FIT vs FITS files

gtg

Newbie. Non-expert in imaging file IT. Confused. ASIAIR saves files with the extension"fit" whereas "fits" seems to be the standard extension for Flexible Image Transport System files. I'm recording with a Canon EOS (OSC sensor, unfiltered). Operationally some programs such as GIMP open the ASIAIR "fit" files as expected. However, Fits Liberator opens the files with a superimposed grid or 'checkerboard' which seems to be related to the Bayer filter variable. There appears to be no control within FL to manage this and produce a more 'normal' looking image. A FL TIFF export image does not show 'checkerboard' but is grayscale. As another example, RawTherapee doesn't open the ZWO files at all, even though "fit" is listed as a recognized extension. So - primary question is whether the ZWO "fit" file is fully equivalent to a standard "fits" file, and, if so, how can I open in RT and FL? (And, yes, I do know that ASIStudio opens the fit files in a full color 'normal view' - I'm mostly interested in learning if ZWO files are fully compatible with the entire FITS world.)

ckoos

Have you tried renaming the .fit file to .fits to see if RT and FL then handle the file normally? It would be interesting to know if the extension was the only difference.

johnpd

I have never been able to open FIT/FITS files with RawTherapee. If I try to open one, it just ignores any file with that extension. I don't know if there is some option you have enable to do it.

Which version of FITS Liberator are you using. The latest is v4.0. It opens and properly displays both .FIT ZWO camera files and .FITS QHY camera files that I have. In looking at the Header data, my ZWO cameras have a "BAYERPAT" value of "RGGB". The QHY cameras .FITS files (created by Sharpcap) have a "COLORTYP" of "RGB", no "BAYERPAT" line. Look at the Image Headers tab and see if a Bayer pattern line or color line exists and what its value is. It may be incorrect.

JohnD

w7ay

johnpd If I try to open one, it just ignores any file with that extension. I don't know if there is some option you have enable to do it.

If you are running macOS, just do what you do with any other file extensions.

Do a Get Info for that file (single click on the file to select it, then do a Command-I), and under "Open with:" in the Get Info panel, select the application that you want to use with that file (e.g., Affinity Photo). Click on "Change All..." if you want to use that same application to open all other files that have the same extension.

Chen

johnpd

Hi Chen,

I have Windows. I even tried adding the .fit extension to the File Browser Parsed Extensions list, but it made no difference. But it doesn't matter. I use Affinity Photo to process .FIT/.FITS files. It does a great job and doesn't send you to the poorhouse. I I want to do some further processing in RawTherapee, I export a .TIFF file from Affinity and then can open it with RT.

JohnD

gtg

Thanks for replies. Am no longer so concerned about file extension; "FIT" or "FITS" seem to be equivalent in the world beyond Zwo. Continue to be perplexed about Fits Liberator. Have downloaded OSC FITS example files of unknown origin (probably NOT Zwo software) which open in FL; in these cases, FL shows 3 planes (RBG) in the pull down option. (None of which display with the 'checkerboard' pattern as might be expected.) This is not the case when I open my Zwo FIT files - FL shows only "Image 1, Plane 1". If I save from FL as a TIFF I get only a grayscale image. In response to comment concerning FITS header - yes, "BAYERPAT" = RGGB in the Zwo-generated files. So I should see 3 "planes" = channels, no? And, yes, a Windows operating environment. My overall goal is simply to generate a single RGB 16 bit TIFF from a Zwo FIT file, so I can set the FL issue aside if someone can give me precise directions for doing that using freeware. Both Photoshop & Affinity Photo seem to be more 'downstream'; for now, I edit using GIMP because it's free and I'm still learning. Once I understand basics I may upgrade to a better processing package. Thanks to all for help.