Thanx for the replies:
I understand that TIFF is not a common format for use. I agree with all commentators.
If you'd be using Aperture like I do, you'd notice that exporting for an External Editor creates either a TIFF file or a PSD file (8 or 16 bit, but no-one serious uses the 8 bit any more nowadays). No matter if you PP in Photoshop or in NIK you are working with either PSD or TIFF. They have BOTH NEARLY THE SAME FILE SIZE! If you save your work in tiff/psd you create a 'blown out' file (like my 40D makes a RAW.CR2 at 11 MBite and the PSD/or TIFF have around 51 MB). Even more so with the 21-25 MB 5D2 files - they jump to 100 MB PSD/TIFF. If I do a panorama with 30 shots it goes in the area of 1 GB per single output... But this is a second topic.
This is why I am asking: how do you keep the SIZE of your post-processed shots within at least the range of a RAW file, i.e. 20-25 MB.
BTW, I do 95% of my work in NIK, so I rely on the external editoring from Aperture.
Is Lightroom different in managing the external editors? And how?
There are recent non-expert opinions against PSD (http://www.philbertphotography.com/blog/tiff-vs-psd-in-lightroom
There are recent views FOR TIFF (http://forums.dpreview.com/forums/read.asp?forum=1006&message=39585535
Even if TIFF is reported up to 50% larger than PSD the speed of processing is 5 times that of PSD in CS5 (http://www.lightroomforums.net/showthread.php?10428-PSD-vs-TIF
I use a maxed out 6 core Mac Pro 2010 with a fast striped RAID too and 8 TB of disk space but someday it will hit the limit too (it's not used solely for photography but video&TV as well and the file sizes there are significantly higher)
So, last question: do you ZIP or somehow compress your PSD / TIFF files for storage?
See, the end of the workflow is not unified - we are all impressed by what the recently developed software can do to our native RAWs and at least speaking for myself I don't know how to finalize my workflow properly. At present I just keep the RAWs AND the TIFFs. Until there is some real advice.
Happy Waiting !
BTW, has someone tried to do a stitch and PP it with a 36 MP file (MF) ? My machine chokes with the 21MP already... I don't know if our computing gear is really ready for postprocessing 36 MP 16 bit files. Storage is not an issue but really advanced postprocessing will be!