Tele Vue Paracorr Type 2
- Tele Vue Optics Inc
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Tele Vue Paracorr
Correct for Coma in your fast Newtonian Reflector
Concept: I have built Newtonian reflectors since my high school days and still enjoy observing with my 12" f/5.3. Knowing how the Nagler eyepiece complemented fast Dobsonians and Newtonians by removing eyepiece induced astigmatism, I now became intolerant of the inherent defect of coma in a parabolic mirror.
Paracorr — more stars, sharper stars, more time to observe.
I decided to try to achieve the same field quality for parabolas as reached by my Nagler eyepiece and 4-element refractor designs. Existing coma correctors seemed to be limited in color correction, spherical aberration and convenience in use. Paracorr (parabola corrector) uses 2 multi-coated, high index doublets, is completely color-free, center and edge, and installs like a Barlow. Coma is corrected so well, the diffraction limited field area of an f/4.5 Dob/Newt is increased 36 times! — Al Nagler
An optical chain is as good as its weakest link. With the development of 82 degree Nagler eyepieces, Tele Vue offers the largest, flattest and best corrected visual fields in the industry. Combine the Nagler revolution, Dobsonian revolution and Paracorr for the ideal mating for spectacular wide and sharp "spacewalk" observing.
Life before Paracorr
Coma makes stars look like blurry comets whose tails point out radially from the center of the field. The faster your scope's speed, the worse the effect. All parabolic mirrors used in Newtonian reflecting telescopes are limited in field sharpness due to coma. Even a perfectly made 13" f/4.5 parabola has only about 0.1 degree diffraction limited field.
Previous attempts to correct for coma have been limited in usefulness. Some correctors were designed mainly for astrophotography. Dedicated coma correcting eyepieces were another approach. However, these were limited to 50 degree apparent fields and would orphan your existing eyepiece collection.
Life with Paracorr
Paracorr is a universal corrector that tightens and intensifies star images on all f-ratios (Visual Paracorr: f/4.5 to f/8, Paracorr Type-2: all faster scopes) without adding any false color or spherical aberration! You no longer have to constantly shift a Dobsonian to keep objects centered for sharp viewing. Using a Tele Vue eyepiece, put M-13 at the edge of the field and enjoy resolving its beauty as it drifts across your view.
Paracorr is easy to use. It slips into your focuser, just like a Barlow. To minimize focuser in-travel, due to additional length, a mild 15% Barlow effect was designed into Paracorr to effectively push the focus out. Paracorr is recommended for use with all Tele Vue eyepieces because our Plössls, Radians, Panoptics, Naglers and Ethos achieve higher levels of aberration correction than competitive models. However, Paracorr is also compatible with other eyepiece makes.
Try Paracorr on your "DobNewt." We think you'll agree that the revolution is complete.
Paracorr Eats Coma
The visual Paracorr can be used with both 2" and 1¼" eyepieces. The imaging models work with DSLR and CCD cameras. For visual use, slip Paracorr into your focuser like a Barlow lens, and your eyepiece into Paracorr. 1¼" eyepieces will make use of Paracorr's special low profile 1¼" reducing adapter. Paracorr is threaded for 2" filters.
VIP-2010 (Paracorr Type 2)
Developed in 2010, this model can make an f/3 mirror act like an f/12 without a Paracorr. Essentially diffraction-limited across the field, it makes the new breed of f/3-f/4 “ladder-less” Dobs possible, and superior in terms of convenience, field-of-view and optical perfection when using top quality mirrors.
The Paracorr Type 2 allows separating the optical assembly from the Tunable Top and using it with Tele Vue imaging system components to permit use with SLR and CCD cameras. APS size formats 27mm diameter are recommended to minimize field vignetting. Ideal for mirrors as fast as f/3.
Note: The Paracorr Type 2 optical assembly is also available in a special adapter housing made by Starlight Instruments for their Feather Touch focusers. This unit avoids the need for a tunable top to optimize eyepiece position. Some Dobsonian manufacturers may also offer the Feather Touch focuser with integrated Paracorr type 2 as standard. Starlight Instruments offers Paracorr Type 2 integrated with Feather Touch focuser or as an add-on if you already have a Feather Touch focuser.
Optimizing the Coma Correction by Using Paracorr's Tunable Top
As you've read, all Newtonian / Dobsonian telescopes can benefit from using a Tele Vue Paracorr (Parabola Corrector) to eliminate coma in the image. One aspect to optimizing this correction is the distance of the eyepieces focus point (field stop location) to the last surface of the Paracorr lens (within a small +/- tolerance of course). Typical eyepieces used with fast Newtonians can have field stop locations differing by as much as half an inch. To accommodate for the differences, we developed the "Tunable Top."
The "Tunable Top" permits optimized aberration control for all Tele Vue eyepieces and many others, by simply loosening a screw and rotating the Tunable Top. The eyepiece barrel height raises and lowers, allowing you to maintain the proper field stop to Paracorr lens distance.
You are buying from an authorized Tele Vue Optics Inc UK dealer.
|Item||Price||Telephone 07496 368981|
|Tele Vue Paracorr Type 2 VIP-2010||£466.00||Delivery to mainland UK only.|