DSS FITS, FITS Liberator to Photoshop?

[Droogie 2001]

I see this question appears fairly regularly so I have been reading through a lot of old threads before posting however none seem to answer my question directly, hence this post.

I have been using DSS for a while now and in general I have been stacking and then choosing ‘Do not apply adjustments’ and saving as a TIFF format.
I suspect these steps are detrimental to the outputted file in that precious data is being lost.
From what I have read I should always use the ‘Autosave’ file and save as a FIT file (32bit?)?
Then go into FITS Liberator and save as a 32Bit TIFF or 16Bit Tiff?
Lastly go into Photoshop and open either the 16bit as normal or open the 32bit and convert to 16bit (using Exposure & Gamma method) on the drop down?

Now I have compared the FITS file which I have saved in DSS with both the Autosave and the ‘Do not apply adjustments’ type and then followed the stages through FITS and then PS.

What I am seeing on either FITS file is that after they have gone FITS Liberator they appear to be being stretched by FITS Liberator. If I compare the images in PS it is clear to see the differences against my current method. The Autosave 32bit version definitely gets stretched more but the 16bit is also stretched but less so.
Whereas using my 'normal' method in PS it displays a darker starting image. In the alternative method these images are clearly showing DSO is clearly visible. Ideally I want to control this myself so I do not want them to appear stretched before I can begin working on them. e.g. Protecting against Stars being saturated from the outset.
I tried to see if I could just switch off Auto Stretching in FITS Liberator (initially I thought this was a non-permanent change but it appears not) but I could not find a way. Am I missing something here? The default Stretch function in FITS Lib is ‘Linear’ but having tried all of the others none see to allow no stretching?

I understand Maxim DL and Astro Art other alternatives but surely FITS Liberator is sufficient for this purpose?

Are my steps correct? Do I need to worry about saving as a FIT from DSS or is this all extra work for nothing?

Thanks

 

[Droogie 2001]

If anyone is interested I download a free tool to export FITS to TIFF, the tool is called AVIS FITS Viewer. This then opens a non pre-stretched image of the TIFF file in Photoshop.

Still not sure whether these are the correct steps to take despite many people stating you must save as a 32bit FIT file in DSS. I am suspecting this exporting to TIFF is the same as just saving the file in DSS as a TIFF? I don’t seem to see any significant differences in the two different lightly processed images.

Either running the file through FITS Liberator is not the correct step to take or I am doing something wrong? As mentioned I am seeing a significantly stretched image if I use FITS Liberator as a means of converting to a TIFF for Photoshop.

This seems to be an important step in beginning of the post processing actions so if anyone can confirm or suggest other methods then this would be very helpful.

[Uplooker]

Hi Droogi,

I am sorry to see that you have not had a reply to you original, or even 2nd, post. I would be very interested in the answer as I am currently experiencing / drowning in a similar state of confusion.

[Droogie 2001]

5 minutes ago, Uplooker said:

Hi Droogi,

I am sorry to see that you have not had a reply to you original, or even 2nd, post. I would be very interested in the answer as I am currently experiencing / drowning in a similar state of confusion.

No problem. I was surprised that there were no responses as its a fairly fundamental issue (for me at least). As I said I couldn't be sure (and still cannot be sure) that it is not something I am doing wrong or a software issue with my laptop.
The fact you mention the you get similar results is interesting.
As I mentioned on my second post I used AVIS but this gives me issues (errors) with a alignment application called Registar (not registax) which is a show stopper as I use this to align all of my LRGB files. So really I am back to using the good old Embedded TIFF file (or the Autosave) on my images.

Hopefully someone will come along and shed some light on the exact steps we should be taking?..