Alternative to Photoshop?

[siovene]

Hello,

I've been an avid Gimp user in the past, but today I learned that it only supports 8 bits per channel, and that means loss of information which I can't afford (given how little information I have to begin with ).

Do you know if there's some free (possibly Open Source) alternative to photoshop for basic astrophotography editing (levels, curves, level masks)?

Thanks!

[Bizibilder]

Gimp is the only one that I could find to use before I bought Photoshop. The two "condenders for your cash" are PS and Pixinsight both of which are mentioned frequently on this forum. You can get PS much cheaper than you think if you have a member of the household who is either a student or member of staff of an educational establishment. Look for "PS CS5 Student and Teacher" on Amazon or similar.

[Deneb]

Paintshop Pro, well it's certainly much cheaper then PS.

Nadeem..

[Naz]

As far as I know, jpeg is only 8 bit, unless you are dealing with RAW. So you gain not a lot with any off the programs. Probably Elements 7 or 8 might suit for RAW / TIFF files, not free but fairly cheap a powerful.

[Shibby]

You really should work with RAW files, because there is a lot of information hidden in the lower end that can be brought out by stretching in 16bit. Unfortunately I haven't found anything free either that can do it. I'm afraid not even Photoshop Elements can do it!

[Shibby]

You've got me interested now. I've just found this: RawTherapee

Going to investigate!

[Shibby]

Apologies for what is now a triple post, but I've had a play with RawTherapee and thought I should update you.

It does indeed support 16 bit luminance curves, as well as many other processing bits and bobs, as well as a nice tool for batch processing images.

To adjust curves, you have to right-click on the curves mode and select 'custom'. The only downside is: I can't see a way to apply curves multiple times, other than saving then re-opening the image.

But still, it does mean that there is an entirely free (open-source) tool that can let us post-process images. I downloaded one of the user-built "bleeding edge" versions. This means it's not guaranteed to be stable, but it is *much* more up-to-date than the last stable release (Sep '09). I personally think this has sticky potential, although I've probably gone and overlooked some other already well-known free solution?

[guyroch]

I have heard of Delphinus (Delphinus homepage) though I have never used it myself. It's free and their documentation says that it's capable of 16 bits processing

Hope this helps.