anorphirith
Established
do you know what this is ?
Double Blade
- Thread starter anorphirith
- Start date
- Latest activity Latest activity:
- Replies 6
- Views 2K
do you know what this is ?
mooge
Well-known
it has something to do with the shape of the aperture blades. they're a bit curved or something. it's not two sets of blades...
Al Kaplan
Veteran
When you open the diaphragm the blades have to go someplace. By making them curved or with a "dog-leg" such as these the blades can open and close to a greater degree without requiring as big an overall diaphragm housing in the lens.
anorphirith
Established
how does that work ? I have a hard time imagining that this is one set of blade. I don't see any hinges.
Last edited:
Al Kaplan
Veteran
It doesn't need hinges. The dog-leg does it. It's one set of blades.
BillBingham2
Registered User
Kind of like a curved knife like here?
http://www.themagicalblend.com/~magic/cgi-bin/cart.cgi/BOLINE0001.html
As each blade moves to close down the size of the opening follows the logarithmic progression of apertures thought the distance between f-stops (2.8, 4, 5.6, 8, 11, 16) on the lens is the same.
Not sure if that helped.
B2 (;->
http://www.themagicalblend.com/~magic/cgi-bin/cart.cgi/BOLINE0001.html
As each blade moves to close down the size of the opening follows the logarithmic progression of apertures thought the distance between f-stops (2.8, 4, 5.6, 8, 11, 16) on the lens is the same.
Not sure if that helped.
B2 (;->
anorphirith
Established
kind of ! thanks
looks like there are 2 layer though, it's not on the same level
do all leica lens have that feature ?
