Polaroid Focused Flash - what now?!

[Dante_Stella]

Do these things just self-destruct over time? I have just tried a second Polaroid 490 flash and have not been able to get so much as a voltage across the PC tip. These things run on two 1.5v AA batteries and have no electronics. So why don't they work?

I have -

• Eliminated the camera as a factor (it fires my Metz 45 and my D700 does not fire the focused flashes).
• Cleaned all electrical contacts.
• Tried multiple flashcubes (which never go bad anyway).
• Checked it on and off camera (it looks like there is a latch on the bottom that may interlock to prevent off-camera firing).
• Tried both lithium and alkaline AAAs to check the differences in negative-end shape.

So what gives here? Cold solder joints? Failing PC cords? This is the type of device that really should be too simple to fail - but for some reason it is...

Thanks
Dante

 

[Sonnar Brian]

The 490 flash is made to work with GE Hi-Power Flashcubes. Once, I modified one to work with regular flashcubes, had to reshape the center of the flash- seem to recall. The center key of the hi-power cube is a different shape from regular cubes.

Last time I fired it on the Polaroid 450, it worked. Been a while, I will take a look.

It's late- I will try to dig it out this weekend. My solution: switched to a Model 180, found in an antique shop for $100.

Can a D700 take a lot of current flowing through it- or does it switch off? I've tested these things by just putting a tip of an INSULATED screwdriver across the leads of the PC cord.

 

[Dante_Stella]

Brian -

As far as I know, flashcube (and -bulb) flashes don't have capacitors in them, so they can't deliver any more power than the two puny 1500 Mah batteries in them.

I have a whole case of High-Power cubes here, and I managed to get one of the flashes to fire in about 65 tries. My gut tells me that either the PC cord or the inside has a bad connection. But it does seem weird that two flashes would have the same problem.

From what I understand, the D700 can take about 280 volts, which is about as much as any electronic flash delivers.

Best,
Dante

The 490 flash is made to work with GE Hi-Power Flashcubes. Once, I modified one to work with regular flashcubes, had to reshape the center of the flash- seem to recall. The center key of the hi-power cube is a different shape from regular cubes.

Last time I fired it on the Polaroid 450, it worked. Been a while, I will take a look.

It's late- I will try to dig it out this weekend. My solution: switched to a Model 180, found in an antique shop for $100.

Can a D700 take a lot of current flowing through it- or does it switch off? I've tested these things by just putting a tip of an INSULATED screwdriver across the leads of the PC cord.

 

[Sonnar Brian]

I just fired off my 490 Flash placing the screwdriver across the leads of the PC Cord. Worked fine- I suspect the PC cord is bad on yours.

My 450 had a "strange" Mod done to it, and I had to take the KEY off of the PC cord to get the shutter to work with the flash. With the KEY in it, the 450 would default to "B"- stay open as long as the shutter release was pressed. Without the Key, had one shutter speed.

I'll see if I can find another 490. Have one somewhere...

 

[Sonnar Brian]

Just a thought: if the PC cord is bad, one from a Polaroid 268 flash could be used to replace it.

Not having luck locating the second 490. Might have given it away already.

 

[dazedgonebye]

Land cameras.com does a conversion to allow the use of electronic flash. Also a rechargeable battery.

 

[Sonnar Brian]

My 450 was probably converted for Electronic Flash, and dedicated for it. BUT- 490 focused flash is great, exposure is dead-on and color balance is accurate. The trouble is finding GE How-Power flashcubes. I went through a case of them, have just a few cubes left. BUT- after picking up the 180, the 450 has been pretty much shelved.

 

[Dante_Stella]

I converted the camera last night after putting the baby away (I actually tested flash operation on him when he was sleeping - needless to day, a Metz 45 at 4 feet range on a sleeping baby is whiteout city).

The one subtlety to converting these is that you want the contacts to barely touch when the first curtain is open. This is because the first curtain opening is only slightly wider than the lens element, and a small amount of shutter bounce is built in (the curtain hits a substantial rubber bumper).

The b*tches are the reciprocity characteristics of the film and flash correction factors. I have a lot more faith in the accuracy of the 45CL-3 than I do in the nominal f/ numbers of waterhouse stops in the lens or the ability of the film to expose properly at 1/20,000 of a second.

Anyone want to buy a case of Hi-Power? I have 24 packs totaling 47 cubes (I tested one cube to make sure they did not go bad with age).

Dante

My 450 was probably converted for Electronic Flash, and dedicated for it. BUT- 490 focused flash is great, exposure is dead-on and color balance is accurate. The trouble is finding GE How-Power flashcubes. I went through a case of them, have just a few cubes left. BUT- after picking up the 180, the 450 has been pretty much shelved.

 

[Dante_Stella]

Initial flash setting with a Metz 45, 3000-speed film and minimum focusing distance: Flash set to f/16 auto mode and ISO 640 (camera set to "flash" - f/50). Works like a charm.