I am just getting ready to start my journey into long exposure photography.
Having just dabbled in long exposures with some screw on filters (NDs, and some vari-NDs), I am now taking the leap with the Lee system. From my wife I am getting the Lee starter kit (with a .6 hard grad ND, and a .6 ND, the filter holder) plus a couple of rings (77 wide, and 82 wide), and from my two kids I am getting the Big Stopper; all bought by me
I have some questions for those of you who have experience and time to answer it.
1. Is the Cokin Z-system (filter rings and filters) compatible with the Lee 100mm system? (same thickness of glass?)
2. How do you calculate the exposure time? I have looked at several videos and posts concering this. They mention reading the exposure at a certain F-stop, then adding time based on your ND stops. Some further argues that ISO, and exposure compensation can be used to extend the time. All this seem correct, but incomplete.. Given that you shoot on the lowest ISO possible, then use EC (to say -3), F 22. Would you not be able to reduce it even more by switching to a lens that have F32 (like the 70-200 II), then add a 2xIII TC, thus getting a F 64, hence buying more time (here diffraction might play a devestating role?).
Not sure if my questions are coherent, or that I might have misunderstood..
Any input would be much appreciated, and if you even want to illustrate it by adding a picture that would be great.
In advance, thank you,