Helix Nebula with DSLR on fixed tripod?

[jman17]

Hi,

I am interested in taking some shots of the Helix Nebula from light polluted skies, but only have a DSLR with an 18-55mm lens on a fixed tripod. Is it possible to get decent shots of the Helix Nebula from within a regional city with this equipment, or would it just be too faint? If doable, what focal length would be recommended? I would be doing hundreds of exposures to try to compensate for the short exposure lengths, and stack them together.

Thanks,
jman17

[Camelopardalis]

Almost no chance...it's faint enough to be a good challenge with an equatorial mount from a dark site with a DSLR.

[cometcatcher]

It's possible, but with a 55mm lens it wouldn't be very big. With a 135mm lens it starts to show structure, but at that f/L your subs on a tripod would only be a second or two. You would need thousands of subs.

[jman17]

Hi,

Thanks for the helpful info, it is appreciated.
jman17

[sil]

I shoot mostly dslr on tripod. Yes its possible, but i havent been able to get a decent looking shot to show from my efforts yet. Plus getting the camera pointed at the correct patch of sky proved tricky for my eyes. A light pollution filter will help but will also reduce your exposures (so again, more subs to compensate.) Smallest f-stop you can use. Find the longest exposure time you can use at that patch of sky while maintaining acceptably round stars (I try for length to be less than twice the width). it will take hundred of exposures. Try to keep helix in centre of shot where lens distortions are least. I take note of which direction the stars are moving across my frame and try placing my target towards the bottom of frame, then lock my remote trigger which fires off 100 shots for me, then I recheck drift and where my target is before locking trigger again. rinse and repeat, readjust framing when target is nearing top of frame so its drift is always across the middle so most frames are at least distortion. I prefer to go light on ISO at around 1600, above that you have a lot of chroma noise to remove thats on top of a colour target so you often lose good signal or just end up with very noticeable noise. Trust in your processing workflow to reveal the target rather than boost in camera so you can see it on screen. Just ensure the stars on/around the target are in your frames.

Good luck, its a tough target and a long focal length is preferable.

[rcheshire]

A homemade tangent arm / double arm / curved rod drive would increase your chances.