Zerochromat 8 inch apo

[triton1]

As above for sale on fleabay only £3000.I,d never heard of them before until reading an old thread on here they use some sort of folded design so may not a true frac.Has anyone ever used one?

[Stu]

They are indeed a folded design, quite complex by the sound of it.

The marketing always suggests they are fantastic, with no CA and easy alignment of the optics but I've never seen an independent review so it's hard to see why you would commit to that sort of spend.

I don't understand why they don't put a unit in the hands of someone well regarded so we should all see if they are good or not.

[spaceboy]

My guess is 8" refractor is going to be a challenge to mount folded or not.

[ollypenrice]

15 minutes ago, Stu said:

 

I don't understand why they don't put a unit in the hands of someone well regarded so we should all see if they are good or not.

I could suggest a few explanations...

Olly

[Peter Drew]

The Zerochromat employs a single element non achromat objective the aberrations of which are corrected by a multiple lens cluster further down the tube near the focal plane. The system is folded with mirrors to reduce the mechanical length. I understand that early experimental versions were hampered optically by issues with the correction cluster which were subsequently addressed. The design is not new but the commercial offering is, I saw one for real at Kelling a few years ago but didn't have the opportunity to view through it, I thought it was undermounted on a HEQ6 at the time. 

[acey]

The eBay item is a refurbished demonstration one with cosmetic defects.

http://www.ebay.co.uk/itm/Zerochromat-8-inch-Apochromatic-Refracting-Telescope-/282103340488?hash=item41aeab5dc8:g:~5wAAOSwYqxXinei

Full retail price is £4200. The company is based in Wales. http://www.zerochromat.net/index.html

It's an f12 dialytic refractor: http://www.zerochromat.net/history.html

https://en.wikipedia.org/wiki/Dialyte_lens

User impressions:

http://www.cloudynights.com/topic/484508-zerochromat-impressions/

http://www.cloudynights.com/topic/475996-zerochromat-is-in-home/

[Stu]

19 minutes ago, acey said:

The eBay item is a refurbished demonstration one with cosmetic defects.

http://www.ebay.co.uk/itm/Zerochromat-8-inch-Apochromatic-Refracting-Telescope-/282103340488?hash=item41aeab5dc8:g:~5wAAOSwYqxXinei

Full retail price is £4200. The company is based in Wales. http://www.zerochromat.net/index.html

It's an f12 dialytic refractor. https://en.wikipedia.org/wiki/Dialyte_lens  http://www.zerochromat.net/history.html

User impressions:

http://www.cloudynights.com/topic/484508-zerochromat-impressions/

http://www.cloudynights.com/topic/475996-zerochromat-is-in-home/

Thanks Acey. Interesting, but nothing European based?

If I were Peter Wise I would chuck one at Olly for a while and see what happens under a dark sky vs the TEC140. We would have to persuade Olly to look through an eyepiece but I'm sure he could cope with that . If the scope is proved to be good then it will sell, until then it's a big ask I think.

[triton1]

Persuade Olly to look thru an eyepiece mmmmm!

[triton1]

Looking at their website their talking about 10,12 and 16 inch both price and size are going to be colossal.oh and the mount too.

[nicks90]

but if its visually as good as something like a tec140 - then surely having something the same size and weight as a 140mm apo - costs the same money - but with 200mm aperture is a no brainer?

[acey]

3 hours ago, Stu said:

Thanks Acey. Interesting, but nothing European based?

One of the user comments was from someone in Prague. The Zerochromat has been around since 2008 and was discussed in a thread here back then, so it seems to have been slow to catch on. Price then was £7000 apparently.

 

[ChrisLX200]

The Zerochromat is f/12 which limits its usefulness significantly, and how thermally stable it is I have no idea but there are a lot of lens and mirror elements inside a very long tube which I doubt would help. I would be asking what advantage (if any) it offers compared to a similar-sized Mak. The very limited test data and absence of reviews would make it a very dubious purchase. I would need a return guarantee if not totally satisfied with its performance before even thinking about buying it, and I'm betting he wouldn't do that.

ChrisH

[ollypenrice]

7 hours ago, triton1 said:

Persuade Olly to look thru an eyepiece mmmmm!

I do it all the time! Where did this idea come from? I have loads of fun observing visually with our 20 inch F4.1 Dob, 10 inch Meade, Leica 8x42 bins and other nice toys. Awe, it isn't my fault if our customers are predominantly imagers, honest. . In fact I got into imaging in the first place because we didn't have sufficient interest from the visual community. OK, I found to my surprise that I enjoyed imaging and am now, well, you know, moderately enthusiastic about it  but I love visual observing. I think I may well retire to it, though retirement doesn't greatly appeal and is not all that likely to happen...

7 hours ago, Stu said:

Thanks Acey. Interesting, but nothing European based?

If I were Peter Wise I would chuck one at Olly for a while and see what happens under a dark sky vs the TEC140. We would have to persuade Olly to look through an eyepiece but I'm sure he could cope with that . If the scope is proved to be good then it will sell, until then it's a big ask I think.

Very unlikely to happen. Peter Wise and I exchanged positions quite bluntly on here. I have clear ideas about the responsibilities of suppliers and manufacturers and there was no meeting of minds.

Olly