Advice on imaging M42

[lune lupine]

I had my first attempt at having a go at Orion last night. Reasonably happy with results; 10 frames mix of 20s and 5s at ISO800 using canon760d and Evolution 8, quickly assembled in Lightroom but no editing. My own thoughts are that:

1. need to practice more on focus (big yes!)

2. perhaps raise iso to 1600?

3. perhaps increase exposure times to 30s - 1M?

4. should i use mirror-lockup on the camera; reading conflicting info on the web?

5. should i invest in some of those fancy filters I see on the market?

 

I'd be interested in feedback around the exposure time suggestions for my telescope in particular. 

[cjdawson]

For the focus.  Get hold of Bahtinov mask. That will help you to get to sharp focus.

For the exposure times.  Take several sets of images.

1. Keep them the same

2. Double the exposure time and see

3. Double that, and see

4. Rinse and repeat.

 

ISO, keep that at 800.  I've done some tests and the noise starts to increase beyond ISO 800. 

 

Mirror lock up.  Yes use it.  Add the 2 second self timer, and the camera will seem to work like normal (just add 2 seconds to your exposure time)   It will help to reduce the vibrations from the camera as the mirror flips up.

 

Filters - Don't bother with them until you have got to a place where you can make use of them.   i.e. having a modded camera.

[lune lupine]

Great advice as always thanks! If I ever get to see some clear skies in my neck of the woods will try all of the above.

Out of interest, is tethered shooting useful in this context? Will be in back garden so hooking up laptop etc with bundled canon eos utility would be easy and having larger screen might help show focus asjustments more clearly?

[wimvb]

If you have the possibility to control your camera remotely, I advise you to do that. Otherwise, I would recommend an intervallometer.

For good focus, a Bahtinov mask is a cheap investment. With remote control, you should be able to do live view on your computer screen. This also helps.

You can test this during day time (not the Bahtinov, though).

Good luck,

[cjdawson]

You might want to look at BackyardEOS.  This will let you use Live view for focusing. there's aids in the software to help you find the best focus.  If your mount is Ascom and you have an electric focuser, you can control it directly from the software too.

Then you can program the imaging session that you want to take, and set it going.  The software will take care of alot of the details for you.  Well worth looking at.

[Owmuchonomy]

I have always used the free Canon EOS Utilities bundled package.  It works a treat.  There is the option to do many things including add crosshairs and zoom the live image so you can focus 'live' and even do your alignment whilst connected.  It doesn't have plate solving though so you need to bear that in mind.  M42 is a relatively bright deep sky object so a good place to practice.  Common practice is to take two sets of subs; one exposed for the trapezium core (which is very bright) and a second set exposed for the gas nebula envelope.  You can then process the image using both sets and avoid burning out the core but keeping all that lovely nebulosity.