Stacking two f/.63 reducers?

[Night Sky Surfer]

Hi,

Has anyone done this? I was wondering how to figure out what the resulting focal reduction would be, or if it would produce a horrific image for which it's not even worth doing the math....

[michael8554]

What OTA ?

What camera ?

The back Focus for a f/0.63 Reducer is 105mm.

Does that mean the camera has to be 210mm back from the first FR ?

Michael

[Clarkey]

5 hours ago, Night Sky Surfer said:

or if it would produce a horrific image for which it's not even worth doing the math

I suspect this will be the answer as the angle of incident light to the second reducer would be completely wrong. In addition, the size of the imaging circle is likely to be very small.

Just out of interest, why would you want to do this anyway?

[Craney]

Guessing  that it will be a psychedelic outcome if at all possible  ( whatever the reduction  0.63 x 0.63 ~ 0.4x ).

If it could be done well, somebody would have described it.

There is a thing called a Night Owl  ( Starizona) that does 0.4x    ( https://starizona.com/products/night-owl-4x-sct-reducer-corrector )

 

[GTom]

Two SCT reducer-correctors? Bad idea, those are not just reducers, they correct coma and field curvature (e.g. Starizona 0.63x): the second corrector would OVERCORRECT the aberrations.

 

What MIGHT work: 0.63x sct reducer and a photographic speed booster, e.g. Metabones EOS-μ4/3 0.64x. This needs a micro 4/3 adapter on your camera (or you can use a converted, compatible micro 4/3 camera). Only zwo and svbony astrocameras can use the only micro 4/3 to t2 adapter on the market at the moment.

Edited August 5, 2023 by GTom