To return to the OP's question, I'm afraid it isn't really a meaningful thing to ask.
A camera does not magnify at all and has no focal length. You can calculate the size of the image on the sensor easily enough given the effective focal length of the optical train, but that doesn't really answer your question at all.
What are you actually trying to achieve?
I don't have an ASI034MC, but I used to use f/30 to f/35 quite happily with my SPC900 and 127 Mak so if conditions allow I'd certainly suggest trying it. Now I use an ASI120 and tend to stay much closer to f/20 to f/25.
James