Which way to go?

[Roy Batty]

Having done some initial imaging using my C8-N and DSLR I think i'm coming to the point at which to progress I'll need to get into a guiding set up. I've already got a web cam, so figure I'll need the shoestring GPUSB guiding box plus PHD and of course a second scope! (most likely piggybacked on the C8-N, so nothing too big!)

But what scope?

Two candidates that I thought I could use as both guide scope or as an imaging scope (if I used the C8-N for guiding) are:

1. SW Evostar 80ED Pro 1

2. WO Megrez 72FD APO

I think I'm leaning towards the WO Megrez 72 as it could be more suitable as also a grab and go scope, plus I'm thinking it's probably better quality wise?

Both these scopes are very similar in price so it's down to which one I will get the most use out of.

Does anyone have any thoughts they can lend to help me make a decision.

cheers

RB

[Andrew*]

From first hand experience, I would either opt to go side by side, or upgrade to an EQ6 if you are going to put two scopes on the HEQ5. I have an HEQ5 with 8" newt and ED80 side-by-side and TBH it's only just okay for visual. I haven't tested it for imaging yet, but I have the suspicion...

I believe the WO72 is a fair bit lighter than the ED80, so you'd be better off with this. Also, if you went for the ADM or TS side by side mount rather than AD's M3 system, which are quite a lot lighter, this might also be of benefit. Saying that, the M3 system is very good...

Andrew

[Roy Batty]

Thanks - Andrew,

I looked up the tube wheights for both of these and there's about 270 grams difference or just over half a pound in old money (to visualise this it's about the wheight of a pack of butter extra).

Still thinking of piggybacking as the way to go rather than side by side, pros and cons for both methods e.g. flexure vs reduced guide star options.

BTW I've seen the HEQ5 marketed with a SW250PX but I can't seem to find accurate tube wheights for the 250PX to work out the wheight difference over a 200mm.

cheers

RB

[MartinB]

Roy, I think either of these scopes will do a good job for you. If you continue with your DSLR I think the longer focal ratio of the ED80 would give you a more useful image scale than the Megrez. Depends whether you fancy doing very wide field imaging or not. From a guiding point of view the Megrez will be the better bet with it's faster focal ratio and larger field of view for picking up guide stars.

One other scope to consider is the ZS66 which is quite a bit lighter and is my own choice of guider.

You will be at the limit for tight guiding with your mount but you should be alright if the set up is carefully balanced and there is no wind. Otherwise, take off the newt and image unguided with the modded webcam and a short focal length refractor - a fantastic combination!

[Roy Batty]

Martin - thanks for the advice.

I think I'll be going for the Megrez.

BTW: had a look at the weight comparison between a C8-N & C10-N, it's 12.2Kg - both marketed on a CG5 mount - so I'm reasonably happy with mounting a 2.2 Kg scope with my C8-N on the HEQ5 pro, although I'll probably purchase an extended Dec shaft to aid balancing.

cheers

RB