How do you make a light tight lens cap?

[Bill, 70's military B&W]

I have several lenses that do not have lens caps, I'm sure that is a common problem. I want to protect the glass and also will probably be using the lens cap as a shutter. What works?
Thanks, Bill

[vinny]

B&h photo sells schneider lens caps. Measure the lens, order the cap.

[Bob Salomon]

Kaiser push-on caps are available from 15mm to 120mm diameter. They will fit virtually any lens (that does not have an external bayonet) light - and dust tight.

[sumo]

I think there was a thread on making a leather lens cap recently on here. I'm assuming you want to use it as a shutter since you want it to be light tight. I find modern caps are generally too stiff to be used as a shutter so they risk making you jerk the camera. This can be solved with the "hat trick" though.

EDIT: Oh, its in the DIY section

[Bill, 70's military B&W]

I've heard of the hat trick, I thought it applied to using the lens cap too. Or is it really a hat? How do you work the slide on the film holder and hold a hat?
I had great concerns about camera movement when taking off a lens cap. Regardless of rigidity of the tripod it is still going to move. If the exposure is 10 seconds or more that may not be a big deal, but for shorter exposures you take a chance for motion artifact.
Bill

[Jim Jones]

You can barely remove the lens cap from the lens, pull the dark slide, hold the dark slide over the lens cap, ease the lens cap out of the way without touching the lens, and control the exposure with the dark slide. At the end of the exposure, slip the lens cap behind the dark slide and onto the lens. Better yet, use a large piece of black mat board as a shutter instead of the dark slide. It's wise to shield the front of the camera with your body as much as possible, especially when using wide angle lenses.

[Jim Graves]

Here are a couple of links to instructions for making your own:
LINK 1
LINK 2

And, here's one I made for a lens I was restoring that has worked amazingly well ... it was originally a white 1 Cup plastic measuring scoop that had a slight angle to the sides that just happened to be the right size for this lens. I cut it to the right depth, roughed it up with very rough 60 grit sand paper to help the paint adhere, and then sprayed it with Rustoleum Flat Black paint from a spray can. It slides on and off buttery smooth. I assumed that the paint would rub off very quickly but it hasn't. Still looks really good ... and if it does eventually wear through at a spot or two it's a 30 second respray to restore it.

[John Kasaian]

I think there was a thread on making a leather lens cap recently on here. I'm assuming you want to use it as a shutter since you want it to be light tight. I find modern caps are generally too stiff to be used as a shutter so they risk making you jerk the camera. This can be solved with the "hat trick" though.

EDIT: Oh, its in the DIY section

Here's the link to my latest adventure
http://www.largeformatphotography.in...ap-in-progress
Making leather lens caps is a bit like birthing children---the first ones come out kind of funny looking, lol!
I think my leather may have been a little too thick, but it works!

[sumo]

The hat trick, as I understand it anyway, is where you take a hat or other relatively deep, concave and light-tight object and use that to cover your lens with the lens cap on. Then from under the hat, take the cap off, wait for the vibrations to die down, remove hat, expose, then replace hat. Then you can replace the lens cap from under the hat. That way you never touch the camera at the time exposure. Well that's the theory anyway. I've never tried it since I don't use barrel lenses (yet!) so I don't know how effective it is.

[Bill, 70's military B&W]

Jim, I really like the links, I'll probably do the first one. You were lucky to find a good fit on your scoop.
Thanks, Bill