DSS is doing my head in.

JB80 (Jarrod) · #1 23-04-2012, 08:00 PM

Hi all, I have never really got the hang of Deep Sky Stacker which I put down to a mixture of things but now it's behaving differently again. I'm not sure what has changed, probably some setting but I couldn't tell you which one.

Basically what is happening now is after it's done stacking and it would normally save a greyish autosave .tif but it seems to jump ahead and autosave a very dark picture like some changes have already been applied.
And then secondly if I go to apply the normal changes to the RGB and Luminosity I get a horrible black and white very noisy image.
I have never had DSS produce this type of thing before.

While I'm here I may as well ask if anyone knows of any alternatives to DSS aswell?

I'm including a couple of .jpegs to give a clearer idea. The first one is the first autosave image I get after it's done stacking and the second one is the horrible B&W one that results from changing the luminance.

So if anyone can help me out I'd appreciate it.

Jarrod

luigi · #2 24-04-2012, 01:14 AM

Maybe DSS is autosaving in 32 bits mode? Then your data is all at the left of the 32 bit histogram and looks dark. You would need to stretch the histogram using the levels or curves tool from your favorite photo-editing program.

I'd suggest to completely ignore DSSs adjustments, just save the result after stacking and then edit it properly. Always use the "save without applying the adjustments" option.

JB80 (Jarrod) · #3 24-04-2012, 02:23 AM

It might be saving in 32bits, I have always had problems with the autosaved .tifs and master darks, mainly photoshop doesn't want to open them and says I don't have enough RAM. Even Gimp when it does open them reduces it to 8 bits.
Where abouts would I change the save settings so it doesn't save in 32 bits?

Normaly I would ignore the DSS adjustments and take the greyish image straight to curves but this has thrown me as I haven't changed anything to my knowledge and really there is not enough data in the darkened image to pull anything out.

luigi · #4 24-04-2012, 05:02 AM

You can just save as a 16 bit tiff file when DSS is done. For the autosaves you can't change the format but you can open the 32 bit files with fits liberator or any other free astro tool and then save them as 16 bit tiffs.

I don't autosave at all, I just save the output from stacking as a 16 bit file without applying adjustments.

Check if DSS is stacking all the photos, maybe your star detection treshold is wrong and DSS is only stacking 1 frame...

JB80 (Jarrod) · #5 24-04-2012, 04:59 PM

I save the outputs seperately without any major problems it's just the outouts have changed.

Stacking didn't seem to be a problem either as there was 4 and a half minutes roughly and it was detecting plenty of stars, I also tried with a different set and got the same results.

JB80 (Jarrod) · #6 26-04-2012, 05:20 PM

After a little investigation it seems that it's not DSS but it's the RAW files themselves causing this, it seems to be prevelant in most of my recent pics. Need to do some more testing if I can.

Now I have to work out why, would it be a setting on the camera causing it or something more internal in the camera?
I'm hoping it's just something simple but not sure how to even check it.