I'm currently setting up a new configuration for wide field photography. Also this configuration should be as small and transportable as possible.
I want to use one of my Canon lenses connected at my (soon arriving) QHY600 color CMOS. I have several lenses but I don't know yet which one will be the best performer. I think that my Canon RF 70-200 f2.8 will be the first choice.
The mount is a iOptron tracker and with the zoom capabilities of the lens I can use a focal length that is ok for the tracker, I hope that I can use it up to 150mm and 1 minute exposure but I have to test how precise the tracker will perform.
Now my question. Does anyone know how I can set the aperture of the lens? I believe that the lens is always at f2.8 if it is not connected to a camera body. Can I set the aperture with the Canon camera connected and then after removing the lens from the body this aperture is still kept? Let's say I have the lens connected to my R5 and set aperture to f3.5 and then remove the lens from the R5, will then the aperture stay at f3.5?