2nd Scope...

[TF Ratio]

Hello again lovely people.

Its been a year and my Skywatcher 200P on its EQ5 have served me well, I was lucky enough at Christmas to get a nice DSLR and Steve at FLO has sorted me out with my adapters etc..

But Its my birthday in a few weeks and I feel that the time is right to expand my kit..

I have been looking at the following scopes:

Celestron 80ED APO Premium Refractor:

http://firstlightoptics.com/proddetail.php?prod=celestron_c80ED_ota&cat=49

and the William Optics Zenithstar 66 SD APO

http://firstlightoptics.com/proddetail.php?prod=WOzenithstar66sd

or the William Optics Megrez 72 FD APO

http://firstlightoptics.com/proddetail.php?prod=WOmegrez72

I was hoping to piggyback the new scope onto the Newt. I primarily want to get into Astrophotography, and I understand that I will need to motorise my setup at some point, but right now I would like a nice refractor, so what do you all suggest…?

All comments gratefully received, including those saying don’t do it and get something else…

[Doc]

Exactly the same set up I'm after.

So I would say great set up. I've heard fantastic reports about the Ed80. For the price it can't be beat. The ZS66 makes a great guide scope or for capturing those widefields.

Good choice.

[jgs001]

I have the C80ED and it's a very nice scope. I posted three images from Friday I took with it. I can't comment on the WO scopes, but they look very nice and lots of people like them. I don't know much about the EQ5 and it's loading limits, but it's something to be aware of, the C80ED weighs in at about 2Kg so if you piggyback that on the 200p how close to the limit are you going to be ?

[adamsp123]

C80ed!

[Robert Claveyrolas]

I am presently working on a piggyback mount of a refractor on a Celestron C8 with a Vixen SXD mount (Max specified load : 15 kg- Max Torque : 370 kg x cm).

I made a careful weight balance taking into account everything (reflector,refractor,dovetails, focusers, CCD cameras, and so on).

I realize it was not reasonnable for me to take bigger than a 72 mm lens, due to margins which my dealers are recommending to take (15% -20%) for astrohotography.

With a William Optics 72 mm (2.2 kg) piggyback on the C8, I got the following values :

Overall mass :11.3 kg (15 kg max)- Torque : 321kg x cm (370 kg x cm max).

With a skywatcher 80 ED Pro (2.98 kg) , I got the following values:

Overall Mass : 12.1 kg - Torque : 354 kg x cm.

I have been rather worried by these conclusions...

I would like simply to point out that other considerations may determine the choice of a piggyback refractor...

[adamsp123]

I am presently working on a piggyback mount of a refractor on a Celestron C8 with a Vixen SXD mount (Max specified load : 15 kg- Max Torque : 370 kg x cm).

I made a careful weight balance taking into account everything (reflector,refractor,dovetails, focusers, CCD cameras, and so on).

I realize it was not reasonnable for me to take bigger than a 72 mm lens, due to margins which my dealers are recommending to take (15% -20%) for astrohotography.

With a William Optics 72 mm (2.2 kg) piggyback on the C8, I got the following values :

Overall mass :11.3 kg (15 kg max)- Torque : 321kg x cm (370 kg x cm max).

With a skywatcher 80 ED Pro (2.98 kg) , I got the following values:

Overall Mass : 12.1 kg - Torque : 354 kg x cm.

I have been rather worried by these conclusions...

I would like simply to point out that other considerations may determine the choice of a piggyback refractor...

According to this - http://www.vixenoptics.com/mounts/sphinxD.html

you have a scope carrying capacity of 50 lbs, mine - the smaller basic sphinx - I have had mine at MAX load (26 lbs) on the HAL tripod and it tracked fine during a photo session (Meade 10" SNT - a large scope).

They are very well built and sturdy for their light weight

So your loading with an 80ED I think would be ok.

[Whippy]

IMO, if you primarily want to get into astrophotography, you'll want to motorise your mount otherwise any imaging other than the Moon would be near impossible. I'd also venture that your EQ5 may struggle with the 200P and a refractor on top.

The recieved wisdom regarding mounts for imaging is the rated payload capacity for the mount is halved, ie: an EQ6 is rated at 25Kg so for imaging 12-13Kg is about your limit.

So, where do you want to go? If imaging is your goal then either of those three scopes would be great, but if you want it also for visual then the 80 purely because it has the most aperture.

Tony..