DSS Nightmares

[TechnoViking (James)]

Hi All,

After quite a successful night of data, ive attempted my first stack in DSS, i have watched videos on youtube and read countless webpages which all seem to contridict each other.
I am having no joy, out of 18 x 30second subs & 7 Darks, DSS tells me it will only use 1 sub to stack!! I have changed the star detection, added a median filter, in 5 different combinations, change the % of frames used, added the model of my camera, checked all the options tabs, ive spent close to 3 hours on this problem, im pulling my hair out here!

See attached error

If someone could possible direct me to a thread, or comment i would be very grateful!

[Peter.M]

My guess would still be star detection limit. The score column is telling you that they all score 0.00, Im pretty sure that can only happen if it dosent find any stars. Make sure you move the slider all the way to the left and tell it to compute the number of stars, it should find some to work with.

[Andy Walters (Andy)]

If your using a Canon camera, you need DSS beta 47 from the yahoo group. (thanks Phil). I was having all kinds of issues until I found that out.
Cheers Andy.

[TechnoViking (James)]

After tinkering around and 7 failed stacks, DSS stacked my subs, but now im finding that the images are horrible and grainy. My guess is that the ISO was set too high

Will have to try again on the next clear night

[carlstronomy (Carl)]

As Andy has already said, I also had the same error you have if you are using a Canon you must use beta 47 which by your screen shot you are not. More info on what you used would help. Also you are stacking JPG's in RGB if your camera can take RAW that is really what you want to work with for better results. With your JPG make sure you are stacking with bilinear debayering, Sigma Clipping method and try between per channel and RGB background calibration see if it helps. Changing the star threshold did not solve this for me, however upgrading the version and trying different settings did. Make changes the worst that can happen is nothing you can change them back.

Carl

[TechnoViking (James)]

Thanks all, i have tried stacking in DSS version 3.3.3 Beta 47, with much the same results.

washed out, noisy pictures. I know I have to post processing with Lightroom, or photoshop, even after using just about every slider available, the picture i get is noisy.

Is it my processing or the subs im working with?

First image - post stack - Lightroom adjusted, cropped rotated
Second Image - Origional 30 second Sub. (resized to upload)
Third Image - Stacked Only using DSS 3.3.3 Beta 47 Autosave (resized to upload)

I just noticed on closer inspection of the origional subs, that there are a mass of red pixels everywhere, im guessing DSS thought this was part of the photo, and not noise? I think it was light pollution from my leds ... sigh...!!

Thanks again

[bojan]

I think your first mistake is using jpg images (judging from the attached image from first post).
You should use RAW, as jpg artefact will affect image quality and besides, you are loosing dynamic range (jpg format has only 8 bits, compared to 14 bits RAW).

As to hot pixels, you have to take dark frames (similar number to light frames) also in raw of course.

Your images look OK to me... yes, there is light pollution visible, and this can be taken care of in DPP ( see here, post #37)

[Octane (Humayun)]

And, flat frames (with associated darks).

H

[TechnoViking (James)]

Thank you everyone for your imput, it seems that 2 factors contributed to the low quality, JPG causing artifacts (Thank you Bojan), light pollution caused by the LEDS reflecting off the wall. I tried stacking some average data from M42 (again only JPG) but i am still happy with the results, the resolution and detail seem to be good, but with RAW im sure they will be much better

H, i will try flat frames next attempt

Bojan, Ive installed the DPP, and will use it

Thank you all again, its onward and upward from here

[ourkind (Carlos)]

Orion looks good James