Shutter vs. Barrel + Shutter

Are there ANY differences whatsoever--in terms of either optical quality or spec ifications--between barrel lenses and the "same" lens that is sold by the manufa cturer ready-made in a shutter?

Is there any risk in having a shutter added to a barrel lens--such as scratching the lens during the changeover "operation", winding up with a less-than-perfect positioning, or anything else?

If you could save a few hundred dollars buying a barrel lens and having a shutte r added, over buying one pre-made in a shutter, would you always get the barrel?

Thank you.

If they come from the manufacturer, the lens in shutter should be the same as in barrel in every respect.

There is no particular danger of damaging the lens by remounting it in a shutter. Typically, the cells just unscrew from the barrel and are fitted, with one or two adapters to screw into the new shutter, and you would usually get your original barrel back (I can't imagine any repair technician having too much of an interest in developing a collection of old lens barrels). See www.skgrimes.com for a description of the process and an excellent resource for having the work done.

With some ultra-wide lenses, there may be some risk of vignetting when mounting in a shutter, but in general, there are no particular risks along those lines with most lenses.