Stacking question

[sullivanrp]

So I plan on doing some stacking of some shots I get during the new moon here soon and I got a few questions...

I hear 15-25 shots of the stars + 10-20 dark frames right after in the same location (due to ambient temperature) is ideal... anyone comment on that?

Also... does stacking remove any chance of a foreground subject when you aren't tracking the stars? I do not have any sort of merlin or tracking head for my camera, I am strictly using a tripod, possibly a DIY remote intervalometer for shooting quickly right after another once I have my shot, and my cam...

Hope someone can help! Thanks

[A.S.I.G.N. Observatory]

Here you go mate. I wrote these to answer these very questions.

BTW, you don't want any foreground objects in astro-images to be stacked.

ASIGN Observatory II Capturing Tutorial

ASIGN Observatory II Stacking Tutorial

I hope that helps mate.

Baz.

[armis]

Originally Posted by A.S.I.G.N. Observatory

BTW, you don't want any foreground objects in astro-images to be stacked.

Having tested it, DSS still works but the output file shows the foreground with motion blur: you're not getting star trails, you're getting foreground trails instead . If the foreground is simple enough, you can always photoshop the original one back in with minimal effort.

[sullivanrp]

Originally Posted by armis

Having tested it, DSS still works but the output file shows the foreground with motion blur: you're not getting star trails, you're getting foreground trails instead . If the foreground is simple enough, you can always photoshop the original one back in with minimal effort.

if something like this:

http://500px.com/photo/1465418

was my foreground... how difficult do you think it would be to do another exposure for it and blend the images with masks or whatever else...?

Also, I take it the blur that would be made (direction wise) would depend on the movement of the stars, correct?

[sullivanrp]

Originally Posted by A.S.I.G.N. Observatory

Here you go mate. I wrote these to answer these very questions.

BTW, you don't want any foreground objects in astro-images to be stacked.

ASIGN Observatory II Capturing Tutorial

ASIGN Observatory II Stacking Tutorial

I hope that helps mate.

Baz.

I've looked em over before a few times haha... guess I just need some clarification on it all... So in order to capture a foreground scene also with the milky way it'll have to be either a very small amount of images stacked, or one shot I take it?

[A.S.I.G.N. Observatory]

Originally Posted by sullivanrp

I've looked em over before a few times haha... guess I just need some clarification on it all... So in order to capture a foreground scene also with the milky way it'll have to be either a very small amount of images stacked, or one shot I take it?

Yep, just take a good foreground shot and mask it in after you have done your stack.

[sullivanrp]

Originally Posted by A.S.I.G.N. Observatory

Yep, just take a good foreground shot and mask it in after you have done your stack.

Thanks I'll try it out, hopefully will get 2 or 3 nights of shooting in so I hope to get at least one stacked or individual frame that I am happy with.

[armis]

Originally Posted by sullivanrp

if something like this:

http://500px.com/photo/1465418

was my foreground... how difficult do you think it would be to do another exposure for it and blend the images with masks or whatever else...?

Doesn't look very tricky at all. I'd be concerned if there were anything like tree branches or complex shapes in there. Take another exposure, goto photoshop, layer, try to match colors where you're going to blend (presumably, just above the mountain shapes) as best you can to make the masking easier, then mask.