Editing jpg files with Lightroom

<p>I just bought LR2.5 and am enjoying learning to use it. I know that it's designed to edit RAW files but I have some old JPEGs and there are times when I want fast continuous shooting when I only save jpegs. So my question has to do with editing jpegs in LR. In the past, using PS, I always first made a TIFF copy and edited the TIFF since it's lossless. Should I do the same in LR? That is, make a TIFF copy and edit that rather than the JPEG? I'm working on many photos so that would be a hassle. I guess the question comes down to whether LR edits JPEGs the same way it does the RAW files by creating XMP files and only applying those changes when you export the file. I'd be interested to hear what experts do when they don't have a RAW file to work with. Thanks!</p>

<p>For minor editing, jpg should work. If you need to do more than that, you might want to convert to TIF. LR will batch process your images, so you don't have to convert one at a time. You could select all the ones you want to convert and go do something else while LR does that chore for you.</p>

Lightroom editing is non-destructive regardless of what the input is. Just don't export over the original JPEGs.

<p>DB Cooper is wrong and David Long is right. You can read an article on this topic by a leading Lightroom expert <a href="http://www.lightroomkillertips.com/2008/qa-is-lightroom-destructive-to-jpegs/">here.</a></p>

<p>You most certainly can convert jpgs to tif or dng. It's done via LR's export function. The original file is left alone, and the new file/format is exported wherever you tell LR to put it, and it gets there as whatever file format you chose in the export dialog. They can then be dragged and dropped right back into LR if you want. LR will batch process the images on export - select as many as you wish, set up the export dialog, click export, and Voila! - tif or dng of your jpg, plus you get to keep the original jpgs. The only downside is that AFAIK you can't make a 16-bit file from an 8-bit source.</p>