Timed Shutter Control

I am trying to figure out how to build a super simple build. I have extremely little electronics experience so I could use some advice.

I have a camera trigger with a two stage button and I want to modify it to trigger ever n seconds. I only need to trigger the second stage and bypassing the trigger is just a matter of connecting two contacts.

I would simply like to replace a switch with a variable timer. I want to take pictures as quickly as possible, so I want to vary the time in order to dial in the optimal timing. So I am looking for this result:

Press a button
wait n sec
connect contact a with contact b
wait n sec
connect contact a with contact b
...
Press a button
Stop connecting

I have been searching online but can't seem to find the right thing. I think I should be using some 555 timer build?

I apologize if this sort of question has already been covered.

 

Yes, it's a 555.
Here's one set up for 12 volts.
1/2 to 1 1/2 seconds off, 25 milliseconds on.
You start it with the power switch and you stop it with the power switch.