Because the different systems for measuring film sensitivity are based upon different criteria, the numbers of any one system have no direct relation to the others and only approximate comparisons can be given. These are sufficiently accurate for general photographic work, however.
Nothing produces the quality and quantity of light generated by a flashbulb. Small, portable, easily fired and relatively inexpensive, flashbulbs are able to provide a tremendous amount of illumination from the palm of your hand.
Certainly, there are electronic flashguns, lasers, and other hi-tech methods of producing light, but they simply don’t match the size and characteristics of a simple flashbulb.
This article will provide you with some of the basics necessary to begin or continue your exploration of flashbulb usage.
As a first step, you need a basic
understanding of photography, manual camera operation, flashbulb specifications and lighting application. This is not as difficult as it may appear.
All flashbulbs have a rated guide number (GN) determined by the original manufacturer. This is a subjective number that is only a starting point for you to refine and determine your own working GN based on equipment, locations, etc. At various times manufacturers assigned different guide numbers to the same bulb depending upon manufacturing, raw materials, testing and marketing requirements.
The guide number is affected by the bulb type, reflector type and size, shutter speed, wall and ceiling color, volume of room etc. You need to perform a variety of test shots to arrive at your own working guide number for a particular type of bulb using your equipment.
To start using the manufacturer’s guide number is all right, most films have enough latitude to compensate for some of the variables. Guide numbers can be obtained from various old photography literature, manufacturers’ photo lamp data guides and at www.flashbulbs.com website.
Once you have the guide number for the flashbulb and film speed ISO/ASA you are using then you are ready to determine your f-stop. If your shutter has an M setting you can shoot at any shutter speed up to 1/500sec. If it has an F setting and you are using focal plane bulbs you can shoot up to 1/100sec. If the camera is newer and only has an X setting you will need to set your shutter speed to 1/30 sec or slower. Should you use a faster speed on X setting the flashbulb will not synchronize with the shutter and a part of your image area will be black.
F-stop is determined by dividing the distance from your lens to the subject into the guide number
f stop = Guide number
distance
For example using ISO 100 color film and blue AG1 flashbulbs with a shutter speed of 1/25 sec and a subject distance of 10 ft.
gn = 140 distance = 10ft
140 10 = F14
Since your shutter probably doesn’t have a setting at 14, set your
f-stop to the next higher available value which is f 11.
In their heyday, a half billion flashbulbs a year were manufactured in many parts of the world such as the USA, Japan, Europe, Korea and China . Today the only remaining producer is Meggaflash Technologies LTD. in the Republic of Ireland .
This company manufactures 3 bulb types: PF200, PF300 & PF330 using the same equipment that Sylvania used in the 60’s. Meggaflashes high quality bulbs are the relative equivalent of the older Number 22, 3, & FF33.
The General Electric Company introduced the first commercially available flashbulb in the United States in 1930. The No. 20 Photoflash lamp contained several sheets of very thin (0.4 to 0.4.5) ten-thousandths inch aluminum foil.
The smallest individual flashbulb made was the AG1 (GN 150, ISO 100 @ /1/30sec, 7000 lumen seconds of light). The largest was the Mazda 75 unsynchronized (used only with open flash technique) 180,000-lumen seconds of light. The No. 3 bulb manufactured by Sylvania was the largest synchronized bulb commercially available, it had a GN of approximately 550 and provided 110,000 lumen seconds of 3800k-color temperature light.
You can see that there is a flashbulb for virtually every application imaginable. Light produced is what determines the cost of a flashbulb so it is important that you choose a bulb based on your intended application. Smaller light output bulbs cost less so pre-planning will be cost effective.
Many flashguns models were made to fire flashbulbs. Companies such as Minolta, Canon, Nikon, Graflex, Heiland Research, King Sol, Honeywell, Zeiss Ikon, Linhof, Kodak, Kalart, Waltz, Accura, Mendelson, Zenobia, Abbey, Samigon, Agfa, all produced devices that let you use flashbulbs with your camera.
Today, all of these items are still available. They can be found listed in the classified section of classic camera magazines, at camera shows, at older photo dealers’ shops, on ebay and by searching the Internet. New sync cords for your older flashguns can be obtained from Paramount Cords, Bronx New York.
The majority of the older flashguns used standard flashlight batteries for power, either AA, C, or D cells. The B-C models used either 15V or 22 1/2V batteries that are still available.
There are many adapters available that will allow you to use various size and different base bulbs in one flashgun. Screw base bulbs can be used in a bayonet base flash and vice versa; AG1 glass base or M3 miniature base can be adapted to any gun. Phillips European flashbulbs can also be adapted.
What kind of an image can you expect by using flashbulbs? Why should I bother with this old technology? What is the difference anyway?
A flashbulb is made up of a base, either metal or glass, a glass envelope usually coated on the interior and exterior with a plastic safety coating, primer paste, a tungsten igniter filament, a filling of shredded aluminum or other alloys with aluminum and oxygen. It fires when a voltage of 3-30V is applied to the ignition filament.
Clear bulbs are used for black and white photography and blue bulbs are used for color film because they are balanced to 5500k, the same as color film. Blue bulbs may also be used with B&W film but they are less powerful because of the blue coating so you lose approximately 2 stops of light.
Due to the inherent nature of flashbulbs, they ignite and burn from the center of the bulb consuming the filling materials towards the glass envelope where they extinguish. This produces a more intense light (halo) in the center of the image plane that tapers off at the edges of the image. Hotter in the center and Hollywood lighting have been used to describe the images obtained with bulbs. It is a uniquely different look.
Electronic flash tends to correct and white out imperfections, flashbulbs bring out the detail in more depth and provide better features in the shadow areas. Bulbs burn slower than electronic flash so I believe they capture more quality in the overall image.
Using flashbulbs today is an attention getter. A photographer will find that many people are very interested in what you are doing and how you apply your craft using bulbs. Recently while photographing the bull near Wall Street in New York City , I was inundated by a group of Japanese tourists who could not believe that I was using a Graflex Press camera and flashbulbs in the rain to capture an image. They all had expensive cameras however they stood by watching me work for an hour. The Polaroids quickly made them believers in the method.
There is considerably more effort involved to use flashbulbs, one has to search out sources for the equipment and bulbs, read manuals and charts, perform tests, keep accurate exposure charts, maintain equipment, dispose of the expendables and carry around a bunch of bulbs. If you are a point and shoot type person then this method is not for you. However if you understand or are willing to find out the difference between Weegee and a Ouija Board, then flashbulbs may provide a key to your photographic creativity.
If you have an artistic desire to capture classic images in a style almost forgotten, are willing to expend the energy involved and want to create a uniqueness to your photographs, then this medium will enhance your skills and help you develop a unique signature style.
