Digital Outback Photo
- Photography using Digital SLRs

 

Photoshop Corner #012

"Linear RAW conversion"

by Uwe Steinmueller

 

 

Often we ask what is the best quality we can get from our RAW image converters (Canon, Nikon, Kodak, Bibble, Qimage). If you have followed the race for the best NEF (Nikon's RAW format) conversion over the last 20 months you know how much differences there are.

Actually the RAW conversion process is divided into two parts:

  • Linear RAW conversion
  • Applying curves, color conversions, White balance, Sharpening, Saturation

Fred Miranda has discovered that it might be the best way to let the Canon RAW processor only do the first part (it provides a linear option) and then to do the rest in Photoshop. In the linear converted image you have all the information which is contained in the photo and it is not degraded by any further image manipulation yet.

 
This is a dark image!
 

Linear RAW image
 

Don't get shocked by the dark linear image (you get the same dark images with RAW slide scans). To bring the linear image to life (only use 16-bit TIFF linear images) you need to be an Photoshop expert or use Fred Miranda's LP (LinearPro) actions. Actually we initiated Fred's take on EOS-1D images as his action was first designed for the D30.

We also experiment with D1x images linear converted with Bibble.

 
Linear RAW conversion for the D30/1D is always needed if you want to get the best from your images as it preserves the all dynamic range available. Linear Pro comes in many variations on sharpness and saturation. We used normal sharpness and low saturation for this test.
 

Normal processed image crops
 

1D LP processed image crops
 
The difference can be subtle but is worth the effort.
 
EOS-1D Banding Removed
 

If you look at the above image you will see the infamous EOS-1D banding. But you will also realize that the LP action minimizes this banding.

This result was so interesting for Fred, that he wanted to go the full way and he also developed a banding removal action (ISO-BR the action set also contains ISO noise removal components) which removes the banding without losing too much sharpness


LP and Banding Removal applied

 

We think the LP and banding removal actions from Fred Miranda are good tools if you work with EOS-1D RAW images.

Fred's banding removal actions also show that there can be done a lot in software to solve the banding issue.

 
 
 
If you want to discus this review post you comments in Fred's Action Newsgroup
 
 

 

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