[sbogar]

Thanks for the responses. Answering them one-by-one.

 

Why is this important to know? Can not think of any valid reason.... That the front element does not rotate is important.

 

There are valid reasons (even if you can't think of them

I am planning a scientific use of this lens.

A rotating inner lens with tiny dust grains changes the flatfield and stray light pattern on the images.

Best if the inner lens does not rotate, but only translates. This is my best bet.

 

Sealing of everything. If you do not shoot in heavy rain or during sandstorms, it is not of that much importance.

 

And if you have this lens sitting outside in a desert for years in an enclosure that opens up during the night?

The lack of sealing may not be critical, if it is about as good as a Nikon or Canon lens.

If the comment meant that sealing is poor in comparison with typical Nikon or Canon lenses then thay might concern me.

 

A lens is round, the image rectangular. Evident how the vignetting would be...

 

The vignetting has cylindric symmetry with respect to the optical axis. This is trivial.

The image is rectangular (but not a box).

 

But which point on the chip does 0.55EV vignetting refer to? Vignetting will be different

on the horizonal edges, vertical edges and the corner. I just want to figure out where the 0.55EV

was measured at (my guess: corner).

 

Of course. But WHY???

 

 

There is no "of course". I have a lens (Canon 200 f/1.8 AF), where focusing does not work

even in MF mode, unless the lens (and its CPU) is powered up by a camera body.

I admit this was a surprise, and reverse engineering was quite an effort.

Glad to hear it would work on this lens.

 

Note: I am not attaching a DSRL to this lens, but mating it with a CCD.

 

Thanks again!

Sapkas