adjusting travel of focus on camera lenses

Hi,

I recently acquired a night vision scope. One problem though, it cant focus on anything beyond about 10 feet. The lens that comes with it has a standard t-ring type addaptor so I was able to put in another camera lens to confirm that the unit does actually work ok. So the issue seems to be that the supplied lens cannot travel back far enough to focus on infinity (or anything more than about 4 meteres away!)

So rather than ship it back to the US and have it repaired, its under warranty but shipping is expensive, I'm wondering about the possibility of doing some DIY.

Firstly, is it possible to adjust the lens so that the range of the focuser is different? i.e. can I change it so that at its infinity setting the optics sit a little further back than they do at present?

if so does anyone know of any websites, or good books that describe the procedure? The one advantage I have is that the lens is fairly large and relativly simple, there is an aperture, but no mechanical f stops.

fyi the unit is one of these www.optcorp.com/cart/ProductDetail.asp?PR_ProductID=866 (I didnt buy it from opt though)

Cheers,
~Al

p.s. Don't suppose any of you B&L folks do maintainence for Bushnell no? worth asking

Sorry Al

B&L sold Busnell and RayBan some years ago and now here in Waterford we only do contact lenses.

Conor