First time Astrophotography Setup with a DSLR Camera... WHAT TELESCOPE/SETUP?

[Wonderboy]

Can you give me some examples of what a telescope with a focal length of 500mm would produce in comparison to a focal length of say 700mm... is it enough to consider upgrading? 

[Demonperformer]

Here is a simulation of M42 imaged with a canon (I don't have the Nikon specs) at 500mm & 700mm. The frame size is the white rectangle, the nebula size is as displayed.

[Wonderboy]

Brilliant, thanks again.

[FaDG]

I've been through your choice process some time ago and changed much over time, as my first choice wasn't the best one, I now realise.

So, you already received a lot of good advice from people that are really top imagers here, let me add something that's not always in line with their suggestions, although I tend to agree with them on most topics.

Mount: absolutely #1 priority. I started with an EQ5/CG5, but then changed it to an HEQ5; I agree with @vlaiv: look at this as your baseline, possibly belt modded. you may need more starting with an 8" reflector, but under that it's absolutely top.

BUT, you didn't include in your list, and it was only mentioned by @Demonperformer but not stressed much, autoguiding equipment, an absolute must for DSOs and reducing your budget for the rest (and load on the mount). You should add an autoguiding camera (ASI120, QHY5, ...) and a short frac (60mm/f4 or 50mm finder) + rings

Scope: I'd be quite reluctant to advise a 6" RC to a beginner, with its long focal length and hard collimation process I expect that you's be in for frustration. This may come afterwards, but to start look into short APOs or Newts (and not above 6" with an HEQ5). As already mentioned  APO  + flattener / Newt + Coma Corrector. That's a must. BARLOW @ prime focus for DSOs: that's a NO, NO.

And please, never, ever, ever consider 1.25" stuff with your DSLR, you'll introduce so much vignetting that you'll be regretting it starting at day 1. 2" should be your baseline. If your LP scale matches Bortle 5-6 and 2-3, then LP filters are not your priority, you can live very well without to start with.  

Scope: the ED80 with FF is a great first choice, and I started there: with a DSLR @ 600mm it is forgiving enough on the guiding, it's lightweight, you don't need to hassle to have it working well, it has good color correction and nice corrected FOV, BUT, and it's a big BUT, at f7.5 it's not a fast scope, unless you get the 0.8x flattener/reducer and work at 480mm f/6.  As a matter of fact, mine doesn't see much light since I got a 6" newt. The SkyWatcher 150pds (it's Synta stuff, like Orion) can easily reach focus with a DSLR + coma corrector, at f5 is much faster than the ED80 and still lightweight enough for the HEQ5. But it's not fire and forget as the ED80 (it needs to be collimated, the alignment of the camera over several sessions is more critical due to the spikes), nor as portable. 

In the end I added a small and fast 72mm APO, you find several at f6, both doublets and triplets: they need a flattener (unless you look into a 65 quadruplet which is already flattened). These are excellent astrographs, easy to use, but more suited for large targets and wide emission nebulae, wide FOV than for small galaxies, planetaires or clusters. So, even for DSOs there is no one size fits all.

So, invest on the mount, as you normally won't be changing it unless going MUCH heavier, and start with a scope that is easy to manage and gives good results (ED80 or shorter APO). Once your imaging skills outgrow your scope, you will be able to sell it and choose the next based on what you like most.

Final remark: why not purchasing used? Astro equipment is USUALLY very well kept and you can get an excellent setup at about 65%-70% of its original price, thus partly solving your budget issue.

Good luck,

Fabio

[Wonderboy]

Thank you so much Fabio for your advice. And to everyone else who contributed, thank you. I really appreciate it.

[FaDG]

You're welcome! Don't hesitate to ask around, and once you start please post your pics. It will be nice to see how it turns Out! 

[jstrandberg]

As an astrophotographer on a budget myself, I can say that I would go with a refractor.  If you can get the equipment you mention within your budget ( I could not get that gear here in the US for under 1,900) I think your Skywatcher EQ35 and the SharpStar 80 will be a nice foundation for learning the hobby.  From my experience I would forgo the flattener and CLP filter and invest in a good finderscope first.  Once you are producing good images and have a good handle on processing, you can add the flattener and CLP filter.  Good luck and have fun, but be patient as there will be a lot more failures and successes during your first few months of learning.

[Demonperformer]

5 hours ago, jstrandberg said:

I would forgo the flattener

Unless the scope is fully corrected (in which case you will never need a flattener for it) you will get field curvature, which will mean that all your stars will get gradually more elongated as you move from the centre to the edge and will be particularly noticeable in the corners. The bigger the chip, the more pronounced the effect, and DSLRs tend to have fairly large chips! This will severely limit how "good" your images will be. This is not to say that you will not be able to learn the art of processing with such images, but you will very quickly become dissatisfied with the results.