Finderscope, how useful

[Timdog]

So I’ve had the Heritage 130 a couple of weeks now and managed to use it to view the moon and have a general look around.  Trying to get experience of which eyepieces are best for finding way around the sky before trying to get close up. It’s so much easier getting a sense of scale with the eye! I have an explore scientific twilight 1 mount/tripod on the way, as simple and user friendly as the dobsonian base is I want a tripod for stability when swapping sites  away from stable table, plus being tall I prefer not be be bent over for the hours it takes me to find anything. 

My question is about right angle finderscopes, I have read some great posts about mounting one on a heritage 130, but wanted to ask how people find using one compared to a straight through. The right angle appeals simply from the comfort of not getting down behind it, but how does the experience compare, I imagine it being easier with a straight one as you are looking directly towards your target area. Also how does the finderscope compare to eg a 32 mm eyepiece. Steep but fun learning curve and keen to get good advice instead of just buying excessive things that won’t make a noticeable difference.

Thanks for reading 

 

[ScouseSpaceCadet]

A right angle correct image finder scope transformed my object hunting in a light polluted urban area. Even better when combined with a red dot finder on a dual finder bracket or a Telrad. Perfect for a newtonian as the finder eyepiece can be positioned in a comfortable position facing you.

Use the red dot to align with a star close to the object, the finder to star hop/acquire, and a long focal length (usually 25mm+) eyepiece to view and centre the image.

Less neck stretching, bending and mental gymnastics as the image is orientated correctly.

Some astronomers will just turn a map upside down, but during these times of smart phone sky map apps it's far easier to view the sky the right way up...

Edited May 24, 2020 by ScouseSpaceCadet

[Stu]

I’m general a RACI (Right Angle Correct Image) finder is a very useful additional, particularly when used in conjunction with a Red Dot Finder as SSC says. The RDF gets you in roughly the right place, then you can refine the position once you know which star you are looking at with the RACI.

There is an argument that if you don’t have an RDF as well, a straight through finder is better as you can keep both eyes open and line up with the target more easily. In fact I started a slightly controversial thread on this very topic not that long ago. I had some support for the view, but would say the majority prefer the RACI option.

This image shows the 7 degree field of view you get with a 6x30 finder, vs the 2.46 degrees you get with a 32mm plossl in a Heritage 130P. The finder certainly allows you to position it correctly in the fov, allowing for orientation of course, then you stand a good chance of having the object in the eyepiece field of view.

[jonathan]

Once the scope is mounted on an AZ with the eyepiece at roughly head-height I think a straight-through 6x30 finder should be perfectly adequate for most tasks, a red dot finder in addition to a 6x30 is a luxury but I wouldn't choose the red dot over the 6x30.  The finder is normally fitted offset and just forward of the eyepiece so it's easy to just tilt your head from the eyepiece to look through, with that in mind you'll have to experiment to find the best height for you, sometimes it's easier to set it for a seated position.

 

[Timdog]

Thanks for the great replies, very useful. Will wait until it’s mounted on tripod to see how it feels height wise, I get the idea of a straight through but using the rdf then the right angle positioned next to eyepiece seems the way to go. 

[Shaun VS]

Using a right angled finder is easier than trying to crane your neck look up when the scope is low down. Having said that I must say I don’t use them, preferring a straight through finder. Why? I agree that the image is the correct way up but it is still inverted left to right. Being a variable star observer I use 200+ star charts. They are generally printed either as per the naked eye or as it will be in the reflector. As such I prefer the finder to have the same orientation as the scope. It’s all horses for courses.