Rule of 600 Canon G1 X

What does the Rule of 600 dictate for an exposure time for a Canon G1 X to avoid star trails? This camera has 15.1- 60.4mm 1:2.8-5.8 indicated on the barrel.

PTaker wrote in post #16913215
What does the Rule of 600 dictate for an exposure time for a Canon G1 X to avoid star trails? This camera has 15.1- 60.4mm 1:2.8-5.8 indicated on the barrel.

Doesn't seem anyone knows the answer to this, I've never seen it discussed on this forum that I recall. I would presume you want to shoot at 15.1mm, I'd take it out and start at 15 seconds and adjust from there based on the results.

G1 X is 1.85x crop factor so you multiple the 15.1 to get 28mm.

The Rule of 600 also depends on your location so definitely play around with it, 21 seconds may be tops; if not try to use 500 instead (17 sec or so max). I use 500 with where I live and show much better result.

the jimmy and Aki78:

Thanks for the info. I'll try 15 to 17 seconds and view the results.

How much of a difference does location matter? I am near Chicago now but will be in Botswana in a few months.