RAEF or a Telrad

[Itabot]

Hi dodgy back can't cope with a straight through stock 90 x 50 finderscope any longer, which is the best option, 90 x 50 right-angle erecting image finderscope or a Talrad standard or Telrad with 90° mirror dew shield? or both eventually, do they both do the same job?

Thanks

[Spec-Chum]

The do a similar job in that they help you locate things in the sky, but they are different in the way they accomplish this task.

A Telrad is a non-magnifying reflex sight; it basically "projects" a crosshair into the sky but all the stars look like they do to the naked eye as you're looking through normal glass.

A RACI on the other hand is a small refracting telescope which gathers more light than the naked eye but also magnifies the image, so what you see through it is not what you see with the naked eye.

In my opinion, they complement each other instead of compete and I use both

[Mike73]

I'd get a Telrad first but dont bother with the 90˚ mirror dew guard, they are about as much use as an inflatable dartboard!

I think the Telrad/RACI combo work really well when observing from somewhere with light pollution, at dark sites you dont need a RACI unless you are going for really faint stuff.

[Moonshane]

+1 for the two posts above. I always use both as my scopes are balanced for both. I also agree on the mirror on the Telrad - waste of time.

some objects need both finders but naked eye or obvious stuff can be found with just the Telrad.

[Steep]

If you have back problems I'd go for the right angled finder first, much less bending and twisting involved in using it. I've said elsewhere that I've tried the Telrad on my 10" dob and found I had to get quite low down and look up along the length of the ota. A Rigel Quickfinder might do the job better since you wouldn't have to bend so low to use it.

[Moonshane]

this is a solution if your Telrad is a bit low

http://www.firstlightoptics.com/finders/telrad-riser.html

[jabberwocky]

I use a RACI and Rigel quickfinder, the Rigel can be used as a red dot finder to get you in the right part of the sky then the RACI finds the object, or the Rigel can be used like a telrad except it has one less ring. The Rigel is much smaller and lighter than the telrad and easier to look through than a telrad, although the telrad can be put on a riser to ease viewing.

the Rigel doesn't dew up as quickly as the telrad either. Also because the Rigel is much smaller than the telrad you have more options of where to place it on the scope, I have mine inbetween the finder and focuser rather than where I had the telrad which was the other side of the RACI.

[Steep]

this is a solution if your Telrad is a bit low

http://www.firstligh...lrad-riser.html

That could help in some situations but it's not the problem I meant, the image below shows what I was thinking of in terms of placement and viewing angle since you can't put your eye right up to the Telrad, I find that awkward because I recently hurt my neck and can't look up and left very well just now.

[Itabot]

Many thanks all for the advice...... I've a burst / torn disc and two more dodgy constant pain 24/7, looking through the eye piece sat upright at the right level is OK-ish, bending over twisting is impossible however slight. As I now understand it a Telrad or Rigel would still require some degree of bending or twisting, am I right?, possibly shortening my viewing time as the pain builds then that's me finished for the night.

Think a RA-Finder may be the best bet for me.

Thanks

[Moonshane]

if observing from home (i.e. not star parties) then maybe you could try a green laser pen. I have heard that some people use them with an optical finder to point the scope initially as you do with a telrad etc. if I understand correctly you simply point it through the finder and it shines out the other side into the sky. I think some use them as a red dot finder too although be careful of aircraft of course and as mentioned don't use them at star parties - you won't be popular.

[Itabot]

Thanks Moonshane, I'll have a look at a green laser pen, any chance they zap clouds as well?

[Moonshane]

Thanks Moonshane, I'll have a look at a green laser pen, any chance they zap clouds as well?

only the REALLY big ones a la Goldfinger

[Itabot]

only the REALLY big ones a la Goldfinger

I'll save up, bet I have enough for one well before the clouds disappear.