Telescope Reviews: Advice on Scope for Observing/DSL Photog in Peru

Mount:
Ok, so, first off, you need to consider your mount first and THEN the scopes to go on it. For astrophotography the mount is enormously important, especially if you want that "most user friendly and/or versatile to upgrade" thing working for you! While the starting level of mounts useable for AP, the Celestron CG-5/Skywatcher EQ5, are cheaper they have serious limitations and given your stated goals I think it makes much more sens to jump up to the next level. At that level you have three choices right now. All three are about the same price point, all three are proven mounts for astrophotography, all three have advantages and disadvantages.

- Orion Atlas EQ-G / Skywatcher EQ6 (proven workhorse, easily controlled from a windows laptop instead of it's hand controller if you want to)
- Celestron CGEM (superior software in the hand controller, had some early teething issues when it first came out)
- iOptron iEQ45 (lighter then the EQ6 or CGEM, good reviews so far, relatively new so not likely to find used as easily)

I think you would do find with any of those three. If you purchase any one of them new that will be 1/2 your entire budget right there though!

Scope:
There is something you should consider when it comes to choosing a scope. Your 60D has quite small pixels, as a result once you get into long focal lengths you will actually find that it will be atmospheric shimmer (seeing) that will limit to your images, NOT how large your scope is. "Average" seeing is said to be between 2 and 4 arc-seconds of shimmer. With your camera if you had a telescope with a focal length of 1000mm you would have a spacial resolution of 0.887 arc-seconds per pixel! You can find out what your spacial resolution and the Field Of View size for any telescope or camera lens on this handy web page here.

So, with that in mind *if* you intended to do astrophotography ONLY and not visual and outreach I would actually recommend a small refractor or small imaging newtonian. This is because for most nights shot focal lengths are the correct match for seeing conditions, lighter weights are easier to autoguide for long exposures, and shorter focal lengths are more forgiving of small guiding/tracking/alignment errors. My usual advice is to start with those wide-field imagers and get a long focal length scope later.

Since however you *do* want to do outreach and given budget limitations I might reverse that usual advice... and appropriately the first scope I have in mind is an 8" SCT (be it a Celestron C8 or a Meade 8"). An 8" SCT with an f/6.3 reducer/corrector will give you a scope with 1280mm focal length for Deep Sky Imaging, 8" of light-gathering for visual and 2032mm of focal length for lunar/planetary imaging without the reducer/corrector. I would consider 1280mm a difficult place to start doing AP and will require some patience as you work out your polar alignment and guiding learning curve but a 8" SCT is a good all-round scope. Thankfully you also have your 70-200 L lens to act as a Very Wide Astrograph Refractor as well.

Accessories (astrophotography):

The absolute minimum is of course something to connect you your camera to the scope! You will need a T-Ring and either a prime focus adaptor or a corrector that will work like one.

I also already mentioned the f/6.3 Reducer/Corrector for a SCT - almost every scope needs something like that, most refractors need a field flattener as do Ritchey-Chrétien scopes, newts need a coma corrector, etc. Plan on something between $100 and $200 for a "xxx corrector" for (nearly) any scope you get.

When it comes to astrophotography at longer focal lengths something you are likely to want in fairly short order is an Autoguide solution. Cheapest and lightest version of that is a 50mm finderscope converted to a guide scope and the basic Orion SSAG or QHY5 guide camera. The Orion Mini Guider package is exactly that.

Other then that dew control would be the next on the list - I do not know how humid or dry your area is but you already mentioned on planning to get a dew-heater... so... guess you have that covered!

Given your lack of light pollution I would not recommend any filters. In the long term you may want to modify your camera to allow greater sensitivity to Hydrogen Alpha light and at that point you may want some narrowband filters such as an H-alpha filter or an O-III filter, but for now... nothing.

Accessories (visual):

Here you will have to rely on advice from others, my focus is more on AP so I do not have a whole lot to add for the non-photo side recommendations.

A Couple Options:

So with all that blather done with... here are a couple of setups you might consider. Prices are approximate *new* rather then used values w/o tax or shipping. You may or may not be able to get things cheaper by buying mount or scope used instead of in a new package.

Option 1: (long term flexibility, short term difficulty)
- Mount/scope package: CGEM and C8 SCT $2199 f/6.3 Reducer/Corrector $135
- t-ring: $15
- Prime Focus Adaptor $25
- Orion Mini Guider Package $350
Total: $2724 - leaving you ~$300 for visual accessories, dew control, etc.

Option 2: (good wide-field imager, good bang-for-buck visual, poor long focal length imager)
- Mount/visual scope package: Celestron CG5-ASGT and C8 $1529
- Imaging Scope: AT65EDQ $599 or if not in stock AT72ED and AT2FF $529 combined
- t-ring: $15
- 2" prime focus adpator ~$30 (not needed with AT72ED/AT2FF combo)
- Orion Mini Guider Package $350
Total: $2523 - leaving you ~$500 for visual accessories. You could also get the f/6.3 reducer/corrector for this setup but be aware the CG-5 may have issues driving the C8 for astrophotography (fine for visual). Some people have had success with a C8 on CG-5 for AP, but more people (me included) have trouble with CG-5 and long focal length.

Option 3: (Image & visual now, autoguide later)
- Mount/scope #1 package: CGEM and C8 SCT $2199 f/6.3 Reducer/Corrector $135
- Scope #2: AT6IN imaging newt $299
- Coma Corrector $135
- t-ring: $15
- Prime Focus Adaptor $25
Total: $2808 leaving $200 for visual accessories. If you get seriously into AP expect to have to purchase an autoguide setup later and probably get your camera moded or get a pre-moded camera

Option 4: (Budget? what budget! We won a small lottery!)
- Mount: CGEM or Atlas/EQ6 or iEQ45 ~$1500
- Scope 1: C9.25 $1400 and f/6.3 reducer/corrector $135 (for visual any time and for long-focal length imaging *when seeing is excellent*)
- Scope 2: 8" Imaging Newt $449 and Coma Corrector $135 (for imaging on most nights)
- Scope 3: AT65EDQ or AT72ED & AT2FF http://www.astronomics.com/main/product.asp/catalog_name/Astronomics/category_name/N1W216AU49AX9M2PF6XX6UH0H6/product_id/ATCC or Canon 300L or 400L lens $huge (for imaging on nights with poor seeing or for imaging very large targets
- Scope 4: your pre-existing Canon 70-200 and 24-70 $0 (for imaging extremely large targets, collections of targets, and for nights with truly terrible seeing
- Other stuff: Autoguide setup, dew straps, t-ring, etc, etc, etc
Total: do you really want to know?

As I write this out I am thinking more and more that Option 3 is the way to go. Lack of auto guiding will limit your exposure lengths but you can do visual right away and have medium (the newt) and wide (your 70-200 lens) imaging capabilities right away as well. Plus the f/4 focal ratio of the newt means you can get away with shorter exposures then you could with a refractor or SCT. Once the AP bug bites REALLY hard you will still need to spend more $$, but less so then option 2 and with less initial frustration then option 1.

Anyway... hope all this is more helpful then confusing! Nothing like info-overload to muddy the waters 'eh?

Let me know if you have questions about any of this. You should head over the the DSLR Imaging section of the forums as well.

Good luck & have fun!

- Sean