My Criterion Dynascope 6 was acquired in the late 1970's. It has served me well over the years. I have kept all the original fittings including the focuser and finder. The original phenolic tube has been refinished with Monokote.

    I acquired a Criterion RV-6 6" newtonian as a teenager. This telescope gave me great satisfaction and was far superior to my Edmunds 3" newtonian. However, as I became more familiar with my hobby, I became more discriminating and wanted more. I began with photographs of the moon and planets. The 6” began showing its limitations. The mount was difficult to aim as it lacked slow-motion controls. Diehard fans of these classic Criterion scopes often make claims of astounding optical quality of these instruments. Unfortunately, I found that the optics of my scope leave something to be desired. Yes, during times of good seeing, my scope does show me such things as the Jovian moons as obvious disks, etc. However, star-testing consistently shows stars to have triangular airy disks. I've  tried all the obvious tricks to try to improve the scope. I lined the inside of the tube with sawdust and is painted with Krylon Ultra Flat Black to reduce light scattering. I remounted the primary mirror by gluing it to the aluminum cell with silicone adhesive after removing the restraining clips to reduce any possible strain. I've even swapped out the secondary mirror. However, the annoying triangular diffraction pattern remains. I'm convinced that it is due to a surface error on the primary.

The Criterion Dynascope 6" keeps collimation well with a solid 4-vane secondary support. The phenolic tube was recently damaged at the front opening. I fixed it with sawdust and Elmer's Wood Glue. Now I have trouble detecting the repair!

The focuser is a little stiff. It's OK for visual use.

NEW! Images obtained with the Dynascope 6.

Mars. Image obtained with my Dynascope 6 and Philips ToUcam Pro webcam using Televue 2x barlow, September 12, 2003, 04:53 UT. This image was obtained under poor seeing conditions.

Jupiter. Image obtained with my Dynascope 6 and Philips ToUcam Pro webcam using Televue 2x barlow and stacking 134 frames, April 2, 2003, 03:21 UT. This image was obtained under poor seeing conditions and gusting winds.

Saturn. Image obtained with my Dynascope 6 and Philips ToUcam Pro webcam using Televue 2x barlow with extension tube on March 22, 2004.

Aristarchus. Image obtained with my Dynascope 6 and Nikon Coolpix 995 Digital Camera (afocal method with Televue 7.0 mm eyepiece) on October 17, 2002.

    I still use my Dynascope 6 regularly, especially when I want to have a quick peak at the sky without dragging out my much larger and more complicated 8." Recently, I gave the scope a facelift by coating it with blue monokote. I also replaced the cork lining of the clutch on the Right Ascension drive. The clock drive still works like a charm.

Links

The Criterion Dynascope Group - a wonderful place to share memories and experiences with fellow Dynascope users.