Large shutter design - help for project

[m1tch]

Hi all,

I am currently in the process of building a 5x4 camera and my own lens, everything is going well except I will be in need of a shutter, due to the f number on the lenses I am building even ISO 3 paper negatives would need to still have quite a fast shutter speed.

I am ok in some instances to stop the lens down to say f11 or a smaller aperture for landscapes, however I am also thinking of using the camera for portraits as well so would shoot fairly wide open which is where the issue comes.

I am unable to source/afford a shutter that is big enough for some of the lenses I am designing so I will need to make my own, I would need it to be very simple to make - I am thinking about something like a spring loaded guillotine or rotary disk with a slot cut in it.

I am thinking that if I can produce something with a fixed speed then I could simple stop the lens down slightly or use ND filters on the lens to make sure that its properly exposed - I would want to shoot quite wide open for the shallow DoF on portraits.

Is there a simple design I can use to produce a shutter? I was thinking about making a double iris/clapperboard shutter of my own design which would allow for variable speeds, however I would want to go with something simpler.

Could I produce something simple like a spring loaded flap infront of the lens something like:

Spring loaded flap in front of lens with small arm sticking out of shutter assembly
A dark slide infront of the lens and infront of the shutter
Open the spring loaded flap to put it under tension
Let the dark slide fall and also release the spring loaded flap
The gap between the falling slide and time take to flap closed would equal the shutter speed
The flap would be sprung to flip downwards to counteract the fact that the slide exposes the top of the negative first.

Can I have some other simple ideas for shutters that can be made, the design would need to be scaled up or down depending on the lens I would be shooting.

[Tim Meisburger]

simplest I know of is the guillotine shutter. There is a design on the front page of the large format site. They do not seem very popular though. Most people use a hat, or use what is known as a "Galli shutter", which is two 5x7 dark slides held in a "v" shape and rapidly shifted across the lens (if you search the site you should find a better description).

I would be quite interested in designs for an adjustable mechanical shutter. I think the roller blinds are fairly simple, and if I was hacking something I would probably look at that, and use a reversible and variable speed motor instead of a spring.

[m1tch]

Thanks Tim, yeah I saw the guillotine shutter, its quite simple and you can adjust the shutter speed depending on the slot gap, however it would also need to be 3 times the width of the lens which in my case is pretty large which is why I was looking at alternatives. I did see that 'Galli shutter' which would be a cool idea, but I would want something a bit more repeatable although I like the low tech and low cost idea!

I will post up the idea a bit later, its really simple but might take a bit of time to calibrate properly, I will have a think about roller blinds, although there might be quite a bit of mechanism behind making those work properly, im trying to keep it simple as possible.

I guess I could look at doing something electronic where I just get a simple solinoid/linear actuator and use that to open and close the shutter - more modern tech but on an older camera - might be interesting as I could look into using a timer - I also guess that this could be done like the Packard shutters with a vacuum/air input.

[DannL]

I've been using a 3.0 ND filter (10x) and a lens cap on my barrel lenses with paper negatives. Rating the paper at ISO/ASA 3-6 depending on the filters used has been typical. This is very manageable under normal daylight conditions with the iris at f/32 44 64 etc. Any faster than that is too unreliable for my hands. I wanted a shutter or to design one for the longest time. I finally acquired one, a Thornton-Pickard front mounted shutter, as part of a outfit I purchased recently. Now that the shutter has been restored I'm perty sure it will give the speeds needed for larger iris openings. I just need to get out and give it a test.

[m1tch]

I've been using a 3.0 ND filter (10x) and a lens cap on my barrel lenses with paper negatives. Rating the paper at ISO/ASA 3-6 depending on the filters used has been typical. This is very manageable under normal daylight conditions with the iris at f/32 44 64 etc. Any faster than that is too unreliable for my hands. I wanted a shutter or to design one for the longest time. I finally acquired one, a Thornton-Pickard front mounted shutter, as part of a outfit I purchased recently. Now that the shutter has been restored I'm perty sure it will give the speeds needed for larger iris openings. I just need to get out and give it a test.

Thanks for that, I think using an ND filter for a longer exposure for landscape should be good, however I think I would still want to shoot it wide open and would need a fast shutter speed for portraits so that there isn't a blur etc.

[Jim Galli]

Consider a design that works like a Cine camera shutter. Look at my "galli shutter (http://www.youtube.com/watch?v=ICLG3HCDlhk)" which is indeed a bit of silliness thanks very much to Eddie Gunks. But the idea is sound. Shutter angle and speed of revolution. So if you had 2 pieces of light material on an axle with an adjustable fulcrum and something as simple as a rubber band you could duplicate most of what a Graflex curtain shutter can do. You can simply adjust shutter angle to get the same effect that the different size openings in the focal plane on the graflex were giving you.

[jp]

If 1/10 or 1/30 is a good slowest shutter speed, you could use a speed graphic.

[Jac@stafford.net]

I can tell you what does not work - at least for me. The pneumatic (bulb and hose) barn-doors front shutter. I'm sure they were good with slow plates, but are too slow for general work (I do not like to use ND filters), and have too much vibration.

I can make a snap-shot of the unit if you wish.

Here is another version of the Galli shutter (http://www.weasner.com/etx/astrophotography/2008/ht_shutter.html).

[TheToadMen]

Ddid you see this website?
http://re-inventedphotoequip.com/Site/Shutters.html
Maybe this is an option that isn't too expensive?

[m1tch]

Ddid you see this website?
http://re-inventedphotoequip.com/Site/Shutters.html
Maybe this is an option that isn't too expensive?

The front element on the lens is over 4", which is why I will have to go with a DIY option, plus the camera is a 'cheap and cheerful' trial to see how cheaply you can make a 5x4 camera and lens.

The larger lens I am making would be something like a 150mm f1.3, a slightly smaller lens I am also making would be a 71mm f0.87.

I might simply use the faster wider lens on the speed graphic and use the focal plane shutter but I would like to shoot wide on my DIY camera and I would also need quite a fast shutter speed (ish) for portraits on either.

Here is my issue, with ISO 6 paper in brightest sunlight shot fully open I would need a shutter speed of 1/2000s, in shade it would probably be something like 1/125s which is where the issue is.

I am perhaps thinking about a fast blade shutter, pivot at one end, blade covers, uncovers and then recovers the lens powered by a spring or band, could make that like a half moon or something.

I am thinking making a rotary shutter powered by a rubber band might be good,

[Steven Tribe]

Earlyphotography.co.uk has a new section on early front-mounted shutters which might inspire the DIY gene!
Writing with experience of Luk, Grundner, Guerry, Copal-sinar and T-P type shutters, there just isn't anything that works at less than 1/60th. Focal plane shutters mounted at the rear, on a solid "box" structure and near the tripod mount, like the speed graflex do achieve much better speeds than this.

[m1tch]

I would need a faster shutter speed rather than a slower one, I don't want to stop the lens down too much as I would be wanting to get some bokeh with portraits, I guess I could shoot in subdued light, I never thought I would have an issue with the lens and the paper negative being too fast lol.

What would be the affect of using an ND filter but shooting wide open? The lens would actually be too large for the speed graphic to handle I think lol I will check the dimentions but I don't think the front standard is wide enough.

I do actually have an unusual camera coming soon with a LUC shutter which I might use for a portrait camera instead - think it shoots 1/4 plate, perhaps I should simply stop the lens down and use an easy to make spring loaded shutter with a fixed speed?

This could be interesting:

http://www.earlyphotography.co.uk/site/entry_S36.html#S6

Ah, also the single blade return shutter sounds interesting:

Band loaded guillotine shutter, when the shutter fires and oncovers the lens it dislodges the band which then allows the guillotine to drop back recovering the lens.

[m1tch]

I have just taken apart the front of one of my project plastic cameras (Vivitar PN2011) to look at the simple shutter arrangement.

It is basically a pivoted flap where a spring loaded notch is pushed against one end of the pivot, once the notch is past the pivot the flap then springs back to the rest position.

Seems quite simple, just need to work out how I would set and trigger it lol even cheap cameras seem to have fairly complex workings!

Edit - ok I think I see whats happening now:

The spring loaded notch is rotated back to sit against a ledge of the shutter, when the shutter release is pressed it moves the surface that the spring loaded notch is resting against, this then knocks the shutter blade on the way past and about 75% though its full travel is is past the end of the shutter blade which then springs back due to the spring tension.

I will have a look at simplfying this design slightly (the shutter is cocked on film advance), I am glad I rememebered that camera, seems a bit simpler than some of the other shutters I have seen lol

I could still go with a horizontal band powered guillotine though, thats fairly easy but its much more bulky.

[jb7]

I don't think you mentioned the design of the lens- or lenses- surely that would have an influence on the size of the shutter needed? For example, if its a rear mounted meniscus type, then you could get away with a much smaller front of lens shutter- whether guillotine or other...

[m1tch]

The front and rear elements are the same size, optical element diameters are either 110mm or 80mm (the 2 different lenses I am building), with the 80mm element lens the focal length will be at around 70mm which is basically both standards together on the camera. I would need a front mounted shutter for that, however could fit a rear mounted shutter on the larger 110mm element diameter lens.

[jb7]

The front and rear elements are the same size, optical element diameters are either 110mm or 80mm (the 2 different lenses I am building), with the 80mm element lens the focal length will be at around 70mm which is basically both standards together on the camera. I would need a front mounted shutter for that, however could fit a rear mounted shutter on the larger 110mm element diameter lens.

If you're building the lens yourself, could you place the shutter in the centre of the lens, where it's meant to be? Everything would be a lot smaller, even a Guillotine shutter...

[m1tch]

If you're building the lens yourself, could you place the shutter in the centre of the lens, where it's meant to be? Everything would be a lot smaller, even a Guillotine shutter...

I will be using waterhouse stops in the centre, I would need to have the shutter cover the whole diameter of the lens though so it would be the same size where ever I put it.

[jb7]

... "it would be the same size where ever I put it."

Not sure that's entirely true, but I won't argue it...

There should be space for waterhouse stops as well as a guillotine or other shutter, depending on design, but I'll let you get on with it...

[IanG]

I have a Norka shutter I bought through this forum, they are easy to replicate, Gandolfi posted a thread here. (http://www.largeformatphotography.info/forum/showthread.php?62128-homemade-shutter-%28BIG%29).

For higher speed I'd modify a TP shutter, these are normally 1/15 to 1/90 but they did sell high speed versions the only difference is the slit width, there's a big variation in sizes available, as the image below shows.

http://www.lostlabours.co.uk/photography/cameras/images/large-tp-shutter_sm.jpg

It would be possible to make something similar.

Ian

[DrTang]

buy a baby speed

saw that sucker in half


use just the back part as a shutter

[TheToadMen]

Wow,
Nice challenge. Let us know how it goes.


The front element on the lens is over 4", which is why I will have to go with a DIY option, plus the camera is a 'cheap and cheerful' trial to see how cheaply you can make a 5x4 camera and lens.

The larger lens I am making would be something like a 150mm f1.3, a slightly smaller lens I am also making would be a 71mm f0.87.

I might simply use the faster wider lens on the speed graphic and use the focal plane shutter but I would like to shoot wide on my DIY camera and I would also need quite a fast shutter speed (ish) for portraits on either.

Here is my issue, with ISO 6 paper in brightest sunlight shot fully open I would need a shutter speed of 1/2000s, in shade it would probably be something like 1/125s which is where the issue is.

I am perhaps thinking about a fast blade shutter, pivot at one end, blade covers, uncovers and then recovers the lens powered by a spring or band, could make that like a half moon or something.

I am thinking making a rotary shutter powered by a rubber band might be good,

[lem22]

Sounds like a really interesting project. I can't help but wonder where one might find a lens with a diameter of 110mm. Hope that's not a dumb question.

[m1tch]

Ok, I have taken delivery of a few older cameras from something I won on ebay - I was just bidding as there was a Purma special and I wanted a spare one lol there were 2 127 box brownies with 2 different simple shutters, plus my cheap point and shoot plastic camera.

On closer inspection they all basically have a spring loaded blade that is flicked and the spring then returns the blade to its rest position, the older Kodak had a much slower shutter with a few more moving parts which covered the opening whilst the blade retracted back.

Here are my comments on the way some of these simple shutters worked:

Plastic camera - shutter blade is pivoted and attached to a spring, on firing the shutter a spring loaded finger is released and flicks the shutter blade open and is then closed via the spring, fairly fast shutter speed
Newer 127 camera - shutter is pivoted and attached to a spring, lots of other spring loaded parts are also attached to stop double exposures etc but it basically releases a spring loaded finger much like the plastic camera
Older 127 camera - 2 distinct movements, on firing the shutter opens and closes, on release of the button it all returns back - on pressing the shutter one blade moves forward which is connected to a second blade, both are pivoted, once the first blade moves and spring has enough force it pulls the second the second blade trips and shoots forwards. On release of the button the first blade covers the opening until both blades are back at rest.

Here are some photos of the shutters I have:

Plastic - not much to see but the front blade is sprung:

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01180_zps61ad9dee.jpg (http://s93.photobucket.com/user/m1tch_2006/media/DSC01180_zps61ad9dee.jpg.html)

[m1tch]

Newer 127 camera:

At rest:

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01188_zps0271928d.jpg (http://s93.photobucket.com/user/m1tch_2006/media/DSC01188_zps0271928d.jpg.html)

Cocked - copper coloured trianular piece flicks the end of the shutter blade

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01189_zpsff284d53.jpg (http://s93.photobucket.com/user/m1tch_2006/media/DSC01189_zpsff284d53.jpg.html)

Shutter is spring loaded, quite a fast shutter

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01190_zps79e5f994.jpg (http://s93.photobucket.com/user/m1tch_2006/media/DSC01190_zps79e5f994.jpg.html)

[m1tch]

Older 127 camera:

Shutter blade on top moves down on the press of the button putting tension on the spring connecting the 2

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01184_zps3730ba00.jpg (http://s93.photobucket.com/user/m1tch_2006/media/DSC01184_zps3730ba00.jpg.html)

Spring pulls the second shutter down once the spring tension increases between the 2

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01186_zps7c5781a6.jpg (http://s93.photobucket.com/user/m1tch_2006/media/DSC01186_zps7c5781a6.jpg.html)

On release of the shutter the first blade is curved and covers the opening until everything is back to the rest position.

What I have learnt about the simpler shutters is that it seems that all that is needed is a pivoted shutter blade which is spring loaded, the other end of the shutter arm is then flicked and then released which then lets the shutter spring back to rest - the power of the spring gives the shutter speed.

I am going to mock up a possible design on how I could create a larger version of this, due to these cameras having all sorts of fail safes and other features (like putting a flag in the view finder informing of a shot being taken) it might be quite simple to make something.

I will have a think and work something out that is simple, cheap and effective :)

[m1tch]

The Q1 has been built:

150mm f1.3

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01204_zpscd4ab5eb.jpg

Looks pretty good on the speed graphic (not attached so not 100% perfect)

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01205_zps25dffd9e.jpg

Crazy crop on the NEX3 though! Image of bicycle across the other side out the window free lensed, 150mm f1.3, ISO 200, 1/160.

http://i93.photobucket.com/albums/l49/m1tch_2006/DSC01209_zps27e170b9.jpg (http://s93.photobucket.com/user/m1tch_2006/media/DSC01209_zps27e170b9.jpg.html)