ulrik Posted August 22, 2005 Share Posted August 22, 2005 I got my 15 mm Voigtl䮤er lens today. When I open the aperture (f 4,5) the aperture blades are still visible as a ~ 1,5 mm thick ring around the optical path. Is this normal with this lens? Link to comment Share on other sites More sharing options...
john_amiet2 Posted August 22, 2005 Share Posted August 22, 2005 Never looked before, but yes, mine looks how you describe. Functions fine. Link to comment Share on other sites More sharing options...
al_kaplan1 Posted August 22, 2005 Share Posted August 22, 2005 Mine too. My 21/3.4 Super Angulon shows a very narrow ring, and my LTM 19/3.5 Canon did the same. Link to comment Share on other sites More sharing options...
ulrik Posted August 22, 2005 Author Share Posted August 22, 2005 Thanks for your quick answers! Ulrik Link to comment Share on other sites More sharing options...
shambrick007 Posted August 22, 2005 Share Posted August 22, 2005 Many wide lenses are like this. Mechanicaly, they could open wider, but the resulting images would be crap! Link to comment Share on other sites More sharing options...
bj_bignell Posted August 22, 2005 Share Posted August 22, 2005 >>Many wide lenses are like this. Mechanicaly, they could open wider, but the resulting images would be crap! Are you suggesting that the lenses are limited internally by a pin, or some sort of restricting device? If so, would it be possible to disassemble and modify the lens to open wider? Or, are they built to only open to a certain aperture, and that's it? Purely from a hypothetical point of view; I won't be modifying my 21mm any time soon, but I can see myself doing it some day... Link to comment Share on other sites More sharing options...
andrew robertson Posted August 22, 2005 Share Posted August 22, 2005 I have a feeling that there's no limiting device. It's just designed so you can't open it up to the full diameter of the inside of the lens barrel. I too own the Heliar 15 (superb little lens BTW). I'm sure if you really wanted to you could open the lens up and simply physically remove the aperture blades. Then you could rig up some kind of whacky Waterhouse stop affair to retain some kind of aperture control. Link to comment Share on other sites More sharing options...
al_kaplan1 Posted August 22, 2005 Share Posted August 22, 2005 You have to increase the diameter of the opening by a factor of 1.4 to gain another stop. That little ring of diaphragm blades you see is so narrow that you'd gain a mere fraction of a stop at best, and perhaps end up with an f/4.3 lens instead of an f/4.5 lens. You'd never see the density difference in your negatives. It would be too small, too subtle. Link to comment Share on other sites More sharing options...
simonpg Posted August 23, 2005 Share Posted August 23, 2005 Yep, sure is normal. Taken any photos yet? Good idea to try it out before worrying about how it looks. Like the others said, not much place for them to go when opened wide! 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