NGC 2438 and M46

[Sunfish (Ray)]

Several NGC for the trouble of one counting invisible friends.

Two image stacks. One containing 57x short C8 6.3 and F8 refractor images in one DSS image and one PS Median stack of 11x 90sec images. All 800iso.

Apparently the star at the centre of NGC2438 is one of the hottest .

Can not quite see the red halo of the blue planetary NGC2438.
or the protoplanetary Calabash just above

I am wondering if I can get longer exposure of the planetary with the C8 now I have guiding working on Ascom/Phd at 3-5 minutes. An STC Duo would be nice.

10 minutes maybe?

[casstony]

Nice image Ray. The planetary makes the cluster much more interesting.

Can DSS stack images from different focal length scopes?

[Sunfish (Ray)]

DSS can do that. I used shots from the c8 with reducer at f6.3 and an f8 refractor with and without the reducer using the same camera DNG files loaded straight in to DSS , using 100% of images in mosaic mode and a few darks from each session. No flats of course. I have been playing with this for a while, tweaking DSS, and when I saw the posts regarding camera arrays as a valid astronomical technique it seemed worth more attention.

It is logical that DSS simply stretches and rotates the images , the same as PS alignment, to line up the stars and remove varied lense distortions so it all matches. There must be a limit. I suppose for some small objects perfect frame alignment , matching optics and no rotation would be preferable. For a cropped field it does not seem critical.

I wonder how much time is right for some of these small objects. Is 10 or 20 minutes required?

[casstony]

Originally Posted by Sunfish

I wonder how much time is right for some of these small objects. Is 10 or 20 minutes required?

Assuming good seeing and tracking, I guess longer is better for fainter objects, but only up to a limit such as full wells, light pollution, camera noise?

[xelasnave]

Ray
How about a thread explaining how you go about it.
Alex

[xelasnave]

And a very nice imaging run with great results.
Alex

[xelasnave]

I am wondering.
80mm on heq5 with narrow band zwo and eight on eq6 wuth a nikon dslr..that would be a stretch.
But I wonder could you gain anything say maybe same camera thru each scope ... but it would be interesting if it could be done in dss ... but it never ceases to amaze me..ot blew me away putting photos in rightvside up with other upside down and it stacked them.Cool.
Alex