Possible Bargain on new Celestron Edge HD 800

[glend (Glen)]

Originally Posted by Atmos

From reading about them, one common thread is to install Tempest Fans to significantly help with cooling.

Well yeah, in north america or europe i can see that, especially where you are bringing a scope outside to plonk it on your portable mount. But my situation might not require them. In an observatory you are pretty much always at ambient, and its not a massive piece of glass anyway, and the tube is vented. I will try it without them. Those Tempest units, like many astro accessories, are expensive little fans, i have a couple of small (50 cent sized) fans that i can stick on it if i want to try them.

[beren]

Last night spent some time viewing through a Meade 8" ACF, first time looking through this type of SCT. Was only using low to moderate magnification with the seeing but the scope was performing nicely, impressed actually especially while viewing Jupiter. Good luck with the choice I was one happy > last night

[LewisM]

Being a classics nut, i must get an old orange tube C8 one day just for giggles. It's fun reading the CN threads on SCT's about how many incarnation of one type of scope guys will go through before they get one that's good enough to keep (the Dynamax thread is amusing, as is the C14 thread). I wish I had grabbed Mental's C8 when he offered it but I was too late.

Good luck with the Edge Glen. Thinking back on the VC200L, I think your choice was wise too. The VC really is a PITA to get right - easily sometimes 2 hrs if imaging. I wouldn't want another closed tube design again though (like the Edge or Mak) - the dew problem was always horrible with the Mak I had, and that was using dew heaters.

[Atmos (Colin)]

Originally Posted by LewisM

I wouldn't want another closed tube design again though

Says the refractor guy

[LewisM]

Much easier to heat a small dewshield

Besides, Canberra humidity is very low (well, not right now lol). I have my dew straps and portable hair dryer (and a swag of chemical hand warmers if the battery dies on me)

[glend (Glen)]

I don't have any dew problems with my Mak-Newt, which is entirely closed, so the Edge HD with its vent ports should be ok. The Mak-Newt corrector heater strap and light shield will even fit the Edge if needed. As to the Tempest fans, i will wait and see.

[LewisM]

You must have low humidity Glen - lucky you! I had issues with my Orion Mak-Newt dewing up, but that was on the Sunshine Coast which is about as humid as a steaming shower.

[glend (Glen)]

Originally Posted by LewisM

You must have low humidity Glen - lucky you! I had issues with my Orion Mak-Newt dewing up, but that was on the Sunshine Coast which is about as humid as a steaming shower.

I don't know, living next to Australia's largest salt water lake is not like the Simpson Desert.

[Gizmo]

Originally Posted by glend

I have run across a special offer (overseas) on the Celestron Edge HD 800 ota, price $1746 Aud equivalent. This seems to be a very good price for this scope, which has a lowest price in Australia of $2399 - 2499, at the moment. Even with shipping and GST it looks like i could land it for $2000. It is a risk but i have dealt with the supplier before. As i am an imager i would need the CCD47 reducer to get to f8 obviously.
What do you think? I want a longer focal length scope but had a bad experience with the GSO RC08 and do not want collimation headaches, is the Edge HD 800 easy to use?

Easy to use.
But beware they have a known issue, just google:
"celestron corrector plate haze"
Collimation can be easy but that depends how perfect you want to get it.

[glend (Glen)]

Originally Posted by Gizmo

Easy to use.
But beware they have a known issue, just google:
"celestron corrector plate haze"
Collimation can be easy but that depends how perfect you want to get it.

Doesn't phase me at all. I checked out Google, I have removed and cleaned my Mak-Newt corrector, so i am not worried.

[Camelopardalis (Dunk)]

Hope you enjoy for its strengths Glen

If so inclined, it'd be plenty capable of good planetary results, as it is the season not that you're larger newt wouldn't of course.

Collimation IS pretty easy as you're only moving the secondary. I wouldn't bother with Bob's Knobs, especially as you've got an obsy. I'm thinking of going back to my original screws as I find I'm compelled to tweak it every session.

The 8 is very easy to keep dew free, placement of the dew heater strap is key. You want to place it on the main tube just behind the thick metal corrector rim but not on it, as it's too thick to be useful.

At native focal length you'll no doubt be seeing limited much of the time, but the ASI1600 is plenty sensitive to get the most out of f/10 on a good night.

There is a focusing trick with SCTs with a moving mirror...always make your final movement anti-clockwise. If you go too far, wind it back past the focal point and approach again. That said, all the 8s I've ever looked through have had very little mirror shift. It's very easy to get good focus with a Bahtinov mask and the stock focuser knob. If you feel you need finer control, make a suitable sized hole in a peanut butter jar lid

I've always been curious about Hyperstar at ~f/2...maybe one day...