10 replies to this topic

[jish1969]

Hi all, I was just wondering if anyone has a preferred adapter for this scope as I would like to give it a try. I've been eyeing the GSO hybrid prism diagonal on Agenda Astro, not sure if there are better options. Thanks in advance!

https://agenaastro.c...m-diagonal.html

Edited by jish1969, 23 July 2024 - 08:22 PM.

[ericb760]

I bought a similar one on Aliexpress and it works just fine. I would stay away from the adapter that drops into the .965 diagonal. I tried that first but the scope would not come in to focus.

[deSitter]

Do you have the original prism diagonal? If so I would just use a 1.25" eyepiece adapter. That will add maybe an inch to the optical path.

 

https://www.amazon.c...r/dp/B0BBYTYLCZ

 

Here's a better mirror diagonal than that strange thing on Agena.. Because this is a mirror it will have a longer optical path than a prism, so you may experience focusing issues - not likely but possible.

 

https://www.amazon.c...r/dp/B0CJY9LD8B

 

-drl

[tony_spina]

Do you have the original prism diagonal? If so I would just use a 1.25" eyepiece adapter. That will add maybe an inch to the optical path.

 

https://www.amazon.c...r/dp/B0BBYTYLCZ

 

Here's a better mirror diagonal than that strange thing on Agena.. Because this is a mirror it will have a longer optical path than a prism, so you may experience focusing issues - not likely but possible.

 

https://www.amazon.c...r/dp/B0CJY9LD8B

 

-drl

Curious on why you think the hybrid diagonal from Agena Astro is strange?. Optically it is very good 

[SporadicGazer]

Curious on why you think the hybrid diagonal from Agena Astro is strange?. Optically it is very good 

I assume it is because it has that shoulder on the 0.965" nose piece that adds to the optical length (apparently needlessly.)

[deSitter]

Curious on why you think the hybrid diagonal from Agena Astro is strange?. Optically it is very good 

The nose piece is pointless.

 

-drl

[deSitter]

I assume it is because it has that shoulder on the 0.965" nose piece that adds to the optical length (apparently needlessly.)

Yes exactly. No one of these diagonals is any optically better than another one. They all use the same good-enough mirrors.

 

-drl

[Kasmos]

Read the product details. The Agena/GSO has a Amici Prism so it's an upright correct left right diagonal. I'm not sure I'd want that since it ads more length to the light path and possibly more CA. I don't like the stepped barrel as well. It was made like that so it can be used on 1.25" visual backs as well. That barrel also looks like a bad design (as in too short), for both formats.

Edited by Kasmos, 25 July 2024 - 01:53 PM.

[VNA]

Hello, because I am curious, you made me buy one with the correct adapter!

After 2 weeks having bought a Askar 185?

No I am not going to make a comparison, but I wonder if the Sears version is close to what Galileo used?

[deSitter]

Hello, because I am curious, you made me buy one with the correct adapter!

After 2 weeks having bought a Askar 185?

No I am not going to make a comparison, but I wonder if the Sears version is close to what Galileo used?

No Galileo didn't have a diagonal or any eyepieces. He had what is known as a Galilean telescope, with a tiny field of view. The eyepiece was a single negative lens.

 

-drl

[ericb760]

Do you have the original prism diagonal? If so I would just use a 1.25" eyepiece adapter. That will add maybe an inch to the optical path.

 

https://www.amazon.c...r/dp/B0BBYTYLCZ

 

Here's a better mirror diagonal than that strange thing on Agena.. Because this is a mirror it will have a longer optical path than a prism, so you may experience focusing issues - not likely but possible.

 

https://www.amazon.c...r/dp/B0CJY9LD8B

 

-drl

I bought both of these for my Meade #226 60mm refractor. The adapter did not work, but the diagonal did. Just an FYI to the OP.