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The Mystery and the Muscle of Bulbs
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Stilagrrl



Joined: 16 May 2004
Posts: 51
Location: SF Bay Area

PostPosted: Fri May 21, 2004 5:08 pm    Post subject: Reply with quote

Hi Micah,

I see that little connector on the Polaroid 268 Flash Gun, but I have used the 268 on my modified Polaroid 110B (modified with a 4x5 Graflok back) plugged into the Prontor shutters PC sync port and it seems to work fine. Granted, I've only fired about a dozen bulbs through it (like Glenn, I only use them for special occasions), but so far, the battery hasn't died. I wonder if the M3/M5s just didn't take as power to fire?

Take Care,
Rachel
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Micah in NC



Joined: 26 Jun 2003
Posts: 94
Location: North Carolina

PostPosted: Fri May 21, 2004 5:44 pm    Post subject: Reply with quote

Quote:

On 2004-05-21 10:08, Stilagrrl wrote:
I wonder if the M3/M5s just didn't take as [much] power to fire?

Take Care,
Rachel


Rachel,
This very well could be the case. I'm surprised that you got the M3/M5s to fire on just 1.5 volts. (I may experiment with my #268 flash on non-Polaroids now!)

I know that some "newer" flashbulbs, like the M2, M3, M5, etc. used newer technology than, say, a huge, old #2 screw base bulb. Some of the newer bulbs incorporated a "rhenium igniter" in the bulbs to ensure more consistent firing. What a rhenium igniter is, I can't say for sure, it's just something I've seen on the bulb packaging.

Good luck with the #268. I'm glad it works! You might want to keep a spare battery handy for that gun, though, or put in a different type--higher voltage--battery in there. Duracell makes a 4.5 volt battery that is AA-sized or thereabouts. Also, there is the 22.5 volt battery in a skinny version that is about a dead-ringer for the AA cell, except the 22.5 volt has square corners (it's not cylindrical like an AA cell but resembles a miniature square lumber post). One of those should fit the #268 gun and give you lots of spare juice for the bulbs and very consistent flashing!

Disclaimer: If you have a 100, 200, or 300-series Polaroid (not 110B--I mean the electric eye cameras), don't plug that 268 flashgun into it if you've hopped up the flash's battery! Put a good ol' AA back in the 268 or you could POSSIBLY fry the camera's "electric eye" exposure system and/or its electronic shutter.

--Micah in NC

P.S. Here is a superb website for the Polaroid fancier: http://www.landlist.org

[ This Message was edited by: Micah in NC on 2004-05-21 10:52 ]
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t.r.sanford



Joined: 10 Nov 2003
Posts: 812
Location: East Coast (Long Island)

PostPosted: Sat May 22, 2004 1:59 am    Post subject: Reply with quote

I have a fuzzy recollection that some of the inexpensive plastic-body box cameras of the late '50s, with molded-in reflectors and sockets for M2 bulbs, used a single cell as a power source -- perhaps AA, perhaps C.

The difficulty about flash in general, and not just bulbs, is the mating surfaces along the circuit. At each of them, you have an increased resistance, and you can't easily get at some of them. You could always tell the people who didn't know what they were doing: they'd lick the base of the lamp, which does little immediate good and soon corrodes the socket contacts, making matters much worse!

For this reason, we who used flashbulbs took a lot of trouble to keep everything tight, clean and bright, including the bases of the flashbulbs (you could tell flash photographers, forty years ago, by the shiny areas on the thighs of their trouser legs).

If I were to do it again, I'd use "Cramolin" or another good contact cleaner, judiciously but frequently, on the battery-box and lamp socket contacts, and any other contacts I could reach. A small piece of emery or crocus cloth would not be amiss, either.
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Stilagrrl



Joined: 16 May 2004
Posts: 51
Location: SF Bay Area

PostPosted: Sat May 22, 2004 5:17 am    Post subject: Reply with quote

Hi Micah,

Thanks for the tip on the higher voltage batteries; I'll look into them. One of the nice things about AA's is that they can be found just about anywhere. However if no modifications to the battery compartment are necessary, I guess even if I did use a higher voltage battery, I would still be able to go back to AA's in a pinch. Oh, BTW, there's no worries about accidentally using this flash gun on a pack film Polaroid, as I had to bend the little connector quite a bit to get it to plug into a standard shutter.

Polaroid certainly didn't make it easy to change batteries in the 268, did they? You have to carry a screwdriver around just to get the battery cover off.

Take Care,
Rachel

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RichS



Joined: 18 Oct 2001
Posts: 1467
Location: South of Rochester, NY

PostPosted: Sat May 22, 2004 2:11 pm    Post subject: Reply with quote

Just a quick note baout switching batteries...

Someone already mentioned not to do this in cameras!!!

For flashes, the story is different. The _voltage_ makes no difference at all when talking flash bulbs! When you trigger a bulb flash, you are basically dead shorting the battery across the wire inside the flash bulb. What you are really talking about here is _power_, not voltage! There's a very goos chance that a 22.5 volt battery can NOT supply as much power as a single AA battery! That is why capacitors were used in later flashes. They took the low power available in batteries and stored it in a large "container". This made available considerably more power to the bulb than just the battery.

If I had to replace a low voltage battery (single or multiple) in a bulb flash, I would look more to the new rechargable batteries available now that have ratings above 1800 or 2000 MA (milliamps). 2 amps would be anout to fire a bulb easily.

Where voltage does come into play is making it across connections. The more connections you have, the more voltage and power is lost. Higher voltages help cross connections, up to thousands of volts which can jump air gaps...

If you can find the MA rating of the batteries in question, then simply multiply it's voltage times it's MA rating to find it's power rating. That's easy for lithium and NI-MH batteries. I don't think alkalines give MA ratings? I would have no doubt they could supply 1000 or more though for standards sizes of AA, C & D. But batteries with higher voltages are actually much smaller 1.5 volt batteries connected together in series to make a bigger battery with a higher voltage. Since the individual batteries are smaller, their power rating drops quite a bit. The best option may be a single AA NI-MH battery rated at 2200 MA or so... If the connections are good!



[ This Message was edited by: RichS on 2004-05-22 07:12 ]
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Top



Joined: 06 Apr 2002
Posts: 198
Location: Northern New England USA

PostPosted: Tue May 25, 2004 8:27 pm    Post subject: Reply with quote

[quote]
On 2004-05-20 20:34, jdman wrote:
Be aware that if you try to use a Heiland to trip a solenoid, and are using flashbulbs the bulb will go off. This is the beauty of the Graflites in that you can trip the solenoid and let the camera sync fire the bulb.

Russ;
I only recently aquired a shutter with both FP/M/X synch and a solonoid, so I got to playing around a little. I made a push-button switch cord that is powered by the the Focuspot socket on my King Sol that runs to the solonoid, and a with a bi-post cord running from the shutter back to the flashgun I can fire the shutter through the solonoid and have the built-in synch of the shutter handle the rest.
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[ This Message was edited by: top on 2004-05-25 15:35 ]
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Stilagrrl



Joined: 16 May 2004
Posts: 51
Location: SF Bay Area

PostPosted: Tue Jun 01, 2004 8:02 pm    Post subject: Reply with quote

Hi. I wanted to update everyone on the progress I've made with regards to using flash bulbs. I've gotten a cable to hook up my Polaroid 268 flash gun and the M3 flash bulbs work great.

I've also gotten a Heiland flash gun, but I'm not sure which model it is. It takes two D cells; it has one port for the shutter and two for extensions; and it came with a 5" polished reflector. It seems to be a pretty basic flash gun. The nice thing is that it came with about 60 Speed Midget bulbs and about 12 #5B's.

After cleaning everything up, I put some batteries in the flash gun, plugged in the sync cord and inserted a #5B bulb. I then loaded up a sheet of Polaroid Type 79 film (ISO 100), set my aperture to around f16 and my shutter speed to 1/60th, the sync to M, went outside where it was pretty dark, aimed at a tree about 8' away and fired. To my disappointment, the picture was completely black. Okay, so I tried again, this time at 1/30th and once again the picture was black. Before I waste anymore bulbs, I wanted to see if anyone had any ideas. Clearly it's not synchronizing, but since my Polaroid flash gun worked on M, I was assuming the Heiland would also.

I'm going to try open flash tonight just to make sure I can get something onto film. Oh, I should also mention that this is not an original Graflex shutter, but rather a Prontor shutter that only has an X and M setting. I read somewhere that some of the Graflex shutters had two different M settings and was wondering if that was the problem.

Thanks,
Rachel
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t.r.sanford



Joined: 10 Nov 2003
Posts: 812
Location: East Coast (Long Island)

PostPosted: Wed Jun 02, 2004 12:21 am    Post subject: Reply with quote

If you're using the same shutter and the same M setting with the Heiland gun as you've been using with your Polaroid unit, and if tripping the shutter fires the flash, then it seems to me that the Heiland gun should synchronize in the same way.

Since it isn't, I can't imagine why it's not, and I'll be interested in hearing from those who have used Heiland D-cell flashguns. (I once had a B-C Heiland gun that worked just like my D-cell "Graflites," but rather more reliably).
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t.r.sanford



Joined: 10 Nov 2003
Posts: 812
Location: East Coast (Long Island)

PostPosted: Wed Jun 02, 2004 1:10 am    Post subject: Reply with quote

...BTW, a useful accessory that was available in my youth was a little adapter that held a common flashlight filament lamp and plugged into a standard bayonet-base flashbulb socket. This allowed you to test the continuity of the circuit, by actually tripping the shutter and seeing that the lamp blinked on, before losing an important shot because your flashbulb didn't go off. It was somewhat effective -- better than a wet fish in the face, anyway.

Something like this would be a helpful tool in trying to find out why a flashgun is not synchronizing with the shutter. Trying to locate one might be frustrating, but it might be possible to rig something up using the base from a spent flashbulb and a couple of short lengths of wire.
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Top



Joined: 06 Apr 2002
Posts: 198
Location: Northern New England USA

PostPosted: Wed Jun 02, 2004 1:17 am    Post subject: Reply with quote

I just got out my two-D-cell Heiland gun to see if it had a focal-plane socket like the big ones (it doesn't).
So much for that fix.
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t.r.sanford



Joined: 10 Nov 2003
Posts: 812
Location: East Coast (Long Island)

PostPosted: Wed Jun 02, 2004 3:22 pm    Post subject: Reply with quote

You mentioned "Speed Midget" bulbs. Are these the kind more familiarly known as "SM" -- gas-filled, fast peak?

Of course, they won't synchronize properly with your shutter on either setting, but it might be interesting to see how they work with X synch at a slow shutter speed.
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Stilagrrl



Joined: 16 May 2004
Posts: 51
Location: SF Bay Area

PostPosted: Wed Jun 02, 2004 5:10 pm    Post subject: Reply with quote

Yes, the Speed Midgets I mentioned are the same as the gas filled SM bulbs. I fired off a couple of them just to make sure they were good, but haven't tried anything on film yet. From what I've read, they're super fast, but not very powerful, so they're normally used close up to stop action. I noticed that one site sells these speed demons for as much as $17 per bulb. Ouch, I just wasted $34! Okay, I've seen other sites that sell them for under a $1.00 per bulb, so now I don't feel so bad

Anyway, I did do some more testing with the Heiland flash and the #5B bulbs last night. What I found is that everything is actually working, but either my math is off (which is likely the case) or the bulbs aren't as powerful as they once were. The package that the bulbs came in says that at a shutter speed of 1/50th with ISO 10 film the GN is 50 and with ISO 32 film the GN is 90. So if the jump from ISO 10 to 32 is about 1.5 stops, then 1.5 stops greater than 32 is about ISO 100, right? Given that, I get a GN of 130 at ISO 100, so at 8' my aperture should be f/16. However, I had to open up to f/11 just to get an image on film. Even then, I was shooting with open flash and the picture is probably 1/2 stop underexposed. Unfortunately, I ran out of Polaroid film at that point, otherwise, I would have tried f/8 at a 1/60th to see what I get. I'll pick up some more film and do more testing later on this week.

Thanks for all of your help.

Rachel
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t.r.sanford



Joined: 10 Nov 2003
Posts: 812
Location: East Coast (Long Island)

PostPosted: Wed Jun 02, 2004 5:57 pm    Post subject: Reply with quote

I think your math is correct; I arrived at a guide number of 160 for an EI of 125.

The filmspeeds you quote are, of course, for the original "Kodachrome" (10)and "Ektachrome" or "Kodacolor" (32).

And thereby hangs a tale! The American Standards Association changed its sensitometric criteria for photographic films some time in the second half of the '50s. When my father bought "Kodachrome" in 1953, it was an ASA 10 material; when I bought it in 1958, the exposure index was 25.

The film didn't change at all; what changed was ASA's determination of what constituted the optimum density range.

This suggests that your guide numbers need to be revised: use 50 for an exposure index of 25 (not 10), and 90 for an EI of 64 (not 32). If you do, you may get a GN in the range of 110 to 125 for EI 125 material...

(Viewed another way, imagine your Polaroid "Type 79" is a 50-speed material, as it would have been under the old ASA criteria.)

In my experience, Polaroid color films tolerate a slight bit of overexposure much better than a slight bit of underexposure. And, shooting outdoors at night, you get no reflection from light-colored walls, ceiling, etc. (always a problem with flash outdoors, even with fast B&W materials -- when you open up enough to compensate for that lack of reflected light, you tend to burn out the foreground -- which is why so many college pep rally pix look the way they do!)

I think you've solved the problem. Why not shoot off a 5B indoors, using 1/30 sec. and a GN of 110, and see what happens?

If people are willing to pay premium prices for "SM" flashlamps, you'd probably do well to look for your best opportunity, and sell them. Your information is correct; they were designed to freeze action, in a day when portable electronic flashguns were costly and cumbersome. They will do that, but they don't put out much light, and they will do nothing that a modern strobe won't do better.
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glennfromwy



Joined: 29 Nov 2001
Posts: 903
Location: S.W. Wyoming

PostPosted: Wed Jun 02, 2004 7:27 pm    Post subject: Reply with quote

17 bucks apiece, eh? Good grief, I'm a millionaire! By the way, those SM bulbs have a flash duration of 1/200 of a second. That's why they were used for moving subjects.
Edit: I think trying to use those obsolete film speeds will cause you more grief than anything. Good judgement and a few test shots will probably give faster results.
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Glenn

"Where everybody is somebody else's weirdo"

[ This Message was edited by: glennfromwy on 2004-06-02 12:33 ]
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t.r.sanford



Joined: 10 Nov 2003
Posts: 812
Location: East Coast (Long Island)

PostPosted: Wed Jun 02, 2004 10:06 pm    Post subject: Reply with quote

...what it boils down to, is open up one stop as the starting-point for further tests!
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