Project:
Star Adventurer and angled viewfinder

Note:
I take no responsibility or liability for what are written here, you use the information at your own risk!

Polar align with an angled viewfinder

When living in Northern (or Southern) as I do at a latitude of 60 degrees there is difficult to look through the polar telescope finder. I have to do something about it. I could built some electronic viewfinder, but that involve more electronics that has to be powered. For my travel mini mount I want it as simple as possible. Long time ago I had an angled viewfinder on my SLR camera. It worked but the image was a bit dim. Maybe something that I can use to my polar telescope finder, or? When I Google on it I of course found that others already have done this. Here is my version of the angled viewfinder.

I bought a simple angled viewfinder on eBay, it has selectable magnification, 1x or 2x, that can be useful. There are a lot of other versions of view finders too and maybe you already have one laying around from your old SLR camera.

The feeling is a little bit plastic but the function looks to be good. This viewer fits directly on my Canon EOS 6D camera, but there are a lot of adapters included to other cameras as well.

This is the entrance to the viewer with a rectangular mount, Canon and other cameras standard.

Of the six included adapters I found the Nikon adapter fits best on my Star Adventurer mount's polar scope.

I have to build a holder / adapter between these two parts, I have seen there are drawings to 3D printers that can be downloaded to made this part, but I don't have a 3D printer, yet.

My girlfriend had a couple of these old film canisters, they fits almost perfect after some modifications.

I cut the length of the canister and made a hole at the end.

With some tape on the polar telescope finder I could easily press the tube on the polar scope.

Maybe it doesn't look very good, but now I can do a test if the function is up to my expectations.

This is how it looks when mounted on the polar scope. I tested it from my balcony, and the image is clear and bright. This should work.

For you who have a 3D printer maybe this is useful, it looks to be same as I have:

• https://www.thingiverse.com/ thing: 2762334 (PariahProps, Thingiverse)

Or a ready made adapter, tips from Birderman APT forum:

• http://www.astrokraken.fr/ polarscope adapter ... (polar scope adapter, Astrokraken)

Now I have to test this on real astrophotography, if I can get the polar align better then I can have longer exposure times or longer focal lengths. It should work on my EQ6 mount also, but normally I polar align with the drift align method in that case.

Update:
Now I have used my angled viewfinder for the first time, what a difference! For the first time I can really see what's in the polar scope. Now I can adjust the mount very exactly to the polar star at the circle. Two minutes exposure time with a 150 mm lens, no problem anymore.

This was the test object:

• ../../my-astronomy-photo/open-clusters/m45-open-cluster.html

To get it even better I need a better adapter to the polar scope and a holder for the red lamp.

Update:
New version, now 3D printed:

Much better function and stability now with the 3D printed adapter, look here how I did it.