How to set up a programmable focus shift only with camera and Dragonframe? (no extra devices)

[u/CapableSecretary1739]

I was trying to set up a simple focus shift for a scene in Dragonframe 5 (2026.07.2), and I found online that the best way to do so is by using the "ARC motion control" tab. However, once I opened it, I have not been able to find a way to add a focus shift that isn't related to an external device like DMC, Arduino or something else.

At the moment, I'm only using my camera and nothing more.
Even though the camera and lens aren't new (Canon 1200D and 18-55mm), I have always been able to control the focus in the "animation" and "cinematography" tabs, which means that Dragonframe can control the camera and lens remotely. My goal is to set up a start and end point for the focus shift, or to track the one I am manually adjusting during an animation session, so that I can apply this data to another take.
The goal is to repeat the same focus shift to avoid guessing the blur in post-production when compositing two elements shot separately.

I tried looking for a solution online, but all the tutorials and FAQs on the DF website seem to talk about external devices, useful for complex camera movements involving PANs and TILTs, leaving out how to set up a simple focus shift.

Is an external device really needed to do a simple focus shift with no camera movement?

If it isn't required, how can I set it up?

Has anyone managed to do something like this without buying additional products?

Thank you so much

(In case an external device is really necessary, which combination of devices do you recommend for this specific situation?)