Need a little help

[lloydsjourney]

Hello Everyone,

Last night was my second night trying my hand at astrophotography with my Celestron Nexstar 6se and Canon 7d attached via a t-adapter. I was using the telescope to find the object and then would switch over tot he camera. Using "live" view I would find the object and refocus.

This worked fine for the moon and Mars. However, I could not seem to get it to work for the Orion Nebula. All I was able to see was a black screen.

Any ideas? Tips?

I tried taking some shots of the Nebula with my 7d attached to my 100-400 mm lens and focused it using "live" view. The tripod and camera are just too shaky for anything great at this point.

Thanks in advance for your time and thoughts.

You can see the images here if you wish.

http://public.fotki.com/lwa11/2010/february-2010/2-20-10-night/

[buaku]

I was trying the same thing with my 7D but with a Celestron Astromaster 70.
I couldn't see anything using live view outside. I tried both M and Bulb modes too.

I also tried it all indoors to make sure that it should work in theory. I found the screen brighter if I put the camera in M mode and set it to 30s shutter speed. Not sure which mode you were using outdoors but maybe playing around with that would help.

Can you focus on any of the brighter stars around the nebula and then maybe move the telescope to the right spot afterwards?

I thought your pics looks great! I'd be really happy to get anything like that with my setup!

Were the moon/mars pics through your telescope?

[lloydsjourney]

The moon and mars were through the scope.

I am pleased with the moon shots and Mars was OK for my first ever attempt. I hope to improve it for sure.

I played around with the focus as you had mentioned but for some reason just could not see the stars thru "live" view.

Maybe it is a simple as changing from the t-adapter that I was using looking through the telescope prism/mirror to attaching the other tadapter that connects directly in play of the scope attachment. The I could also use the reducer to get shorter exposure times.

Just not sure as it is all new to me.

Problem I have had with all of that is finding the nebula or stars without first getting them in the scope using the spotting scope and eyepiece.

I also have not figured out how exactly to set up the tracking on something if you are not using the skyalign.

The instructions that come with the telescope are lacking in my opinion.

[buaku]

Those look nice though the scope. With mine Mars is just a little dot.

I'm hoping someone else chimes in with experience about what can be seen with live view. All I keep reading is that people zoom into like 10 times to make sure things are in focus, but all I ever saw was a black screen.

I would think the focal reducer would help. I haven't tried bypassing the diagonal yet, weather has been lousy for the past few days, and it's not getting any better yet.

I don't even have a tracking mount, so I know I won't be getting sharp pictures. But if I can at least get something, then I'll feel better once I do save up for a nice mount. I know it will take a lot of practice.

Another option is to get some sort of off axis guider or radial guider I think. With one of them you can have the camera and eyepiece attached at the same time, at least you wont' have to swap the camera and eyepiece.

All this is very new to me too!

[chris.bailey]

Welcome to the wonderfully frustrating world of Astrophotography :-)

For a start I would suspect that hanging a 7D off the back of your nexstar will make it very tail heavy. You will need to add some weight to the front of the scope to help redress the balance a bit. With the single point of mounting, scopes like the Nexstar are quite sensitive to balance and the 7D is quite a heavyweight. Once balanced tighten everything up tight.

I would not put a DSLR into the diagonal, direct couple it to the back of the lens cell. There is too much movement in the various couplings to the diagonal to work effectively.

You will not be able to see the Orion Neb itself on the live view screen. I personally dont like live view as it it is bright enough to wreck your night vision but if you do want to use it you will be limited to focussing on a bright star. Use the zoom function to find one and take your time. Focus is one of the major points for getting decent pics. Google Bahtinov Mask. Easy but fiddly to make but a real aid for DSLR focussing.

Being ALT AZ you will be limited to taking 20-30 second frames before field rotation starts blurring the stars. I would start by setting your 7d to ISO 800 and 20 second exposures. At 20 seconds you should just about be able to see the Orion Nebula on the preview screen though it is better still to capture to a laptop.

Having a laptop outside with a copy of Stellarium on it is a real boon to finding your way around.

Take as many 20 second exposures as you can and then stack them in Deep Sky Stacker.

http://www.pbase.com/chris_bailey/image/73417225 was my first ever astrophoto taken ALT AZ with a 10D using short sub frames albeit with a slightly larger scope.

Have fun

[lloydsjourney]

Thank you Cris. That gives me a few more things to try. It will be a learning curve. I look forward to the challenges.

How did you get your shot unguided?

[chris.bailey]

How did you get your shot unguided?

The mount itself was tracking albeit in Alt and Az which necessitates short frame duration (to avoid field rotation). No need to guide (using a seperate scope and camera) on such short duration exposures.