Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Refractors

Pages: 1 | 2 | (show all)
jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: Japanese shoot out new [Re: hottr6]
      #5552503 - 12/03/12 05:51 PM

Good question.

The Antares "Vixen Spec" optics are really good. The only Carton optics I have to compare them to are 60mm optics. I'd say that the coatings (single layer MgFl on each surface) of the Vixen Spec lenses is better than the thin or nonexistent coatings used on some of the surfaces of the Cartons I have. In terms of figure quality, they're both very, very good.

"Worth it" is a very personal question, I think. The optics certainly are excellent. But how much is an extra 8mm of aperture "worth" in dollar terms? For me, I'd likely pass on a new cell and enjoy it vignetting and all. If I was going to invest in improving the OTA, I'd scrap the whole shebang and have a new OTA, cell and focuser built. But that would be a huge investment in what was a very cheap set of optics ($650 for the OTA when I bought).

Regards,

Jim


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ain Soph Aur
professor emeritus
*****

Reged: 08/11/11

Loc: West Tennessee
Re: Japanese shoot out new [Re: jrbarnett]
      #5552598 - 12/03/12 06:56 PM

The Faworski sourced Carton 100/1300 in my OTA is MgFl coated and the cell was provided with the lens. The next time I remove the dew shield I will measure clear aperture.

I use a 2" Crawmach 2-speed crayford, 2" Baader Click-Lock dielectric diagonal. With the ES 82* 30mm it can achieve a respectable crisp to edge ~1.9 degree FOV. Some day I will replace this EP with an ES 100* 25mm.


Post Extras: Print Post   Remind Me!   Notify Moderator  
jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: Japanese shoot out new [Re: Ain Soph Aur]
      #5552695 - 12/03/12 07:49 PM

The carton 60mm units I have are coated only on one surface (the outer surface) leaving 3 surfaces uncoated. You need to check clear aperture from the rear of the scope, not at the objective end. Look in through the focuser tube and see if you can see the lens edges and spacers. In an Antares scope, you cannot.

Regards,

Jim


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ain Soph Aur
professor emeritus
*****

Reged: 08/11/11

Loc: West Tennessee
Re: Japanese shoot out new [Re: jrbarnett]
      #5552743 - 12/03/12 08:17 PM

Just did a quick check from the focuser end and I can see spacers.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Astrojensen
Post Laureate
*****

Reged: 10/05/08

Loc: Bornholm, Denmark
Re: Japanese shoot out new [Re: Astrojensen]
      #5554303 - 12/04/12 05:13 PM

I checked up on Galakuma's site of old Japanese catalogues and the ONLY two companies I can find that has sold a 102/1300 scope are... Vixen and Carton. The only mention of the Vixen version is in the 1981 catalogue and the Carton version is only shown in the 1985 catalogue. This of course doesn't mean that they can have sold them for several years afterwards. Vixen also offered a 102/1500 version in 1981. In 1985 and later, Vixen shows only the 102/1000 version, which is still being made to this day. Upon close scrutiny it is evident that the Vixen and Carton 102/1300mm OTAs look A LOT like one another, although they are not identical. There are some detail differences, but also strong similarities. They use, for example, the same accesory threads on the focuser! Most of the smaller accesories are completely identical. It is clearly evident that they have used the same supplier for accesories, so I consider it likely that this could also have been the case with the optics. All their 0.965" eyepieces seems to have come from the same supplier that made 0.965" eyepieces for Kokusai Kohki.

The mystery is where the refractor objectives came from. A subcontractor? Carton supplied them both? Vixen supplied them both? (the hints "from a Vixen supplier" on several homepages seem to rule this option out) Both made their own lenses? (unlikely, as mentioned)


Clear skies!
Thomas, Denmark


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ain Soph Aur
professor emeritus
*****

Reged: 08/11/11

Loc: West Tennessee
Re: Japanese shoot out new [Re: Astrojensen]
      #5554816 - 12/04/12 11:06 PM

Nice sleuthing Thomas! My Carton lens came from Sheldon Faworski, I will email him tomorrow and see if he will share details on the lineage of his Carton lenses.

Post Extras: Print Post   Remind Me!   Notify Moderator  
jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: Japanese shoot out new [Re: Astrojensen]
      #5555377 - 12/05/12 09:54 AM

Vixen clearly has some in-house manufacturing capability. While it may have outsourced its achromatic refractor optics, it still makes its mounts in-house.

Do we know if Carton has (or ever had) any similar manufacturing capability in-house? I know that Televue rebranded a Carton EQ mount for a short time, so perhaps Carton, like Vixen, has some manufacturing capacity of its own.

But the optics industry in Japan has been rife with subconrtacting and rebranding since its inception. The plethora of identical 1960s and 1970s Japanese refractors under different trade names and brands evidences this. Whose to say that Towa or some other Japanese optics fabricator didn't make the OGs for both Vixen and Carton?

Here's a review of a 4" f/13 Carton:

http://www.scopereviews.com/page1j.html#6

Notice that the author puts the optics right around 1/4 wave in spherical correction. Notice also that he mentions that a 4" f/10 Carton was available as well. That would tend to suggest a common supplier given similar products 4"/1300 and 4"/1000.

Regards,

Jim


Post Extras: Print Post   Remind Me!   Notify Moderator  
DaveTinning
super member


Reged: 01/03/09

Loc: Central England
Re: Japanese shoot out new [Re: jrbarnett]
      #6397899 - 02/26/14 09:23 AM

Hi,

I came across this thread just now and found it to be an irresistible read. As a long time fan of long achromats I was delighted a few months ago to find a Vixen Pulsar F13 102/1300 achromat, complete with original Vixen altaz mount and fixed wooden tripod.

I've had the lens serviced by a respected UK optician ES Reid who estimated the lens at 1/4 wave with slight overcorrection. Interestingly he made a 90mm aperture stop and thought that this moved the lens from a "good" rating to "excellent"..truth be told, it seems excellent to me whichever aperture is used. CA is very slight and it just looks the business - very like an old Unitron.

I will post some pictures if anyone is interested in seeing it.

cheers
Dave


Post Extras: Print Post   Remind Me!   Notify Moderator  
terraclarke
Post Laureate
*****

Reged: 05/29/12

Loc: Just South of the Mason-Dixon ...
Re: Japanese shoot out new [Re: DaveTinning]
      #6402669 - 02/28/14 09:19 PM

By all means. I would love to see them. Please post pictures.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Fomalhaut
scholastic sledgehammer


Reged: 08/16/08

Loc: Switzerland
Re: Japanese shoot out new [Re: Rutilus]
      #6403183 - 03/01/14 04:58 AM

Quote:

I always tend to use a yellow filter for the planets as it helps me see more detail,
even with the Tak I stick the filter on.




Did I understand you properly? You tested an achromat versus a superapochromat on planets by using a yellow filter on both?? Thus suppressing most of those wavelengths where the apo is
far superior - and thus not letting it display its full potential???

Sorry, but if I have understood you correctly then this test between a boosted achromat and a handicapped apochromat does not seem of relevance to me.

Chris

Edited by Fomalhaut (03/01/14 02:16 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
terraclarke
Post Laureate
*****

Reged: 05/29/12

Loc: Just South of the Mason-Dixon ...
Re: Japanese shoot out new [Re: Fomalhaut]
      #6403779 - 03/01/14 01:01 PM

Wow, that's rather harsh!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Bonco
Post Laureate
*****

Reged: 04/17/06

Loc: Florida
Re: Japanese shoot out new [Re: Fomalhaut]
      #6404112 - 03/01/14 04:16 PM

Quote:

Quote:

I always tend to use a yellow filter for the planets as it helps me see more detail,
even with the Tak I stick the filter on.




Did I understand you properly? You tested an achromat versus a superapochromat on planets by using a yellow filter on both?? Thus suppressing most of those wavelengths where the apo is
far superior - and thus not letting it display its full potential???
Sorry, but if I have understood you correctly then this test between a boosted achromat and a handicapped apochromat does not seem of relevance to me.

Chris




Every individual has certain eye sesitivities. Evidently yellow works for this observer. I don't think the filter negates the useful info of his post. Bill


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jim Curry
Carpal Tunnel
*****

Reged: 10/29/07

Loc: STL
Re: Japanese shoot out new [Re: jrbarnett]
      #6406044 - 03/02/14 05:02 PM

Actually Jim, if I understand correctly, the cell in back of the lens could be bored out 5mm to get you back to 100mm through put. You wouldn't need a new cell.

Jim


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
30 registered and 30 anonymous users are browsing this forum.

Moderator:  FirstSight, panhard, star drop, dr.who 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 3367

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics