Possible Bargain on new Celestron Edge HD 800

[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?

[LewisM]

Haven't read a lot of glowing reports on them, including people moaning of fluffy stars etc. Here is one review: http://joebergeron.com/edge.htm

Others continually say that without fans, the scope is very slow to eliminate thermal waves - so, you'd want the fan kit.

Seems a fair bit of money for a "maybe" scope (like most SCT's - some are terrible, many are OK, most are never excellent) - blunt, but there ya go.

[glend]

Thanks Lewis, i have read that report before but forgot about it. I think i will reconsider after reading that report again. I have also checked out some of the Astrobin photos and i can see what you mean about fluffy stars.

[dannat]

some fo the cloudy nights folk prefer them to the meade ACF's, flat field advantage..as always the sample-sample variation will hurt you if they ship a bad one, otherwise go for it
seems easy to use from reports i read, casstony as one i think

[glend]

Thanks Daniel. I am reviewing how far i can stretch my budget. I may have to consider a proper RC or ODK and that means waiting.

[casstony]

In temperate climates you'll want active cooling and there is sample variation from OK to great. I've got one with excellent optics and the one Ian Fry owns has A grade optics too; Ian has considered selling his previously, you could see if he's interested in selling.

Precise collimation is easy using an artificial star inside the house and the 8's tend to have very minimal mirror shift so the collimation stays good.

I haven't imaged through mine but it has mirror locks if needed.

[LewisM]

Heck, Ian would sell the Harbour Btidge if he could.;)

He is in buying mode now so might be opportune time as Tony suggests :)

[LewisM]

Spoke to Ian - he sold it already

[glend]

Looking closely at the Vixen VC200L, optically seems great, same price point, but Lewis in a past thread seemed to think they area tough to collimate, which i want to avoid. Views? Lewis do you miss yours?
Nuts it seems ti be discontinued.

[LewisM]

Not hard, but equal to the RC's. You really need a Tak collimation scope otherwise you end up leaning at windmills. You THINK you have it spot on but are really way off.

The spider vanes also need replacing or thinning.

Nice visual scope, but needs a lot of work to make it an imaging scope. Terry Robson knows how to if you go that path.

My recommendation: personally, if you need 8", a Vixen R200SS Newtonian with flattener and modified spider, or the Skywatcher clone Quattro. The Tak Epsilons are superb, but well outside your imposed budget, even for the 130.

[rrussell1962]

I'm on my second VC200L. I sold my first one and regretted it for 10 years. I've never used the Tak collimating scope. To collimate without it you really do need the Vixen extension for the focuser draw tube. Without it you can't collimate the secondary properly. The older ones (mine) are easier because they had 3 primary mirror clips and you can collimate the secondary by racking out the focus until their reflection in the secondary disappears at the same time. The newer VC's have a retaining ring on the primary which may be not as easy to see as the 3 mirror clips.
My experience is that the only way to properly collimate the primary is by star testing. The VC200L is very sensitive to collimation, but it does hold collimation well. Once collimated it performs very well for visual allowing for the large secondary obstruction and the thick vanes.

[Camelopardalis]

Edge 8 is a great little scope. The Celestron reducer brings it down to f/7-ish.

Collimation is critical, or at least, readily noticeable if it's out. The scope is very light (about 6kg bare). The TEMPest fans take minutes to fit, but in Brisbane I don't have much need to use them as the temperature doesn't drop all that quickly.

IMO you're more likely to be seeing limited with a scope of that focal length.

I've imaged with both my Edge 8 and 11 and if I could guarantee better seeing more regularly, I'd do more DSO imaging with them. As it is, those nights of good seeing rarely seem to coincide with New Moon so I'm left planetary imaging.

From my understanding, large stars are a given with slow reflectors :shrug:

[glend]

Thank you Gents for your suggestions and experiences. Lewis i don't 'need' an 8" , it was the focal length that attracted but it was going to be reduced anyway for imaging in those designs. I have a very nice carbon strut 10" f5 imaging newt that i built some years ago, which is 1250mm fl. I had tried an 8" RC for about a year but could never get reliable collimation, despite having all the tools (Tak scope, Howie Glatter Ring laser, etc) and gave up on it in the end - too frustrating. So i am very leary of more collimation problematic designs.

[LewisM]

The VC-200L is still available locally. You know where ;) His price is decent too.

There is a 2nd hand VC-200L in the trader - I sent an enquiry weeks ago, no response.

[glend]

After reading a comparison of the Vixen and Edge on CN i decided to go with the Edge HD. Its on the way. Thanks folks.

[cydonia]

I wouldn't"t say the comparison between the Edge and a AP 155 is fair other then for curiously sake. AP155 $10k or more for OTA, Edge 8 with fork and tripod $2400.

I received a new standard 8" sct a while ago and the level of detail on Jupiter I got Last week was jaw dropping.

The QC of modern SCTs is a lot higher now, I have owed a total of 5 SCTs over 20 years and I think Celestron is producing some of the best SCTs they ever have now.

[glend]

What the? Who is talking about an AP 155? Wires crossed somewhere.

[cydonia]

My apologies, I thought the review http://joebergeron.com/edge.htm was comparing the two

[glend]

Actually what i said was a comparison not a review, however, in the 12 March thread started by neb1 there was a link to a review here:

www.chuckhawks.com/vixen_VC200L_telescope.htm

and keep in mind it was compared with a standard C8 not the Edge HD.

The comparion thread i was talking about is here:


https://www.cloudynights.com/topic/569709-vixen-vmc200l-vs-celestron-c8-edge-hd/

I don't think i need to defend my choice, but considering my budget, and wide spread user base, and Astrobin images, the Edge Hd was my choice.

[Atmos]

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

[glend]

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 :thumbsup: I was one happy >:party: 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]

Says the refractor guy :P :lol:

[LewisM]

Much easier to heat a small dewshield :) :P

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

[glend]

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]

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

[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.

[glend]

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]

Hope you enjoy for its strengths Glen :thumbsup:

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...