Criterion RV-6 Dynascope


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Brand and Model:Criterion RV-6 Dynascope
Price ($USD):no longer availa
Type:Newtonian
Attributes: un-checked Go-To un-checked PEC
Aperture:152mm (6")
f Ratio:f/8
Focal Length:1200mm
Finder:5x24
Electric Power:A C
Mount:G.E.M. with Drive
Tripod:G.E.M.
Weight (lbs):lbs.
Dimensions (w/h/d):
Description:

Vote Highlights Vote
Criterion RV-6 Dynascope
This is my second rv6 in 25yrs. first one bought new fr criterion in 1976. sold when i got the 8' sc bug. sold the c-8 !

I now own a 1960's model rv6 paid $100.00 for it!! had mirror's recoated by QSP OPTICAL TECH. with 98 and 96 percent coatings. I have seen this scope
as well as my first rv6 out perform larger
sc's and newt's over the past 25yr.s.

Overall Rating: 10
Optics:10 Mount:6 Ease of Use:10 Value:10
Weight: 10 (Trustworthy Vote)
Date:
By: blueangel
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=75600


Criterion RV-6 Dynascope
I own one since 1976. It was the "apo" of the seventies.

Overall Rating: 10
Optics:10 Mount:9 Ease of Use:9 Value:10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.143.227)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=584310


Criterion RV-6 Dynascope
Due to the modifications I've made to the telescope I've elected to only vote on the optics in order to be fair.
This is my 2nd RV6. Sold my first back when I didn't know what I had. About a year ago purchased an MN61 hoping to duplicate some of that magic. It was not to be. While the MN61 gives sharp images and very flat field considering its short focal length its light thru put seemed to be somewhat restricted. Therefore it was sold and a very used RV6 ota was purchased for $190. All parts on the RV6 have been replaced and the mirror has been recoated by Spectrum. The parts list includes the following: crawford 2" focuser, curved vane spider with 1" secondary, Russell 60mm right angle finderscope, tube end rings and dust covers from Parks, and mounting rings from Orion. The focal length was figured to be around 1250mm so the primary was moved forward 1.5" inorder to maximize the 1" secondary and provide more in travel for Speer and Whaler's fabulous 82 degree eyepieces.
Under the sky the scope performs very well. Festoons continued to be visible on Jupiter while using a 4.8mm eyepiece with only average seeing conditions. The scope's star test had nearly identical symmetric patterns on either side of focus. And last but not least my RPD 30mm 80 degree field of view eyepiece displayed no sea gulling or field curvature when used with this scope. Don't get me wrong, this may in part be attributed to the F8.3 focal ratio, but only in part since this eyepiece has been used with other F8 scopes with not nearly the same results.
So needless to say I'm very happy that my efforts have been rewarded. This would not have been the case had the RV6 optics not lived up to their lofty folklore.
Larry

Overall Rating: 10
Optics:10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.147.32)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=443026

>Due to the modifications I've made to the telescope I've elected to only vote on the optics in order to be fair.
>     This is my 2nd RV6.  Sold my first back when I didn't know what I had.  About a year ago purchased an MN61 hoping to duplicate some of that magic.  It was not to be.  While the MN61 gives sharp images and very flat field considering its short focal length its light thru put seemed to be somewhat restricted.  Therefore it was sold and a very used RV6 ota was purchased for $190.  All parts on the RV6 have been replaced and the mirror has been recoated by Spectrum.  The parts list includes the following: crawford 2" focuser, curved vane spider with 1" secondary, Russell 60mm right angle finderscope, tube end rings and dust covers from Parks, and mounting rings from Orion.  The focal length was figured to be around 1250mm so the primary was moved forward 1.5" inorder to maximize the 1" secondary and provide more in travel for Speer and Whaler's fabulous 82 degree eyepieces.
>     Under the sky the scope performs very well.  Festoons continued to be visible on Jupiter while using a 4.8mm eyepiece with only average seeing conditions.  The scope's star test had nearly identical symmetric patterns on either side of focus.  And last but not least my RPD 30mm 80 degree field of view eyepiece displayed no sea gulling or field curvature when used with this scope.  Don't get me wrong, this may in part be attributed to the F8.3 focal ratio, but only in part since this eyepiece has been used with other F8 scopes with not nearly the same results.
>     So needless to say I'm very happy that my efforts have been rewarded.  This would not have been the case had the RV6 optics not lived up to their lofty folklore.
>Larry

Where can I get additional lensese for my 6" dynascope.  I have an 18mm and a 12.7mm and would like something stronger for planetary viewing.  ALso, I would like to tighten the scopes movements, it swings to much.  Any suggestions?

I purchased mine about 25 years ago, still have it, still works great.

Thanks.

Ed

Criterion RV-6 Dynascope
I have had my RV 6 since 1980. Upgraded it with a set of TeleVue Plossls in the late 80's and a Lumicon O III Filter. Have always been pleased with its great performance.

Overall Rating: 10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.71.47)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=406767


Criterion RV-6 Dynascope
This is one of my favorite telescopes. I had one as a youngster but it was stolen and I had always wanted to get another and so I finally did (took me nearly 30 years!). The one I bought had to have some restoration work done on it but it was well worth the effort.

It's hard to beat this scope for visual use on the Moon and planets and double stars. If you're lucky enough to live in dark sky country, this telescope will also give very pleasing views of deep sky objects but of course is limited in it's light gathering power.

The only thing that needed improvement was the focuser. Mine would grab and bind and whenever I needed to change eyepieces I would quite often end up "slewing" the telescope as I pulled on the eyepiece. I finally stopped it by replacing the stock focuser with a JMI RCF and that works well.

Optically these telescopes normally perform just beautifully. Saturn is absolutely gorgeous, Jupiter shows 6 belts/zones with much detail visible within the belts and the Moon is awe inspiring. I routinely push the scope up over 300X on good seeing nights without complaint and the star tests are nearly perfect.

The mechanics of the scope are certainly adequate for the task they were designed for and for the price would be hard to beat. To set up or store the telescope, it's easiest to remove the OTA from the mount and make two trips. However, I can pick up the entire scope and move it around to clear trees and other view blocking objects if I need to.

If you like the style and performance of a well made "classical" 6" f/8 reflector, you can't go wrong picking up one of these scopes.

Overall Rating: 10
Optics:10 Mount:7 Ease of Use:8 Value:10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.191.46)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=307018


Criterion RV-6 Dynascope
I have mine for 36 years. It is the best telescope I have ever owned and I've had SCT's, Schmidt-Newtonians, and refractors (including a 4 inch apochromat). No 8 inch SCT or 4 inch refractor will equal the optical performance of the RV-6.

Overall Rating: 10
Optics:10 Mount:7 Ease of Use:8 Value:10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.189.129)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=217203


Criterion RV-6 Dynascope
I purchased the Dynascope RV-6 Dynascope in the 1960's and if I recall correctly I paid $199 for it. I have to say that the RV-6 was a superb optical instrument, period! When I showed my wife a view of Saturn through the scope, she thought I was kidding her and had slipped in a slide picture. The moon and planets just snapped into focus with clear bright sharp images. The Orion nebula showed the trapezium and nebulosity with excellent detail. The only drawback of the telescope was when attempting to take long exposure photographs. The worm gear of the drive had a periodic error rate that made the images slew. I made the mistake of selling the scope to my friend and neighbor when I moved on to a Celestron Powerstar 8 SCT. A few years ago we sent the primary mirror out for a recoating and my friend is still using the RV-6. I am sorry to say that the SCT never quite matched the RV-6 for sharpness of image even though I had Celestron fix the SCT's optics which were not ground properly when I had first purchased the scope.

If you come across an RV-6 with the original optics, even if the mirror needs a recoating, check it out. It may be the best buy you'll ever see.

Overall Rating: 9
Optics:10 Mount:8 Ease of Use:10 Value:10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.55.137)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=201032


Criterion RV-6 Dynascope
I have seen the best views of Saturn of any 6" aperature with an RV-6. excellent optics/OTA

Overall Rating: 10
Optics:10 Mount:9 Ease of Use:8 Value:10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.195.27)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=155985


Criterion RV-6 Dynascope
I purchased mine in 1972 and it still works. The tube needs replacement, the drive could be refurbishing or replacement, and the mirror recoated (although it still performs well), but I feel fixing these items will be a much better investment than a Maksutov or similar short focal length scope for near 10x the cost. The mount has always been a teeny bit sloppy. Taking the necessary time to balance the tube properly will eliminate this . The setting circles when aligned correctly will rarely put the desired object in view even with a low magnification eyepiece (20 mm or more). The finder tends to come out of collimation at times if you are not tight enough with the set screws and the finder tube then gets scratched or indented by the screws. I have never had trouble with an eyepiece falling out of the holder. To be safe, I crimped the holder a bit more. Mine has slots cut out in it just for this purpose. Images have always been flat out to edges and well defined even at high magnification (150 - 200x). Overall, the $150 I spent has been paid for over and over again with a scope that has stood the test of time.

Overall Rating: 9
Optics:9 Mount:8 Ease of Use:9 Value:10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.6.242)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=53379


Criterion RV-6 Dynascope
An obvious 10 rating - the mount is tremendous (about 5X the mount that you get on current Celestron/Meade products costing $1,000 plus - in weight, stability, and quality), the optics can't be touched - it is a totally perfect package. Mine tracks pretty much 60 minutes to the hour (the RA motor drive). If you can find a good used one (no new one's out there!!!!) - buy it! The focuser is the weakest part but still very usable and not a real problem - it is just that there is no set screw or other mechanical means to secure the ep in the focuser so you have to make sure you don't let ep fall out when you move the scope.

Here are my notes from recent November 2001 observing session at dark sky site of local Louisville Astronomical Society. This was second night out with the scope after purchasing it from the person who runs the Yahoo discussion/ message board and the Criterion Dynascope Web site. He restored this one to perfection.

Went to dark sky property with LAS tonight. Let's see...,,,

1) Put a laser collimator in ep - I don't know how they work but one
of guys in LAS that owned it said my scope was about 95% in
collimation and no real need to fool with it this evening. How's that
after shipping it UPS!!!
2) Lot's of folks were interested in this treasure. They found it
interesting. Several guys liked the views of this scope better than
the 8" SCT's.
3) Bagged lot's of DSO I never could find with the Celestron G-8 probably due to
different f/ratios. Tonight I logged:
* M92 globular cluster - awesome and a glittering little jewel.
* Ring Nebulae. Much better image than in the G-8. Could see dark
area within ring and faint glimpse of central star. Was very large
(larger than Jupiter) in 10mm ep.
* Saturn. Glimpse of Cassini but planet was low in light
polluted area of the property. Best view was with 17mm ep.
* Dumbbell nebulae. Awesome awesome awesome. Very clear and
bright. Looks like pics in books minus the colors. Bigger than I
thought it would be.
* M2 Globular cluster. Not as easy to resolve stars but still a
jewel. I think I like globular clusters the best of all DSO.
* Jupiter. 2 bands, clearer than last night - moons in slightly
different positions tonight. Spectacular.
* Orion nebulae. Again awesome - 25 mm ep was way cool - so
bright and well defined. Could resolve 4 star trapezium easily

I am just amazed at how easy the mount is to use - so intuitive. So
much easier than the Celestron G-8 and so easy (well, easy is relative) to find
objects. I wish my little wife handled this well. I love it (her, too)!!!

So....if you can find a good one - buy her right away!!! Same with a woman!!!!

- Mark in Louisville KY

Overall Rating: 10
Weight: 1 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.125.157)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=39501

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