Now this is probably obvious to some, so please take it easy on me!
We all know that if you want to stop down an SCT or Newt, you
make an off-axis aperture, like this:
Or on a refractor, it's in the middle.
Now what if we want more aperture, but instead of making a bigger
hole, we make more small holes, like:
What happens to the image?
I'm actually thinking about this in relation to using multiple small
(affordable) red ERF filters for solar observation (in conjunction
with the appropriate blocking filter) using a refractor, but this
could also be applied to an SCT or Newt.
Cheers,
Jason.