I'd like to open FITS files in CC

Me too

Ok, the .tiff I get from stretching in Siril is 1080wx1920h.  Here are three screen shots.........the first is the .fit file opened in Siril, the second is the .tiff file I get from Siril after applying a Histogram AutoStretch, and the third is what the final image looks like after editing in Photoshop using the Astro Panel Pro X plugin.  It is just a little time consuming to have to go through Siril, as sometimes with galaxies other steps have to be performed with the background and such before saving as a .tiff...............wanted to find a way to go straight from .fit to .tif that is usable in PS.  Again, thanks!

What do you mean by stretch? What should the finished TIFF dimensions be?

Fiji is a fork of ImageJ. You can use either.

https://imagej.net/ij/download.html

https://imagej.net/software/fiji/downloads

Tried to get ImageJ to give it a run, but site says not available for download....redirected me to something called Fiji which I am trying to get, but says it is a European server and so far have had it crash twice for "time-outs".  Will try again later and see what happens.  Thanks to all for your patience with a rookie!

Don't have Mac, working on Windows and cannot seem to get the results you mention......................also not sure what Liberator 4 is.............tried the Libetrator Plugin for PS, did not work, tried the stand alone Liberator, could not get it to work, and have tried the on-line converter with no success.  

Not sure I understand the "animation", the .fit file is just a stack of 259 individual exposures and should have no animation embedded anywhere to extract.  I guess the bottom line is that some other program has to be used to stretch the .fit file before it can be saved as an editable image in PS, something like Siril or Pixinsight...............just was hoping to be able to convert the .fit to .tif without all the extra steps.  

This is the png that I get from ASIStudio, the .tif needs to be the same to edit in PS:

ImageJ opened and converted the file just fine, recognizing that it had three frames and playing an animation.

This what i get when exporting your sample Fits as a 32 bit tiff from Liberator 4 on macOS Sonoma 14.3.1 and Photoshop 2024 (ps ver 25.5)

What is the image supposed to look like as far as the aspect ratio goes?