Save stitched raw's back in raw

[cdmihai]

Hello,

Is there a way to stitch several raw files into a panorama and then save the result back as a raw file?

I'm asking because, as you realise, it would be really helpful to edit it in ACR, saving all those highlights and all.

Thanks.

[dcclark]

I think you have a serious misunderstanding.

"RAW Files" are not images. They are raw data which must be processed by a RAW converter before they become an image. The raw converter, among other things, chooses how to map the data to become colors -- this is why you can modify the color balance of a RAW file when editing.

So, there is no such thing as "saving the result back as a raw file" -- once you have an image, you can't go back to it being raw again.

Note that being able to change things in ACR and then modify them later is only because ACR saves all of your "changes" into a totally separate "sidecar" file, and when you reopen the raw file, ACR automagically re-converts the RAW file into an image, applies your settings, and shows it to you without telling you what it's doing.

[acedrew]

The closest thing to that is to save the image as a 32Bit TIF, this will preserve most of the color and luminosity data. You will not be able to edit it quite the same as a raw file, but you will have more flexibility than with a JPG.

Andrew Rodgers
Perfected Perspectives -- Photography by Andrew Rodgers | Andrew Rodgers (acedrew) on Twitter | Login | Facebook

[cdmihai]

Hmm, skimming through this article, it seems that it is quite hard, next to impossible to do that (meaning that a LOT of effort must go into it, a whole lot of math to revert some transformations).

The guys at Canon, (since they built it, they know the internals better than anyone), could do it with a lot of money and especially a lot of effort wasted

In conclusion, it's just not worth it, better stick with saving it as a 32 bit TIFF.

[sybren]

As RAW files are generally 12 or 14 bits, 15-bit tiff would be enough. Bibble Pro 5 supports 16-bit tiffs, so you can process it again in pretty much the same way as a RAW file.

As RAW files contain sensor data, they are limited to sensor physics. That means that every pixel only has one colour channel, and the other two channels will be interpolated from the surrounding pixels. A TIFF image contains all three colour channels in each pixel. That means that after stitching and editing a TIFF file contains more useful information than a RAW file. Going back to the one-channel-per-pixel case would mean throwing away information, hence wouldn't be a good thing.

[fletch]

For what it is worth it is possible to edit TIFF (or JPEG) files with ACR. Just use the "Open As" dialogue box in Photoshop.