Tele Vue's model TRF-2008 0.8x Reducer / Flattener converts TV-85 to 480mm f/5.6 and TV-76 to 380mm f/5.0 for flat field, fast photography. While optimized for TeleVue's TV-85 telescope, it is quite effective with all doublet or triplet refractors with a focal length range of 400mm - 600mm.
Fully multi-coated 3-element unit inserts directly into 2" focuser on the telescope side. It accepts standard T-rings (M42x0.75 thread) for DSLR cameras.
Installation is simple. Just thread your camera's T-ring (not included) onto the 0.8x Reducer/Flattener. Then, attach the T-ring to your DSLR camera. Remove the diagonal from your telescope’s focuser and replace it with the flattener/camera assembly. Your telescope’s focal length and f/ratio will now be 0.8 times their normal figures.
"This accessory is a must-have for someone planning to use the TV-85 photographically" - review in Sky & Telescope, July 1999.
Manufacturer part number: TRF-2008
Feb 10, 2017
Works quite well on the Equinox 80EDPros: Cons: Comments:
I tried it on my two Skywatcher 80EDs, it was not suitable for the f/7.5 Evostar, but worked quite well with the f/6.25 Equinox. Vignetting was negligible with a Canon APS-C sensor at the standard 55mm distance. If you want to see sample images of that configuration, google for TRF-2008 vs Altair Lightwave 0.8x - the latter proves a good match for the Evostar.
This review was provided courtesy of AgenaAstro.comAug 8, 2014
Use with some cautionPros:
Difficult to UseComments:
While this can be made to work in some systems, I've found that the stated backfocus distance required (~56mm) is inaccurate. While I am not using a Televue scope, I have tried this in a variety of f/6 (Stellarvue, Orion and William Optics) and consistently found that ideal distance to be closer to 46mm. While this may not be an issue for some, for users of CCD cameras that want to include a filter wheel and OAG in the imaging train, this short distance can pose a serious problem!
This review was provided courtesy of AgenaAstro.comOct 31, 2013
Great addition to the kit!Pros:
Easy to Use,Quality Lenses,Strong Construction,Accurate,Flat fieldCons:
I added this to my collection to use with an 80mm f/6 APO refractor for increased field of view with an APS-C imaging chip (Canon 40D and 400D).
I'm very impressed with the field flatness with this configuration ... circular stars to the corners!
One negative is noticeable vignetting when processing faint objects, so FLAT field frames are essential to balance up the image.
This review was provided courtesy of AgenaAstro.comSort by