Packard Shutter Mods

[SteveH]

All,
Im looking around to find a packard shutter to modify (to use on my DIY meniscus project). Here's a quick schematic I drew up; I plan on replacing the pneumatic cylinder with an electromechanical solenoid. I still have some math to figure out, but it should work OK. 1/30th might be abit fast (1/15th might be as well...); as I haven't began to look at actuator speeds yet.
Both switches will be actuated by a typical shutter release. S1 is to be used for the 'speed' exposures, whereas S2 is a bulb/focusing switch. It isn't the best way; but my electronic engineering is quite limited.

Thoughts ?

 

[Jon King]

A couple of comments.. S3(the 'bulb' switch?).. will short the LM555 output, which would be low, to your +9Volts. A better way might be add a throw to S2, and make a bulb setting, and trigger it with S1 as you would your normal 'speeds'. The other thing is your timing resistors seem to be set up in a mix between what is normally done as the one shot mode and the oscillator mode. I'm sure you can make it work, but the normal design equations won't give you the right values. Good luck with the lens and the shutter timer!

 

[jimgalli]

At risk of raining on another re-invention, why not buy an old Tektronix C53 oscilloscope camera and use their circuitry? Plus you get a neat old packfilm holder to mate to your home made lens for instant results. Plus the lenses in these are right up your alley anyways as they were corrected for a rather spherical near surface so they're wacky for normal things.

 

[SteveH]

A couple of comments.. S3(the 'bulb' switch?).. will short the LM555 output, which would be low, to your +9Volts. A better way might be add a throw to S2, and make a bulb setting, and trigger it with S1 as you would your normal 'speeds'. The other thing is your timing resistors seem to be set up in a mix between what is normally done as the one shot mode and the oscillator mode. I'm sure you can make it work, but the normal design equations won't give you the right values. Good luck with the lens and the shutter timer!

Jon,
Ah, thanks for pointing that out. An idea that wasn't thought out - obviously.
I was going to try the design out tonight; but I cannot manage to find my breadboard. I then learned that RadioShack no longer carries such items !?
I need to do some more research on the 555 to make sure I have it right; which it doesn't seem I do

Thanks,

 

[SteveH]

Niffty item Jim, checking it out now.

I like reinventing the wheel it seems. If nothing more, its an excellent way of going poor

 

[SteveH]

Jon,
I found this link;
http://555-timer.clarkson-uk.com/operation/mono4.html
That seems to be exactly what I have been looking for (and, failed at making myself). Oh well, at least I am a better machinist than EE

 

[df cardwell]

Any idea how ACCURATE and repeatable a Packard is ?

It is.

.

 

[Jon King]

Well.. I scanned a sketch of what I was thinking, but before that - Jim Galli had a very good idea. If the shutter you can buy will do what you want, and i think with some disassembly and duct tape it might work. What I sketched should work - I'm sure of all but the bulb setting, and it should work. There are differences between what I sketched and what you have - the changes in the switch placement, diode and extra resistor are on purpose. If you want to continue here, or pm, I'd be happy to help out if I can.

 

[SteveH]

Jon,
Thanks for taking the time to help me out. I found the issues you pointed out late last night; and made my corrections. Hopefully I can fibd a breadboard and give 'em a whirl.

 

[glbeas]

By attaching a return spring to the linkage in the right place you will be getting down to your average solenoid controlled electronic shutter except it will act like a press shutter, cocking as you trip it. Bet you'll never find a press shutter as big as a Packard! Have fun and definitely show us what you come up with.

 

[SteveH]

The latest and greatest...

 

[SteveH]

Update...
I just completed building the circuit (although I haven't completed the pot bank), and it works flawlessly. Im going to be taking it off of the breadboard and soldering it up later this evening.
I'll post pics then.

Thanks again to everyone for your help !

 

[SteveH]

Some quick shots before I transfer it over.

 

[glbeas]

Thats pretty cool. What of the battery arrangement? One big hassle I had with my electronic shutter on my LF was the original battery was expensive and short lived. Fortunately I found it worked perfectly with a couple of AAA cells at a slightly lower voltage than the original. Nice part about that is these are available at any convenience store if they die while out shooting. I mounted the cells in some Radio Shack battery clips on the back of the lens board so the appearance is still fairly vintage. Good luck with yours!

 

[glbeas]

One suggestion, maybe in a later mod, is the times you have for the speeds. I notice the longest time in the circuit notes is 1/2 second. Will the 555 set for extended time periods? You may want to set up times up to 30 seconds or more for LF work. My electronic times to 32 seconds which is really convenient when shooting stopped down or in low light, especially when dealing with reciprocity corrections.

 

[SteveH]

For the moment, Im using a 9v battery.

As for the final power source, that's still up in the air. I need to get a shutter, then see what solenoid will work on it. Once I have that, I'll pick my power supply based upon what the solenoid needs to operate.
The timing circuit has a wide latitude in voltages, up to 15vdc I believe. The issue is that you only get 2/3 of that coming out of the chip, at 200ma max. Hopefully that will be enough to toss a relay large enough - we shall see.
One problem that I may/may not have is throw length of the solenoid. Anyone have a clue as to the throw length of the pneumatic piston on a 3" packard shutter ?

Regards,

 

[SteveH]

One suggestion, maybe in a later mod, is the times you have for the speeds. I notice the longest time in the circuit notes is 1/2 second. Will the 555 set for extended time periods? You may want to set up times up to 30 seconds or more for LF work. My electronic times to 32 seconds which is really convenient when shooting stopped down or in low light, especially when dealing with reciprocity corrections.

I can get a max of about 10mins out of the 555; but I think anything over 30s or so isn't going to be very accurate (10% +/- with these caps). I put the bulb function in there for that purpose; I can just lock my cable release and use a stop-watch.
Im guessing that 1/15th or so is going to be my real-world max speed (if that...). So that would give me 1/15, 1/8, 1/4, 1/2, and 1s; along with bulb.

 

[glbeas]

From what I can see of pictures of them it'll be a max of an inch.

 

[jimgalli]

Steve, an inch or so is about right. I have a packard from an old process camera application that already has a solenoid in place. I have no idea what the voltage was. How would you tell? It's quite a little mechanical action though. Takes a good bit of power mainly to overcome the return spring that re closes the shutter when voltage is removed. You'll be surprised how much work that little air piston actually accomplished. With air, suction re-closed the shutter in most cases so the return spring wasn't necessary. Also nicer for B because you simply drained the air out while the blades were wide open and it stayed open. With electric operation you'll have to overcome a rather nasty return spring the entire time the shutter is open in B. Fine for 28vdc but could be a big time battery drainer in your case. Ahh the frustrations of building a better mouse trap. Did I mention I routinely get 1/25 1/8 1/4 1/2 1+ using nothing but the bulb that the old guys used.

 

[RobertP]

Doesn't Packard make an instantaneous shutter now that works with just the bulb activation?

 

[glbeas]

It may be possible to get a solenoid that powers in both directions and remove the return spring. And yes theres and instant version, I saw one on Ebay, had two pneumatic cylinders instead of one.

 

[SteveH]

Thanks for the info Jim. I wonder why all the old electronic shutters used such high voltages ? I saw an old ilex setup on ebay today, and it was quite a large package - no wonder why they weren't ever popular.

Yes, I know there are 'instant' packards. But I don't want to be stuck with one shutter speed. My whole purpose here is to have a shutter that has accurate-ish speeds in the common ranges. Plus, Im trying to be cheap

Again, I've never seen a packard as of yet, so Im not sure how Im actually going to apply this. But, I suppose, that is 1/2 the fun...

 

[jimgalli]

Quickie lesson on Packards of (which I am a fan because they work.) #5 Packard. Simple piston that opens and closes by air / vacuum. #6 Packard is the most common. It works the same but it has a pin that slides in and out from the front. When the pin is in it gives a constant 1/25th every time air is supplied. Remarkably repeatable if checked with a shutter speed tester. When the pin is 'out' it works just as the #5 does. The 5 and the 6 with the pin out have a lot more control than you would realize or think. If you squeeze and release the bulb just as fast as you can, bang it open and suction closed, it gives a very nice 1/8 second. If you slow that down just a bit......1/4 second, over and over. Slow it more, 1/2, 1, 1+ to minutes. Almost no one now gives this simplistic invention the credit it deserves. I can put a Nikon FM on 1/4 or 1/8 or 1/2 and listen to it 3 times, and I'll guarantee you I'll get very nearly the same thing with a Packard. Look at the stuff at my web pages. It's getting to where about 90+% of the pics I've got loaded there are done with a simple Packard shutter. The proof is in the puddin'. Of course this is from a guy who is happiest tooling around town in a 1939 Ford Pickup

One other Packard I didn't mention is the #8. It simply employs 2 pistons to accomplish what the #6 does with the push pull pin. Seems like a lot of extra bother and at 53 I'd forever be grabbing the wrong bulb. It has 2.

 

[argus]

Jim,

that's an excellent technique you describe there, that I've been practising for some time now. Most things that I'll write are similar to your experience, but some minor things can be added.

I've got a rather large packard shutter (7 1/2" board) and combined it with a HAMA digital sensor cleaning air bulb (everythin from HAMA, expept for negative sleeves, is featured digital these days...) that I paid way too much (14 Euro, argh). That particular bulb features a hole at the end that allows for some control with a packard shutter.
I don't know if all bulbs feature a hole (not at the blowing end, dumbo), but I do know that older models feature a valve (I also have an almost operational curtain shutter with a valve-featuring bulb).

I tested the times with my DV cam (visual: 24 frames/sec) and my Mamiya ZM Quartz (auditive: I like it better than a Nikon ), and came to the following times:

1. pin installed in shutter
- aggressive burst with closed bulb (thumb on the hole): 1/25th second
- soft burst with opened bulb (uncovered hole): appr. 1/15th second

2. pin removed from shutter with closed bulb:
- fastest push&release possible : 1/8th second
- with some excercise you get more control over the slower shutters speeds.

To close the shutter with the pin removed, the bulb must create suction and that's why the bulb should be squeezed and closed by covering the hole and release.

After reading your post, I went back donwstairs to play with the shutter and thus got similar results as you did.
The HAMA bulb I have, gives me a bit more advantage than you describe:

- without the pin in the shutter and the hole uncovered, I can perfectly emulate a T-setting: squeeze the bulb (shutter opens) and release for focussing. To close again, squeeze, cover the hole and release the bulb; great for +10 seconds exposures.
I guess that with older bulbs featuring a valve, the same is accomplished?

- with the pin installed: gently squeeze the bulb with uncovered hole and the shutter goes into T-setting. To close, just refire the shutter.

Packard shutters are wonderfull. Simple in desing and yet very effective. Other exposing techniques exist. I remember someone (Kerik?) doing an accumulated exposure of 6 subsequent burst to get the appropriate exposure time. Not bad, but you must be lucky as not to move the front standard for a hairs' thickness!

Greetings,
G

 

[Asher Kelman]

This is a wonderful thread that attests to the great design of the simple Packard shutter.

If anyone has any extra comments or mods that are better than the bulb or can give control of a solenoid with some advantage, I'd like to know. For example an off the shel timing circuit/controller would be intriguing.



Asher