Shooting without a shutter

[Michael Graves]

Hello, everybody. I searched the forum and found a few scatter posts, but no specific details. So if I'm repeating old hat, forgive me.

I just obtained an 18" Wray Apo Lustra lens in a barrel. It covers 8x10 with massive room for movements, so I'm anxious to play with it. Is there a recommended method for covering and uncovering the lens with some degree of timing accuracy? I'm planning on carting a spare darkslide with me to act as a shutter blade. How "fast" of a shutter speed can one reasonably repeat consistently?

[Steven Tribe]

"So if I'm repeating old hat"

You answered your question - any old hat will do or something that will hang on the front until you have replaced the dark slide. I bet my 18" F10 apo lustrar was cheaper than yours - can you beat £2.50 with flange?

[wfwhitaker]

Two darkslides and practice.
http://www.apug.org/forums/forum44/22200-jim-galli-shutter-barrel-lenses-drum-roll-please.html

[BetterSense]

You may want to check this out

http://www.apug.org/forums/forum44/22200-jim-galli-shutter-barrel-lenses-drum-roll-please.html

[Michael Graves]

"So if I'm repeating old hat"

You answered your question - any old hat will do or something that will hang on the front until you have replaced the dark slide. I bet my 18" F10 apo lustrar was cheaper than yours - can you beat £2.50 with flange?

Yup. Got it from the local newspaper ripping apart their analog copy camera. I asked if I could have the lens before they hauled it off to the trash. Had to take it lensboard, iris board and all. Anybody need an iris board for a big old copy camera? Free for postage!

[Michael Graves]

Two darkslides and practice.
http://www.apug.org/forums/forum44/22200-jim-galli-shutter-barrel-lenses-drum-roll-please.html

Thanks, guys. I had not seen this one. Guess I'm gonna look pretty funny in my office for the next few days zipping dark slides back and forth across my lens.

[lenser]

Michael,

Dark slides will work, but they have some reflectivity since they are relatively slick. So, if the light is behind you, you could actually bounce light from the back of the dark slide into the lens causing fogging of flare. I use an 8x10 piece of corrugated cardboard covered in black velvet. Dark slides, set aside for just this purpose, and sprayed with some kind of black flocking would also work and prevent any possibility of that kind of bounce back.

[Robert Hughes]

For my 8x10 with barrel lens, I stop down to f/45 or f/60 and used the lens cap as a shutter for a second or so. I haven't needed to get faster shutter speeds yet, as the sun hasn't been out in the last month ...

[stealthman_1]

Practicing the Gali approach on a digital camera set to bulb and comparing the images with known shutter speeds will get you pretty close on what you can do.
As Jim notes, 1/125th is quite doable, and 1/50th is pretty easy. The trick is to make sure you have the shutter angle close or you will have a stop difference right to left.

[Robert Hughes]

I built a guillotine shutter for about $1 in parts that does 1/30 sec repeatably.

[numnutz]

I built a guillotine shutter for about $1 in parts that does 1/30 sec repeatably.

Any chance of some photographs or drawings? I am thinking of making one of these myself, possibly powered by elastic bands.

nn :)

[numnutz]

sorry - double click - itchy finger etc.

nn :

[Glenn Thoreson]

Neutral density filters and tiny apertures are your friends. It's pretty easy to get speeds down into the one second or longer range with slow or medium speed film. A polarizing filter will give you two stops. It doesn't need, or maybe even want, to be inthe polarizing orientation. It's the same both ways. Add a yellow #8 filter to that and you get 3 stops, etc. ND filters are pretty expensive these days but you can work around it. I built a drop slit shutter for one lens. I can get an easy 1/30, and 1/50 if I really shove it down. Very likely to shake the camera, though. 1/4 second and slower is pretty easy to do with just a black card. I listen to shutter speeds a lot. I test a lot. I can tell within reason, speeds from 1/15 and slower just by ear. There's always the Packard shutter but I have better luck doing it myself. Good luck, Michael. :D