Simple finderscope advice please

[Swithin StCleeve]

I'd like a simple 10X (or thereabouts) 'right way up' finderscope. Any recommendations folks?

I'm renovating my old 10" dob, and would like one of these to go alongside my Telrad finder. I'm sick of easily navigating the sky through bins, and then having to re-think the positions of everything through a wrong-way round finderscope. And don't get me started on those 45 degree finderscopes. How do people manage? 

[Dark Vader]

I use one of these on my 8" Dob with a Rigel alongside. Much easier on the back and neck.

Andy

https://www.firstlightoptics.com/finders/skywatcher-9x50-right-angled-erecting-finderscope.html

[johnst]

Astro Essentials do a replica of that, also at First Light Optics and I've had it about 6 months and find it very helpful on my WO Megrez 72 so go for it!

[Swithin StCleeve]

I had a right-angled finderscope and found it awkward, but it wasn't the 'right way up'. Is the proper word for this 'erecting'? You know, like when you look through binoculars and it's a true image, instead of upside down?
The angled finderscope was on our society's 16" dob. I remeber moaning that I was looking through the finderscope "in the wrong direction, at things upside down".
I'm not sure about the angle, I like to look in the direction of what I'm looking at. Don't you find it a hindrance when you're initially lining up your scope Mr V?

[Cosmic Geoff]

Note there are two varieties of right-angle finder - those that leave the image flipped L-R (as with a telescope diagonal) ant those with a prism that completely corrects the image - known as RACI.  Somethimes they look the same and the terminology is confusing. If in doubt ask the retailer.

I agree that a straight-thru finder is (literally) a pain in the neck.

[johnst]

The Astro Essentials is the correct image as in looking through your Vinod and I have no problem in looking 'down' rather than up and it's certainly more comfortable to view! 

John 

[johnst]

Sorry, should say Binos 

[Dark Vader]

14 minutes ago, Swithin StCleeve said:

I had a right-angled finderscope and found it awkward, but it wasn't the 'right way up'. Is the proper word for this 'erecting'? You know, like when you look through binoculars and it's a true image, instead of upside down?
The angled finderscope was on our society's 16" dob. I remeber moaning that I was looking through the finderscope "in the wrong direction, at things upside down".
I'm not sure about the angle, I like to look in the direction of what I'm looking at. Don't you find it a hindrance when you're initially lining up your scope Mr V?

Not really, though it took me a while to "get my head around it", if that makes sense? Way I look at it is you're looking through 90° through the eyepiece anyway, it's just not upside down and back to front.

I'm by no means good at finding my way around anyway which is why I got the Rigel as well. I'll do the initial lining up through that, light pollution permitting then switch to the 9x50.

I forgot to mention I use a "Wixey" type digital inclinometer magnetically attached to the tube as well. Makes finding the altitude a bit easier.

Edited April 6, 2021 by Dark Vader
More info

[Spile]

13 minutes ago, johnst said:

Astro Essentials do a replica of that, also at First Light Optics and I've had it about 6 months and find it very helpful on my WO Megrez 72 so go for it!

I agree and have the same finder. It performs no better or worse than the Skywatcher straight-through finder but is a lot easier on my back.

https://www.firstlightoptics.com/finders/astro-essentials-9x50-right-angled-erecting-finderscope.html

The Telrad would be my first "upgrade" however.

[Swithin StCleeve]

Some great replies folks, thanks.

My only problem with the Telrad is that under not quite dark skies, you can only see naked eye stars. Last night I was trying to find Caroline's Custer, just to the left of Sirius, and through my bins I could see exactly where it was, but I had to guess where I was pointing the Telrad, because the stars I saw in my bins weren't visible to the naked eye. If my bins were attached to my scope, I'd always hit the right spot.  

Edited April 6, 2021 by Swithin StCleeve

[Spile]

7 hours ago, Swithin StCleeve said:

My only problem with the Telrad is that under not quite dark skies, you can only see naked eye stars

That is very true and why a combination of tools is useful. The key is that the Telrad reduces the amount of time needed at the straight-through finder which means less strain on your back.

So I would always choose a Telrad + straight through finder over a RACI alone. Indeed, if I had to give up every finder, the Telrad would be last to go.  

[Louis D]

If you're careful with a green laser pointer, you could swing the telescope onto the target while sighting it through the bins.  I've been at star parties where one person puts a scope on a target and lights up the point in the sky with a laser that other scope owners can then align onto since there's little to no parallax.

[Swithin StCleeve]

A bit of a belated update on this, but I've found an erecting finderscope and I've fitted it on my dob, with the Telrad finder. My thoughts are - I can get in the area with the Telrad, (and that will help with my needing to 'look along' the finder, in the direction of the object), then I can use the finderscope to star-hop the fainter stars that I can't see via the Telrad.
I don't know the magnification of the finderscope yet, but I can compare with my 10X50 bins, and get a good guess. 
I've really found the suggestions on this thread helpful, thanks guys. 

[John]

It's likely that is a 9x50 finder. Many of them are 9x. It looks very similar to the 9x50 RACI ones that I use. I have a similar arrangement on my 12 inch dobsonian except that I use a Rigel Quikfinder instead of the Telrad.

I've arranged the eyepiece of the finder so that I can quickly move from it to the eyepiece of the scope, which helps when using higher magnifications in the scope - the target has less time to drift off !

Edited May 21, 2021 by John

[Kimboman]

Hi 

I also use the Sky- Watcher RACI 9x50 finder it is a great piece of kit and a would think that other makes are similar.

I also use the Baader red dot finder as well 

[OpusElite]

On 06/04/2021 at 12:30, Swithin StCleeve said:

... If my bins were attached to my scope, I'd always hit the right spot.  

Other than weight and awkward head position, why couldn't binoculars be mounted on a telescope as finders?

Or perhaps dismantle a set of binoculars and use one half as a finder. There are 90 degree viewers for attaching to camera viewfinders, so that would make it easier on the neck. 

I have some old 10x50's laying around and a 90 degree viewer I recently acquired .. Will let you know how it goes. (If the clouds ever part)

 

[John]

27 minutes ago, pcdunx said:

Other than weight and awkward head position, why couldn't binoculars be mounted on a telescope as finders?

Or perhaps dismantle a set of binoculars and use one half as a finder. There are 90 degree viewers for attaching to camera viewfinders, so that would make it easier on the neck. 

I have some old 10x50's laying around and a 90 degree viewer I recently acquired .. Will let you know how it goes. (If the clouds ever part)

 

No reason at all.

It was not long ago that many DIY finders were based on half a pair of binoculars with a cross hair added to the eyepiece field stop.

Getting a 90 degree prism to work with a binocular can be challenging though because the 90 degree prism or mirror diagonal eats up quite a bit of the focal length of the objective lens so the body needs to be shortened to allow focus to be reached.

It has been done though:

Edited May 22, 2021 by John

[Voyager 3]

4 hours ago, Kimboman said:

Hi 

I also use the Sky- Watcher RACI 9x50 finder it is a great piece of kit and a would think that other makes are similar.

I also use the Baader red dot finder as well 

Do you starhop ? If not you don't need a finder because a RDF is more than enough to do alignment of your go-to . 

[OpusElite]

8 hours ago, John said:

No reason at all.

It was not long ago that many DIY finders were based on half a pair of binoculars with a cross hair added to the eyepiece field stop.

Getting a 90 degree prism to work with a binocular can be challenging though because the 90 degree prism or mirror diagonal eats up quite a bit of the focal length of the objective lens so the body needs to be shortened to allow focus to be reached.

That's a great looking finder.

I was thinking along the lines of using a camera 90 degree viewfinder, which negates issues with focal length.

I bought this one for using on my mounts polar scope, but it could serve as dual purpose for finder scope as well.

[Starwatcher2001]

I use a finder made from 1/2 a pair of binoculars on my DIY Dob. I didn't use the prism though as I wasn't interested in a RACI, so needed to add extra length with a piece of plastic drain pipe. As John mentioned, I also did the cross-hair trick with a couple of lengths of thin fuse wire. Using the side of the bins which has the diopter adjustment allows a small amount of variable focus.

I have it mounted on the top end of the tube and kinda lean in and look sideways which isn't too bad on the neck.

[Stephenstargazer]

I have used skywatcher/clone 9x50 finders and did not like the rather small field of view and dim eyepiece for star hopping. In that respect the 6x30 raci works better! Antares make a 7x50 raci with a good eyepiece and widefield of view that gives a bright image. Expl Scientific seem to make something similar in straight but erect, not tried one. Vixen 7x50 (s/h?)  also give a fine view but straight, inverted. Anything near the zenith is hard with a straight finder.

Have sold my DOB but would chose the Antares  with a Telrad. There are also 10x60 available but they are heavy to balance. Seems like finders are very much personal choice and never perfect!

Edited May 23, 2021 by Stephenstargazer

[Richard_B]

On 06/04/2021 at 11:42, johnst said:

Astro Essentials do a replica of that, also at First Light Optics and I've had it about 6 months and find it very helpful on my WO Megrez 72 so go for it!

I have this as well.;Been very please with it