RAW image recording / lens abberation correction

[character_stops]

My question involves which image-recording quality matters when one is planning to use lens correction data. Although one of EOS Utility manuals mentions how Digital Photo Professional can resolve peripheral aberrations, it only mentions chromatic corrections only for images such as those recorded RAW. What precisely are right and wrong recording quality choices, in regard to their correlation to the correction data that software uses to fix aberrations? 

[amfoto1 · Accepted solution]

Peripheral illumination correction merely corrects optical vignetting that's inherent to many lenses. In other words, it corrects the eveness of illumination across the entire image frame, where without it the corners and edges of the image might be a little darker than the center of the image. It's most common in wide angle lenses.

Distortion and chromatic aberration corrections are only applied in-camera when you process RAW files into JPEGs. So, in other words, if you want them done in-camera you must have the camera set to produce JPEG or to RAW+JPEG for these corrections to be applied.

The same corrections can be applied during post-processing by Canon Digital Photo Pro RAW conversion software. If you had the corrections enabled in-camera, then allow DPP software to process "as shot", it will apply them the same way as if it were in-camera. Alternatively, you can manually override the corrections in post-processing.

Many other post-processing RAW conversion softwares can do similar. For example, Adobe Lightroom (Adobe Camera Raw) has a lot of lens correction profiles built in that can be applied automatically, as well as manual controls for all three types of correction. DXO software appears to be an even more advanced lens correction software.

If done in post-processing, the end result from the RAW conversion can be a file type other than 8 bit JPEG, such as 16 bit TIF or PSD, etc. If the processing is done in-camera, you can only get JPEG files.

I hope this makes sense.

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Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & EXPOSUREMANAGER 

[jazzman1]

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@jrhoffman75 wrote:
I read on the Internet a while ago (for what ever veracity you want to apply) that the direct camera to printer (PictBridge) feature and then in-camera RAW processing was driven by the emerging "non-Western" market where immediate access to computers is limited.

One can shoot RAW and also have the ability for limited editing in-camera that could be printed or sent via WiFi.

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Thanks John for that info.  I'll surely file it away for future reference

Forgot to say.  My 60D has in Camera Editing of RAW files also.  That's on top of also having RAW + JPEG,  and RAW to JPEG Conversion. 

[character_stops]

great suggestions!

[jazzman1]

I know the feeling

[ebiggs1]

"Corrections are in the camera mostly for those without access to a Pc, for editing, ..."

And of course this is misleading and not totally true.  The main reason your camera does some editing to a RAW file is so it can be converted to a jpg.  Otherwise you could not view it on the LCD screen.  The camera makes a small data file that tags along with the RAW file.  You computer reads this data file so it can display the image, too.

The RAW file, however, is not altered by this data tag.  You must convert a RAW file in order to use the RAW file.

Most cameras allow you to make a RAW+jpg and then you do have two different files. One is altered to the settings you told the camera to do and the RAW is left alone, untouched as usual.

Personally I never do this and us ethe file type I need.  98% of the time it is a large RAW.

[character_stops]

Thanks. I don't think I'll ever have reason for wi-fi or emailing a picture. As to having just the RAW, I agree. Sometimes white balance becomes a problem, which is harder to fix post-process on a JPEG, so I think I'll just save card space and go with just the RAW.

[jazzman1]

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@character_stops wrote:

Thanks. I don't think I'll ever have reason for wi-fi or emailing a picture. As to having just the RAW, I agree. Sometimes white balance becomes a problem, which is harder to fix post-process on a JPEG, so I think I'll just save card space and go with just the RAW.

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