Moving toward astrophotography, away from alt-az

[Nemesis6]

I've recently found out about the shortcomings of the ALT-AZ type of telescopes, mainly field rotation. I want to eventually do deep sky images. I'm currently using a SkyWatcher 130PM Synscan Alt-AZ, and I know that this particular scope cannot achieve focus with DSLR's unless I use a barlow lens, so I'm wondering: If I moved to a higher-end scope still in the SkyWatcher series(I was thinking the Skywatcher 200), will I still encounter this issue? I got my previous telescope this this place: harrisontelescopes.co.uk, and upon checking their website again, I can see they have the SkyWatcher 200, but I don't know which one to pick. I've been told that if I want stability, I should go with an HEQ5 mount. Here's my list of options: Harrison Telescopes Ltd

Another little quirk I've noticed: On my current scope, focusing is extremely hard at high magnification. Just trying to touch the scope pushes it out of focus... Is there any remedy to this?

[sgazer]

hi,

"ollypenrice" is writing a useful guide on imaging which should help, but to answer your questions;

some of the Skywatcher scopes (possibly yours, but not sure) allow direct connection of the DSLR to a t-thread on the focuser tube which should allow focus (best to check with the supplier first). This is not ideal though as you may want to use 2" filters (although the EOS-clip filter which fits inside the Canon DSLRs is great too), in which case you'll probably need a 2" to t-thread adapter to go into a 2" focuser. Some Skywatcher reflectors are now designated -ds, which have a dual speed focuser and the primary mirror further up the tube to help to achieve focus. I would also recommend a comma corrector.

You should look at the focal ratio of the scope rather than going for aperture. The 200p(-ds) will be quite heavy and if you add a guiding scope this could be pushing the HEQ5 to it's limit. Guiding is extremely useful for longer exposures (2min+) and doesn't require perfect polar alignment (I set my tripod on 2 marks on the ground each time and it's fine).

With a DSLR and the dual speed focuser and a bahtinov mask, the focusing will be easy, it's not particularly high magnification or long focal length.

[riklaunim]

Your newtonian has rack and pinion focuser (description on FLO), so either change the focuser or buy OTA from the new SW photographic series - 130 or 150 mm like this one.

Then if you want to use DSLR - just add coma corrector, 2" light pollution filter (SW LPF for econo, IDAS LPS 2 for best) and you are ready to go.