Getting into flashbulb lighting and looking for some help

[backseatpilot]

I acquired a Crown Graphic with all the trimmings several months ago, and one of the accessories that came with it was the Graflite Jr. flash gun. While the Graphic is getting some other work done, I decided to get the Graflite working and try to use it. It was a bit of a failure, and I'm trying to figure out why or what steps I should be taking to troubleshoot.

I bought a whole mess of GE #5 bulbs ("Guaranteed Rhenium!") and installed the 5" reflector on the base. My Ricoh TLR has an M-sync setting, so I plugged the flash into that camera and set it to M. The bulb boxes have guide numbers listed by film (not by ISO); camera had some HP5 loaded and I figured Tri-X was close enough to that so I went with that. I'm trying to do this all in our tiny dining room, and I can realistically only get about ten feet away from my test subject, so I picked a GN of 280 for 1/500 second. Maxing out the camera at 1/500 and f22 should make the whole thing a little overexposed.

Took two shots to finish off the roll of film, developed it, and... totally transparent frames with the exception of a couple of small dots where the flash bounced off a picture frame on the wall. Given the enormous light output I keep reading about old flashbulbs, I was expecting to be half blinded when the flash went off in such a small space, but it was a bit of a letdown. Can these bulbs go bad after all this time?

 

[AgX]

Yes, flashbulbs can get bad. But this process should hardly effect their output or sync, but the safety of people near them.

As the bulbs obviously got fired, there is nothing to look for output-wise.

 

[Helge]

Don't start also using bulbs FFS! We are trying to keep them secret and exclusive. There is only so many left.

Your Ricoh TLR, what exact model is that?

Anyhow 500 is way too fast to use any bulbs output sensibly.
And @ f22 it's no wonder you didn't get anything.

To get all the lumens from a bulb, even fast ones, with a leaf shutter (most leaf shutters at least), you should go to 1/25 or slower. Already at 50 you are cutting the ends off the burn cycle.

Bulbs are all about (or also about) embracing (subtle) motion blur effects, at the same time as getting enough lumens to piss them away on filtering and bounce.
The output is huge, but it's spread out over time.
Bulbs can go bad (or they were bad in the first place). But IME it's quite rare.

 

[Helge]

Yes, flashbulbs can get bad. But this process should hardly effect their output or sync, but the safety of people near them.

As the bulbs obviously got fired, there is nothing to look for output-wise.

The most usual way for bulbs to fail (rare still) is incomplete burning. The detonator is triggered, but the zirconium or equivalent is not fully burned due to a number of possible factors: Leaks, bad packing of the material, too much voltage etc.

 

[AgX]

"Leaks, bad packing of the material, too much voltage etc."

-) Leaks cannot lead to incomplete burning (unless there is a real hole in the glass, even then unlikey, I may test this)
-) Bad Packing cannot lead to incomplete burning (but may affect the output curve)
-) Too much Voltage cannot lead to incomplete burning

 

[benveniste]

Bulbs can go bad, but it's more likely that shutter timing is off. A #5 bulb requires a delay of about 20 milliseconds. A 1/500th shutter speed is 2 milliseconds. If the bulb fired late, it would account for the results you saw. My suggestion is that you try a less demanding film/subject combination to allow for a longer shutter speed.

 

[Helge]

"Leaks, bad packing of the material, too much voltage etc."

-) Leaks cannot lead to incomplete burning (unless there is a real hole in the glass, even then unlikey, I may test this)
-) Bad Packing cannot lead to incomplete burning (but may affect the output curve)
-) Too much Voltage cannot lead to incomplete burning

Nitrogen and oxygen are not meant to be in bulbs, and not over decades.
Packing of the thread or bad thread, can lead to incomplete or bad burning.
Try putting a Edison base bulb in a household outlet and tell me what the result is. The detonator evaporates before it gets a chance to explode and the burn cycle is diminished and incomplete.
And you need to push in the safety relay/change the fuse (so don't try it really).

 

[BrianShaw]

The comments about shutter speed are very important. Did you, or the GN table, adjust for “shutter efficiency “? To do that, there is a different GN for a variety of shutter speeds. If not, you were not using the majority of the flash light with that exposure. Unfortunately, you tried the most demanding conditions on your first try.

What film did you use? Was the room pitch black? Are you sure that the synch on your Ricoh correctly synchs?

And, more so… when you wrote that you were “let down” by the bulb brightness… what exactly do you mean? It should have been bright enough to make your eyes blink a few times.

BTW, the best aid for shooting bulbs is an older (1970’s seems best) Kodak Master Photoguide.

 

[AgX]

Nitrogen and oxygen are not meant to be in bulbs, and not over decades.
Packing of the thread or bad thread, can lead to incomplete or bad burning.
Try putting a Edison base bulb in a household outlet and tell me what the result is. The detonator evaporates before it gets a chance to explode and the burn cycle is diminished and incomplete.
And you need to push in the safety relay/change the fuse (so don't try it really).

-) Oxygen just is the only content of such bulbs
-) at bad packing still all metal will burn, watch cast metal burning
-) a ignitor will rather evaporate at low voltage (thus current) as here it takes more time for it to reach ignition temperature)

 

[backseatpilot]

Don't start also using bulbs FFS! We are trying to keep them secret and exclusive. There is only so many left.

Your Ricoh TLR, what exact model is that?

Anyhow 500 is way too fast to use any bulbs output sensibly.
And @ f22 it's no wonder you didn't get anything.

To get all the lumens from a bulb, even fast ones, with a leaf shutter (most leaf shutters at least), you should go to 1/25 or slower. Already at 50 you are cutting the ends off the burn cycle.

Bulbs are all about (or also about) embracing (subtle) motion blur effects, at the same time as getting enough lumens to piss them away on filtering and bounce.
The output is huge, but it's spread out over time.
Bulbs can go bad (or they were bad in the first place). But IME it's quite rare.

I've got a Ricohmatic 225. Makes sense that if the shutter timing has shifted a little, it can have a big impact on the exposure with the bulb. I was ultimately hoping to verify the box guide numbers or build my own table - where would be a good place to start "calibrating"?

 

[backseatpilot]

The comments about shutter speed are very important. Did you, or the GN table, adjust for “shutter efficiency “? To do that, there is a different GN for a variety of shutter speeds. If not, you were not using the majority of the flash light with that exposure. Unfortunately, you tried the most demanding conditions on your first try.

What film did you use? Was the room pitch black? Are you sure that the synch on your Ricoh correctly synchs?

And, more so… when you wrote that you were “let down” by the bulb brightness… what exactly do you mean? It should have been bright enough to make your eyes blink a few times.

BTW, the best aid for shooting bulbs is an older (1970’s seems best) Kodak Master Photoguide.

By "let down" I meant that I was expecting it to be a lot brighter. It did not make me blink or anything; compared to my dinky Godox electronic flash I'd even say the Godox at max output was brighter.

 

[AgX]

The comments about shutter speed are very important. Did you, or the GN table, adjust for “shutter efficiency “? To do that, there is a different GN for a variety of shutter speeds.

At bulb tables you will find exposure times up to 1/1000 sec, to control output ogf strong bulbs, if necessary. And shutter efficiency should be calculated into such tables.
Or do I overlook something? (Is see the OP used "just" the GN.)

 

[Helge]

I've got a Ricohmatic 225. Makes sense that if the shutter timing has shifted a little, it can have a big impact on the exposure with the bulb. I was ultimately hoping to verify the box guide numbers or build my own table - where would be a good place to start "calibrating"?

It's quite simple, don't use such short speeds with bulbs. It's a waste of bulbs.
You might as well use electro flash then.

Calibrating a leaf shutters trigger timing is very rarely necessary. And it's hard to do.
It's quite easy to see if it works though, by using the lowest and shortest setting on a manual flash, look through the open back of the camera in a dark room, and look for the flash through the shutter.

 

[AgX]

bad thread, can lead to incomplete or bad burning.

I wonder what you mean by bad thread. Even at a leaked bulb the humidity should not harm the thread.

 

[Jim Jones]

Exposure for #5 flash bulbs is usually calculated for longer shutter speeds. The flash bulb emits light over a span of about 1/30 of a second, with most of the output being concentrated in the middle half of that time. At 1/500 second, you were utilizing only a tiny slice of the flash lamp's output. When When using flash bulbs with a between-the-lens shutter, a shutter speed of 1/30 or longer is usually suggested, and the aperture is determined by dividing the subject distance by the bulb's guide number. The guide number depends on the film as well as the particular bulb. It has to be adjusted for different bulb reflectors and the environment. I can't find find the basic guide number for GE #5 bulbs at the moment.

 

[Helge]

I wonder what you mean by bad thread. Even at a leaked bulb the humidity should not harm the thread.

Thread that is impure or too thick.

 

[Helge]

Exposure for #5 flash bulbs is usually calculated for longer shutter speeds. The flash bulb emits light over a span of about 1/30 of a second, with most of the output being concentrated in the middle half of that time. At 1/500 second, you were utilizing only a tiny slice of the flash lamp's output. When When using flash bulbs with a between-the-lens shutter, a shutter speed of 1/30 or longer is usually suggested, and the aperture is determined by dividing the subject distance by the bulb's guide number. The guide number depends on the film as well as the particular bulb. It has to be adjusted for different bulb reflectors and the environment. I can't find find the basic guide number for GE #5 bulbs at the moment.

Just out of genuine curiosity: Was I that incomprehensible the first time I explained this? Or do people only read the OP?
Seen it repeated a couple of times already.

 

[AgX]

Given the enormous light output I keep reading about old flashbulbs, I was expecting to be half blinded when the flash went off in such a small space, but it was a bit of a letdown.

If I am right the GE #5 got about GNm 60.

Which is same as strongest hammerhead flash. Nothing to blind you by reflected light.

 

[Helge]

M3 is approximately the same rating.

Other than showing off, there is really no good reason to use bulbs at 500, unless it's all you have at hand.

The slightest mistiming/variance in the bulbs burn cycle, will be enough to bring the numbers way down. The timing of the switch might be spot on, but the peak of the burning will have a bit of variance to it.

Underlining the FP bit is I know not strictly related to leaf shutters, but its important to keep in mind that we are dealing with mechanical and chemical systems that has some variance to them.

 

[AgX]

GE explicetely have it about shutter settings from 1/25 to 1/1000 for their lamps.
And in the table for their #5 they go up to 1/500:

 

[BrianShaw]

By "let down" I meant that I was expecting it to be a lot brighter. It did not make me blink or anything; compared to my dinky Godox electronic flash I'd even say the Godox at max output was brighter.

Sounds like a bad bulb or bad ignition . I’ve found the Graflite Jr to be inferior to the 3-cell Graflites in terms of reliability. But if the bulb ignites it should give all that it can.

At a dollar a piece, experimenting with bulbs is expensive but has to be done. Generally they are very reliable. The worst experience I ever had was with a GE bulb and a Graflite Jr trying to use the internal circuit if a SuperGraphic. Mostly non-ignitions and I gave up before figuring out the problem. A 3-cell handle works nearly 100% for me.

 

[benveniste]

At bulb tables you will find exposure times up to 1/1000 sec, to control output ogf strong bulbs, if necessary. And shutter efficiency should be calculated into such tables.
Or do I overlook something? (Is see the OP used "just" the GN.)

Here's another table for a #5 bulb from graflex.org. In theory, a 280 GN was a reasonable choice:

GE® Number 5 Flash Bulbs Class M (Medium Peak)​

<=1/25​ 1/50​ 1/100​ 1/200​ 1/400​ EI​ Guide Numbers for 4-6 Inch Polished Reflector For satin reflector open 1/2 stop. For doors, open 1 stop. For close indoor spaces, close 1 stop.​ 16​ 110 95 80 70 55 20​ 120 110 90 80 65 25​ 130 120 100 90 70 32​ 150 130 120 100 80 40-64​ 190 170 150 120 100 80-125​ 260 240 200 180 140 160-250​ 380 340 300 240 200 500-800​ 650 600 500 440 360 ​

 

[AgX]

Which equals exactly two large hammerheads.

 

[BrianShaw]

Note to those who may not know: The GN table images, above, are for TUNGSTEN film speeds. Daylight film speeds may differ. Also, the tables that reference fim brands/types are likely not the same speed as the same film/type made today. So don't forget to factor in all of the changes between the film of the flashbulb era and today; check your GN calculations carefully.

 

[Helge]

Sounds like a bad bulb or bad ignition . I’ve found the Graflite Jr to be inferior to the 3-cell Graflites in terms of reliability. But if the bulb ignites it should give all that it can.

At a dollar a piece, experimenting with bulbs is expensive but has to be done. Generally they are very reliable. The worst experience I ever had was with a GE bulb and a Graflite Jr trying to use the internal circuit if a SuperGraphic. Mostly non-ignitions and I gave up before figuring out the problem. A 3-cell handle works nearly 100% for me.

If you are paying a dollar per bulb you are not shopping around enough.

eBay is not (can’t really be stressed enough) a price catalog.
Show me your listing on eBay and we’ll talk.

Bulbs can be had for way less almost regardless of size.
No one is using them. And they, especially in big lots, take up a lot of space.
People are, and should be, glad to get them unloaded to a worthy user.