Better Finderscope

[STOL]

Hello people. I have a 8" nexstar EVO and it came withe the Red dot finder scope. I'm not impressed with this item, which I had before on another scope. I would appreciate suggestions for a superior finder scope. Thanks guys. Geoff

[Bigzmey]

Welcome to TSS Geoff!

If you are looking for better quality reflex sight Rigel QuikFinder or Telrad Finder would be the choice.

https://www.firstlightoptics.com/finder ... sight.html

https://www.firstlightoptics.com/finder ... onomy.html

If you are looking for an optical finder I would go with RACI

https://www.firstlightoptics.com/finder ... scope.html

[Gordon]

+1 on the Telrad / Rigel!

[OzEclipse]

Hi Geoff,

There is no right and wrong and there will be many opinions on this and that is an indication that your own mileage may vary. This is my opinion. Find what is right for you.

I have a Telrad on my 18" Dob. It's very good for locating bright stars to calibrate a GOTO or Digital Setting Circles(DSC). My 18" Dob has a Nexus Digital Setting Circle System so I mainly use the Telrad to calibrate GOTO. On some occasions, I have had problems such as a flat battery or a bad connection to the encoders. While you can use the Telrad, oh how I longed for a decent sized optical finder for star hopping.

A Telrad is ok as a primary device for finding objects and better than the cheap red dot finders but it is still the same principle. You are looking through a piece of glass with a red LED circle projection. There is no optical enhancement so you are limited to seeing a little less than you can see with the naked eye because the glass absorbs a little bit of the light. This is ok provided the object you see is near bright reference stars. All of these finders use a projected red dot or circles in the case of the Telrad.

If you are using a finder as the primary locating device(no GOTO or DSC), then in my experience, get the biggest aperture finder you can manage.

My 6 inch reflector has no GOTO or DSC. For more than 40 years, I had an 8x50 finder. Someone gave me an old pair of 9x63 binoculars that were unrepairable. I removed the objectives and turned one into a new 8x63 finderscope using PVC plumbing tube.

.

I replaced the poor quality binocular eyepiece with a cheap but decent quality 25mm Plösl. It works great, the extra 20% light grasp over the old 50mm finder is helpful. The old finder was made from an old 50mm binocular objective that was not as good optically as the 63mm objective so the new finder gives me a much better image.

That said, it's a luxury. A 50mm finder, widely available commercially is fine. There are three types:
1. Straight through finder
2. Right Angle finder
3. RACI (Right Angle Correct Image) finder.

RACI FINDER.

Straight through finder.

Right Angle Finder.


RACI (Right Angle Correct Image) finders are more comfortable to use but you are not looking in the direction of the target and can take some getting used to. I have always found that the straight through finders are more intuitive to use. I first look through with both eyes open using the naked eye star field in my left eye and the finder field superimposed to quickly show me exactly where the finder is pointing. But they do require much more goose-necking on the part of the operator than a right angle finder. If you are going to buy a right angle finder, you may as well spend the extra and get the RACI version. The ordinary right angle finders have the image right way up but reversed left to right.


Joe

[STOL]

Thanks for the replies people. Since I first posted this question, I have purchased the RACI. It came yesterday and now I'm completely baffled. The mount for the red dot finder scope which I removed is tiny. The base of the RACI is huge. I have read quite a few recommendations for the RACI for my brand new 8" eco. At the moment I'm waiting for a callback from Celestron Tech support. I hope I can get an explanation of why it is so wildly incompatible.

[OzEclipse]

You can buy finderscope bases for about USD25. You will have to mount it yourself which may mean drilling and screwing it into the OTA.

https://www.testar.com.au/products/find ... bQQAvD_BwE

[Bigzmey]

Thanks for the replies people. Since I first posted this question, I have purchased the RACI. It came yesterday and now I'm completely baffled. The mount for the red dot finder scope which I removed is tiny. The base of the RACI is huge. I have read quite a few recommendations for the RACI for my brand new 8" eco. At the moment I'm waiting for a callback from Celestron Tech support. I hope I can get an explanation of why it is so wildly incompatible.

Depending on the manufacturer RACI come with different style bases. The base might be included with your RACI. If not you can buy one and attach to the scope.

[OzEclipse]

If you are not confident about drilling in which will require accessing the tube interior to remove the drill swarf, you could alternatively use a high strength adhesive and glue the base to the OTA. If you decide to do this, repost here and we can give you some specific advice.

Joe

[STOL]

Joe, that sounds the better alternative, the glue. i'm a lifelong machinist so I wouldn't blink regarding the drilling but yes, I'm concerned about the swarf floating around with the mirrors, and even then I couldn't screw into sheet metal. I'd need nuts or a backing plate inside the tube. I can't believe that Celestron did this. $2300.00 scope with no option to upgrade from a $13.00 junk finder. None of this explains how other Nextstar 8' EVO owners upgraded to the RACI. I am confided. Geoff

[Bigzmey]

There are already tapped holes to accommodate 2d finder base. Looking at the Evo pic they are next to the red dot finder with screws in them.

[Bigzmey]

To illustrate. Here is the RACI base attached to my 8" SCT using the holes which are already there, and you can use the holes on the other side as well.

[Ylem]

Telrad or Rigel.

[STOL]

My apologies to all you great guys. I'm a Moron. After studying the photograph of the finder in the Amazon picture I saw that the 2 lock screws at the bottom of the female dovetail are locked on to a male dovetail that is mounted to the tube. So I went looking for the box and inside there was the male dovetail base. I had to confess. Hope I can still be in your club. I promise, I'm not usually this stupid. Geoff

[Bigzmey]

My apologies to all you great guys. I'm a Moron. After studying the photograph of the finder in the Amazon picture I saw that the 2 lock screws at the bottom of the female dovetail are locked on to a male dovetail that is mounted to the tube. So I went looking for the box and inside there was the male dovetail base. I had to confess. Hope I can still be in your club. I promise, I'm not usually this stupid. Geoff

Happens to the best of us.

[Flyhigh7]

My Telescope came with a Red Dot finder too but I knew I wanted a RACI so I bought Celestron's RACI 50mm Finderscope. I like the illuminated dual crosshairs.