I tried to take some pictures of the night sky with my Canon RP. I know that I have to focus on something in the distance and with my old Canon 5d mkii, it was always easy to autofocus even on bright stars or planets.
However, I had a hard time with the focus with the RP, as there was no moon, no distant lights and autofocusing on the stars did not particularly went well… I ended up using the focus peaking and manual focus on bright stars and some iterations to get the focus right.
I wondered, if there is a better and more reliable method to get the focus right? I found it interesting that with the 5D it was always super easy (even by pointing to the sky) but with the RP (with presumably a much better autofocus system) it was very tricky…
My approach for this is manual focus, and zoom in on the live view, a far as it will goe if need be (on my Nikon it’s something like 12x) and then rock the focus ring from side to side until the star is as small as it will go. I don’t know how you magnify the LV on your Canon but I’m sure it would allow that somehow?
Yes zooming in is possible and that was also my approach with the manual focus. But I found it much harder than on the 5d, where I was able to use even the autofocus.
Maybe I have to try the different autofocus modes (i.e. spot, zone etc) and check which one performs best.
That’s the approach I’m using too. In this case I would recommend turning the focus peaking off. Just try to get the stars as small in diameter as possible. This is a case where I would use manual focus over auto focus anyway. A good manual focus lens (with a linear and smooth focus ring) helps also.
Last night, the sky was almost clear. I focused on Jupiter without the peaking, which worked out quite well.
The manual focus is still a bit fiddly, but works good enough.
Can you not set the rotation speed for the manual focus for RF lenses (I have the RF 24-105 f/4) on a Canon EOS RP? I thought I saw that once, but the only setting I found was if it is speed dependent or linear. In that particular case I would like to have a really slow focus though.
edit: okay maybe I misremembered that with the sensitivity adjustment. I searched the whole handbook and could not find a thing. The only settings that I can find is, as I already said, C.Fn. III-4, where you can change between speed-dependent and linear. Here, the speed-dependent is actually useful, as it allows for much finer adjustments but if you slip your finger by accident along the focus ring, you are much more out of focus.