brenda_carpenter2 Posted February 8, 2007 Share Posted February 8, 2007 Hi, I hope someone can help me with this situation. If I have studio lights set up for correct exposure at f8, shutter speed 1/500, normal lens at 10 feet, how will I need to compensate fstop if I change to a longer lens and move to 30 feet? Will I have significant light fall off? Thanks for any help you can give me. Link to comment Share on other sites More sharing options...
garry edwards Posted February 8, 2007 Share Posted February 8, 2007 Brenda, The distance of camera to subject makes no difference to the exposure and so needs no compensation. I'm a bit puzzled by your statement that you're using a shutter speed of 1/500th - very few cameras can synch at this speed, and in any event there just isn't any point, in all normal studio circumstances, in doing so. Link to comment Share on other sites More sharing options...
mrstubbs Posted February 8, 2007 Share Posted February 8, 2007 Hello Brenda, Light travels at over 186,000 miles per second. If it measures f8 at 10 feet then it will measure f8 at 30'. Link to comment Share on other sites More sharing options...
mark u Posted February 8, 2007 Share Posted February 8, 2007 Your exposure will change if you move your lights relative to the subject, or the subject relative to the lights. Moving the camera and using a longer lens to give the same framing will have no effect. Link to comment Share on other sites More sharing options...
edsel_adams Posted February 9, 2007 Share Posted February 9, 2007 I'm somewhat puzzled over Garry's answer about sync speeds. Almost all leaf shutters sync to 1/500th? As for Brenda's question, only when the "subject to light" distance changes are exposure values changed. Link to comment Share on other sites More sharing options...
garry edwards Posted February 9, 2007 Share Posted February 9, 2007 Ensel is right - leaf shutters can normally synch at all shutter speeds - but leaf shutters are in a very small minority, most people today use cameras that have focal plane shutters. And I stick to my original point; most of the time, there is no benefit in using studio flash at very high shutter speeds. Link to comment Share on other sites More sharing options...
conraderb Posted February 9, 2007 Share Posted February 9, 2007 if you do not change teh subject-to-flash distance, your exposure settings do NOT change. think of a man on a stage with a spotlight on him. if you move the spotlight away, he gets dimmer. if closer, brighter. but does the audience (the camera) see his brightness level differently depending on whether they are in the front row or the back row? he gets larger and smaller, yes, but not dimmer or brighter. if you have a DSLR, this should be obvious, but I assume you are shooting film. Link to comment Share on other sites More sharing options...
brenda_carpenter2 Posted February 9, 2007 Author Share Posted February 9, 2007 Thank you so much for your help. It's just what I needed. I am using a Bronica ETRS and Kodak Portra. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now