31 replies to this topic

[EsaT]

so if i got a diff eye piece and Barlow what would you recommend 

Barlow doesn't often work well for getting good magnification steps without planning eyepieces around it.

Also to get full benefit from Barlow for all eyepieces it needs to be 2" size.

 

Though GSO 2" 2x ED Barlow would be good for the price and gives good medium magnification step from bundled 30mm eyepiece, or 30mm Ultra Flat Field

28mm UWA starts getting toward heavy for Barlowing.

 

Then about 10mm eyepiece would give good next steps with Barlow.

Anyway for high magnifications your local seeing conditions can be serious limit and Barlowing would give some idea what's possible before getting separate eyepieces.

(also telescope cooled to ambient is very important for those)

[Fishonap]

In a light polluted sky, the dim field stars are barely noticeable. Basically the sky glow wipes out a lot of the bloated stars at the edge. Under dark skies you see more stars, including the ones at the edge bloated from coma.

Also a larger mirror makes those bloated field stars at the edge brighter, and more noticeable.

So yeah, big aperture, dark skies, coma will be more problematic. It makes perfect sense.

coma corrector? recomendations

[Neanderthal]

Your Apertura is a GSO product, GSO makes a nice coma Corrector that is sold under several labels, typically around $135 new. If you can make all your eyepieces parfocal (one reason to stay in a singular eyepiece family), then you'll be able to use just a single spacer with the corrector, probably another $25. If you can't or decide not to make the eyepieces parfocal, then a tunable-top corrector like the TeleVue Parracor 2 would be easier to use. The P2 is considerably more expensive than the GSO. Depending on how close you get the spacing right on the GSO, the view will be well corrected to almost the very edge (the P2 is considered the best here on this forum). Buy used if you can.

 

At f/5, I would use the scope as-is without a corrector and see if coma distracts you, let your eyes be the judge. If you are someone that critically observes an object all the way to the edge of the field, then yeah, you are probably going to appreciate a corrector. Some folks seem to be more concerned with judging eyepieces than they are with just observing what's up in our beautiful universe. If you are observing in enough light pollution, I think it'll be a meh purchase. Using David Lorenz's map:

 

https://djlorenz.git...erlay/dark.html

 

My home residence has a brightness rating of 18.79 mag/arcsec², for me, it's a waste of money at this brightness. At my other address, the brightness rating is 21.72 mag/arcsec², and I can easily see the coma, though it doesn't distract me or make my time at the eye piece any less enjoyable. The darker skies are where the corrector can really show it's value, though many folks still go without one.

[Fishonap]

Update:  So, wife pulled the trigger and ordered me the ad12 for Xmas can't unbox until Xmas that part sucks but hey.  we do live in dark skies so i can view every night and we don't have clouds here so that is great.  thank you all for the information.  i will use the eyepieces that come with it for the mean time and try out others at the monthly get together or see if the library will let me borrow some of theirs as well.   

[Astro_In_Tampa]

Congratulations on the AD12! You're going to love it. I've had mine for about a year and a half and love it. Someone mentioned the Astrotech UWA line and I wanted to chime in and give it a plug. The 30mm EP that came with my scope is less than nice to put it mildly. I picked up the Astrotech UWA 28mm EP and I was just stunned at the difference it made. It's like literally looking through a portal into space. Best $99 I've spent on the hobby. I also picked up the Astrotech UWA 7mm and 4mm EP's and love them too. When conditions allow, I put the 7mm EP in the 2x Barlow that came with the scope, and wow.... Amazing views! Difficult to track planets as they move pretty quickly out of your FOV, but if you can follow them at all, you'll really like what you see. As for the Hyperion Zoom.... That would be a hard no for me. I bought a SVBONY 7-21mm zoom EP for $40 and it works just fine. I've even put it in the 2x Barlow and you can get really crazy with it trying to zoom in on things. I'm sure the Bader Hyperian offers slightly better views, but I don't know that they're 6 times the price of the SVBONY better. YMMV as they say here. 

 

The biggest issue I've had with my AD12 is getting it collimated properly. I had a problem with the secondary mirror rotation. Since the AD12 comes with a fixed secondary mirror, I had to modify it using the "milk jug washer" fix. You can find all the details on here about how to do that. I also replaced the springs and collimation screws. I think those three things are a must if you own that scope. All very simple things to fix, and pretty cheap as well. But they will make a world of difference in your viewing experience. Anyway... Congrats again and let us know how it works!!

Edited by Astro_In_Tampa, 09 December 2024 - 10:05 PM.

[A Star Geezer]

Fishonap

Your wife is so nice pulling the trigger for you, but so mean making you wait. But then with a new scope you have a 2-3 week of clouds to look forward to. I know I've had 3 hrs of clear skies since Nov 26. On that night my wife "found" a gift from santa under the tree and let me open it, 8-24 mm zoom. 

[Overtime]

I just noticed a few things to keep in mind. I recently hurt my right arm and at and around the same time got tendonitis in my wrist. Iy may only be a 8 inch scope but its still hard to move in my location ( lots of steps). Its even harder now. One other thing to think of you're about to make a sizable investment. Depending on what happens in the future will you still be using it? Or will it end up collecting dust? My 8 inch is getting less use then I had been prepared for. I am sure this has happened to others.