I'm thinking of getting a refractor to use in place of my 8" Celestron SCT. I would be using it for visual and also occasionally attach my DSLR to it. I'd only need the OTA because I would mount it on my current HEQ5Pro.
What would people recommend? I don't want to spend a fortune. Would something like the Skywatcher SW120 be OK?
Why replace - why not as a complement to? I have both, and use them for different purposes (C8 for planetary and DSOs, and as a general workhorse), and refractor for low-power rich-field observations.
By replace I really mean short term. We've sold our property and are putting all our gear in storage. I would like to take my scope to where we're going to live for the time being, but I was thinking something a little more portable would suit me better during that time. Hence a refractor. When we eventually get back into a place of our own I'll set up my stuff again and use the two scopes.
The bulk and weight of a 120mm refractor ( I own one ) in its case is about the same as an 8" F5 Newtonian tube assembly .
I would recommend something like a 6" SCT on a Skywatcher AZ4 mount for something fairly compact and light with useful light gathering and focal length , and Dobsonian like movement ( the AZ4 is essentially a push too style mount with large teflon bearings and adjustable friction clutches with no need to lock the axis or grapple for a slo-mo knob or cable in the dark ) .
Just noticed you intend to still use the HEQ5 - probably would still recommend a c6 - you would be too disappointed in the light gathering if you go from an 8" down to a 4" aperture .
you would be too disappointed in the light gathering if you go from an 8" down to a 4" aperture
Actually, 120 mm = 4.72 inches
I guess the trade-off advantage of the refractor for a 'grab-n'-go' scope is that it is not easily miscollimated, the OTA is relatively light (4 kg), and, as I noted above, although the light-gathering capacity is much lower than the 8" SCT (39% of it, based on considerations of the secondary), the FOV is much wider thanks to the short focal length.
I'm glad your maths is as good as mine . Given the information that a SW 120mm in its case would be hardly more portable than a C8 I suggested a ( 4" ) 100mm refractor instead. I certainly wouldn't recommend the 120mm F5 SW Achro- having looked through one I cannot see it is much use for anything but low power wide field views .
I certainly wouldn't recommend the 120mm F5 SW Achro- having looked through one I cannot see it is much use for anything but low power wide field views
But that's EXACTLY what I use it for i.e., 14 to 67 x magnification in the 4.5 to 1.2 degree TFOV range. It's right at home in this niche...
thanks everyone for your replies. I've decided that astronomy isn't a priority at the moment. I'll just probably put all my gear into storage until who knows when. it will still be accessible in the storage unit. better get a few nights in before we move.
All good Stewart , do you have a pair of binoculars at all ? just for the times when the sky calls ,, and yes it will .
Good luck with the move .
Brian.
Yes Brian, I have bino's. And I'll also have my camera. I think, when time permits, I'll have a go at some nightscape photography. Should only be 6 - 12 months before we're into a place of our own.
i.e., 14 to 67 x magnification in the 4.5 to 1.2 degree TFOV range. It's right at home in this niche...
All good Stewart , do you have a pair of binoculars at all ? just for the times when the sky calls ,, and yes it will 
