In article , Alan Browne
wrote:

My plan is to make RAW files of may old dia pictures


... forgot to mention, you won't be able to make "RAW" as that usually
implies in digital photography, but definitely TIFF which will carry the
full depth of colour for each scanner pixel location in CYMK (or other
colour schemes if you prefer), but not RGB bayer with the raw values for
each pixel.

he originally wanted to know what lens to use on his camera (see
subject), in which case raw would be the proper choice. tiff should
*never* be used in a digital camera. there is *no* benefit and only
drawbacks.

if he decides to use a scanner, then tiff would be the proper choice in
almost every case (this is not one of the exceptions).

tl, dr version: TIFF is a fine format.

for certain things it is. not all.