A few weeks ago, I got myself a nice, cheap, big brass lens. Originally, it must have come from a magic lantern projector – however, I betcha I can make it work for me!
The lens seemed OK, the focusing pinion was present and working, and the iris smooth and operational with only the glass being really really dirty. After a good clean it turned out that the lenses were actually in pretty good shape with only a few minor scratches.
Seeing I’d like to keep it that way, but also because the lens comes without any form of a shutter mechanism, I set out to make myself a lens cap. And it’s easy! I followed the instruction as written up by Alex Timmermans in 2010 – you can find his description here.
What you need:
- thin cardboard, about A4 in size (depending on the size of your lens)
- a piece of thin leather in a colour of your choice
- some water in a bowl
- cling film
- clamps or clips
- (clear) tape
- a ruler
- Emery board or sanding paper
- sturdy rubber band/ tie wrap
- a sharp blade
- a pair of scissors
- a cutting mat
- Oh yes, and the lens you are making the cap for!
Step 1: Cut a spacer. Take your cardboard and cut a strip long enough to wrap around your lens once. It should be about 2 cm wide, max. Make sure it fits well, tape the ends together and cover in (clear) tape. Let the tape cover the ridge of your lens as well, this will protect against the glue we’ll use later on. My cardboard was really thin, so I used two layers of strips as spacers.
Step 2: Cut the sides of your lens cap. You will take your cardboard again and cut 2 strips to fit around the spacer. First cut the one, wrap it round and make sure it fits exactly. Secure with a bit of tape, then cut the second one to fit snugly on top. The width will depend on your lens, but again, should be max 2 cm.
Now take those last two strips off and glue them together, slightly overlapping at the ends to be able to secure them into a ring. Use the edge of the lens as your mold and use clamps/ clips to keep them in place till dry. Remove the ring from the lens.
Step 3: Again, taking your bit of cardboard, glue the ring from step 2 onto that (make sure to wipe the edges of excess glue) and, once dry, cut it out using a sharp blade. smooth down the edges using an emery board or sanding paper.
Step 4: Take a piece of thin leather, large enough to cover the cap. Soak it in (tap) water for at least 30 minutes as wet leather is much easier to shape.
Pull a large piece of cling film over your lens and put the lens cap on top. Cover the cap in glue, squeeze out the excess water from the leather (don’t wring it) and cover the lens cap with it. Pull it tight – slowly and gently – as to not tear the leather. Make sure it’s smooth on top and as well as it gets round the edges, then secure with a rubber band/ tie wrap. Leave the dry overnight.
Step 5: Take the cap off the lens and cut off the excess leather. Be smarter than I was and make sure you’ll leave enough the cover the inside of the cap! If you’re familiar with some tailoring techniques, you can cut away some of the excess in V-shapes on the insides of the cap as well, to smooth it out nicely. Put glue on the inside, and clamp the leather down to dry. Put a strip of cardboard between the leather and the clamps, or you may be left with some permanent marks on your cap.
Step 6: Try the cap on your lens. Is it a snug fit? Great! You now have the option of covering the inside of the cap front and you’re done. Mine was a little loose so I had two options:
- cover the inside rim with more leather / a cardboard strip, giving it a tighter fit and a better finish.
- put another kind of space filler in.
I was (dare I admit it?) a little lazy and didn’t really want to mess about too much with the interior finish. I decided on a non-classic feature: a handle, the provide a better grip on the lens as it’ll serve as my shutter too.
I cut another strip of cardboard, folding it over and taping it with clear tape, leaving only the outer edges bare. I folded it round the cap and secured the ends on the inside with a bit of glue. I put some clamps on it whilst it dried and presto! I was done too 🙂