Hi Marc,
just go buy one, they are cheap on Ebay and work 100% of the time. I have had mine for a couple of years and plan to use it again today.
This was taken at night via traditional method but it is at night.
Same as this one.
However, for day time you need
the trigger. Day time you cannot capture lightning reliably. It would be a one in a million shot to capture it.
This image was triggered by it.
This one was also triggered by it but it was sheet lightning(not definable in the image). The sheet lightning was thick on that day the trigger kept releasing.
Have fun and stay safe.