| No RAW processing program ever modifies the original RAW file. But note, with programs like LR, saving or exporting as TIFF is generally unnecessary. The whole point is that that even though your RAW files is not modified in any way, LR automatically keeps track of the adjustments oyu make to each fiel, so the next time you view the file, it will look the way you adjusted it to look. Exporting to another format is soemthing you'd normally only do when you have a very specific reaosn - like submitting to a client, uploading to a web site, etc. And in the case of web upload, you wouldn't normally need a full resolution version, and certainly not a TIFF. the expected use model is to just make you adjustments but never save or expoert anything except for the images where you need a TIFF or JPEG for some reason - and then, you can generally batch convert those. That is, do all you processing, and then when you're doing, select the subset of images for which you need a TIFF then kick off a batch conversion of those; then select the subset for which you need a web-resolution JPEG and kick off a batch conversion of those.
This same type of workflow is actually possible with Photoshop too (using Bridge), but LR is really optimized for it. |