Flash bulbs.

[JohnRichard]

Didn't want to start a new thread:

Tilt-A-Mite - I own one of these and have been trying to find a battery replacement option for years. What do you guys recommend?
I want to use this flash (or one like it) with my Voiget Vito B.

 

[DWThomas]

Didn't want to start a new thread:

Tilt-A-Mite - I own one of these and have been trying to find a battery replacement option for years. What do you guys recommend?
I want to use this flash (or one like it) with my Voiget Vito B.

I just tried a Google search on "Eveready 504 battery" and got a lot of hits. It appears the original is no longer made, but there are alkaline cell replacements.

I still have a Tilt-A-Mite, but it hasn't been used in decades and I would bet putting a $15 battery in it would show me the capacitor is shot! Perhaps there could be a way to replace the combination with a newer capacitor and some sort of off the shelf lithium battery(ies). Only having about 20 flashbulbs in my possession, I think it will just remain a souvenir of days gone by, albeit a handy and clever gadget in its day.

 

[Hatchetman]

I bought a battery online about a year ago. I assume they are still available.

 

[brianmquinn]

They are on sale on Ebay now,

Exell A220 504A Alkaline 15V Battery NEDA 220 LR154 10F15

The seller ebay ID is:

batteriesinaflash

 

[Helge]

I’m suddenly confused by the X and M settings after looking at this old inlay in an packet of Philips bulbs:

I always used the M setting, thinking it would give me the maximum amount of light.
After all that is one of the reasons to use bulbs. The guide number of even small bulbs is a
whopping 40 in meters as you can see.

This inlay makes it seem as though you get maximum utilization by setting the shutter to 30-25 and X‽

If someone knows what’s right for maximum utilization please chime in.

 

[AgX]

For M-synch and for 1/60 the curves for shutter and combustion run in phase, the nominal shutter closing takes place the same time the combustion has ended. This should be the ideal combo.
Here 1/30 could not deliver more exposure.

Why X-sync at 1/30 yields 1 stop more exposure is hard to explain from combustion- and shutter-curves and made me wonder in past too.
Theorethically I come to the same exposure as with M-sync at 1/60...


Anyway,..
Just keep in mind that PF1B and AG3B are powerful lamps, compared to electronic flashes. Both yield about GNm40.

 

[BrianShaw]

That bulb takes 18 milliseconds to peak. The total burn duration is about 35 milliseconds (including about 7 millisecond ignition). The ramp to peak is a lot steeper than the decay to extinction. Any shutter speed faster than 1/30 will result in the film not seeing the full burn.

 

[AgX]

Brian, your description of its characteristic curve is very much different from the Philips PF3 curve I got at hand.

Anyway, your explanation does not say why at "wrong" synchronisation and long exposure time output-yield is better than at at seemingly right synchronisation.

Best explanation to me would be that M-synch is not optimum for that very bulb model. (However, graphs show the opposite.)

 

[BrianShaw]

Brian, your description of its characteristic curve is very much different from the Philips PF3 curve I got at hand.

we’re discussing PF-1b, not PF-3 (class M)

I corrected the peak from 15 to 18 milliseconds. Sorry about the error.

For pf-1 see flashbulbs.com/Phillips/ph-6.html

For pf-3 see flashbulbs.com/Phillips/ph-4.html

 

[BrianShaw]

In general... I find the OEM recommendation sheet to be the most accurate regarding GN, etc. I’d trust it. I can’t prove this but believe they are based on sound empirical data.

 

[AgX]

What do mean by OEM?
I use both, the Philips charts on the boxes or as insert and Philips handbooks.

 

[BrianShaw]

What do mean by OEM?
I use both, the Philips charts on the boxes or as insert and Philips handbooks.

OEM - Original Equipment Manufacturer

I’m in total agreement... when using Phillips bulbs, I used their data sheet or handbook; when using Sylvania... etc. generic guidance is okay but it’s difficult to know the veracity of that information.

 

[eli griggs]

Just to add that the Morgan and Morgan also has extensive bulb date, IIRC.

Good luck.

 

[AgX]

Out of memory I would say that lamps with same designation do not differ in stated GN between manufacturers, aside the fact that the respective film speeds/speed ranges may slightly vary, which may hamper first-sight comparison.

 

[BrianShaw]

Out of memory I would say that lamps with same designation do not differ in stated GN between manufacturers, aside the fact that the respective film speeds/speed ranges may slightly vary, which may hamper first-sight comparison.

Thanks to standards.

The amount of “minor” variation is endless (almost): reflector size, texture, shatter-shield or not; shutter and synch accuracy; subject-to-flash measurement accuracy... one could keep the discussion going forever if picking nits.

it seems, though, that the answer to the question asked is that the Philips suggestion is probably the best available answer...

 

[Helge]

I still don’t feel I’ve had a satisfying answer as to why X 30/25th would give more light, over the same speed at M?

If indeed it does‽

It’s rare that I use bulbs at speeds faster than that, as you in darker circumstances want maximum contribution from ambient (which is no problem to keep still enough with leaf shutters), and almost always want to use the bulbs output to its fullest in daylight for fill/shady forground lift (which is only possible at long speeds).

If the bulb already starts outputting significant light as the blades start to open at X sync (as opposed to M sync, where the bulb is triggered as the blades are fully open), is that countered by catching the tail end of the dying down of the light with X sync?

At those long speeds, the shutter would seem to start closing well after the bulb has completely burned out, at both X and M?

PS.

we’re discussing PF-1b, not PF-3 (class M)

I corrected the peak from 15 to 18 milliseconds. Sorry about the error.

For pf-1 see flashbulbs.com/Phillips/ph-6.html

For pf-3 see flashbulbs.com/Phillips/ph-4.html

Never heard of PF-3, but isn’t all of these smaller bulbs M (medium speed) type bulbs?

Perhaps this could be of interest:
https://www.petervis.com/Cameras/philips-photoflux-flashbulbs/how-to-use-guide-numbers-page-6.html
(Second last paragraph).
And:
https://www.petervis.com/Cameras/philips-photoflux-flashbulbs/time-light-curves-page-4.html
And:
https://www.petervis.com/Cameras/philips-photoflux-flashbulbs/shutter-synchronisation-page-3.html

 

[BrianShaw]

First, I’m willing to bet that’s based on empirical data and can be trusted. Look at the illumination curve and map both the shutter open and shutter speed times... it might make more sense. It seems that you either have done that or at least understand in your head how it works.

in short, though... you said it already: the way to capture the full burn of the bulb is x synch at >1/30 sec. M synch will cut off part of the rise, and fast shutter speeds cut off a varying amount of the tail end light.

or in other words, the bulb peaks in 15 milliseconds. M-synch throws away the first 17 or so milliseconds of light.

https://upload.wikimedia.org/wikipedia/commons/1/13/GE-Synchro-Press-No.11.svg

https://www.photrio.com/forum/threads/mx-synchronization.63166/#post-898621

 

[Helge]

First, I’m willing to bet that’s based on empirical data and can be trusted. Look at the illumination curve and map both the shutter open and shutter speed times... it might make more sense. It seems that you either have done that or at least understand in your head how it works.

in short, though... you said it already: the way to capture the full burn of the bulb is x synch at >1/30 sec. M synch will cut off part of the rise, and fast shutter speeds cut off a varying amount of the tail end light.

or in other words, the bulb peaks in 15 milliseconds. M-synch throws away the first 17 or so milliseconds of light.

Thanks Brian!
I think that’s a good and satisfying answer.

But don’t let that stop anyone else from commenting.

 

[eli griggs]

When did Philips produce its last flash bulbs and who continued to when... ?

 

[AgX]

or in other words, the bulb peaks in 15 milliseconds. M-synch throws away the first 17 or so milliseconds of light.

Not quite.
M-synch has the shutter completely open after 17msec or so. The PF1 has its peak at 18msec. But that does not mean that combustion output before that does not yield an exposure. Keep in mind that even shutter exposure time is related to t0.5, thus there is exposure. Both shutter-opening and combustion-rise take place in this period. The difference to continuous lighting is that the light source is not at full power during the opening time of shutter, and the added part of exposure during the shutter opening time thus is lesser with incandescent flash.
Before combustion starts, the shutter has already begun to to open. To calculate the exposure yield during this period one needs exact opening parameter of the shutter.

 

[BrianShaw]

Not quite.

Then please answer the question that was asked.
I’m really curious as to how you explain it.
Your answer in post 33, “Best explanation to me would be that M-synch is not optimum for that very bulb model. (However, graphs show the opposite.)“ is, ummm, errr, not very informative.
Bye

 

[AgX]

Well, at M-synch a part of the flash output gets lost as I explained above. However I could not explain a full stop difference. That is in theory. The tables are likely made by experimenting with real cameras...

 

[Helge]

Well, at M-synch a part of the flash output gets lost as I explained above. However I could not explain a full stop difference. That is in theory. The tables are likely made by experimenting with real cameras...

- Well, just to put a point on it: 25th of a second is 40 milliseconds.

- M will trigger the bulb a bit before the shutter has started to open (or is when then shutter has fully opened? I've seen conflicting explanations) to allow maximum use of the light.
Wikipedia say: "M-Sync is timed to fire the flash 20 milliseconds before the shutter reaches its peak opening, allowing the two events to coincide".
http://camera-wiki.org/wiki/Flash_sync

- According to curves, the bulb takes a little under 10 millisecond before giving any significant light, then peaks at around 20 and extinguishes completely at 35 milliseconds.
The missing part of the equation is how long it takes for the blades in a typical leaf shutter to fully open?

40 milliseconds visualisation (sadly not comparable line to line due to proportional spacing)

M sync:
"O" = flash switch is connected in the shutter. "*" = flash burn period output start and stop. "I" = shutter starts to open and closes completely.
O---------*-I----------10----------20-----*-----30----------I

X sync:
"O" = flash switch is connected in the shutter. "*" = flash burn period output start and stop. "I" = shutter starts to open and closes completely.
IO---------*-10----------20----------30-----*-----I

Is this correct?

Seems both of them is about equal, with a small, theoretical advantage to X sync since M cuts off an insignificant part of the early curve of the light, and the shutter might not be completely open until after a few milliseconds (this is really the main unknown).
Both are within the forty millisecond window to use the light.
Both have the same amount of ambient exposure.

Philips,Osram and Sylvania etc. probably had their reasons for recommending X sync.

The question that beckons is, why exactly?

And what is M sync for then?

Almost all bulbs seems to have about the same firing latency.
Is it only for shorter shutter speeds to catch the peak of the curve (with reduced guide number naturally)?

 

[BrianShaw]

M synch was intended to ensure that even the fastest leaf shutter shutter speed (400) caught Th e peak illumination of the flash bulb burn.

compare your computations with the curve I linked in post 42 (in a later edit so perhaps you didn’t see it). That curve is for a different bulb but the graph clearly shows what’s going on.

at this point, though... I think you have sufficient understanding. it might be time to forget the academics and burn a few bulbs and sheets of film!

 

[BrianShaw]

P.S. not intending to be condescending or anti-intellectual in any manner... please recall that this question was asked-and-answered several generations ago. Best way to get maximum utilization of a flash bulb is to follow the GN recommendation.