M42 - First ever DSO

[johankj]

My first capture of a DSO.

Used Canon D1000 in prime focus on SW 127 Mak, on an alt-az goto. This is a single 30 second shot (one of the better ones) at 1600 ISO. I've only cropped the picture to about a third.

I find it incredibly hard to find good focus, any suggestions? Any other suggestions are welcome too

[Beyond_Vision]

A very nice first attempt much better than my first paltery attempts

I would suggest buying a focusing aid called a Bahtinov mask. If you do a search on here or google you will find it easily.

Regards

Kevin

[dlp]

You can try focusing on a bright star first using 'live view' - Betelgeuse would be a good target, then slew to M42 without touching the focuser/camera and snap away!

David

[James4]

A great first DSO! My first shots were of blank sky and blurred stars ...

My focus routine is to turn on 'Accurate GoTo' in the Utilities Menu.

I then pick the object (M42) I want to image. The GoTo now finds the nearest bright star to M42 and slews to it. I focus on the star using 'Live View' - use the zoom button to enlarge the star all the way. Once I have the star in the centre of the field and have it focused, turn off Live View, hit enter and the scope slews to M42. M42 is bright enough to focus on it directly, but this routine works for other DSO that are invisible on the camera screen. Good Luck!

[johankj]

A very nice first attempt much better than my first paltery attempts

I would suggest buying a focusing aid called a Bahtinov mask. If you do a search on here or google you will find it easily.

Regards

Kevin

Thanks Kevin

I have invested in a universal bathinov mask with adjustable rubber spikes for different diameters.

But its just a blury mess. I think I can discern two spikes on one side. It's not very helpfull. Am I doing it wrong? Is my mak out of colmination? Maybe shorter exposures...

[johankj]

You can try focusing on a bright star first using 'live view' - Betelgeuse would be a good target, then slew to M42 without touching the focuser/camera and snap away!

David

That's easy enough to try thanks

[johankj]

A great first DSO! My first shots were of blank sky and blurred stars ...

My focus routine is to turn on 'Accurate GoTo' in the Utilities Menu.

I then pick the object (M42) I want to image. The GoTo now finds the nearest bright star to M42 and slews to it. I focus on the star using 'Live View' - use the zoom button to enlarge the star all the way. Once I have the star in the centre of the field and have it focused, turn off Live View, hit enter and the scope slews to M42. M42 is bright enough to focus on it directly, but this routine works for other DSO that are invisible on the camera screen. Good Luck!

Thanks James

I don't think I have that option in my Goto, but I will try focusing in Live View.

[ollypenrice]

If the Bahtinov mask is not made for something pretty much like your own f ratio and aperture it won't work properly. They are dedicated to a specific aperture and FL.

Judging a star by eye may be the best you can do at the moment but it is not accurate enough. You discover this when you use a mask or a FWHM measurement. The final adjustments these allow you to make are quite significant but do not make a perceptible difference to the appearance of the star. Good focus really is critical and affects not only resolution but noise.

The result you have there is very worthy indeed and unguided at a long FL and slow FR, so under tricky conditions. Good one.

Olly

[johankj]

Thanks for the info and the praise Olly

I've printed of a Bathinov mask from astrojargon on a transparancy. I hope this will help me get a crisper and clearer picture.

Next time I will try to do many exposures (subs?) and stack them in DSS.