RACI Finder....Yes or No?

[Marmot]

Hi

Another question for all you more experiences people🙂

 

I currently have a red dot finder as supplied with my scope. I get on with it OK although sometimes I do find I end up in some uncomfortable positions trying to look through it to line everything up.

The other common finders would appear to be 6x30 or 9x50 finder scopes in either a straight through or 90degree configuration.

I find the idea of a 90deg finder appealing as it looks like it may be physically easier to access. However, due to the fact that it magnifies what you look at, how easy is it to locate targets with it.?

I would appreciate any views people may have as I am trying to work out weather or not it would be a worthwhile investment.

 

in case it makes any difference, I am purely observing and my scope is a Skywatcher ST 120 refractor.

 

[Nightspore]

3 hours ago, Marmot said:

Hi

Another question for all you more experiences people🙂

 

I currently have a red dot finder as supplied with my scope. I get on with it OK although sometimes I do find I end up in some uncomfortable positions trying to look through it to line everything up.

The other common finders would appear to be 6x30 or 9x50 finder scopes in either a straight through or 90degree configuration.

I find the idea of a 90deg finder appealing as it looks like it may be physically easier to access. However, due to the fact that it magnifies what you look at, how easy is it to locate targets with it.?

I would appreciate any views people may have as I am trying to work out weather or not it would be a worthwhile investment.

 

in case it makes any difference, I am purely observing and my scope is a Skywatcher ST 120 refractor.

 

 

 

There was a time when I used an RACI in combination with a reflex sight.

 

 

Although I decided that it added too much weight and was unnecessary.

 

 

Bear in mind there are two types of these finders; some have conventional prisms and mirror-reversed images. Mine all have Amici prisms to give a correct image.

 

 

They magnify at around 6x or 8x or 9x normally. Magnification shouldn't interfere with target location but it's not always easy to know exactly where the scope is pointing. I prefer to just use a long focal length 2" eyepiece with a wide field now to locate targets at or near the zenith.

 

 

I only really use one on my 102mm Mak now though. I have a Rigel reflex for line of sight. 

 

 

The RACI on the Mak aids target acquisition in twilight when the Rigel reticule isn't bright enough.

Edited May 29, 2021 by Nightspore

[Marmot]

Thanks for that input.

Interesting that you mention about using a 2” eyepiece as a “finder”. I have wondered if a low powered EP would suffice, as long as it had a decent field of view. I do have a 2” Skywatcher Aero ED, which has a 68deg FOV (the only 2” EP I own🙂) so it would be interesting to see how that would work. (I haven’t used it yet as it’s a fairly recent acquisition!)

[Nightspore]

1 hour ago, Marmot said:

Thanks for that input.

Interesting that you mention about using a 2” eyepiece as a “finder”. I have wondered if a low powered EP would suffice, as long as it had a decent field of view. I do have a 2” Skywatcher Aero ED, which has a 68deg FOV (the only 2” EP I own🙂) so it would be interesting to see how that would work. (I haven’t used it yet as it’s a fairly recent acquisition!)

 

If it's the 35mm Aero ED I believe it would give about 17x with your scope. Probably give just under 4 arc degrees of TFOV which is close to the diameter of 8 Full Moons. I reckon that would work.

[Marmot]

1 hour ago, Nightspore said:

 

If it's the 35mm Aero ED I believe it would give about 17x with your scope. Probably give just under 4 arc degrees of TFOV which is close to the diameter of 8 Full Moons. I reckon that would work.

Its actually the 30mm so it gives about 20x, but that doesn’t sound to different to the 35mm that you mention. 

[Nightspore]

6 hours ago, Marmot said:

Its actually the 30mm so it gives about 20x, but that doesn’t sound to different to the 35mm that you mention. 

 

In that case, roughly 3 arc degrees, 24 mins. About 6.5 Full Moons.

Edited May 30, 2021 by Nightspore

[Carbon Brush]

Finders are subject to practical considerations, as mentioned in detail earlier. They are definitely not 'one size fits all scopes' devices.

There is also the individual preference. I like a 50mm finder to gather the light. I also like a right angle on most scopes.
I also like a correct image as this is intuitive when moving the scope by hand.
I have one scope that has both 50mm RACI and a Rigel Quickfinder.
However, there are those who choose differently. None of the choices are wrong.

Fortunately finders are not expensive items, so you can buy one to try. If you don't like it, then sell it on, or save it in case you think you will find it suits you with a different scope.

 

Enjoy the journey, David.