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zack
21-Jan-2010, 10:46
Hi everybody,

I haven't been active around here for a while, but I thought I'd share an interesting discovery I made the other day.

Surplus Shed has a bunch of these electronic shutters right now:
http://www.surplusshed.com/pages/item/m3259.html

As you can see, they're cheap. I bought one and I've got it set up and working perfectly. It'll eventually make it into a new LF camera I'm building. The shutter assembly is controlled by a simple solenoid. It also has flash sync.

24 Volts seems to be what it takes to drive the shutter. It does work at 12, but the blades seem a little sluggish. I put together a simple relay circuit for mine so I could control it from a PocketWizard. The MultiMAX I'm using works great for a number of reasons:

* I can specify the shutter speed by setting specific contact times in the MutliMAX.

* I can do neat multiple exposure things with the Intervalometer feature.

* The Multipop feature lets me fire the shutter REALLY fast, which not only looks and sounds awesome, but will also lend itself to some even neater multiple exposure projects.

* Since it's a PocketWizard, I can fire the shutter wirelessly.


I've put together a few videos showing the shutter in action. Here's the first:
http://www.youtube.com/watch?v=HEif9X8hABQ

and the second (high speed drive mode):
http://www.youtube.com/watch?v=MgBEKz6Y8kY


There's still a bunch left to do. I need to figure out just how the contact times in the MultiMAX relate to actual shutter speeds, since I'm going through a relay and a solenoid. I haven't hooked up the x-sync yet, but it's a very simple switch and my multimeter says it works fine. Of course there's the whole process of mounting a lens on it and getting it in a working camera too...

Anyway, just thought I'd share.

-Zack

vinny
21-Jan-2010, 11:09
very cool. ease up on the coffee next time you decide to pick up a video camera:)

zack
21-Jan-2010, 11:16
I blame a one-handed iPhone :)

Steven Tribe
21-Jan-2010, 15:16
"Sorry - this item is currently unavailable"

Steven Tribe
21-Jan-2010, 16:37
And guess what! One of my least favorite sellers (with restricted insight in things optical and photographic - and especialy their market value) suddenly has one for sale (you know where) with a text that seems taken from the Shed place! Price is no longer $15.

Mike1234
21-Jan-2010, 18:34
Who is this "least favorite seller"? :)

erie patsellis
21-Jan-2010, 22:15
781 in stock @ $99 BIN??? d'bag doesn't even start to describe how I feel about people like this.

Mike1234
21-Jan-2010, 22:24
I have ten various solenoid activated shutters pulled from repro cameras and a dozen controllers. Most of them are larger (some much larger) than the one at SS. However, I don't have the time right now to figure out the wiring to make them work.

Jim Graves
21-Jan-2010, 23:37
So if he purchased their entire stock of 781, one can reasonably assume he paid less than the advertised price of $15 apiece ... let's guess around $10 apiece for that volume which would total $7,810.

Now selling at $99 apiece ... that is an 800% markup. All he has to do is sell 79 to get his money out and the other 702 pieces are gravy ... should he actually be able to sell those, his profit would be $69,500!

A gouge or a smart investment?

The bay sale # is 280454928991

Jim C.
22-Jan-2010, 01:07
Surplus Shed had them on sale for $ 7.50 via an email flyer

Steven Tribe
22-Jan-2010, 03:14
Perhaps Zack could explain the unbelievable co-incidence of his starting a thread - with quite a "sales pitch" atmosphere about it - at the same time that a marketing campaign has been started by someone who has just collared the market?

I can see that the shutter opens - but what about time controls under 0.5 secs? Working out a controling unit and callibrating will take quite a long time and is certainly beyond my electronic capabilities. 24 volts seems to add to transportability problems.
What can it do that a Packard can't?

Steven Tribe
22-Jan-2010, 04:11
I wondered where the 781 on offer came from. He modified the listing after I found it and included data about his speculative bulk purchase later. I think this action is best described as shooting himself in the foot! A bit like " please BIN at my price of 99$" and " really difficult to get hold of - I only have 781".

The price will come down. He always seems to list his things (non-cine anyway)at a high precise figure - $99 or $199 (not realising that this signals a revenue wish from his side rather than his placing a market value on the item) - and then eventually has a real auction after a few months of no response.

Carsten Wolff
22-Jan-2010, 04:14
Perhaps Zack could explain the unbelievable co-incidence of his starting a thread - with quite a "sales pitch" atmosphere about it - at the same time that a marketing campaign has been started by someone who has just collared the market?

I can see that the shutter opens - but what about time controls under 0.5 secs? Working out a controling unit and callibrating will take quite a long time and is certainly beyond my electronic capabilities. 24 volts seems to add to transportability problems.
What can it do that a Packard can't?

Exactly, and at that price we're deep in good Packard, or other s/h mechanical shutter territory, such as e.g. Copal(-Press), Alphax, etc......99$...for somethng that's gonna give you crappier results, (read: more awkward to mate to many lenses, let alone to use, and heavier to boot) ...you gotta laugh....good luck to the seller....:)
For $15 I would have thought about it, may be....

zack
22-Jan-2010, 06:27
Looks like I created quite the ruckus...

I have no connection to the seller on ebay (anyone have a link?). It agree it's a strange coincidence that they all disappeared from the shed the same day I posted my little writeup. The whole project was just something fun for me to build. I actually got my shutter for $7.50 because the shed was having a sale, so it was hard to say no.

Time controls under .5 seconds are easy, since I'm using the a multimax to control the shutter. You can see in my video that I can specify the contact time, which equates to how long the coil on the relay is energized. As I mentioned earlier, I don't know exactly how that translates to a specific shutter speed, since I'm sure there are delays involved with switching a mechanical relay and moving a solenoid.

The shutter will completely open and close with a contact time as short as .02 seconds, which is 1/50th I believe (since there are delays involved before the shutter opens, I suspect my shutter speed is actually faster than 1/50th). The multimax can hold it open for 99.99 seconds on its own, but I can also just continuously trigger it either via the test button or remotely from another radio.

Steven Tribe
22-Jan-2010, 07:20
OK Zach. You are lucky that he hasn't found the videos yet and that you state in the videos where you got it. So he won't refer to your videos in his item listings as people would put 2 and 2 together and realise this is a case of true "entrepreneurship" on his part!
I think I understand the system with the controller but I feel the mechanical/friction inertia will limit precision. Capability will surely be the same as a Packard? Item no. has been mentioned before -280454928991.

zack
22-Jan-2010, 08:03
I put together an image with comments explaining how everything works, mostly:
http://zack.loseby.net/images/pw-shutter-comments.jpg

I'm sure the mechanical aspects reduce the consistency to a degree, but I'll be using it for x-ray film, so my exposures will probably be in the multi-second range anyway. It sounds pretty darn consistent. It'll be interesting to start doing the actual measurements. The fun part about this project for me isn't having a perfectly consistent shutter. It's really just having a large format camera I can fire from far away, and on set intervals, and at 30FPS, on a single sheet of x-ray film, woohoo!

I have some scrap wood that I'll be assembling into a rough body this weekend. The lens will probably be some weird element I got from the same place, at least to start.

Skorzen
22-Jan-2010, 08:56
I found these two line kinda funny next to each other:

"SHUTTERS WILL ARRIVE HERE BY JAN. 28TH

781 PIECES IN STOCK.
"

Len Middleton
22-Jan-2010, 09:28
I would expect the various bits could result in a delay on the shutter tripping, but I would think that consistency of speed is likely to be more comparable to our standard lens shutters (Compur, Copal, Prontor, Compound), than a Packard.

In experiementing with my Packard No. 6, I am able to adjust the speed by a full stop or more on the instantaneous setting, based upon how hard and fast I sqeeze the bulb.

And BTW, what is the acceptable speed tolerance for our standard lens shutters? 1/3 stop for B&W, 1/10 stop for chromes?

My $0.02,

Len

Steven Tribe
22-Jan-2010, 11:16
New quote from the listing:

Q: Do you have any instructions on how to set the shutter speed?
A: Hi, these fire at one speed and I believe there is some ways to adjust the speeds with a variable voltage resistor or equivalent. I am doing research today and will add to the description as I learn. Blessings.

I wonder how he will react when he finds Zack's videos?

zack
22-Jan-2010, 11:16
I would expect the various bits could result in a delay on the shutter tripping, but I would think that consistency of speed is likely to be more comparable to our standard lens shutters (Compur, Copal, Prontor, Compound), than a Packard.

Looks like you're right:
http://zack.loseby.net/images/lagtime.jpg

I used the multimaxes lag time measurement to measure the time between when it triggered and when it received a sync pulse from the shutter. As you can see, I hooked the sync line from the shutter up to the shoe of the radio. I only saw that .0194 deviate by a whopping .0002 at the worst in about a dozen tests.

This means that it takes .0194 seconds for the shutter to fully open after the multimax triggers.

So the math for figuring out the exact shutter speed is:
MultiMAX Contact Time Setting - .0194 + Time for Spring to Close Shutter(I don't have this number yet. Ideas?) = Shutter Speed in Seconds

If I don't account for the time it takes for the shutter to slide closed, for a Contact Time Setting of .02:
.02 - .0194 = .0006 aka 1/1667th

1/1667th seems too fast, but .02 is the fastest contact time that lets the shutter open at all. Maybe my method of measurement isn't suitable for these faster speeds. A .1 second contact time would give me .0806 seconds, aka about a 12th of a second, which seems right.


Does my math look OK here? College Algebra took me a couple tries...




P.S. You can't adjust the shutter speed with any kind of resistor/potentiometer... Mr. shutter hog has no idea what he's talking about.

Robert Hughes
22-Jan-2010, 12:00
P.S. You can't adjust the shutter speed with any kind of resistor/potentiometer... Mr. shutter hog has no idea what he's talking about.
Just use a 555 timer IC with a resistor/potentiometer. The circuit is dead simple for anyone who knows which end of a soldering iron to hold.

zack
22-Jan-2010, 12:06
Just use a 555 timer IC with a resistor/potentiometer. The circuit is dead simple for anyone who knows which end of a soldering iron to hold.

Yep, The MultiMAX is pretty much acting like a fancy 555. I remember having a lot of fun with them in my old electronics classes. You could probably throw a photoresistor in there and make a metering large format camera. HMMMMMM...

BrianShaw
22-Jan-2010, 12:14
Just use a 555 timer IC with a resistor/potentiometer. The circuit is dead simple for anyone who knows which end of a soldering iron to hold.

Speaking as someone who once held the wrong end of a soldering iron... a 555 timer circuit is easy for even me!

Robert Hughes
22-Jan-2010, 12:31
Speaking as someone who once held the wrong end of a soldering iron...
I once stuck a soldering iron in my ear. "What's that crackling sound? Oh, it's my hair on fire! AAARGGH!!!"
Something about taking ineptitude to the next level...

Jack Dahlgren
22-Jan-2010, 12:32
Looks like you're right:
http://zack.loseby.net/images/lagtime.jpg

I used the multimaxes lag time measurement to measure the time between when it triggered and when it received a sync pulse from the shutter. As you can see, I hooked the sync line from the shutter up to the shoe of the radio. I only saw that .0194 deviate by a whopping .0002 at the worst in about a dozen tests.

This means that it takes .0194 seconds for the shutter to fully open after the multimax triggers.

So the math for figuring out the exact shutter speed is:
MultiMAX Contact Time Setting - .0194 + Time for Spring to Close Shutter(I don't have this number yet. Ideas?) = Shutter Speed in Seconds

If I don't account for the time it takes for the shutter to slide closed, for a Contact Time Setting of .02:
.02 - .0194 = .0006 aka 1/1667th

1/1667th seems too fast, but .02 is the fastest contact time that lets the shutter open at all. Maybe my method of measurement isn't suitable for these faster speeds. A .1 second contact time would give me .0806 seconds, aka about a 12th of a second, which seems right.


Does my math look OK here? College Algebra took me a couple tries...
.

I don't see how you can figure out shutter speed without understanding how long it takes for the shutter to close. The lag between when you apply power and when it opens doesn't mean much unless you know that.

zack
22-Jan-2010, 13:15
I don't see how you can figure out shutter speed without understanding how long it takes for the shutter to close.

Excuse me while I think out loud here:

I know the shutter will be held completely wide open for the Contact Time I've set minus ~.0194 seconds. That .0194 seconds is composed of the relay's coil being energized, the relay closing the contacts for the 24 volt line, the solenoid beginning to move, and the time it takes the shutter to completely open and thus close the x-sync contacts. So I know the time it takes for the shutter itself to open is some value less than .0194 seconds.

Assuming it takes a similar amount of time for the shutter to close as it does to open (totally guessing here), I'd expect that it would only start to really affect my exposures at fast shutter speeds. Even if the entire .0194 seconds was taken up by the shutter opening/closing (and it isn't), that's only about a 25th of a second total when you combine opening and closing, and that 25th of a second is all composed of the shutter closed down to varying degrees, which would still give me a pretty accurate shutter. Of course it's possible the shutter takes a lot longer to close than it does to open, so that's still up in the air.


I made a diagram to help me understand the concept here. Please excuse its terribleness:
http://zack.loseby.net/images/shuttergraph.jpg

The "Beginning of trigger" point is the instant the shutter begins to open. "End of trigger" is when it begins to close, which is when the MultiMAX opens the contacts and de-energizes the relay. All this leads me to a few more questions:

* When measuring the speed of a leaf shutter, do you usually account for the opening and closing actions? Technically the shutter is acting as a constantly changing aperture during those times, right?

* How long does it take for my relay to close its contacts? Maybe I can use the lag time measurement on the multimax again. Hmm.

Thanks for everyone's input so far :)


-Zack

Len Middleton
22-Jan-2010, 13:18
Looks like you're right:

I used the multimaxes lag time measurement to measure the time between when it triggered and when it received a sync pulse from the shutter. As you can see, I hooked the sync line from the shutter up to the shoe of the radio. I only saw that .0194 deviate by a whopping .0002 at the worst in about a dozen tests.

This means that it takes .0194 seconds for the shutter to fully open after the multimax triggers.

So the math for figuring out the exact shutter speed is:
MultiMAX Contact Time Setting - .0194 + Time for Spring to Close Shutter(I don't have this number yet. Ideas?) = Shutter Speed in Seconds

If I don't account for the time it takes for the shutter to slide closed, for a Contact Time Setting of .02:
.02 - .0194 = .0006 aka 1/1667th

1/1667th seems too fast, but .02 is the fastest contact time that lets the shutter open at all. Maybe my method of measurement isn't suitable for these faster speeds. A .1 second contact time would give me .0806 seconds, aka about a 12th of a second, which seems right.

Does my math look OK here? College Algebra took me a couple tries...

P.S. You can't adjust the shutter speed with any kind of resistor/potentiometer... Mr. shutter hog has no idea what he's talking about.

Zack,

The mechanical inertia (solenoid magnetic build up, open the shutter blades, then spring closing the shutter) will impact the delay and determine the fastest shutter speed.

The delay will impact action photography, but likely much less a concern on this forum. Although I have used a 45 Technika handheld at vintage car races...

Rather than "doing the math", might it make more sense to breadboard one of those shutter speed detection circuits discussed on the forum that inputs into your computer's speaker input. It eliminates the math and many of the potential variables.

If of course you have one of those Calumet (or other) shutter testers, then the breadboarding effort is moot.

Actual measurement of the effective shutter speed will provide you with the information you need with regards to consistency.

And actually you can "change" the shutter speed through resistors to reduce the voltage. As you noted yourself, it was sluggest at 12V. But not likely to be as consistent and repeatable, as a "snappy" 24V operation with properly controlled time.

Good luck with your efforts,

Len

Robert Hughes
22-Jan-2010, 13:57
* How long does it take for my relay to close its contacts? Maybe I can use the lag time measurement on the multimax again. Hmm.

The answer is so simple. Reprogram your MultiMax to begin the shutter actuation 0.194 seconds BEFORE you press the trigger. I mean, it's not rocket science... :rolleyes:

Dan Fromm
22-Jan-2010, 14:06
Hmm. Where's my bottle of Thiotimoline?

Robert Hughes
22-Jan-2010, 14:09
Hmm. Where's my bottle of Thiotimoline?
Either you used it up, or you're going to...

Jack Dahlgren
22-Jan-2010, 16:14
The answer is so simple. Reprogram your MultiMax to begin the shutter actuation 0.194 seconds BEFORE you press the trigger. I mean, it's not rocket science... :rolleyes:

Getting even more off-topic... I think I remember seeing a digital camera which actually started taking pictures continously when you pressed the button halfway and would in effect take the picture before you pressed the button. The button would select the image you wanted and the rest would flush out of the buffer.

domaz
22-Jan-2010, 16:44
New quote from the listing:

Q: Do you have any instructions on how to set the shutter speed?
A: Hi, these fire at one speed and I believe there is some ways to adjust the speeds with a variable voltage resistor or equivalent. I am doing research today and will add to the description as I learn. Blessings.

I wonder how he will react when he finds Zack's videos?

It would be funny if moderators would move this entire thread to F/S just to make it harder for the guy to link directly to the information here.

el french
22-Jan-2010, 19:03
And actually you can "change" the shutter speed through resistors to reduce the voltage. As you noted yourself, it was sluggest at 12V. But not likely to be as consistent and repeatable, as a "snappy" 24V operation with properly controlled time.

Good luck with your efforts,

Len

What will happen if you increase it to 36v or higher?

Len Middleton
22-Jan-2010, 19:15
What will happen if you increase it to 36v or higher?

It may not significantly increase the shutter speed, but will increase current and the stress on the insulation, thereby likely causing it to fail prematurely...

mandoman7
22-Jan-2010, 21:55
I'd say the opening size is a significant restriction. Most of the big, fast portrait lenses will need bigger openings. If the shutter had a 3" opening then a lot of people would want one.

Dave Grenet
22-Jan-2010, 23:07
It may not significantly increase the shutter speed, but will increase current and the stress on the insulation, thereby likely causing it to fail prematurely...

I'm not sure about these shutters, but other magnetic shutters (the Prontor Magnetic shutters to be precise) recommend a 30V, 50ms pulse to open the shutter followed by 3V to keep it open (as long as you like). This makes the driving circuit (and power supply) more complex but ensures fast opening times and less stress on the shutter.

David McNiven
23-Jan-2010, 09:51
A while back I was looking for ready-built controllers for a similar project.
pc-control.co.uk sell a standalone programmable controller at a reasonable price called the pc hawk but resolution as I understand from their website is only 0.1 sec. - no good to me but maybe of use to some of you?

VictoriaPerelet
30-Jan-2010, 13:12
Just use a 555 timer IC with a resistor/potentiometer. The circuit is dead simple for anyone who knows which end of a soldering iron to hold.

555 is convenient on proto boards, but once you decide on complete circuit/device/enclosure for field use it practically get's very flaky/messy unless you are setup with practical board layout and packaging production.

We used to do quite a lot of commercial high speed work and now I'm experimenting with stroboscopic effects for my editorial LF work. Basic Stamp (http://www.parallax.com/tabid/295/Default.aspx) or similar programmable controllers are very practical and packable + in most cases one may easily field reprogram them rather messing with soldering on location.

Len Middleton
30-Jan-2010, 14:44
For someone looking for a Prontor electric shutter, see: http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=200431567058&ssPageName=STRK:MEWAX:IT

Note, I have no knowledge of the seller, so you are on your own...

Steven Tribe
12-Feb-2010, 08:49
Our friend on e**y has now apparently sold his first shutter. He had reduced his starting price to $49 and the winning bid was a little over 100. Just two competitive bidders! So 1 sold - 780 left.

IanG
10-Mar-2013, 07:40
Over 3 years later and he still has 775 left :D

Ian

Jim C.
10-Mar-2013, 18:23
3 years, has it been that long ?

evan clarke
10-Mar-2013, 18:44
I bought a dozen of them at $25. I got a Stop Shot controller and can be accurate at 1/30th at 12v dc