6" Leaf Shutter

[illumiquest]

I'm one of those idiots who enjoys shooting overly large lenses, ones with rear diameters of 6inches and while most of my work with these has been with wet plate, I'd like to try shooting more film outdoors and with fill flash.

Which leads me to the question of whether other folks are in similar situations and if there would be any interest in a very large leaf shutter with less vibration than a graflex shutter and capable of high speeds with flash. I'm working on designing something but would like to see if it's something that other's may be interested in or if I'm the only idiot in the bunch and should just make a custom job.

 

[removed account4]

hi giles

does hub ( packard ) make custom shutters ?
maybe there is one that is SYNC'D that they make
or can make already so you don't have to reinvent the wheel ?
i worked for somene who had a giant packard on a giant lens way back when
and it was sync'd ... so i know they do it, or used to do it ...
sadly i don't need a giant shutter like that at the moment ;(

 

[cowanw]

I am sure many of us have rigged up 5 inch Packards for this purpose and would be interested.

 

[illumiquest]

Thanks guys. I did look at the packards, kind of started down this rabbit hole because I found a 5" one at a flea market. I figured I could just put a bigger solenoid actuator on it and bang it open and closed faster. Problem is that tops out pretty quickly at around 1/8th of a second due to the inertia involved with moving that much mass forward, stopping it and then moving it back again. My next thought is to try a two curtain approach with one 5 leaf shutter directly in front of another. With that setup the leafs could be spring actuated rather than solenoid or other means. One shutter would start open, the other closed, the closed one would open and after the desired delay the open one would shut. This could easily be controlled with a micro Arduino computer that I had built. The flash could be triggered either electronically in the software or mechanically when the first shutter reaches wide open.

I'd have to experiment to see how quickly a shutter of this size could be moved but I should think that 1/60th would be attainable. But then again, I'm not an engineer.

 

[Dan Fromm]

Hmm. My little Speed Graphic's curtain shutter stops with a tremendous bang, but runs smoothly. OP, have you used a Speed Graphic?

 

[illumiquest]

Hey dan, I have used speed graphics, the issue with those is no flash sync above, 1/20th or something like that?

 

[shutterfinger]

Are you familiar with vintage Studio Shutters? https://www.ebay.com/sch/78997/i.html?_from=R40&_nkw=studio+shutter The Vitax listing shows the blades clearly near the end of the pictures.
The shutter size determines the number of blades. The blades double as the aperture. A cable release or air bulb trip the shutter and the aperture setting limits how far they open. Depending on how fast you are determines the shutter speed up to a maximum of 1/25.
I have owned one (my avatar photo was made with one) and I had to make two new shutter blades for it to make it usable. I do not have any pictures of the shutter but they're fairly simple.

 

[Dan Fromm]

Hey dan, I have used speed graphics, the issue with those is no flash sync above, 1/20th or something like that?

Slower that that, unless you use flashbulbs.

You could use an ND filter, a slow shutter, and a more powerful electronic flash. Abhorrent thought, but ...

 

[illumiquest]

Working on putting together a prototype to see if things work in the real world but on screen it doesn't seem too difficult.

 

[WilmarcoImaging]

Pretty cool, please report the test results.

 

[Trask]

How about drawing on the design of the shutter in the Olympus Pen half-frame SLR, which has IIRC a rotating shutter — so no reversing the direction of mass and dealing with the resulting inertia? I will confess that I’ve never taken a leaf shutter apart so have no practical experience with designing or using large shutters.

 

[Ed Sawyer]

I have a fairchild night shutter which came with an aerial lens. It is big, but motorized and has dual sets of leafs, both are spring fired and recocked with the electric motors. With the right controller I have seen people fire these super rapidly, like a motordrive (5-10fps). I will have to look at the times but I think it did at least 1/100. It is 3" across in diameter. Built with the level of uber-precision that only a military contractor can pull off...

 

[Ian Grant]

I have Half plate Thornton Pickard roller blind focal plane shutters while these are designed for rear fitting on field cameras there's no reason why they can't be used behind a lens like the normal Between Lens TP roller blind shutters. It would be possible to add flash sync.

Ian

 

[Dan Fromm]

Trask, the Williamson F.134 and successors (F.139, Agiflite) shot 6x6 on 70 mm film and used a huge rotating sector shutter. Huge. The idea might work for the OP.

Ian, the T-P shutters, like Graphic shutters, sync with electronic flash only at a very low shutter speed. The OP wants to use electronic flash at a high speed. My suggestion that he consider an ND filter with electronic flash and a curtain shutter seems not to have been noticed.

 

[Ian Grant]

Ian, the T-P shutters, like Graphic shutters, sync with electronic flash only at a very low shutter speed. The OP wants to use electronic flash at a high speed. My suggestion that he consider an ND filter with electronic flash and a curtain shutter seems not to have been noticed.

Dan, the TP shutters aren't like the Graflex. so you could flash sync at 1/90, they are fixed "full" slit width and run faster than the Graflex, significantly at the higher tensions. The exception is the high speed versions which are quite rare, I have one the slit is narrow and you get up to 1/1000 depending on the tension but you're stuck with that narrow slit for focusing etc.

I don't know what size the largest Gitzo studio shutters were, mine's post WWII with flash sync and fits the front of a lens 84mm to 74mm diameter, but the Instant speed is about 1/30.

Ian

 

[jimgalli]

Wollensak had a shutter years ago, the Optimo, where the blades were directional. Full open then closes with out changing directions. Next cycle it returns. They claimed 1/300th with that idea. Your double blades doesn't gain much since for flash sync the first set must be fully open before flash and second set can't begin closure until after the flash. You might gain a little bit. You're doing the same thing with 2 sets of blades that Wollensak did 100 years ago with one set. Theirs was like a butterfly blade. One that covers goes inside while the unseen part comes into view and covers, all in a single motion direction. Then goes opposite direction next time.

Flash bulbs could burn long enough for a traveling slit to get flashed light during the entire travel. We used to have some specialty ones around here that could burn 1.3 seconds.

The Packard remains the most elegant solution to my mind. It's so easy to sync.

 

[Ian Grant]

Not the Optimo.must be another one Jim. I have a couple of Wollensak Velosto shutters that's the British name for the Optimo which was already a Registered Trade name here in the UK for a camera. I had to repair my first so I'm quite sure the blades open then close like Compurs etc.

Ian

 

[jimgalli]

Like this one. Trust me.

 

[illumiquest]

I do like the simplicity of the packards but the speed is an issue.

 

[Ian Grant]

Jim I do(n't) trust you My Velosto's are identical to this Optimo. We could both be right, it may be a way of obtaining a higher shutter speed with the larger Optimo shutters but the smaller ones work like a Compur, my first is with a Kodak 170mm f7.7 Anastigmat, a dialyte and very sharp like the 203mm f7.7 Anastigmat/Ektar, the others an early B&L Tessar but I've not repaired it yet.

I'd like to see inside an Optimo like the one you linked to, I doubt any were imported into the UK - I've never seen any in adverts, only Kodak used them here and only until the Compurs became available.

I'm going to have to convert you to TP roller blind shutters, Burke and James were the US distributor usually with their own name on them They seemed to prefer the aluminium cased versions but my guess is few survived as pre WWII aluminium tends to corrode easily, they are rare on Ebay here in the UK.

Ian