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I am interested in doing astrophotography with my canon dslr using long exposure timelapse using the intervalometer built-in.
Which type of telescopes (Newtonian v/s Cassegrainian reflectors) are recommended for astrophotography.
I am somewhat new to this and hence some help is appreciated.
Regards
It doesn’t seem to matter much whether you use a Newtonian or a Cassegrain. That from personal experience and from reading the metadata attached to many images on the web.
What is by far the most important is that the telescope tracks the sky properly. Getting everything mechanically balanced makes the mount’s job much simpler!
Having an autoguider is not essential but certainly makes life immensely easier. Without it you need to have a very well set up and high quality mount and/or take lots of short exposure subs then throw away any which show unacceptable trailing.
It all really depends on what you want to do – but short focal length refractors are a popular starting point for imaging. The wider field of view will be more forgiving of tracking errors, and many are a good match to a DSLR.
As Paul says – a good tracking mount is essential. And GOTO is useful. If you can get good 30s exposures which you can stack you will find a huge range of potential targets in reach.
Callum
A special case of “short focal length refractor” is a lens specifically designed for the camera in question. Telephoto lenses are especially flexible in what they can be used for. I’ve taken snapshots with a 80-300mm telephoto of star fields which look quite nice. Never had the skill or patience to do it properly though. Those who do learn the technique have produced some amazingly good work. You may like to try this approach to cut your teeth before spending serious money on a telescope. Invest in a good mount first.
I have had success with F/4 Newtonians on a good GOTO mount. At the other end of the scale a short focal length lens on a portable tracking mount should give pleasing results when images are stacked. I use 50 to 200mm prime lenses but ive had good results with 18-105mm zoom range. If you are interested in timelapse, then it would be possible to put long exposure wide angle frames into a movie that includes foreground objects.
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