[Leica] R4s Question

[Steve Hickel <smhickel@x2.alliance.net>]

Hi all, 

I am the proud new owner of an R4s, mint- condition. Fred good job!! I also
now have a lens and if all goes well it will be a deal too. The lens is a
35/2.8 Elmarit. Very nice looking lens with some heft. My question is about
the camera but I would like to know peoples opinion about their good
experiences with this lens or camera or both. No negative comments yet. I
need to bind with my new camera and potential new lens. Also, most of you
know Don sold me his 50/2 Summicron 2-cam but that is not here yet. Anyway
here is the question:

Since I don't have a manual for the camera. There is a knob on the front
left of the camera about the 8:00 position (this is looking at the camera
from the front). What is the purpose of that knob?

Question 2. The camera has next to the speed control know an indicator that
goes from M to A to A. It seems that the A's are aperature priority
(eventhough the book I have says the camera is a shutter priority camera).
What are the differences in the A's and which is which?

What other hidden features are there that anybody can think of that I
should know. Thanking you in advance. 


Steve