I have a little question regarding the sensor distance on my SX h18 cam and i have always thought the backfocal distance has been 18.5mm. But now i have read that it is 23mm.
Which one is true?
I have calculated that the thickness with the filterwheel (29mm) and camera is either 47.5mm or 52mm depending on which measurement is right.
I ask of this to know how much spacing i will need the ts-optics 2" x0.79 reducer/flattener which i still waiting for.
The R/F wants a backfocus of 61mm.