Possible fast shutter solution for barrel lenses, could this work?

[DraganB]

Hi Friends,

I have a Tessar 7.5cm f/2.8 barrel lens without a shutter.
To use it handheld, I need a short shutter speed. Would this be a way to achieve that—a mini guillotine shutter?

Attaching a spring from a ballpoint pen to the two pins. The slit width determines the shutter speed.

 

[reddesert]

You can try ...

If there were an easy solution to this, it would be in more common use. I don't think this will work well for some reasons: the ballpoint pen spring isn't strong enough (you can get a better spring); the blade will need to slide easily and precisely in the channel or friction will hang it up or give you poor repeatability; the force on the pin is not in line with the center of mass of the blade and this will torque the blade against the channel, increasing friction; and so on. You might find that building a rotating sector shutter works better, because it is easier to deal with bearing friction at the single axis of rotation. Look at the Univex Mercury camera for an example.

The actual path of least resistance here is to get a Speed Graphic or Baby Speed Graphic (2x3) with a focal plane shutter, and put your lens and film holder/back on it.

 

[DraganB]

You can try ...

If there were an easy solution to this, it would be in more common use. I don't think this will work well for some reasons: the ballpoint pen spring isn't strong enough (you can get a better spring); the blade will need to slide easily and precisely in the channel or friction will hang it up or give you poor repeatability; the force on the pin is not in line with the center of mass of the blade and this will torque the blade against the channel, increasing friction; and so on. You might find that building a rotating sector shutter works better, because it is easier to deal with bearing friction at the single axis of rotation. Look at the Univex Mercury camera for an example.

The actual path of least resistance here is to get a Speed Graphic or Baby Speed Graphic (2x3) with a focal plane shutter, and put your lens and film holder/back on it.

good idea, like this?

 

[bernard_L]

I've been toying with the idea of building a shutter from the swinging arm of a dead disk drive. Those things move fast; maybe less so when loaded with a piece of dark slide, but still... Never went any further than daydreaming.

 

[Dan Fromm]

Which camera do you want to use the lens on? How fast is "fast"?

 

[Saganich]

That reminds me of larger version of the Kodak Hawkeye shutter.

 

[DraganB]

Which camera do you want to use the lens on? How fast is "fast"?

1/100 would be good

 

[Dan Fromm]

1/100 would be good

In that case, mount your lens in front of a cock-and-shoot Compur or Copal #1 shutter. Front mounting requires a threaded bushing, perhaps cup shaped. Front (female) end threaded to accept the rear of your 75/2.8 Tessar, rear (male) threaded M40x0.75 to screw into the front of the shutter. I'd like to suggest a Polaroid MP-4 Copal #1 Press shutter, but in my experience these inexpensive gems' top shutter speed of 1/125 is usually slower than you'd like. Same goes for Prontor Press #1. Still worth considering, but ...

 

[grahamp]

There is some good information on guillotine shutters at Large Format Photography Scroll down to the Misc. section.

 

[DraganB]

Hi Dan,

Fortunately, I have four of those in my collection right away. As soon as the Tessar 7.5cm/2.8 arrives, I’ll try it. I already had this option in mind but couldn’t test it yet; the Tessar might go too deep and touch the shutter. Thanks for your tip.

 

[Dan Fromm]

Hi Dan,

Fortunately, I have four of those in my collection right away. As soon as the Tessar 7.5cm/2.8 arrives, I’ll try it. I already had this option in mind but couldn’t test it yet; the Tessar might go too deep and touch the shutter. Thanks for your tip.

I must not have been clear. The lens goes in the adapter, the adapter goes in the shutter. If the lens is threaded M40x0.75 at the rear it will screw directly into the shutter, just don't screw it in too far.

Your old Compurs may not match the post-WW II Compur/Copal standard, check before ordering an adapter.

I asked which camera you intend to use the lens on. This matters. According to https://www.pacificrimcamera.com/rl/00498/00498.pdf, it won't quite cover 6x6.

 

[DraganB]

I must not have been clear. The lens goes in the adapter, the adapter goes in the shutter. If the lens is threaded M40x0.75 at the rear it will screw directly into the shutter, just don't screw it in too far.

Your old Compurs may not match the post-WW II Compur/Copal standard, check before ordering an adapter.

I asked which camera you intend to use the lens on. This matters. According to https://www.pacificrimcamera.com/rl/00498/00498.pdf, it won't quite cover 6x6.

It is for use on a 6x7 camera. I measured the shutter, it’s M40 but I can’t measure the exact pitch. The Tessar already has an M39.8/0.75 screw mount, but as you can see in the photo, it might really go in too deep. If I understand you correctly, the complete barrel lens is screwed in from the front, and no lens is mounted at the back. My English is not good, so I use translation programs.

 

[Dan Fromm]

Thanks for the photo. I see the problem. If it is real, a cup-shaped adapter will solve it, but coverage will be a problem. Whether the lack of coverage will bother you depends on your preferences. De gustibus non est disputandum.

 

[DraganB]

Thank you, Dan.

It’s more about taking pictures with these old lenses than achieving technical perfection in my photography. I’d use digital if perfection mattered to me. I have a kind of fetish for lenses from before WWII—or even WWI. I just need the image to be sharp in the center with illumination to the edges. Vignetting and edge softness are part of the picture.

 

[MTGseattle]

There's a 24volt shutter for sale on ebay that I have been curious about. I re-read the listing and if I am understanding things correctly it may max out at 1/32.

 

[Ian Grant]

1/100 would be good

That's easy, a small Thornton Pickard Poller blind shutter. 1/10 to 1/90, but they made them for higher speeds as well - up to 1/1000.

Alternately front mount a Leaf shutter. I have a Compound #3 that I can use for some brass lenses, and a Gitzo for my larger Petzvals & RR lenses.

Ian