberation correction settings have any affect on RAW files. Specifically, with regard to sharpness. My assumption is that they only affect JPEGs, and RAW files are truly that - RAW.

Ultimately, I'm needing to squeeze every bit of sharpness out of these RAW files, and I don't want anything impeding or compromising them.

Thanks in advance.

 

[Loswr]

Not really. The only setting that actually affects the RAW data is Long Exposure NR, which takes a dark frame and subtracts that from the image data before writing the RAW file.

If you use DPP to convert the RAW files, the settings from the camera will be applied by default in DPP.

Also, note that the in-camera settings do affect the small jpg preview image that's embedded in the RAW file, and that preview image is also used for the histogram data when you review the shot. So, picture style and other settings can indirectly affect the RAW file if you make exposure changes based on those data.

 

[georgecpappas]

On the topic of chromatic aberration reduction, I spoke with Canon tech support and was told that Chromatic Aberration information is placed in the RAW file as tagged data . It is used there by DPP and it is up to other RAW processing software to make use of it as well.

Adobe's Lightroom 4 has its own lens profiles and chromatic aberration reduction capabilities so it is unclear how it will use the Canon data or whether it needs to in order to provide good results.

My early look at LR 4 RC that has support for the 5DMKIII shows good results with whatever adobe is doing. When I select lens profile correction and CA elimination on 5DMKIII images the results are very good. I was also pleased to see that Adobe had profiles for almost all of the Zeiss ZE lenses that I use.

I think this is still an evolving area; especially given the acknowledged issues with DPP and a potential fix/firmware update for the camera. Canon Tech support also verified the DPP issue and indicated that a new version would be forthcoming "soon"...

 

[3kramd5]

In one interview, it was stated that the lens corrections in DPP will double the size of the RAW. Makes me suspect it's doing something other than adding metadata.

 

[Loswr]

In one interview, it was stated that the lens corrections in DPP will double the size of the RAW. Makes me suspect it's doing something other than adding metadata.

I really don't see how that's possible - DPP isn't going to add data to the RAW file! I suspect miscommunication of some sort - along the lines of, if you want DPP's CA corrections but want to process RAW files with other software, you need to first process the RAW in DPP and save as a 16-bit TIFF, and that resulting file will be much larger than original RAW file.

 

[3kramd5]

http://www.arihazeghiphotography.com/AH_CW_interview/

AH: What new improvements are offered in the new Canon DPP software in combination with EOS 5D Mark III?



Chuck Westfall: We targeted three new features for the new version of DPP that will be released together with the EOS 5D Mark III:

· Support for the 5D Mark III’s HDR mode.
· Support for the Multiple Exposure mode of the 5D Mark III and EOS-1D X.
· A new feature called Digital Lens Optimizer processes RAW images to achieve ideal optical characteristics for all types of optical aberration or diffraction, effects of a low-pass filter in front of a CMOS sensor, etc. This function improves image quality particularly in the image periphery in addition to the image center. This function is made possible because the entire design-through-manufacture process, for camera, CMOS sensor, EF lens, and DPP, is carried out entirely at Canon. Images are processed optimally using lens information in the image files (focal length, subject distance, and aperture) and lens data specially for the Digital Lens Optimizer. (However, the size of a .CR2 file will be two to three times larger after applying the Digital Lens Optimizer.) Adjustments are made for such aspects as spherical aberration, chromatic aberration, astigmatism, curvature of field, sagittal halo, chromatic aberration of magnification, axial chromatic aberration, diffraction, and the effects of a low-pass filter in front of the CMOS sensor. DPP’s Digital Lens Optimizer will be usable with any of 29 compatible lenses initially. It works with .CR2 files from EOS models released since 2006 (EOS 30D and forward).



Maybe they are just packaging a lot of additional combination-specific processing information within the CR2 file format, but I find it hard to believe they'd need >20MB. Or yah, like you suggest maybe it must be rastered in the process and at highest quality that will yield much larger files, and the .CR2 in that bold sentence was a mistake.

 

[Loswr]

Interesting, thanks! Perhaps someone can weigh in and report if it's actually true...

 

[3kramd5]

Interesting, thanks! Perhaps someone can weigh in and report if it's actually true...

Here's a not-too particularly helpful link:

http://cpn.canon-europe.com/it/content/education/tipsandtricks/3204.do

DPP v3.11 includes a new Digital Lens Optimizer (DLO) tool that is designed to improve image resolution. DLO imitates lens performance, with a series of mathematical functions replicating each stage of the journey of light through the optical path. Using this information DLO can correct a range of typical optical aberrations and loss of resolution caused by a camera’s low pass filter, by applying an inverse function to each shot to take the image nearer to how the scene appears to the naked eye. This creates detailed, high-quality images with manageable file sizes, providing photographers with maximum image quality and greater flexibility.

Maybe they do indeed say "this lens causes this to happen at this pixel, so if we adjust the reading at that pixel by this amount, it will correct it" and actually re-write the RAW. They could also embed the original untouched raw for archival purposes (which would directly double file size).

From the CW interview, it isn't limited to 5D3. Anyone with a camera from the 30D on up should be able to try it out. I think I'll install DPP 3.11 when I get home and see if it outputs raw or raw-like files (i.e. not bitmaps).

 

[Mt Spokane Photography]

In one interview, it was stated that the lens corrections in DPP will double the size of the RAW. Makes me suspect it's doing something other than adding metadata.

I really don't see how that's possible - DPP isn't going to add data to the RAW file! I suspect miscommunication of some sort - along the lines of, if you want DPP's CA corrections but want to process RAW files with other software, you need to first process the RAW in DPP and save as a 16-bit TIFF, and that resulting file will be much larger than original RAW file.

It does write it to the Raw file, I tried it and the file size jumped to almost 52mb. Adobe does not read the additional data, and I doubt if any other raw processor does. I then saved it(from DPP as a tiff and it jumped to almost 130mb!

I then exported as a full tiff from lightroom and it was 72mb.

The file from lightroom was much sharper due to the DPP issue.

 

[xthebillx]

Thanks.
My assumption was mostly correct, save for the long exposure NR.