08-12-2020 08:30 AM
08-12-2020 09:38 AM
What is this information going to be used for?
Night sky photography
Some type of projection
Why is it needed?
08-12-2020 10:17 AM
"...the projection circle or diameter of image field, of my Canon lenses."
You are simply asking, what is the angle of view (AOV) of my lens. I am sure there is an equation to figure that out somewhere. Should be easy to find or figure out.
If your thought is to use a 35mm (EF or R) type lens on a MF camera forget it.
08-12-2020 10:56 AM
08-12-2020 10:57 AM
It is more complicated than that, angle of view depends on the sensor.
Think of an EF lens on an EF-S camera. The angle of view is narrower than that you would get on an EF camera. So the image circle is larger, and some is "wasted" around the APS-C sized sensor.
08-12-2020 11:00 AM
08-12-2020 11:20 AM
"It is more complicated than that, angle of view depends on the sensor."
It is complicated or at least hard to understand or grasp. The AOV never changes on any lens. It can't. The smaller sensor is exposed to exactly the same AOV, it simply doesn't see the excess because of its size. This is how we get an equivalent FL.
If on the other hand you wanted to go to a larger sensor the image circle or AOV might not be large enough to cover the MF sensor. You will be left with a black ring around your photos.
The dimensions of a 35mm sensor are typically 36×24mm. I imagine the image circle that Canon EF or R lenses produce will fill that with the appropriate circle diameter. Since it is not square the rest gets wasted just like a crop sensor does.