Would you buy a 100mm LCD shutter for $400?

[polyglot]

Hypothetically I can build 100mm LCD shutters (for barrel lenses) and sell them for about $400. They'd do 1/500 up to hours of exposure, plus intervalometer and x-sync. Optionally radio remote controllable for extra cost.

So, is there a market here? Your affirmative reply will not be taken as an undertaking to purchase!

Any other comments welcome too...

[Steve Smith]

How opaque is it in it's 'closed' setting?

I used to work with Raychem's flexible LCD panels and those would not be opaque enough to form a shutter.


sSteve.

[cosmicexplosion]

yeah tell us more about it, clearly new technology,

how clear is it how dark is it

[polyglot]

Waiting on an answer from manufacturer but they're pretty dense. Note that these are pi-cells with compensating film, which gives much higher contrast than a normal (let alone flexible) LCD. Plain TN cells are not suitable at all because of viewing angle limitations causing light leaks.

[Corran]

If it was easy to adapt to a lensboard or something that would be quite interesting...

[Lachlan 717]

I'd have a good look at one!

[polyglot]

Corran: it would be a flange, which you would bolt to the lensboard of your choice. You would then need a flange adapter of the appropriate size to bolt your (brass barrel) lens to it.

You could in principle make an adapter so that you can screw copal-compatible cells into it, but I don't see that as particularly important since we can already buy working copal shutters. The aim is to provide a fast* accurate shutter for very large-diameter lenses for which there is currently nothing available.



* faster than the ~1/15 you get from a Packard.

[cosmicexplosion]

what about my 300 f2.5 i need atleast 150mm?

[jp]

how clear is it
how dark is it

That's what I'd want to know too.

It may need an AR coating on the side facing the lens.

If it was a good shutter replacement, $400 would be OK.

[E. von Hoegh]

When clear, how much will it degrade the image?

[Robert Hall]

I think E, and others hit it on the head. If it affects visual quality at all, I wouldn't be the slightest bit interested.

[domaz]

I think E, and others hit it on the head. If it affects visual quality at all, I wouldn't be the slightest bit interested.

Using the typical large mechanical shutter with a barrel lens generates a lot of vibrations. A LCD shutter, I'm assuming, generates no vibrations at all. If it degrades the image slightly I'm betting it's still better quality than the typical large barrel lens/large shutter setup that generates vibrations galore.

[E. von Hoegh]

Using the typical large mechanical shutter with a barrel lens generates a lot of vibrations. A LCD shutter, I'm assuming, generates no vibrations at all. If it degrades the image slightly I'm betting it's still better quality than the typical large barrel lens/large shutter setup that generates vibrations galore.

Vibrations can be damped. Image degradation cannot be restored.

Besides, for $400, if I wanted a shutter that big I'd make a roller blind, or if it was winter and I needed a project I'd make something like a huge Copal square. Speeds faster than 1/30 don't interest me on an 8x10.

[Jim Galli]

Using the typical large mechanical shutter with a barrel lens generates a lot of vibrations. A LCD shutter, I'm assuming, generates no vibrations at all. If it degrades the image slightly I'm betting it's still better quality than the typical large barrel lens/large shutter setup that generates vibrations galore.

???? This is a rediculous assumption unless you have some scientific proof. The beauty of the packard is that all of the moving parts offset each other almost perfectly and there is really NO vibration.

In answer to the OP, I would have to say, I'd need to see how cumbersome it is, and evaluate whether there really is a need or not. Check my site. I've been able to make almost any image I ever wanted to make with 1910's technology. Not closed minded. Just need to weigh any real gains against any real losses.

[E. von Hoegh]

???? This is a rediculous assumption unless you have some scientific proof. The beauty of the packard is that all of the moving parts offset each other almost perfectly and there is really NO vibration.

In answer to the OP, I would have to say, I'd need to see how cumbersome it is, and evaluate whether there really is a need or not. Check my site. I've been able to make almost any image I ever wanted to make with 1910's technology. Not closed minded. Just need to weigh any real gains against any real losses.

Big Compounds and Ilexes do generate vibrations. Anything that moves will.

[Jim Galli]

Big Compounds and Ilexes do generate vibrations. Anything that moves will.

Show me some science. Don't just state things unequivocally. Parts that get thrown radially outward and then radially inward offset each other for a net zero effect. I think you're wrong. But I'm willing to listen.....

[E. von Hoegh]

Show me some science. Don't just state things unequivocally. Parts that get thrown radially outward and then radially inward offset each other for a net zero effect. I think you're wrong. But I'm willing to listen.....

*sigh*
I can't "show" you anything. I can type a description, though. Those parts that "offset each other for a net zero effect" are actuated by other parts that don't get offset. The ring that actuates the leaves moves fifteen or twenty degrees, stops for the duration the shutter is open, then moves in the opposite direction to close the leaves - which, by the bye, contribute their own little perturbations to the mix, their inertia causing the shutter to move slightly around it's fore and aft axis. In the case of a Compound, the mainspring (under the cocking lever) has an input to the complex vibrations of the whole shutter as it starts, pauses, and completes it's travel.

I can go on, but don't see the point.

Edit - Those four cylinder engines in Model A Fords have two pairs of pistons always traveling in opposite directions. By your logic, there should be no vibrations. So, why does a four rattle your teeth ?

[Kirk Gittings]

I think E, and others hit it on the head. If it affects visual quality at all, I wouldn't be the slightest bit interested.

[Jim Galli]

*sigh*
Edit - Those four cylinder engines in Model A Fords have two pairs of pistons always traveling in opposite directions. By your logic, there should be no vibrations. So, why does a four rattle your teeth ?

Mine has a counterbalanced crank ;)

[E. von Hoegh]

Mine has a counterbalanced crank ;)

What does that do?

[Jim Galli]

What does that do?

Hijack over. Sorry Polyglot.

[Andy Eads]

Regarding vibrations and big shutters; big shutters have big mass as do the lenses they carry so inertia reduces any vibrations from the much lighter weight shutter blades and rotating mechanisms. I've used some huge shutters and never seen a vibration problem from any of them.

Regarding optical matters; this shutter would behave like a glass filter in front of the lens. It will have some effect on the rear focus point. If there is any diffusion in the crystal structure, that would degrade the image. How much? We must test!

Regarding the fun factor; I envision some fun stuff. For example, if it is an lcd array, it could be programmed to produce an aperture of any shape or size. Think of the bokeh possibilities! It could also screw things up if a pattern in the subject interfered with the lcd pattern.

Just thinking....

[Leigh]

What are the exact optical characteristics of the LCD in transparent mode, e.g. refractive index, color fidelity, etc?

Unlike a real shutter, an LCD shutter is in the path of the image-forming light, and will introduce aberrations and distortion.

- Leigh

[Steve Smith]

Isn't the front surface a polariser as well?

Regardless of any real or perceived problems with it, I think it's an interesting idea worthy of some experimentation.


Steve.

[Steve Smith]

Big Compounds and Ilexes do generate vibrations. Anything that moves will.

Not if the movement of one part is countered by the movement of a similar opposite part. e.g. six shutter blades evenly spaced will cancel out each others movement.


Steve.

[buggz]

Forgive my ms-understandings, this not directed to anyone personally.
But, I believe the root word and action is movement, period.
Counteracting, suppression, whatever you call it, it's still movement of some kind.
Thus my continued use of sand bags w/ long telephotos on smaller formats.
Even though sometimes a minimal improvement in sharpness, but is easily seen in any test I've tried.


Not if the movement of one part is countered by the movement of a similar opposite part. e.g. six shutter blades evenly spaced will cancel out each others movement.


Steve.

[Jay DeFehr]

Regarding vibrations and big shutters; big shutters have big mass as do the lenses they carry so inertia reduces any vibrations from the much lighter weight shutter blades and rotating mechanisms. I've used some huge shutters and never seen a vibration problem from any of them.

Regarding optical matters; this shutter would behave like a glass filter in front of the lens. It will have some effect on the rear focus point. If there is any diffusion in the crystal structure, that would degrade the image. How much? We must test!

Regarding the fun factor; I envision some fun stuff. For example, if it is an lcd array, it could be programmed to produce an aperture of any shape or size. Think of the bokeh possibilities! It could also screw things up if a pattern in the subject interfered with the lcd pattern.

Just thinking....

I'm with you, Andy. Anything that moves, or enters the light path degrades quality, in an absolute sense, but only absolute fools deal in absolutes. And, yes, imagine the possibilities! One could be programmed to produce the diffusion patterns used in Imagons, Softars, etc., for instance, or infinitely variable, and/or graduated in any pattern neutral density, and the list goes on. Imagine one that was user programmable in the field. I think it's a fantastic idea, though I don't know its feasibility. A perfect example of forward thinking and applying new technology to old problems. I hope it proves out, and if it does, I will buy one, and hope it could be made compatible with the Sinar F/P system in the same way the Sinar shutters are.

[Jay DeFehr]

What are the exact optical characteristics of the LCD in transparent mode, e.g. refractive index, color fidelity, etc?

Unlike a real shutter, an LCD shutter is in the path of the image-forming light, and will introduce aberrations and distortion.

- Leigh

Very practical questions that will have to be addressed, although I wouldn't have said "Unlike a real shutter", since LCD shutters do exist and are functional.

[Leigh]

Hi Jay,

I used the phrase "unlike a real shutter" because an LCD shutter cannot
match the performance of same in either transparency or opacity.

While it may be a functional analog, it is not a functional substitute.

- Leigh

[false_Aesthetic]

I think the real question is

How many megapix will this be?




Joking aside, this sounds rad. I'd love to see one and put it to some funky uses.

[Vaughn]

No, this is something I would not be interested in. I usually do not use less than 1 second, and often have the darkslide pulled and then wait for the right time to make the exposure. Shutter needs to block 100%.

And the less things without batteries, the better for me.

[polyglot]

For those still interested, I can't get a straight answer from the manufacturers wrt contrast, so I'll probably just buy a small sample myself and do some testing.

[JR Steel]

Another variable. How would it be affected by temperature in the field?

[Leigh]

LCD response slows at low temperatures.

They are liquid, after all. :D

- Leigh

[Old-N-Feeble]

I'll bet the OP could add a temperature probe to compensate within +/-10 percent accuracy. However, I too worry about image quality through the device.

[polyglot]

Performance should be pretty consistent from -20C (well, certainly 0C) to +85C. You want to operate outside that range, too bad.

Clearly I'll need to demonstrate photos taken through a smaller prototype before offering these things for sale. Assume that if quality is insufficient then they won't be made available unless you swear to use it only for petzvals or worse ;)

[genotypewriter]

Performance should be pretty consistent from -20C (well, certainly 0C) to +85C. You want to operate outside that range, too bad.

Clearly I'll need to demonstrate photos taken through a smaller prototype before offering these things for sale. Assume that if quality is insufficient then they won't be made available unless you swear to use it only for petzvals or worse ;)

Looking forward to it. Don't let the naysayers get to you. Progress doesn't come out of thin air. Hope you come up with a good solution that works for some conditions even if it doesn't for all conditions. Not even LF itself is good for all conditions any way :)

GTW

[Struan Gray]

Polyglot: I say go for it. Experiment trumps armchair theory every time.

There are, however, some things to look out for.

1. You may need an auxiliary shutter if the darkslide is going to be pulled for a long time. The pi cells I have stumbled across (in other applications) have extinction ratios of a 200:1 to 300:1. That means you can safely pull the darkslide or remove the lens cap for 10-20 times the exposure duration with no issues whatsoever (assuming you don't have things like car headlights around). Practical, but it would require discipline/understanding on the part of the user.

2. In front of the lens the LCD may introduce flare. Behind it it may introduce flare and a bit of spherical aberration. I honestly doubt either are going to be a big deal with the sort of vintage portrait lenses which currently use a Packard or a hat.

3. Polarisation may bite you. First the 'on' transmission will be one or two stops down from a simple hole, and that may tip the balance for those really fighting for enough light like ULF or wetplate users. Also, there may be interactions with polarisation in the scene in front of the camera, leading to uneven skies or visible stress patterns in glass and plastics. Finally, anyone wanting to use a polariser for the usual photographic reasons would either have to be able to rotate the shutter, or would have to use a circular polariser out front instead of a linear one.


I don't think any of these are deal breakers. I would love to have an updated Sinar shutter using this technology, the bigger the better. If you are thinking of fully commercialising the idea (as opposed to a shareware-like make-a-profit-but-not-a-living business model) I suspect your biggest problem will be competing with all the eBay copycats who jump on the bandwagon once you have done the hard work of proving the idea works.


PS: 100 mm is a little small for my 'problem' lenses. 130-140 mm (fit inside a typical 4x5 format frame) would be *much* more interesting.

[E. von Hoegh]

Not if the movement of one part is countered by the movement of a similar opposite part. e.g. six shutter blades evenly spaced will cancel out each others movement.


Steve.

You are utterly wrong, I posted an explanation why should you care to read it.

[Jay DeFehr]

Polyglot: I say go for it. Experiment trumps armchair theory every time.

There are, however, some things to look out for.

1. You may need an auxiliary shutter if the darkslide is going to be pulled for a long time. The pi cells I have stumbled across (in other applications) have extinction ratios of a 200:1 to 300:1. That means you can safely pull the darkslide or remove the lens cap for 10-20 times the exposure duration with no issues whatsoever (assuming you don't have things like car headlights around). Practical, but it would require discipline/understanding on the part of the user.

What if you stacked two LCD shutters?

Could an LCD shutter be made large enough to use at the focal plane?

One application I see is for using lenses like my Verito, which are aperture-dependent in their effects, so if I want to shoot in bright natural light at wide apertures, I need either a fast shutter or a slow film (or a ND filter).

[Old-N-Feeble]

Jay... The website for the LCD states that it can be pulse-modulated to mimic infinitely variable ND... a very cool thing providing the device has negligible impact on image quality.

[cabbiinc]

$400 would price me out (I'm so poor I can't even pay attention) but a few thoughts.

1) would it sync with flash? at what speed?
2) could you also use it as an aperture? If so how small? What shape?
3) could you use it as an ND filter?

[BetterSense]

Do you have a link to the LCD website?

[Old-N-Feeble]

Only five pages to this thread and folks won't read them... ?

[Jason Greenberg Motamedi]

Yes! I would be very interested in such a shutter, and would certainly pay $400 for it assuming that it had X sync and did not significantly degrade the image. Having a variable ND filter would be fun, but not a necessity for me.

One thing I have seen with a few large LCD windows is that they tend to have a color-cast. My recollection is that they are slightly blue. This could be an issue.

[Leigh]

it can be pulse-modulated to mimic infinitely variable ND
The statement only speaks to variation between the two endpoints. It does not imply high density.

Also, the variability attainable with PWM is not infinite, since the pulse width changes in discreet steps.

- Leigh

[Old-N-Feeble]

The statement only speaks to variation between the two endpoints. It does not imply high density.

Also, the variability attainable with PWM is not infinite, since the pulse width changes in discreet steps.

It's close to enough to "infinite" for photographic purposes... and the limited density was already addressed.

[E. von Hoegh]

It's close to enough to "infinite" for photographic purposes... and the limited density was already addressed.

Actually I don't think it is, the PWM seems to be more geared to eyes.

[BetterSense]

Is 'extinction factor' in stops, or transmission?

A factor of 300 is not terribly large. If your shutter speed is 1/500th of a second, that means you only have a second or so that you can have the lens cap off.

I still think this is a very cool idea and would still like to see the datasheet. I happen to believe that vibration is a bigger deal than people think it is, and a variable ND could have tons of applications.

[Struan Gray]

What if you stacked two LCD shutters?

That would make the dark state darker, but would add to all the other problems, unless you could persuade a manufacturer to make a monolithic unit with two stacked light valves one on top of the other.

I suspect that would be much more expensive, certainly more expensive than learning to keep the lens cap on until ready to shoot. For most shooting you would have time to manually remove a cap, wait a few seconds for vibrations to die down, take the shot, and then put the cap back on. Bright lights at night, particularly ones that move are more likely to be a problem than taking a regular daylight shot.


Could an LCD shutter be made large enough to use at the focal plane?

Sure. There may be finesse involved in matching the drive circuit to large areas, but for a simple on-off-variable ND arrangement you only need a single big electrode front and back. Using a pattered LCD to make variable apertures, or to filter colour, would require the equivalent of a flat panel screen with an addressable array of electrodes or drive transistors, which is not impossible, but will cost. I don't even know if existing applications include such spatially varying panels - the ones I've seen are used as shutters for things like stereo projection of alternating left and right eye images.


One application I see is for using lenses like my Verito, which are aperture-dependent in their effects, so if I want to shoot in bright natural light at wide apertures, I need either a fast shutter or a slow film (or a ND filter).

I think this exactly the sort of use the OP envisaged. I have a Sinar shutter which goes up to 1/60s (nominal) but it throttles some of the lenses I have, which seems against the spirit of having all that lovely glass. My understanding is that pi-cells have response speeds of a few milliseconds or so, which means 1/100 should be achievable, 1/1000 much less likely. Flash sync should not be any problem. Limiting the transmissivity of the 'open' cell should also be easy, and as you say, for fast lenses in bright daylight it could be useful to be able to use the shutter as a programmable ND filter.

[Struan Gray]

Is 'extinction factor' in stops, or transmission?

Transmission: it's usually the ratio of the transmitted intensity for the 'on' state and the 'off state'.


A factor of 300 is not terribly large. If your shutter speed is 1/500th of a second, that means you only have a second or so that you can have the lens cap off.

1/500 is probably a bit too fast to hope for, but yes, this is the 'problem' I was alluding to - if you want speeds of the order of 1/100 of a second you will have to use an auxiliary shutter, or have an accurate and steady hand to remove and replace the lenscap/darkslide.

On the other hand, with the variable ND idea incorporated this is only an issue if you are trying to capture moving obects. If you just want to take a photo of a barn in bright sunlight there is no problem.

[Michael Clark]

Hook up to a small computer or iPhone and make an center filter program for wide angle lens.

[Old-N-Feeble]

I'm not certain but I don't think this type LCD can be made to appear graduated. The OP would need an LCD made with that feature and I suspect that may further degrade image transmission... but I don't know. It surely would increase the cost of the device.

[Michael Clark]

Figured might as well go whole hog , some one will figure it out eventually.Those center filters are expensive.

[polyglot]

The shutter I'm considering (and the manufacturer, LCD Technologies, is linked a few times earlier in the thread) is a single cell, so it won't give you centre-filter type behaviour. A dynamic grad ND filter is something I've always wanted but it's a much more complex beastie with many more issues to solve, like making sure the pixels aren't visible and finding a means to actually input the shape you want into the controller.

Pi cells can be modulated at hundreds of Hz, which means that you can easily have an exposure of 1/500 and probably 1/1000 worth of light, though that exposure might be spread across about 1/200 of realtime and it wouldn't be much better at stopping action than a mechanical shutter at 1/250. Think of a triangular waveform (for example) of translucency, you'd get half the light through that you might expect from looking at the waveform endpoints. Of course you can have flash sync at any speed supported by the shutter. You could even trivially program it to have the flash syncing at any or several points in the exposure duration, not to mention different flash outputs at different times, etc. And you can program some lead in the flash output to deal with any latency you might have in your flash radio remotes so that it will sync reliably even at the very fastest speeds.

I'm trying to buy a ~50x50mm sample at the moment (large enough to cover the front or rear of my 150/5.6) for testing purposes and of course I'll let people know how I get on.

[Shutter]

How would a pixel be visible? Woudn't that mean that the LCD shutter had to be within the depth of field?

[buggz]

Please hurry up with this! *8^)
I just got ripped off on a Sinar Copal shutter, and am looking at trying to buy another one, sigh...

[BetterSense]

I seriously looked through the thread 3 times and still don't see the link. It must be my age.

[polyglot]

I seriously looked through the thread 3 times and still don't see the link. It must be my age.

Sorry, I think maybe it got linked in the APUG version of this thread.

LCD Technologies (http://www.liquidcrystaltechnologies.com/) and note the pi-cells not the (S)TN.

Edit: I've nearly bought a 25x50 sample with driver chip, just need to sort out 1/4-wave film.

[polyglot]

How would a pixel be visible? Woudn't that mean that the LCD shutter had to be within the depth of field?

At f/45 or so you can expect an annoying texture if the ND is on the front/rear of the lens, particularly if the screen is low-res. If it were totally OOF, you'd not get a graduation effect.

[Shutter]

Only in special cases, otherwise even specs and dust particles in lenses would be visible - and I never ever saw that, even with an f-stop of 45 or higher...

[miss_emma_jade]

http://www.liquidcrystaltechnologies.com/tech_support/LCDShutterConsiderations.htm this kinda rules it out doesnt it?

[polyglot]

http://www.liquidcrystaltechnologies.com/tech_support/LCDShutterConsiderations.htm this kinda rules it out doesnt it?

Except, as per previous postings, that applies to (S)TN cells. Pi cells don't have the viewing-angle issues.

[cyberjunkie]

That would make the dark state darker, but would add to all the other problems, unless you could persuade a manufacturer to make a monolithic unit with two stacked light valves one on top of the other.

I suspect that would be much more expensive, certainly more expensive than learning to keep the lens cap on until ready to shoot. For most shooting you would have time to manually remove a cap, wait a few seconds for vibrations to die down, take the shot, and then put the cap back on. Bright lights at night, particularly ones that move are more likely to be a problem than taking a regular daylight shot.



Sure. There may be finesse involved in matching the drive circuit to large areas, but for a simple on-off-variable ND arrangement you only need a single big electrode front and back. Using a pattered LCD to make variable apertures, or to filter colour, would require the equivalent of a flat panel screen with an addressable array of electrodes or drive transistors, which is not impossible, but will cost. I don't even know if existing applications include such spatially varying panels - the ones I've seen are used as shutters for things like stereo projection of alternating left and right eye images.



I think this exactly the sort of use the OP envisaged. I have a Sinar shutter which goes up to 1/60s (nominal) but it throttles some of the lenses I have, which seems against the spirit of having all that lovely glass.
.......
Limiting the transmissivity of the 'open' cell should also be easy, and as you say, for fast lenses in bright daylight it could be useful to be able to use the shutter as a programmable ND filter.


I couldn't agree more.
The best solution for big, fast, giant lenses currently is the Sinar/Copal shutter.
Unfortunately it's limited to slow speed (which sort of defeats the scope of acquiring expensive soft focus or fast portrait lenses, if you must use them stopped down!), and it's also a vibration machine :)
Many professionals happily used the Sinar shutter for years, but the main use was in studio, with FLASH!
That way the vibrations are of no concern... and the Sinar gives its best.

Whatever it is your opinion about Sinar/Copal vibrations, the lack of fast speeds makes it a poor match for fast lenses, which must be used wide open to get the image quality they're famous for.
An LCD substitute, with max speed of 1/500sec, would be almost perfect. 10cm internal diameter is already very good, and sufficient for the most part of those lenses, but i agree that a 14cm shutter would wide enough for the vast majority of those brass chimneys i find so attractive (and which i would not be able to afford in the foreseeable future :))

400 USD isn't exactly cheap for a shutter (you can get a working Sinar for much less), though i don't think that's so much, if we consider the kind of lenses which would be matched to such a shutter, and their PRICE.
We all know that there are people who would happily pay 4/5000 USD for a nice Perscheid, so i think that $400 for a shutter that allows them to shoot wide open would be considered perfectly acceptable, if not outright cheap!

BTW, if a very small series would be 400, and IF the first batch works well, i am sure that there would be more interest than what we could expect as of today.
Not a large scale, industrial item, but probably a few hundred pieces. Such number would make the shutter somewhat cheaper to produce, and a better price would increase the number of interested parties.
Just speculating... unfortunately i am not so sure that a LCD shutter (good for the intended application, and with no major optical flaws) would be feasible at a do-it-yourself level.

have fun

CJ