Power on button & voltage check LED
The F2’s advance lever has to be pulled out to switch power on the finder. This is generally not a problem for most users, except for some people who use their left eye on the finder and have the F2 mounted on a motor drive. I have therefore created a new modification that replaces the self timer mechanism with a momentary power on button, which works in parallel with the advance lever activated switch. ie either pulling out the advance lever, or pressing the power on button would activate the finder.

Also, I have added a precision comparator integrated circuit (IC) that checks the voltage level of the batteries. The power check LED would distinguish if the battery voltage falls below 2.5V. This feature is very useful for finders (DP-2, DP-3 and DP-12) that do not have a power check feature.
F2 with power on button
and power check LED
Modified F2 body mounted on a MD-2