[Leica] summarit

[dpost at triad.rr.com (Dan Post)]

Not an urban legend at all- the natural lubes tend to evaporate over 
time, and like the oily buildup on your kitchen range hood, the lighter 
elements of the lube condense out on the glass. This schmutz really 
louses up the contrast and sharpness, even if it is not 'really bad 
looking' from the outside. The remaining lube on the helicoid also is 
much stiffer- like beeswax at times, and makes the focusing stiff.  I 
had DAG do a CLA on mine and the difference in the quality of the 
resulting photos was very evident. Much sharper than I had anticipated 
from such an old formula, and better contrast as well. The 'bokeh' if 
used wide open is nice, and since I do use the boxy shade on mine at all 
times, I have had no problem with flare... well, let me say that you 
don't want to use it to shoot sunsets!  :o)
IF you have a nice example, it is worth keeping.
Dan ( I bokeh'd in the kitchen, and I bokeh'd in the hall; I bokeh'd on 
my finger, and wiped it on the wall....) Post