Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

New Chromacor - RayCorr

refractor accessories lens making
  • Please log in to reply
69 replies to this topic

#51 Jimmy462

Jimmy462

    Mariner 2

  • *****
  • Posts: 286
  • Joined: 22 Apr 2014
  • Loc: Putnam County, NY

Posted 26 July 2018 - 07:00 AM

Yes, I have 8" Zerochromat and I am very satisfied with it. Zerochromat has an advantage - optic design is usable also (at the same time) as ADC for planetary astronomy.

Hi Psion,

 

Regarding ADC capabilities, how is it that the Zerochromat can accommodate for that adjustment? I ask as I've been keen to make some travel plans this summer to visit the Custer Institute Observatory out in Southold, NY on Long Island (~41.08° N, 72.47° W) for a look-see how their 10-inch model fares on the (low-riding) planets.

 

New telescope, Zerochromat, arrives at Custer Institute & Observatory - Suffolk Times | Suffolk Times:

http://suffolktimes....te-observatory/

 

smile.gif

Jimmy G

 

Edit: I put the question to the Vendor here...

 

10 inch f12 Super Zerochromat - Vendor and Group Announcements - Cloudy Nights:

https://www.cloudyni...er-zerochromat/


Edited by Jimmy462, 26 July 2018 - 07:32 AM.


#52 Psion

Psion

    Viking 1

  • -----
  • topic starter
  • Posts: 987
  • Joined: 27 Apr 2005
  • Loc: Czech Republic, Prague

Posted 27 July 2018 - 12:13 AM

Zerochromat has 3 knobs for adjusting one mirror. In this position, you can adjust with this knob mirror and you remove atmospheric refraction, that's very easy. Two upper knobs have to be parallel to the plane of the horizon.

Attached Thumbnails

  • Zerochromat.jpg

  • Jeff B and Jimmy462 like this

#53 Psion

Psion

    Viking 1

  • -----
  • topic starter
  • Posts: 987
  • Joined: 27 Apr 2005
  • Loc: Czech Republic, Prague

Posted 28 July 2018 - 02:17 PM

I've tested Chromacor N and ES AR152 (152/1200 achromat). RC index 8.1, with Chromacor + 90° mirror RC 3.8, with Chromacor + 90° prism RC 2.5.

 

For comparing (S2N = RC index):

 

@pud4.jpg

 

Source


Edited by Psion, 28 July 2018 - 02:18 PM.


#54 Jimmy462

Jimmy462

    Mariner 2

  • *****
  • Posts: 286
  • Joined: 22 Apr 2014
  • Loc: Putnam County, NY

Posted 28 July 2018 - 04:20 PM

Zerochromat has 3 knobs for adjusting one mirror. In this position, you can adjust with this knob mirror and you remove atmospheric refraction, that's very easy. Two upper knobs have to be parallel to the plane of the horizon.

 

Thank you! :)



#55 Jeff B

Jeff B

    Fly Me to the Moon

  • *****
  • Posts: 6120
  • Joined: 30 Dec 2006

Posted 28 July 2018 - 04:50 PM

Psion, could you please explain for me your chart a little more as I don't understand your terminology.  What are S2N and RC index?

 

Thanks.

 

Jeff 


  • junomike likes this

#56 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 17229
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 28 July 2018 - 05:56 PM

Psion, could you please explain for me your chart a little more as I don't understand your terminology.  What are S2N and RC index?

 

Thanks.

 

Jeff 

I'd like further explaining also although my understanding is that Halb is half (or halfway) meaning more Halbaprochromat means Semi-Apo.

That was my findings with the Chromacor + 6" F8 Achro also.


  • Peter Besenbruch likes this

#57 Psion

Psion

    Viking 1

  • -----
  • topic starter
  • Posts: 987
  • Joined: 27 Apr 2005
  • Loc: Czech Republic, Prague

Posted 29 July 2018 - 02:14 AM

Psion, could you please explain for me your chart a little more as I don't understand your terminology.  What are S2N and RC index?

 

Thanks.

 

Jeff 

You can see this thread:  https://www.cloudyni...e/#entry8026273

 

This is a formula to calculate RC index: http://rohr.aiax.de/RC_Index.png

 

It depends on the diameter of a lens and focal length. You have to measure a distance between 3 Fraunhofer lines C-F-e and calculate RC index. This is only about chromatic aberration, not about other optic aberrations. Strehl in three lines will be best, but it isn't easy to measure it.

 

There is a lot of test of the telescope: http://r2.astro-fore...php/de/berichte



#58 Jimmy462

Jimmy462

    Mariner 2

  • *****
  • Posts: 286
  • Joined: 22 Apr 2014
  • Loc: Putnam County, NY

Posted 29 July 2018 - 08:41 AM

You can see this thread:  https://www.cloudyni...e/#entry8026273

 

This is a formula to calculate RC index: http://rohr.aiax.de/RC_Index.png

 

It depends on the diameter of a lens and focal length. You have to measure a distance between 3 Fraunhofer lines C-F-e and calculate RC index. This is only about chromatic aberration, not about other optic aberrations. Strehl in three lines will be best, but it isn't easy to measure it.

 

There is a lot of test of the telescope: http://r2.astro-fore...php/de/berichte

Hi Psion, etal,

 

Just to add to your links...I did stumble on this rather, um, "lively discussion" regarding the Rohr RC-Index whilst doing my homework regarding testing refractors (i.e. SW150ED vs. APM152ED, etc.)...

 

Astrotreff - Astronomie Treffpunkt - Der geschönte RC Wert:

http://www.astrotref...TOPIC_ID=196550

 

Google Translate: (English)

https://translate.go...6550&edit-text=

 

...wherein the participants opine on the validity of discarding various frequencies of the spectrum using the RC-index's "night vision" (DSO observing) bias as relates to "daytime" (planet, moon observing) eye sensitivities.

 

 

Fascinating discussion (if one can read past the personal sniping), IMHO, for those interested in better understanding the RC-index test-result materials as provided at Astro-Foren...

astro-foren.com - Berichte:
http://r2.astro-fore...php/de/berichte
 

...and what they do and do not reveal.

 

:)

Jimmy G



#59 AntarcticDave

AntarcticDave

    Mariner 2

  • -----
  • Posts: 290
  • Joined: 03 Feb 2009
  • Loc: Denver, CO

Posted 01 August 2018 - 04:02 PM

Late to the conversation, but I would be interested for an Antares 1529 (6" f6.5).



#60 Greenflash1

Greenflash1

    Sputnik

  • *****
  • Posts: 38
  • Joined: 04 Jun 2018
  • Loc: Santa Fe, New Mexico

Posted 31 October 2019 - 08:29 PM

So...the Raycorr is a fictitious thing? Now links and not ever listed for sale?



#61 Jeff B

Jeff B

    Fly Me to the Moon

  • *****
  • Posts: 6120
  • Joined: 30 Dec 2006

Posted 31 October 2019 - 11:46 PM

So...the Raycorr is a fictitious thing? Now links and not ever listed for sale?

Despite a lot of study and maybe even a prototype or two, Istar never commercially produced the Raycor and probably never will.

 

Now Valerie D of Aries, the maker of the Chromacor, has been looking into a new type of Chromacor with larger aperture and which would have better performance both on and off axis.  However, it would be very expensive and, again, suitable for larger aperture achromats, say 200mm and larger.  And only if there was enough of a commitment (meaning actual orders with deposits) to make them.

 

Jeff


  • Jon Isaacs, doctordub and francesco italy like this

#62 ISTAR Optical

ISTAR Optical

    Vendor- IStar Optical

  • *****
  • Vendors
  • Posts: 263
  • Joined: 09 Aug 2009
  • Loc: Tucson, Arizona

Posted 07 November 2019 - 03:23 PM

Despite a lot of study and maybe even a prototype or two, Istar never commercially produced the Raycor and probably never will.

 

Now Valerie D of Aries, the maker of the Chromacor, has been looking into a new type of Chromacor with larger aperture and which would have better performance both on and off axis.  However, it would be very expensive and, again, suitable for larger aperture achromats, say 200mm and larger.  And only if there was enough of a commitment (meaning actual orders with deposits) to make them.

 

Jeff

If Valery does not produce his new Chromacor we might revisit the project in the future. But since he is the original designer and producer I would much rather offer large ISTAR doublets with his new large-format Chromacor.  We have just finished designing two new doublets, namely 220 f/15 R35-S ("S"  stands for "Slim"), and 250 f/15  in addition to our existing lineup of R35 doublets offered in F/5 to F/11 range. Valery's new Chromacor could work great with many of these, I think.  I sure hope he pulls it off.


  • mitsos68 likes this

#63 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 17229
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 07 November 2019 - 07:21 PM

Good to see ya back Ales.


  • meade4ever likes this

#64 ISTAR Optical

ISTAR Optical

    Vendor- IStar Optical

  • *****
  • Vendors
  • Posts: 263
  • Joined: 09 Aug 2009
  • Loc: Tucson, Arizona

Posted 07 November 2019 - 07:32 PM

Good to see ya back Ales.

Thank you, Mike.  It's good to be back, especially with the most serious health issues finally behind me. Hope it stays that way. 


  • GlenM, meade4ever, francesco italy and 1 other like this

#65 Steve Allison

Steve Allison

    Apollo

  • *****
  • Posts: 1032
  • Joined: 25 Nov 2016
  • Loc: Olympia, Wash. 98502

Posted 08 November 2019 - 06:27 PM

Good to see ya back Ales.

+1 !



#66 39.1N84.5W

39.1N84.5W

    He asked for it

  • *****
  • Posts: 3987
  • Joined: 24 Oct 2006
  • Loc: cincinnati

Posted 09 November 2019 - 01:10 AM

Where do we sign up for Chromacor?

#67 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 17229
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 09 November 2019 - 09:19 AM

Where do we sign up for Chromacor?

AFAIK only via a "Wanted Ad" in the classifieds..........



#68 39.1N84.5W

39.1N84.5W

    He asked for it

  • *****
  • Posts: 3987
  • Joined: 24 Oct 2006
  • Loc: cincinnati

Posted 09 November 2019 - 02:29 PM

I mean for a new run...

#69 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 17229
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 09 November 2019 - 04:43 PM

I mean for a new run...

Didn't know there was a new run being considered (aside from chitter chatter).



#70 mitsos68

mitsos68

    Ranger 4

  • *****
  • Posts: 348
  • Joined: 21 Jun 2012
  • Loc: Athens - Hellas.

Posted 15 November 2019 - 08:18 AM

Hi,

 

here is a daylight sample taken with:

1. Nikon D300

2 APM 8" f/9 refractor

3. Chromacor II O1 at 161mm from focal plane.

 

Image at prime focus.

 

Regards

 

Dimitris

Attached Thumbnails

  • cable4_chr.jpg
  • APM CHROM II 0! Testsmall.jpg

Edited by mitsos68, 15 November 2019 - 08:26 AM.

  • Jeff B likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: refractor, accessories, lens making



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics