2 replies to this topic

[ArandomPilot]

Hello CN community,

 

Being in the Marines has given me a great opportunity for imaging. Being here on Twenty-Nine Palms base gives me access to some of the darkest skies in California. So, I'm going to hone in my astrophotography skills once again after a nearly 7 month hiatus. This where I need to be pointed in the right direction. 

 

Imaging: 

 

For this, my primary targets are mainly LBN and LDN objects. My telescope of choice is the spacecat 51 with a ZWO 1600mm Cool. 

 

What should my ideal exposure time be? 

How much data would be needed to get a nice image? 

 

Processing:

 

For these projects, I will probably stack in DSS or PI. Post processing will be in PI.

 

 

What type of processing techniques in PI would bring out the most nebula without taking in a ton of noise?

[EGregerson]

with great seeing, longer should exposure work great. but there are qualifiers.  there are post/threads on this site that address that specifically for the 1600. for example the post  'sub exposure tables for ASI 1600'  Clear Skies. 

[Rasfahan]

The "optimal" sub exposure times cited are really "minimal" sub exposure times to swamp the read noise of the camera. You also need to check that you don't blow out too many stars. If you do, you need to take two exposure length: One "read noise swamping“ for the faint nebulae and one shorter one for the bright stars. You can star extract and combine in post. 

 

How much data you need really depends a lot on the subject you shoot. The brighter the subject, the less integration time is needed for a "good" image. But then, with the RedCat you'll also have a lot of sky around the main object. Usually you will find some IFN and other faint structures. So, go for as long as you can. I found from Bortle 1 I could get very pleasing images already in 4 hours for brightish targets. If you put in 10h or even 20h, you'll have stunning data, even for the fainter nebulae.

Edited by Rasfahan, 05 February 2023 - 09:17 AM.