I am a newcomer to CN, looking for advice on equipment. I hope this is the correct forum for that. [Edit: Originally posted in the general CN equipment forum, but later moved to the correct EAA forum.]
Background: I have done visual (eyepiece) astronomy for years, using very basic equipment (90mm achromatic refractor and a basic mount).
Goals: Invest on new equipment to switch to EAA / OAP, and eventually also get into AP.
Main interest: DSO.
Requirements and limitations:
a) Light pollution: Observing/imaging from my Bortle class 6 backyard
b) Lightweight equipment (I have some difficulty carrying heavy items)
c) I prefer equipment (mount/control, camera, guiding camera) that are compatible with free software and linux as much as possible (EQMOD, ASTAP, INDI library, etc)
Plan: My equipment investment plan, for a total of ~$4000:
- Scope, an 80mm f/6 triplet ED APO CF, e.g.:
Orion ED80T CF 6lbs 80mm f/6 FPL53 triplet APO: ~$950 (2nds $750)
Or: Explore Scientific ED80 CF 80mm f/6 FCD1 triplet APO: ~$850
- Camera, a CMOS OSC TEC (color needed for EAA?, cooling needed for AP):
ZWO ASI 294 MC Pro: ~$1000
Or: ZWO ASI 183 MC Pro: ~$800
- Mount, capable for future AP:
Orion Sirius EQ-G goto, 30lbs payload, ~$1050
Or: Sky-Watcher HEQ5 Pro goto, 30lbs payload, ~$1150
- Accessories (filters, reducers, adaptors, rings):
LPR filters, reducers, tube rings, dovetail bar, T-adaptors: ~$500
- Guider (optional for EAA, needed for AP):
Orion Magnificent Mini Deluxe AutoGuider package: ~$400
Does the above look like a good plan for my goals?
Specifically I have the following questions:
Q1. [Rephrased] I am mostly interested in wide field DSOs, but it would be great to get fine details on some small DSOs. The 80mm f/6 + 294MC (my initial choice) will be excellent for large DSOs with a FOV of 2.3x1.6 degs, but its 2''/px image scale is too course to detect the remarkable M87 jet, as this CN thread seems to indicate.
Getting a larger scope or adding a second finer-pixel camera (e.g. 183MC has 2.4um px size, compared to the 4.6um of the 294MC) would be great solutions to this dilemma, but the cost would be too much for me.
So I am thinking of two low-cost approaches, while keeping the 80mm f/6 scope:
- Get the 183MC camera ($200 less than the 294MC), and add a strong focal reducer: Use the reducer for wide views, and exploit the finer pixel size of the 183MC (1''/px image scale with the 80mm f/6 scope) for finer details of smaller DSOs. This combo is known to detect the M87 jet.
- Or, conversely, keep the 294MC and add a high quality 2x barlow. My guess is that under good conditions the barlow will add significant finer detail (image scale becomes 1''/px) and the 294MC will then be able to detect the M87 jet, but I could not find any hard confirmation.
So my question is: Does any of this make sense? For the 80mm f/6 scope above, are there strong reducers suitable for AP (without back-focus issues)? Or, will good quality 2x barlows work for AP?
Q2. Since my payload won't exceed ~10lbs, can I use a lighter 20lbs-payload mount to do AP (like Orion SkyView Pro Eq GoTo, or Sky-Watcher EQM-35 GoTo)?
Edited by adg, 17 May 2019 - 03:11 PM.