50mm Elmar hiding a stop?
Just got a 50mm collapsable 2.8 Elmar today as an everyday lens that I allows me to keep my camera in my coat pocket when I'm not in shooting mode. Anyways, I'm playing with it, and I noticed I can get the aperture ring to go a decent distance past the f/16 tick. To make sure I'm not partaking in bad science here, I'm running this past you guys who have been at this a lot longer then I have. I put the lens on my scanner and scanned it at 2400 dpi and aperture at the f/16 tick, and where it stops when I go past it. Opened up these files in photoshop and used the measure tool to see how wide the openings are.
f/16 tick = 3.1mm
Past the f/16 Ttick = 2.1 mm
50/3.1 = 16.
50/2.1 = 23.
Looks like the lens may be hiding a stop. Is there a reason why I wouldn't want to mark my own DOF scales for f/22 on this lens and use it in this position? Is my procedure completly obtuse? If I use it this stopped down, will it defract to the point where its softer then mud through a frosted window?
Maybe a short test roll is in order.