Dear Torben, I have the same problem as Jeff under OS X 10.5.8. When I do what you suggest I can choose Mricron, but on hitting the "Change All..." button the default reverts to Preview. Curiously this is a problem that might be specific to Mricron - when I select something else I can change the default. It also does not depend on Mricron being in a subfolder in Applications. Has anyone else seen this - or, ideally, worked out a solution? Thanks in advance, Alexander On 5 May 2010, at 12:11, Torben Ellegaard Lund wrote: > Dear Jeff > > What you would want to to is to right click (or ctrl+left click) on > the file and select show info (or alternatively select the file and > hit apple+i). Under "Open with" you can select your favorite image > viewer, you can apply this setting to all files by hitting the "Ret > alle ..." button (pardon my danish). Please note that you should > only do this for the hdr files, the img extension is also used for > disk images. > > > Best > Torben > > > <Skærmbillede 2010-05-05 kl. 12.04.44.png><ATT00002..txt>