LCD shutters - any experience? 4x5 FP shutters?

[bglick]

Hi Dan, thanks for your response....

> That films are better isn't controversial at all, but the big gain in lenses since WWII is not in central resolution, it is in coverage. Your application -- nominal 6x7 negatives shot with lenses no shorter than half normal for the format -- doesn't need lenses with much coverage. And at the apertures you seem to have in mind to use, f/11 or thereabouts, modern lenses' improved sharpness, if any, will largely be lost to diffraction anyway.

I think you will find this not to be true. If you shoot the same test target with the same modern film and switch between modern hi rez lenses and post WWII lenses, the differences are huge. View Chris Perez site for more information on this. An example, my Mamiya 7 lenses on his tests resolve 120 lpmm, whereas post WWII glass is in the 60 lpmm range.... I would say this difference is huge... both on MF film also, same coverage? is it possible, all his test results are wrong, he is very tehncially astute.... I see the differences with my own eyes..

> It sounds to me like you've drunk from the same well as the gigapixel and Ross zealots and are warming up a propaganda engine parallel to theirs.

Drunk? yeah, I have been accused of this before, but not with propoganda, but rather with sound test results and good application of accepted scientific practices. A good dose of common sense and facts is rarely well received by everyone, I accept that, but I am willing to stand "in the line of fire" to solicit opinions of other enthusiasts.

> Why don't you just put better lenses on a well-sealed well-baffled Sputnik and be done with it?

The only issue resolved with a spud body is a roll film advance, and lens spacing... i still have the same focus issues as before, and I loose ground glass focussing...thsis is not the camera i want, but it sounds like it would suffice for you, so try one, I am sure it would do well.. I would be happy to give you constructive input and encouragement if you decide to!

> And if you use a Graflex focal plane shutter, well, vibration can be tamed too.

I have seen tests results from firing a camera with an open shutter, with dark cloth over lens, using long exposure, vs. the same with new copal shutters using shorter exposures.... modern shutters cause vibration, older , massive size shutters cause more vibrations... they all reduce resolution, not a good mix with super high resolving lenses, hence why Sinar probably switched to LCD shutters, as they were removing the bottleneck of resolution, hampering expensive lenses and digital backs. I would like to perform this same experiment with high resolving digital lenses, but I do not have any yet...

As an experiment, I may just try this, shoot test target with digital camera, so no film plane issues.... then fire at fast ss speed, slow shutter speed, then fire on bulb with dark cloth over lens, remove dark cloth expose, then put dark cloth back over and close shutter, and compare results. This should be interesting... would you accept the results, regardless of the outcome?

Even in a hail of gunfire, good things can surface! Thanks Dan!

[Brian C. Miller]

Bill, who sells LCD shutters? Sinar seems to use them integrated into a product, but they don't sell them as a seperate accessory. The LCD shutter in the Sinarback is used for a live feed of the subject to a monitor. (Google search)

Schneider sells the Rollei electronic shutter, but it is mechanical and only controlled electronically. It seems to require a seperate controller to operate. There is a PDF, but I can't read German. Schneider accessories page

Pardon my head scratching, it isn't from dandruff. I'm just trying to build a mental picture of the camera and the final application. I have a couple of 35mm stereo cameras, and of course they use fully mechanical shutters. The dual Nikons have been fine for what subjects I photograph, which are things that don't move, or don't move much. I've never had a problem with shutter vibration interfering with a stereo photograph, especially when the camera is mounted on my Bogen 3036.

From what it sounds like, you plan to build from scratch a camera with two lenses. The back on it is a 4x5 film back, right? Otherwise I guess you wouldn't be considering using a Graflex-type focal plane shutter. I can understand the need for precise synchronization of two physically seperate shutters when photographing subjects with fast motion.

What I really don't understand is the need for the barest minimum of vibration when the viewing size will be 6x7cm. What film will you be using?

[bglick]

> Bill, who sells LCD shutters? Sinar seems to use them integrated into a product, but they don't sell them as a seperate accessory. The LCD shutter in the Sinarback is used for a live feed of the subject to a monitor. (Google search)

You could be right.... but other companies make LCD shutters, they would be customized.....

> Schneider sells the Rollei electronic shutter, but it is mechanical and only controlled electronically. It seems to require a seperate controller to operate. There is a PDF, but I can't read German. Schneider accessories page

Yep, they even sell their own brand shutters, all too wide, 80mm is the smallest diameter. I need max. 70mm center lens spacing.....

> Pardon my head scratching, it isn't from dandruff.

it's OK, good for the scalp......

> I'm just trying to build a mental picture of the camera and the final application. I have a couple of 35mm stereo cameras, and of course they use fully mechanical shutters. The dual Nikons have been fine for what subjects I photograph, which are things that don't move, or don't move much. I've never had a problem with shutter vibration interfering with a stereo photograph, especially when the camera is mounted on my Bogen 3036.

It most likely is not a problem.....but if I need a custom shutter system, I may try to eliminate all vibrations.... "problem" is a relative term. I use many shutters.....

> From what it sounds like, you plan to build from scratch a camera with two lenses. The back on it is a 4x5 film back, right? Otherwise I guess you wouldn't be considering using a Graflex-type focal plane shutter. I can understand the need for precise synchronization of two physically seperate shutters when photographing subjects with fast motion.

Camera, 6x17 back with 56x63 dual images, Digitar lenses with sync focus and shutters.... Final images are displayed this size also, with 4x magnfication lenses in viewer.

> What I really don't understand is the need for the barest minimum of vibration when the viewing size will be 6x7cm. What film will you be using?

220 Velvia..... Again, in the end, I may settle for dual synced copal shutters, but this is by last resort, I want to improve on this.... if not possible, the copals will suffice....

[Struan Gray]

Bill, I am sorry if something I wrote has sent you off after wild geese. When I mentioned Sinar shutters I was referring to the mechanical shutters used in their Auto-aperture system with DB-mounted lenses. I use an older version of these with my barrel lenses and the central opening is large enough at 80-90 mm to accomodate two medium-sized lenses side by side without vignetting at f11.

I didn't know that Sinar offered an LCD shutter on their latest digicams. The old arguments against LCD or electro-optic shutters are that the wide area ones are of poor optical quality while the high quality, small area ones only work with collimated light. Both sorts polarise the light on imput, sucking over half your intensity away and interfering with on-lens polarising filters. Both sorts need hefty power supplies to get up to photographic speeds. Obviously Sinar have solved the issues for a 645-sized chip in the studio, but there may not be a suitable shutter for you to use on doubled-up 6x8 in the field.

[bglick]

> Bill, I am sorry if something I wrote has sent you off after wild geese.

Geeese are good.....

> When I mentioned Sinar shutters I was referring to the mechanical shutters used in their Auto-aperture system with DB-mounted lenses. I use an older version of these with my barrel lenses and the central opening is large enough at 80-90 mm to accomodate two medium-sized lenses side by side without vignetting at f11.

Sinar also has focal plane shutters for 4x5, will work behind my lenses. I will investigate.....

> I didn't know that Sinar offered an LCD shutter on their latest digicams. The old arguments against LCD or electro-optic shutters are that the wide area ones are of poor optical quality while the high quality, small area ones only work with collimated light. Both sorts polarise the light on imput, sucking over half your intensity away and interfering with on-lens polarising filters. Both sorts need hefty power supplies to get up to photographic speeds. Obviously Sinar have solved the issues for a 645-sized chip in the studio, but there may not be a suitable shutter for you to use on doubled-up 6x8 in the field.

Your probably right, but I can't help to investigate this one..... the potential is huge, but I am sure there is reasons this technology has not flooded the photographic community.... I will report back....

Bill

[bglick]

For those interested, I learned some interesting facts about LCD shutters....

Pros

Fast shutter speeds with certain types, 1/10,000 th second easy.... and consistent

Zero Vibration, no loss of image sharpness

Some LCD's only have .3 stops of light loss when open

Easy to sync for stereo camera :-)

No loss of image quality, equal to putting UV filter on front of lens.

Reliable firing as electricity controls the timing.

For small apt. shutters, relatively cost effective considering their benefits

Cons

Larger shutter area price becomes very expensive...

Very sensitive to cold weather, max. shutter speed dependent on ambient temp

Some will zap up to 1.3 stops of light when open

Some require duty cycle, i.e. must be powered on as much as off, equally, or damage will occur to LCD

Some polarize light, not sure how this would react in the back of the lens.

Some use high voltages, 100 volts at 30 Hz and require special transformers.

Large lenses require large shutters, price becomes more prohibitive.

Light leakage when shutter is closed.... about 3%, but this adds up, so secondary dark slide required.

There is different types of LCD shutters, so I did not want to bore the list with each, but this is some of the interesting facts as they would apply to photography.. If this technology is ever perfected further, some day, they may be the shutter de jour. Tell then.... Looks like I will stick with Copals, unless I find a good LF focal plane shutter, but still no luck...

[GPS]

Bill, you should stick with a Holga. The right camera for you.