Do I need a finder scope/rdf with a goto?

[Ollienttm]

Hi, I am buying a sync? scan goto mount off a member on here to put my sw 130pm on as I hopeless at finding owt up there and wondered if I still need a finder scope or rdf? The rdf I have is Rubbish hence me not getting much use out of my scope to date but am hoping with the goto I will get much more satisfaction from it.

I have just managed to secure membership to my local astro society to for the year which I am well happy about as they have a massive scope on site plus a nice concrete viewing area that I may get some decent use out of my scope from now. Sorry for going on I do that

[pvaz]

You still have to align the goto on a couple of bright stars and the rdf will make that task faster, so keep it.

[Ollienttm]

You still have to align the goto on a couple of bright stars and the rdf will make that task faster, so keep it.

my rdf is useless so I find by eye with scope, very difficult with the the mount I have which is why I am upgrading to the goto. I know I have to align but I figure after aligning it should work itself so if I only need it to find a star or two I should be ok without I just wondered what others did

[rowan46]

I have a nexstar go-to and I definately use the rdf for aligning it. as pvaz says it makes the process much easier can I ask what is wrong with your rdf. Is it aligned properly to your scope?

[Demonperformer]

my rdf is useless

I know the problem. I have tried various options with my 6SE and have finally settled on a Wixey. I can use an astro prog to get the altitude, point it roughly in the right az direction and a bit of a sweep centres the star. Then I let it find my second alignment star and, if I have done everything properly upto this point, it gets there no prob and I am aligned.

Simples:).

[Ollienttm]

It is not aligned properly no. When I do align in daylight come night time it is way off where I am looking if it even works the thing is Rubbish Might be better off putting a finder scope on there but didnt think it was worth the extra money to keep spending on such a basic scope tube. I can usually find saturn and mars with a bit of patience, actually a lot or patience Am hoping now that once goto is aligned I wont have to mess about with looking anymore as I get bored of looking at empty skies.

[brantuk]

Even when you're aligning with a goto system it's still best to center the object in the finder, and then center it in the ep (and adjust the finder if needed). It makes things a lot more accurate in my experience. I assume this applies with an RDF as much as with a finder scope. Once you've aligned scope with finder in daylight (usually around dusk) then so long as the scope isn't moved or the finder touched, it shouldn't be too far out come darkness. But do adjust the finder/rdf once you have a recognisable object in the ep.

Hope that helps.

[Ollienttm]

I tried doing just that with saturn in the ep but by the time I have tried to actually move the rdf the tube moves and its still way off Maybe it is just me being a hopeless git

[Astro_Baby]

YOu will need good alignment for the GoTo to work in my experience with Synscan. About 9/10th of the frustration is going through the alignment procedure only to get an 'ALIGNMENT FAILED; message at the end of it. Finding stuff with the main scope optics and being sure of them being centred enough to suit Synscan would be a nightmare.

I cant see what probs your having with the RDF - mine always worked fine. It may be the mounting shoe on the scope is a bit loose (they often are). That can be tightened up easily enough.

I use an optical finder with corsshairs which are aligned perfectly to the main scope optics and then use the crosshairs to centre the alignment stars.

[brantuk]

I wouldn't align on saturn cos it's a bit big, moving quick, and quite near (relatively speaking). Using stars gives more accuracy and a higher power ep. I usually start around 30mm and realign with progressively higher mags up to 20mm or 15mm if I can get away with it. Then there's PAE which I haven't yet had chance to try.

[ollypenrice]

You will want some kind of finder. I am without one, temporarily, on one of our mounts and initial setup is a ruddy nuisance! You just need something to get you close enough to pick up the first star so a red dot would be fine. I like Telrads, a bit big but dead easy to see, normal (non watch-type) batteries and reliable over many years.

Olly