Pimping my 70mm achro

[RobertI]

I recently bought a Celestron Starsense 70, purely for the Starsense attachment, which I put on a better scope and effectively retired the 70mm scope as it was largely plastic and mount and tripod were awful. But in a quick test I actually thought the optics were ok, so I have taken the scope off the terrible mount, put it in some rings and mounted it on my Mini-giro and Horizon tripod. What a difference! The scope is now stable and adjustable. Part of the reason for doing this is I think it is now the perfect scope for lending to friends, relatives and any budding astronomers who want to have a go. And for kids, it looks like a ‘real’ telescope. I expect I will also enjoy doing some testing against my other scopes. 

Before………

 

After……

 

 

Edited June 18, 2023 by RobertI

[happy-kat]

That looks great for sharing, hope the test goes well

[Louis D]

Try it with some yellow (#8 or #12), yellow-green (#11), or light green (#56) filters to see if narrowing the pass band sharpens things up a bit on high contrast objects like Venus and the moon.

[RobertI]

11 minutes ago, Louis D said:

Try it with some yellow (#8 or #12), yellow-green (#11), or light green (#56) filters to see if narrowing the pass band sharpens things up a bit on high contrast objects like Venus and the moon.

Thanks, yes I have a yellow filter so I shall bear in mind. 👍

[Jim L]

At f/10 and with a chromatic aberration ratio of 3.63 chromatic aberration should be reasonably well controlled, but I like Louis’ idea of experimenting with filters to see if you can get even more out of it. I’m a big fan of the #11 filter in fast achromats because it gives noticeable improvements without causing an egregious color change through the eyepiece like the #12 can sometimes do.

In any case, it looks like an excellent loaner scope for your astronomy curious friends and family.

[bosun21]

I gave mine away to someone who works with the scouts once I removed the Starsense unit of course.

[Stu]

Looks like a nice little scope. Out of interest, how easy is the StarSense unit to remove and attach to another scope? Can someone post a link to where it has been done? Thank you 🙏 

[Stu]

Found one 😊

 

[RobertI]

15 minutes ago, Stu said:

Found one 😊

 

Yes that’s the thread I’ve been looking at too Stu. I was planning to try John Inderby’s finder dovetail and ballhead approach so I can attach it to any scope, although the finder shoe is very close to the eyepiece on the 102ED and might not be ideally placed. For now I’ve just attached the whole unit to my 102ED with cable ties, which works fine as I can mount it further up the scope and out of the way. 

[RobertI]

Another reason I like the 70mm scope as a good “lending” scope is that it has a RACI prism diagonal, so beginners don’t have the confusion of upside down images. Also I like the red dot finder as it’s low profile and holds alignment really well. I was also thinking of replacing the knob on the mount’s Vixen dovetail clamp with a hex bolt, so the scope is permanently attached to the mount - the reason is that at night the alt locking knob feels identical to the clamp knob, and a couple of times at night I have almost disconnected the scope from the mount! 
 

[bosun21]

5 hours ago, Stu said:

Found one 😊

 

I fitted the Starsense unit onto my 12” dobsonian as well as my 8” when I still owned one. I tried it out on my Starfield 102 and EQ5 but due to the ever changing angles of the EQ mount pointing I gave up and bought the full go to upgrade kit. I was considering mounting it on a ball head attached to one of the mounting rings but abandoned this as well due to my thinking that moving the ball head would knock the Starsense out of alignment. I may be wrong about the last point and so I just use it on an alt/az situation for which it works fantastic.