Flashbulb Questions

[hunter]

So, I've started messing with flashbulbs a bit after coming to a chamber I couldn't do with a couple of slaves. Someone on the trip had some M3Bs which worked great. I'm planning on experimenting with bulbs before my next big trip and I've got a couple of questions:

-Has anyone used clear bulbs for color photography with a digital camera? I know blue were designed for color but I'm not certain it is such an issue with digital.

-Looking around at the total Lumens I get the impression that AG1 bulbs are not much of an improvement over an electronic flash. Is this correct?

-Any preference on M2/M3/5? Short of a really huge room I don't think I'll have the patience to carry in the really large bulbs.

-Any bad experiences with the bulbs shattering and spraying glass in the cave?

Thanks,
James

[CaverScott]

-Any preference on M2/M3/5? Short of a really huge room I don't think I'll have the patience to carry in the really large bulbs.

-Any bad experiences with the bulbs shattering and spraying glass in the cave?

Thanks,
James

I always preferred the M3's - Lots of light in a small, compact, sturdy package. I never played with the M2's. I do have quite a few M5's that I used on "easier" trips. And the Press 25's, I used a bunch of those as well.

No, not a one.

[hunter]

CaverScott,
Thanks for the input. Did you use both clear and blue bulbs?

James

[Dave Bunnell]

I wrote a piece on this very topic for the new NSS photo book, page 112.

If you have a digital camera that allows some degree of control over the white balance settings, clear flashbulbs are my preference as they offer about 1 more stop of light than the blue coated bulbs.

Some cameras will allow you to actually set a color temperature in Kelvin units, and to balance clear bulbs to daylight you want to use a setting of 3800 for clear bulbs with aluminum filaments (larger bulbs and bayonet bases like the M5) and 4200 for those with zirconium (smaller ones like M3). Other cameras just give you presets matching things like incandescent (tungsten, about 2800 K) and fluorescent. My Oly 8080 actually has both white (3500) and cool white (4200) fluorescent settings so these can match the clear bulbs pretty well.

The difference between a big bulb and a smaller one can be only an f-stop or two, assuming the same reflector. This can be more than made up by raising the ISO on your digital camera. With a good DSLR, you pay much lesss of a penalty for this than you did for film. I shot the photo below with just two clear M5 flashbulbs, at ISO 800 on a NIkon D70s:

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[hunter]

Dave,
Great, Thanks! You've sold me on the photo book! I have a Rebel XT so I'm pretty sure I can change the temp easily enough, just have to look in the manual. The clear bulbs seem a bit more common on ebay at least. I got a mixed bunch of M2/M3/M5 and 25 something so I'm planning on experimenting but I'd like to avoid using to many in learning.

Thanks,
James

[hunter]

Dave,
Before I spend the money, you are referring to "On Caves and Cameras" correct?

James

[Dave Bunnell]

Dave,
Before I spend the money, you are referring to "On Caves and Cameras" correct?

James

Yup, that's the one. There's a wealth of info in it.

Dave

[CaverScott]

CaverScott,
Thanks for the input. Did you use both clear and blue bulbs?

James

I only used the Blue bulbs since I was seriously shooting before digital cameras were so common. I have amassed quite an inventory of clear and blue bulbs I keep meaning to sell off someday.

[Todd]

I have amassed quite an inventory of clear and blue bulbs I keep meaning to sell off someday.

Hi there
If you do get around to selling them, I (like probably a lot of people) might be interested, depending on sizes and prices. I've just started using them and I'm burning through my supplies pretty fast!
-Todd

[hunter]

Bulbs are certainly getting a bit more pricey. While I'm on the topic anyone want to get rid of (or know of a way to get) an adaptor for M2/M3 to whatever the base is for GE5?

James

[CaverScott]

I have amassed quite an inventory of clear and blue bulbs I keep meaning to sell off someday.

Hi there
If you do get around to selling them, I (like probably a lot of people) might be interested, depending on sizes and prices. I've just started using them and I'm burning through my supplies pretty fast!
-Todd

I found a stash of M3B's when I lived in Indy and bought them by the gross/case (12, 12 packs = one gross or 144 Bulbs). I would consider selling a few cases at $70 a gross, plus shipping. I have a bunch of clear M3's as well. If you want 5B's or Press 25's, ask me about them and check my old logs. Drop me an email using scottfee at bellsouth dot net if you are interested.

[Dave Bunnell]

:yeah that:
Bulbs are certainly getting a bit more pricey. While I'm on the topic anyone want to get rid of (or know of a way to get) an adaptor for M2/M3 to whatever the base is for GE5?

James

There are adaptors to allow an m3 to go into a bayonet base, but I've never seen the other way around. Best bet is to check ebay. You'll find lots of flashbulb firers there as well, and sometimes odd lots of them with accesories like the adaptor you want.

[rcoomer]

I use blue M2s for smaller passages, like canyons or narrow stream passages, and then clear M3s or M5s for just about everything else. The 5s are harder to get and I didn't see much benefit.

I use the screw type 2 and 3s for big stuff, but be careful, I have a failure rate of about 1 in 3, with maybe 1 in 10 exploding.

The only time the smaller bulbs explode is when they are very wet. My failure rate on them is more like 1 in 50, and that's usually the gun that was the problem.

I shoot auto white balance and then modify the RAW file afterward if needed.

I'm grounded to the surface for quite a while though, so my collection of bulbs will last me for a while.

[hunter]

rcoomer, thanks for the tips!

and then clear M3s or M5s for just about everything else. The 5s are harder to get and I didn't see much benefit.

By this you mean you didn't see much benifit using M5 over M3?

When the larger bulbs explode on you how bad is it? I'm worried about getting glass all over a cave and about hitting a subject. Maybe some sort of clear cover over the unit?

Thanks,
James

[rcoomer]

I haven't seen much difference between the M3's and M5's so far. A lot of times i just mix them in the same bag I hand off with a flashgun. Though if I really paid attention there might be. It's mainly the M2 and the M2B that I see as much dimmer, and better for more intimate shots in tight areas.

We had a #3 edison bulb explode in Camps Gulf. It was in a large shop light reflector and sent out a ring of glass about 15' around my wife who was holding the flash. She had just raised the flash over her head, saying she had a voice in her head telling her to do so. She had fired several others in a lower, more upright positon. The room is big enough, no one else was close to her, but in a smaller area, it could have been a problem.

I think I still have dirt in some of my cases from where they scooped up the glass and tossed it in to carry it out. Other bulbs have just popped off their base and sent a shower of sparks, but otherwise remained mostly whole.

Many of the large bulbs I have are really old and the coatings are peeling off.