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View Full Version here: : Field Flattener for 14" RC


benklerk
10-05-2019, 11:11 AM
I'm working though my setup half way done now,

I have put down a deposit for a GSO RC 14", will I need a field flattener for a KAF-16803 chip size?

I know you need one for smaller RCs depending on the sensor size, but for a 14" mirror can I get away without the use of one?

The camera has a thread M68 female.

billdan
10-05-2019, 11:43 AM
Hi Ben,

Yes, you will need one for a 50mm diag sensor.

The radius of curvature of a RC at the focal plane is approx 12% of the focal length.

Starizona gives an example of a 12.5" F9 RC across a 35mm diag full frame sensor.

It states the radius of curvature at the focal plane is 360mm, the required depth of focus to cover a 35mm diag sensor is 613 microns but the actual depth of focus is only 257 microns.

The link to Starizona does not work anymore so I have attached a saved Word document that I created a few years ago for you to read.

Cheers
Bill

benklerk
11-05-2019, 08:54 AM
The biggest I could find without spending 1000s$ on a flattener is the TSRCFlat3.

Now has anyone used one?

https://www.teleskop-express.de/shop/product_info.php/info/p6972_TS-Optics-Full-frame-size-Corrector-for-RC---Ritchey-Chr-tien-Astrographs.html

Logieberra
15-05-2019, 01:21 AM
I really liked the AP CCDT67 on my 12” RC...