Why Purchase from All-Star Telescope?
Free Expert Support
Whether you are a first timer needing help with setting up or an enthusiast that can't quite make that one thing work, our expert staff are ready to support your needs. With decades of knowledge and first hand experience we've been there and we can help you through it!
Stress Free, Secure Transactions
You can trust purchasing and delivery with All-Star Telescope. All of our transactions are 100% secure and Level 1 PCI DSS compliant thanks to Shopify's ShopPay platform. For additional protection, we insure 100% of the value of every shipment we make. If it get's lost during shipment, we replace it. If it gets damaged during shipment, we repalce it. We make sure your product arrives exactly as you would expect it to; we promise.
We also ensure privacy protection. We never keep any of your credit card information on file and any of your personal data is stored accordign to our policies.
30 Day Return Policy
Buy with confidence knowing that we accept returns up to 30 days after purchase. We want you to have something you will actually use and we are confident that we keep good quality products in our store with No Junk.
Price Match Promise
Shipping around for the best price is tough, we make it easier by offering the best pricing in the market. But if you find a better price on an in-store item somewhere else we will match it!
Product Description
In general, for the widest image field using a telescope, use Prime Focus photography. This technique uses the telescope in place of the camera lens. It requires a cameras with a removable lenses and available T-Ring accessory (check with any photo store).
To maximum contrast in your prime focus photography, use the TeleVue Camera adapters. Blackened anti-reflection threads minimize stray light reflections. To enhance your creative palette, we machined 48mm filter threads into the end of the adapter. Fits standard DSLR camera T-rings. Available for 2" and 1.25" focusers.
Field of View
You can calculate the field size of the resulting Prime-Focus images as follows:
Field Angle° = (Imaging Chip Dimension ÷ Telescope Focal Length) x 57.3°
The most popular cameras used for Prime Focus are Full-Size and APS-C sized Digital SLRs. Employing the above equation, the following example fields of view are for a TV-85 (600mm focal length):
DSLR with Full-Size chip (36mm x 24mm) on the TV-85 will yield:
- Field Angle (long dimension) = 36 ÷ 600 x 57.3° = 3.44°
- Field Angle (short dimension) = 24 ÷ 600 x 57.3° = 2.29°
A DSLR camera with an APS chip (about 22mm x 15mm) on the TV-85 will yield:
- Field Angle (long dimension) = 22 ÷ 600 x 57.3° = 2.10°
- Field Angle (short dimension) = 15 ÷ 600 x 57.3° = 1.43°