Quote:
Originally Posted by DavidTrap
Most flatteners have a recommended distance between the flattener (usually measured from the the thread starts, not the edge of the flattener) and the imaging plane. The distances for Canon's are ~45-46mm (have a look on google). You need to allow the thickness of the T-adapter as well (usually about 10mm). Therefore a standard DSLR & t-adapter will give you a minimum of 55mm from back of the flattener to the imaging plane.
Varying this distance changes the "focus" of the flattener and usually the degree of "reduction". Get it right and you'll be a happy astrophotographer. Get it wrong and you'll look like you're in the cockpit of the Millennium Falcon
as hyperdrive is engaged.
DT
|
So if a given flattener requires a certain distance (or small range of distances) and the distance from flange to sensor is obviously known for any given camera (plus width of T-ring) then the 'spacer requirement' should also be known. Seems like there should be a list of cameras and required spacing with each flattener, but they don't have them with any online adverts. They simply show a picture of flattener + T-ring + camera. Should it be that simple???