Can't Decide 8SE or CPC 800 GPS SCT

[Bigzmey]

There are different strategies for designing EP set for your scope. I prefer to use SCTs at their native F10 focal ratio and the EP set I have recommended above was selected for F10.

If you decide to use the 0.63 reducer your SCT will operate at F6.3 ratio and you will need to change EP focal length range and make a few substitutions.

[Bigzmey]

Thanks JayTee. I was looking at the Celestron 2" XLT Mirror Diagonal earlier. I read that mirrors are more efficient reflecting light than prisms that bend light with a little loss.

I would advise against that diagonal. Look at that diagonal pic and notice that diameter of the barrel with SCT connector smaller than 2" diameter of the EP holder. This is because it uses T2 connector to connect to SCT which has smaller diameter than proper 2" connector. So your will not achieve full benefits of your 2" EPs with that diagonal.

I know Baader BBHS has a high price tag, so my second recommendation would be this Altair 2" prism. Prisms work great in slow scopes like SCT and Maks and you will get better performance than with typical dielectric mirror.

https://www.altairastro.com/altair-2-in ... 2038-p.asp

[JayTee]

Yeah, there's regular mirror, and 99% dielectric mirrors, and prisms. My 69 year old eyes can't really tell the difference.

[Bigzmey]

Yeah, there's regular mirror, and 99% dielectric mirrors, and prisms. My 69 year old eyes can't really tell the difference.

Generally speaking the quality of a typical diagonal went up, so when you casually observing and not comparing side by side, I agree, it will be hard to tell the difference.

However, if you pushing your scope to the limit trying to resolve mag 14 galaxy or split a tight double the difference become obvious.

When I tested side by side a dielectric and a prism I was quite surprised to see how much more detail you resolve on Jupiter with a prism.

[Flyhigh7]

Yeah, there's regular mirror, and 99% dielectric mirrors, and prisms. My 69 year old eyes can't really tell the difference.

Then I'm sure my 73 yr old eyes won't either even after the cataract surgeries.

But I do want to take full advantage of a 2" throughput weather I see the difference or not because if I don't it will haunt me forever. I do like that the mirrors are lighter than the prisms.

I really need to learn the performance of this 9.25 OTA with EPs at 1.25 and 2" before I experiment with a focal Reducer. I will purchase the recommended EPs by Bigzmey and maybe use that to get a discount on the scope.

[Bigzmey]

Yeah, there's regular mirror, and 99% dielectric mirrors, and prisms. My 69 year old eyes can't really tell the difference.

Then I'm sure my 73 yr old eyes won't either even after the cataract surgeries.

But I do want to take full advantage of a 2" throughput weather I see the difference or not because if I don't it will haunt me forever. I do like that the mirrors are lighter than the prisms.

I really need to learn the performance of this 9.25 OTA with EPs at 1.25 and 2" before I experiment with a focal Reducer. I will purchase the recommended EPs by Bigzmey and maybe use that to get a discount on the scope.

There is another option. The scope comes with 1.25" prism which is not bad and a couple of Plossls. You could start observing with that and decide on what diagonal and EPs to buy once you get more experience.

There are many options for EPs, diagonals, etc to consider. To a degree that depends on how nuts your about observing. I am as nut as it gets. From April to November I spent every clear sky weekend in the desert observing. So, my demand for equipment performance might be different from normal people.

[Flyhigh7]

I am as nut as it gets. From April to November I spent every clear sky weekend in the desert observing.

I'd be just as nut if I could be out in the wonderful dark skies of the desert. The only good news I have about my light polluted sky is that before my cataract surgeries I couldn't see more than 3 to 5 stars in a clear night sky. After the surgeries I'm now seeing 15 to 25 stars so my sky is not as polluted as I initially thought. But it's nothing like the beautiful diamond studded sky above your head.

[Bigzmey]

Another option to consider is a zoom EP. Baader makes good quality zoom which covers 8-24mm range which is perfect for the 9.25". You could get the 2" 36mm Aspheric EP for the wide field low power views and the zoom could cover the rest.

https://agenaastro.com/baader-8-24mm-ma ... 54826.html

You may decide to get later the full set of EPs, but zoom is still nice to have for it's utility.

Or you could just start with 1.25" each diagonal which comes with the scope and the zoom, and while observing think on what or whether you need any other EPs

[Flyhigh7]

Interesting but the link is for 2 items so I'm confused It has a 1.25" a 2" 8-24mm Hyperion Universal Mark IV Zoom Eyepiece # HYP-ZOOM 2454826. Would I get them in both 1.25 and 2" or just choose 1 of them?

[Bigzmey]

Baader 8-24mm Hyperion Universal Mark IV Zoom Eyepiece # HYP-ZOOM 2454826

The zoom is actually 1.25" but it comes with 2" adapter so if you use it alongside 2" EPs you can swap EPs easily.

[Flyhigh7]

Ahh! I got it! Thank you for the clarification. In defense of my stupidity I spent the night tossing and turning thinking EV 8 Edge,has Starsense, EV 9.25 has a better mount, EV 8 Edge can be brought out assembled, EV 9.25 can be carried out in lighter pieces, EV 8 Edge is smaller, EV 9.25 has a BIG Aperture, Edge, Aperture, Edge, Aperture, Edge, Aperture, Edge, Aperture, Edge, Aperture, Edge, Aperture..................

Then I just got up a 2:30 AM and browsed the Celestron web site for the 50th time. LOL Thank you all for being so patient with me.

I don't like the red dot finder on the 9.25. Would much rather have an illuminated 8*50 with crosshairs or Starsense. What are your preferences for a finder scope?

[Bigzmey]

Between plain EV 9.25" and EV 8 Edge I would definitely pick plain 9.25, because aperture is the queen for visual.

As for the finder since you will be using it only once during the session for the alignment, red dot will work just fine.

I only deploy my 9x50 finder when using manual mount.

[Flyhigh7]

I understand but I do like to manually hunt stuff down. I've already decided on the Evolution 9.25 and may seal the deal tomorrow. I'm hitting the sack now to dream about giant globular clusters coming into focus on my 9.25. I'm sure I'll have more questions tomorrow. Thank you very much for all the help.

[Flyhigh7]

First, I want to thank you all for your guidance and holding my hand through this BIG decision and I'm happy to announce I have placed an order with High Point for:
Celestron Evolution 9.25 Telescope
Baader Hyperion Aspheric 36mm EP
Baader Hyperion Aspheric 8mm EP
Powermate Barlow 2.5
They threw in free suppression Pads and the Free Set Up Expert (if I decide to use that)

High Point no longer carries the Pentax EPs
I was going to also get the Baader 2" Diagonal BBHS but they told me the Baader 2" EPs actually fit into a 1.25" diagonal and are not true 2". That confused me so I dropped the BBHS (for now).

[Bigzmey]

First, I want to thank you all for your guidance and holding my hand through this BIG decision and I'm happy to announce I have placed an order with High Point for:
Celestron Evolution 9.25 Telescope
Baader Hyperion Aspheric 36mm EP
Baader Hyperion Aspheric 8mm EP
Powermate Barlow 2.5
They threw in free suppression Pads and the Free Set Up Expert (if I decide to use that)

High Point no longer carries the Pentax EPs
I was going to also get the Baader 2" Diagonal BBHS but they told me the Baader 2" EPs actually fit into a 1.25" diagonal and are not true 2". That confused me so I dropped the BBHS (for now).

Congrats on the scope purchase. As for the Powemate Barlow and Baader 8mm EP you money could have been spent more productively.

To start there is no Baader Aspheric 8mm. Aspherics only come in 31mm and 36mm and only 2". What you have purchased is Baader Hyperion 8mm. Plain Hyperion (not aspherics) is an old design which was outperformed by newer EPs. You could buy better EP for the same money.

Powermate 2.5x is good barlow, but you can't use it with 2" EPs like your 36mm and there is no point barlowing 8mm because that would push your scope to empty powers (the image becomes dark and void of details).

Finally, one can technically use Baader 2" EP in 1.25" diagonal, but you loose all benefits of having 2". Your EP effectively becomes 1.25" 36mm EP.

I am disappointed with High Point, either they were pushing on you slow to sell items or their staff have limited astronomical knowledge. Most likely a bit of both.

[Flyhigh7]

I'm disappointment in them too based on what you say but they were not pushing me. I went through a list of stuff then asked questions and seems I was misled about a few things. I know I can't use the Tele Vue 1.25" Barlow with 2" eyepieces or with the 8mm as that exceeds the scope max but according to them the Baader Hyperion Aspheric 36 mm 1.25"/2" Eyepiece with Free Case can be used in a 1.25 diagonal. I add this after I had added the Baader BBHS 2" Diagonal but when I added the 1.25 8mm Baader I asked If I need the 2" Diagonal for the 32mm Baader he said that fits both 1.25 or 2" so I backed out the 2" Diagonal as I was under the impression that my order has no 2" EPs.

[Flyhigh7]

I just read an outstanding review of top notch Diagonals and as this is now the weakest link in my system I want to upgrade my diagonal.

So new question: Seeing as I so far will have a only 1.25" EPs but may at some time in the future add some 2" EPs, and I want to upgrade my Diagonal, is it better to buy a quality 1.25 diagonal now and then buy a 2" diagonal when I get 2" EPs or should I just buy a 2" Diagonal with the 1.25 adapter for it now or will their be some loss adding the adapter in the system???

Which way will be more efficient as far as photon loss?

Thanks.