Is it possible to stitch panoramas AND process in RAW

Question

Hi,
i'm trying to get to grips with my first photos in RAW, which I took because they were high contrast landscape scenes with bright highlights and dark shadows.
It seems the simplest way in Digital Photo Professional is to use the highlights slider, and then the shadow slider, then save a jpegs for printing.
However, some viewpoints I took several shots to stitch as panoramics and there doesn't seem to be a stitching facility in DPP for RAW, but there does in Image Browser EX, so I guess I can only stitch jpegs.   I've stitched these into panoramas but then obviously can't process to improve the shadows and highlights separately in opposite directions (I can only change the brightness of the whole image).   Presumably I'm trying to do something that's impossible?
Is the only way to improve exposure on a panoramic to first process the shadows/highlights in each individual RAW file separately first, then to convert these to jpegs, and then to stitch my "improved" jpegs?    My only concer with this is that I might not get all the shadows and highlights matching so the panorama stitch might be weird and obviously a stitch.

Answer 1

RossK wrote:
Skirball, Once I'd converted a RAW file, so that I can stitch the jpegs into a panoramic, you mentioned converting it back to RAW.   I didn't realise you could convert back - is that a jpeg being converted back to RAW. 
If I understand right RAW files can be TIFFs, but using the Canon software they each have CR2 after them.
No, you certainly can't convert a jpg back to RAW.  I'm questioning whether it's possible to edit a RAW file at a pixel layer, as would be required for stitching.  John seems to think it is, and he seems to know his stuff.  I don't do a whole lot of panos, and when I do using the same exposure settings and converting TIFF has worked fine for me, so I haven't really looked into using RAWs.  I've never heard of it, and based on my knowledge of RAW and photo editing it seems difficult, but there's a lot of people out there a lot smarter than I am, so who knows.
RAW files need to be demosaiced.  Each pixel in a sensor can only sense one color, Red, Green, or Blue.  So a pattern known as a bayer arrangement is used and a demosaic process is run during RAW conversion so that the full spectrum can be used for every pixel (based on the colors in the pixels surrounding it).
When you manipulate a RAW image in an editor you're actually looking at a jpg preview of what the image would look like with the settings applied.  The RAW file isn't a usable image until those presets, and the demosaic, is applied.  So editors use a smaller preview so it can seamlessly show you roughly what it should look like as you adjust settings.
So, if an editor can do that, it theoretically should be able to show you previews of a couple of RAW files, let you stitch them together, and yet maintain the RAW so you can still adjust based on the stitched preview.  Once everything is set the program then crunches the numbers and computes a final raster image, most likely TIFF, for viewing.  It seems reasonable to me, I just don't know that editing programs such as Photoshop have that capability yet.
Photoshop has something called Smart Objects, which allows you to an object (be it a vector image or RAW file or whatnot) into a layer and still preserve the ability to go back and edit that base object.  But I don't know that you have the ability to do something to the level of a photomerge.  You could probably manually mask the photos together, if that's what you're trying to do.  But again, I don't think it gains you anything, other than complexity, over just using a TIFF.  Tiff is lossless, and at 16 bits it contains a ton of information you have to toss out just to look at it on your monitor anyway.  It will suffice for what you're trying to do.