Save my images as .fit or .tiff?

[swag72]

Using the Atik 314L I have an option to save my inages as either a .fit or a .tiff file. Which is better and why?

Assuming that I just chuck it all into DSS at the minute and then hope for the best!!

[Rob_Jn]

Hi Sara,

I would always save them as FIT. Fits is the astronomical standard used by professionals and holds extra data in the header of the file such as date, time, exposure etc.

Rob

[Catanonia]

Yes hold as FIT and then you have all the info if you ever need it.

DSS / PixInsight / Maxim etc can read them and when you need to convert to TIFF.

[Photosbykev]

I used to use 16 bit Tiffs but I have switched to FIT files for astro work. The only odd thing I've noticed when I swapped formats is that the FIT images load into programmes upside down.

[steppenwolf]

I save my images in both formats. The FIT is the most important because of all the other data held in the header. For some objects, I find that a 16bit TIFF file is perfect for moving into PhotoShop for further processing and for others, a FIT file loaded via 'FITS Liberator' seems to allow for greater stretching, especially when using my one shot colour camera and importing each colour individually.

Always keep your FIT file so that you can return to the original data in the future should you wish to start the post processing again.

[swag72]

OK, thanks then folks - .fits will remain!

[ollypenrice]

I save my images in both formats. The FIT is the most important because of all the other data held in the header. For some objects, I find that a 16bit TIFF file is perfect for moving into PhotoShop for further processing and for others, a FIT file loaded via 'FITS Liberator' seems to allow for greater stretching, especially when using my one shot colour camera and importing each colour individually.

Always keep your FIT file so that you can return to the original data in the future should you wish to start the post processing again.

By Gad, this fellow knows some stuff! Individual importing of colours from an OSC. Clear as mud to me, Holmes...

Olly

[steppenwolf]

Individual importing of colours from an OSC. Clear as mud to me, Holmes...

It's a technique that works really well on hi dynamic range objects like M42 where you run the risk of a burnt out core. Stretching the individual (RGB) channels straight from the FITS file allows processing each channel to get the best dynamic range. Once each channel is optimised, you can then re-combine them into a single RGB image and adjust the histogram to get the correct colour balance. If you'd like to see a worked example, I can arrange it.

[ollypenrice]

It's a technique that works really well on hi dynamic range objects like M42 where you run the risk of a burnt out core. Stretching the individual (RGB) channels straight from the FITS file allows processing each channel to get the best dynamic range. Once each channel is optimised, you can then re-combine them into a single RGB image and adjust the histogram to get the correct colour balance. If you'd like to see a worked example, I can arrange it.

Thanks for the clarification, Mycroft! I won't trouble you for a worked example but I'll have a look-see at this. Thanks, Steve.

Olly

[planesaver]

Hello, I've recently started practicing image processing (beginner) to prepare for when I finally get my scope setup. There is a website (Misti Mountain Observatory - Astronomy Pages) that I've downloaded some FITS files, and haven't figured out the procedure, steps to process them. I'vd also downloaded DSS, IRIS, GIMP, FITS Liberator, Castrator, RegiStax 6, and I bought Adobe Photoshop Elements 10, and Astronomy Tools for Elements. I know some of these programs are better for certain things, (DSS is best for deep sky, long exposure, and Registax is better for webcam I think). Anyway, I'd like to try these FITS, as the images on that mistisoftware site are amazing. Any help would be greatly appreciated. Jeff

When I load the different FITS...L, R, B, G I don't see any colour at all. When I stack, I still don't get colour. Am I suppose to process them seperate, and then stack? I'll keep searching for Tutorials, but I think I'm just getting confused with all the programs I'm trying to use. I should just figure one out, and then move to the next. Thanks.

[steppenwolf]

I think you will find that the individual colour sets have already been stacked into 'masters' so the next part of the process is to assemble the final colour image from the individual L, R, G and B files.

For example, in Gimp, load in the RGB files first. Select any one and type CTRL A followed by CTRL C to copy it to the clipboard. Next click on File - New to produce a new blank file of the same dimensions.

Now click on Colors - Components - Compose and choose which colour file you want to populate each of the three 'channels with. Voila! - a colour image.

Now load the L channel type CTRL A and CTRL C to copy it to the clipboard, go back to the new colour image and type CTRL V to paste the Luminance channel on top and change the blend mode to 'Value'.