Flash bulb questions

[rbiemer]

I recently got some flash bulbs and today, I got a Kodak Pony 135 camera and Standard Flash Holder.
I haven't used bulbs since I was a kid and then either Dad or my Grandfather set the camera for me.
So, I'm ignorant about using these things.
The bulbs I have are "SM, F Type" and there is a little chart on the box that says for "Film speed ASA Tungsten" 64-125 the guide number is 75 with a shutter speed of 1/25 to 1/50.
I should set the f stop by dividing the guide number by the distance?
So, for 10 feet(for example), I should set the f stop to f/8?
How can I calculate the guide number for faster films?
And, should I make adjustments for daylight vs tungsten films?

Any help is much appreciated!
Rob

 

[Sonnar Brian]

Guide number/ distance gives F-Stop. GN doubles when Emulsion is 4x. So GN 60 at ASA 25 becomes GN 120 at ASA 100.

I'm showing my age here.

 

[rbiemer]

Thanks, Brian!
The year before I started using the high school's cameras, they stopped using flash bulbs. Some kid had a pocketful and generated enough static electricity to set them all off. Burned himself in a very sensitive area and the school bought electronic flash units for their cameras. So I missed learning this stuff by very little time.
Rob

 

[ZorkiKat]

[...]
And, should I make adjustments for daylight vs tungsten films?

Any help is much appreciated!
Rob

If the flashbulbs are 'blue', they're for daylight type films. Usually they'd be marked with a "B", like AG1-B or M2-B. But otherwise, unmarked, they'd put out a light which is too yellow for daylight film but somewhat too blue for tungsten films.

I don't know if the previous recommendations still apply- in the past, colour negative films were marked 'universal' which meant that they could be exposed with ordinary flashbulbs and corrections were done in printing. That's what they recommended for Kodacolor. But when used for synchro-daylight flash, the blue bulbs were required.

There was a colour film balanced for clear flash bulbs which eliminated the need for blue bulbs or conversion filters.

Or you can get a pale blue (81?) filter to put over the clear bulb for daylight balanced shots.

Note that the above info is what I got from various 1950s camera books. I wasn't around then....😀

However, I had used a considerable amount of AG1 and M2 flashbulbs...I found a lot of them cheap.

 

[rbiemer]

The bulbs I have are clear and the flash has a clear cover. I am going to shoot some and see what I get with out any filter and I have a pale blue filter that I can put on the lens that I will also try. And, if I need to I can adjust color balance in the computer. As well, I will be shooting some B&W film which I don't think I need to worry about as far as daylight/tungsten balance.
I think I have about 6 dozen all togehter so I can play/experiment a bit.
Rob

 

[Spavinaw]

Rob,
As you said you have F Type bulbs. Your camera is synchronized for M Type bulbs. You can Google flashbulb synchronization for lots infornation that is too much to repeat here. The recommendation I found was to use a shutter speed no shorter than 1/30 second. Before I wasted a lot of bulbs and film, I would run a test. If I had film in the camera, I'd take one picture with flash at 1/25 and see how it came out. If the camera was empty, I'd take off the back, look through the lens, take a flash shot at 1/25 with the lens wide open and see if I saw the light from the flash through the lens. Then you'll know if it works or not.

 

[rbiemer]

Yesterday after noon, I shot a few flash bulbs--the camera will not fire the flash at any speed slower than 1/50. After that I loaded some film and will be seeing what I get on this first roll.
I had forgotten how much fun using flash bulbs is!
Rob