How to make Lenscaps
Date: June 05, 2011 12:59PM
Having a cap for your lens is almost essential. Both for protection, and also in our case, as a 'shutter'. Lots of methods exist for making a cap, from very crude to museum quality. I'm going to give you a way to make nice caps, using common materials.
If you are only needing one, or two caps, maybe its best to let me make them for you, but if you have a lot of lenses, then getting the stuff together and learning how to do it is a nice skill and pleasant diversion.
Caps are frequently called 'leather' but for the most part are not.
Heres what you will need;
Chipboard, this is the medium thick cardboard used to back up pads, the grey stuff.
Velveteen ( black is good, but red will work fine too)
contact cement (weldwood in the red can)
Leather grained bookbinders cover paper
1/4 inch luan plywood
bench sander (or sandpaper on a block)
band saw (or a small hand saw and talent)
test your velveteen for 'glueabilty' by sticking a small piece to some scrap chipboard. make sure it sticks. some velvets and velveteens will NOT stick, the glue dosent work with them. cotton velveteen seems to always work for me.
So, first off.......all paper, including chipboard has a 'grain'. cut a small strip of you chipboard and see which way it will roll up easily...thats 'with the grain'. You want to cut a long strip which will turn around your lens hood three times. If you have a big lens and short cardboard, just cut smaller strips, bevel the ends and glue together to make a longer strip.
now, cut a strip of velveteen long enough to go around your lens hood one time. Determine how wide you want your cap, for long hooded lenses, it can be up to an inch or so, its easy to use this method for any width but when they get shorter than 3/8" it gets more difficult. For medium to large lenses,an 1 1/4 strip is wide enough, you will sand this down top and bottom when it is dry, when you shape the cap.
Turn the lenshood over, and trace out the diameter on the luan plywood, and carefully cut it round on the bandsaw, and then smooth out the uneven cuts. it should end up being just a BIT larger than the lens hood, maybe a millimeter or less.
round over the face of this plywood disc gently on the sander, just to give a nice slight curve to the front of the cap.
Glue on the velveteen to the back of the disc (wood glue, sparingly applied), and then cut the excess velveteen off, it does help to cut it just a hair larger.
coat the entire strip of chipboard with a thin wood glue layer, and glue the velveteen strip to one end. so about 1/3 of your strip is covered in this cloth.
gently, and evenly, wrap the glued strip around the lenshood, the velvet end first, take care to do this right since for the most part you only get one attempt. Dont wrap it too tight, as it DOES SHRINK in drying. The larger the cap, the more shrinkage, so it is good to actually wrap a few layers of blue tape around the lenshood, to give room to shrink.
Now slide off the glued ring, and a bit in from the one end, run a line of glue. CAREFULLY push in the plywood disc from the back, and when in position at the front, it will come into the glue area.
At this point, you want this to dry. Its OK to leave the cap on the lens as it dries, this will reduce shrinkage.
next day (overnight drying is best), trim off the excess at the front of the cap, and on the sander smooth it all out, and flatten down the bottom of the cap. Once it is shaped and dry, you are off to the next step, covering!
Leather grained paper is used by bookbinders for covers. this is what you want to source. I bought a huge roll, like 4 feet by 50 feet, but smaller amounts are available. This is the covering to your cap.
Cut a long strip, to go around the cap one time *make it a bit longer and trim it as you glue down the end*. cut a piece large enough for the end of the cap also. Coat the cap with contact cement, and also coat the leather grained paper pieces. After this has tacked up, wrap the long strip once around, a little excess on the top (trim this off) and leave 1/8 on the bottom. roll this bottom excess inward, and then press the cap down very firmly on a smooth surface and the paper will glue to the bottom edge of the cap. Take the oversize top paper and lay it on the top of the cap. press firmly, and trim around the edge. roll this edge down, to stick it better and smooth it down. I take a drywall screw, and using the head (not the pointy threaded part) hold that and indent a ring around the outer edges of the cap sides (just for looks). Depending on the color you want, you can now paint this, I have dark green paper and usually just rub some black semigloss paint on, and quickly rub it off...this leaves a darker shading to the paper.
If the cap is tight after it dries, you can use a round cylinder object to press down from the inside as you rotate the cap on a table, side pressure will increase the size of this a bit and help it have a nice smooth fit.
Good luck, this all works well and makes a dandy cap.
(This information is for this forum only and may NOT be copied and posted anywhere else)
Edited 9 time(s). Last edit at 06/05/2011 06:46PM by Ray Morgenweck.