EQ mount quality

[Owen]

Yet more questions for any of you who can spare your time and experience...

If/when I do purchase an EQ mount for astrophotography using my Skywatcher ED80, I've been advised to save a bit longer and get something along the lines of a SW EQ5 or better, rather than splashing out sooner on an EQ3-2 or similar.

My question is - why? Not that I doubt the wisdom of this advice, but having had no experience of these mounts I want to make a more informed decision. For example; do the cheaper mounts have more vibration? Less accurate tracking? Etc......

If it's the case that the cheaper mounts would simply only allow shorter exposures, < 1 minute say, before error starts to show - but would be just about as good as a more expensive mount during that minute - it might be a sacrifice I'm willing to make. Any you get my point, please advise!

Cheers

[Mike Hawtin]

Hi Owen,

To directly answer your question about cheaper mounts, yes they do have less stability, less accurate tracking, less carrying capacity, in short less of everything. It is the same as with most things we buy, you get what you pay for and to my mind the EQ5 would be the minimum I would consider starting out with.

In my experience you will need a mount you can "grow" into, the chances are your first scope will only satisfy you for so long. I can guarantee that if the imaging bug does bite you then you will soon start dreaming of more focal length for the smaller objects. Your ED80 is fine for wider fields but to take good images of galaxies etc you will need a set up which will give you about 2 arcsec/pixel resolution which in turn requires a decent mount to track and guide at that sort of image scale and an EQ3 is simply not up to the job.

Hope you find these comments helpful.

Mike

[Helen]

I'd second the advice on getting the beefiest mount you can afford/handle. The advantages are as you summise related to vibration, accuracy, quality of motors, weight capacity etc. What that translates into is how long you can expose before getting odd shaped stars, and how many of your subs even at shorter exposures are useable. Lower end mounts tend to have more random/mechanical related errors and you can therefore have to discard a large percentage of your subs.

All that said, its about compromise: cost, weight, quality, and how those relate to what you want to achieve. There's a good discussion here http://stargazerslounge.com/imaging-discussion/147565-rant-about-eq3-2-a.html which might help.

Helen