The soft casing of this Sigma lens is big and takes a lot of space in the bag. I need another form of protection from all those knockings and jostling that are inevitable while the lens is in the bag during handling. I need to take care of it even from scratches so I decided to make a protective jacket for the lens.
I folded a camping mat around the lens and did some markings. Then I laid it flat and drew the outline for the jacket and cut it. A piece of black cotton cloth was then glued and covered all the surface area and lastly I sewn Velcro® straps on three locations. Since there was empty space at the mount side of the jacket with the lens inside and to prevent the jacket from caving in, I cut out strips from the camping mat and made a circular filler for the space.
In retrospect if I were to do it again, I shall glue on one side with cloth of the same exact size and on the other side with cloth of bigger size and then just fold it over.
During one of my outings, I found another use for this jacket. Since the lens is not weatherproof, I found it quite adequate to use as a protection against the weather when it drizzle slightly.
Update 27 January 2012:
It can also be used as a backup lens hood. Tried and tested recently when I forgot to bring along the hood.