|
The 55mm in the case of the flattener with my scope is from the shoulder on the male threads on the camera side for their standard setup, but in this one the lens set is quite deeply set down inside that point so they are able to accommodate backfocus anywhere up to about 100mm by means of changing the depth of the rear tube of the flattener, in my case they made it in three screw together sections.
The Celestron 0.63 reducer/corrector for my SCT is the opposite where you have to watch out not to put fingerprints on the camera side lens as it is literally at the end of the threads!
|