Originally Posted by Fl_Gulfer
I just conected a SMC-A* 300 f4 to my K20D and took a few shots and noticed when I hit the green button nothing happens, I thought it was suppose to make a few adjustments like it does with my other manual lenses. I have it set on "A" and the camera on manual also tryed it on Av. Is there something I'm missing?
It's a very sunny day and if i shoot at something in the shade it's very under exposed and in the sun it's over. I know I still haven't learned how to use the lens yet since I just got it a hour ago.
Thanks Guys
Jack
if a lens has the "A" setting there is no need for the green button
the green button is for step down metering for those lenses that lack any electric contacts, therefore the camera is clueless as to what the aperture is, so you press the button, the camera steps down, meters, and sets the shutter speed.
when you put the lens in "A" mode, you can use any of the cameras modes, Av, Tv, ATv etc etc without pressing any additonal buttons
yes, it really is that simple.