Tele Vue Optics Article Page

If you have an 8” f/10 SCT with the 1¼” diagonal, as I’ve had since the early ‘70s, you can simplify your eyepiece collection while gaining dramatically better viewing experiences with a few Tele Vue eyepieces.

You basically need only 3 eyepieces to cover the range from low power with maximum field to high power for planetary viewing.

For low power viewing, you may already have a 25mm or 26 mm Plössl eyepiece that came with the scope. These will likely give you a fairly decent image and field of view with a 1¼” diagonal. But the superior coatings, construction and edge sharpness of Tele Vue’s 32mm Plössl will yield better performance, especially for those who wear eyeglasses and need long eye-relief. If you must wear glasses to correct astigmatism and know the astigmatism value, it's best to call Tele Vue for specific advice. However, you can gain maximum field, sharpness and contrast with a wonderful 68º field by using the 24mm Panoptic. The expansive view, darker sky background and higher magnification yields more detail and more exciting low power viewing.

Note, you can further dramatically increase low power viewing by adding the 2” Everbrite mirror system with its 1/10 wave, 99% reflective broadband dielectric coating. With appropriate 2” Tele Vue eyepieces, your maximum field can be increased from 0.76º to 1.3º, (three times the area). If you stay with a 1¼" diagonal, you may find that replacing your stock 1¼” prism or mirror diagonal with a 1¼” Tele Vue Everbrite diagonal will give noticeably sharper, brighter images.

At medium and high power viewing, 82° Nagler or 100° Ethos eyepieces yield “spacewalk” viewing for open and globular star clusters, planetary nebula, and galaxies.

And for high power viewing you’ll see more field viewing the moon, planets such as Jupiter with its entourage of moons using Nagler and Radian eyepieces, all with far more comfortable eye-relief than the “peep-hole” eyepieces usually supplied with your scope.

		Power	Field
1. Low Power, Maximum Field for 1¼” Diagonal	Either 32 Plössl or 24mm Panoptic	63x 85x	0.76º 0.76º
1a. Low Power, Maximum Field for 2" Diagonal	Either 55 Plössl or 41 Panoptic	37x 50x	1.30º 1.30º
2. Medium Power, for 1¼” Diagonal	Either 14mm Radian or 12mm Nagler Type 4 or 13mm Nagler Type 6 or 13mm Ethos	145x 169x 156x 156x	0.41º 0.48º 0.50º 0.64º
2a. Medium Power for 2" Diagonal	17mm Ethos	120x	0.83º
3. High Power for 1¼” Diagonal	Either 10mm Radian or 10mm Ethos or 9mm Nagler Type 6	203x 203x 226x	0.30º 0.50º 0.35º

You’re welcome to call our staff at 845-469-4551 for more in-depth, personal advice to fit your needs and budget. If you have 10" or larger-size SCT's you'll want to discuss the important field size advantages of 2" eyepieces, and the possibility of needing only 2 eyepieces to meet all your needs.

Getting the Most Out of Your 8” Schmidt-Cassegrain with Tele Vue Eyepieces