genm79 0 Posted April 6, 2011 I have a question for all the gurus. I am looking at 2 similar lenses. But I notice the Iris is slightly different. One has a Range of F3.1 ~ F22, while the other is F3.1 ~ T3000 (Equivalent to F3000) Can someone teach me what does T3000 means? How does it relates to F number? Thanks in advance. Share this post Link to post Share on other sites
Soundy 1 Posted April 6, 2011 No idea what "T3000" means (can you provide make and model of this lens?) but in both cases, the second number refers to the smallest aperture of the lens, and as far as CCTV cameras go, f/22 means it's effectively closed... anything higher just means it's more closed. It would be very rare you'd want the lens closed down that much anyway, so ultimately, I don't think that factor would make a difference in your lens choice. Share this post Link to post Share on other sites
