Flash/electronics nerds... how possible is this idea?

M Carter · Jan 31, 2022

First off, this is something concept-wise I need like a mofo, but I have zero intentions of soldering it up myself, well past my pay-grade, and getting electrocuted doesn't appeal to me.

So picture a standard shoe-mount flash, a tube is maybe 1" wide or so on a big one? No idea how much longer tubes are available. Then picture something like a box, six feet long and maybe 3-4" deep, with one long side open, and it's reflective inside.

Inside the "box" is a row of flash tubes, like a dozen of 'em, wired together to the electronics. The front of the box could have diffusion velcro'd to it. AC powered vs. batteries, a level or two of dial-down would be nice. Like laying a dozen Vivitar 285's down in a row, all synced together. That would be enough power, esp. with the 4-stops of dial down on the Viv.

So basically a very low-profile "strip light" flash. (I'll spare you the "Why's" unless interested, but no, a row of strobe heads with strip softboxes would be too bulky by a mile).

I'm guessing someone into the mechanics of flash could rig something up, but no real idea. I guess I could get a bunch of 285's on eBay and sync them all together, but what a pain. LED tubes are getting more powerful all the time, while that solution would visually work, it would get me into low shutter speeds and the hassle of turning off all the modeling and focus lights before pulling the trigger, and bring up issues of motion blur. Damn, I wish I was one of those arduiono/3D modeling kids...

AgX · Jan 31, 2022

M Carter said:
Like laying a dozen Vivitar 285's down in a row, all synced together. That would be enough power, esp. with the 4-stops of dial down on the Viv.

Here seems some misconception of yours. Adding more tubes will not have the output rise. The maximum output is defined by the capacitator capacity. To raise outpit you would have to build a respective generator. Buying for a few Euros each some on-camera fllashes woud be the more economical approach. Advantage of your solution is to have tubes and generator seperated. But this then would be the same as commercial solutions without pilot lights. Putting several tubes on a generator also has it pitfalls

wiltw · Jan 31, 2022

As AgX pointed out, dividing the electric charge of one storage capacitor into multiple flash tubes does NOTHING for output intensity.

If you use MULTIPLE flash capacitors into multiple flash tubes, that does increase intensity, but NOT as fast as you think

one tube + capacitor = 1x or 0EV
two tubes + capacitors = +1EV
four tubes + capacitors = +2EV
eight tubes + capacitors = +3EV
sixteen tubes + capacitors = +4EV

Pieter12 · Jan 31, 2022

wiltw · Jan 31, 2022

Pieter12 said:
Why?

why what?

Pieter12 · Jan 31, 2022

Why make this contraption?

M Carter · Jan 31, 2022

AgX said:
Here seems some misconception of yours. Adding more tubes will not have the output rise. The maximum output is defined by the capacitator capacity. To raise outpit you would have to build a respective generator. Buying for a few Euros each some on-camera fllashes woud be the more economical approach. Advantage of your solution is to have tubes and generator seperated. But this then would be the same as commercial solutions without pilot lights. Putting several tubes on a generator also has it pitfalls

It's not for more power, it's for a wider coverage. I have piles of Speedo packs and heads, but the projects I'm doing could use a very long and narrow, low-profile strobe head. Like my comparison to an LED tube, but not continuous light.

M Carter · Jan 31, 2022

wiltw said:
As AgX pointed out, dividing the electric charge of one storage capacitor into multiple flash tubes does NOTHING for output intensity.

If you use MULTIPLE flash capacitors into multiple flash tubes, that does increase intensity, but NOT as fast as you think

one tube + capacitor = 1x or 0EV

two tubes + capacitors = +1EV

four tubes + capacitors = +2EV

eight tubes + capacitors = +3EV

sixteen tubes + capacitors = +4EV

It's not for power, it's to have a very long but low-profile light source. Note my comparison to LED tube lights, but as I said, I don't want a continuous light. Or that a row of heads with strip lights is too bulky.

M Carter · Jan 31, 2022

Pieter12 said:
Why make this contraption?

Below is the darkroom stuff I'm doing lately. The model seated and the tree roots in the foreground are a life-sized set; the background is a scale model, about 18" tall, all composited in the enlarger, no scanning (color is from hand tinting).

To make the masking as natural and error-free as possible, I need the white background behind the person and full-sized set to be right at the edge of brightness, so I have nice density in the neg to create the masking needed. If I get really good density behind her, I don't need much of a "mask" at all for hair and stuff, it can overprint when the background is composited in.

But some of these sets are very difficult to get even lighting on the BG that doesn't illuminate the model - easiest remedy would be to raise the set a foot off the floor, but for now I'm not renting studio space for these and I'm limited by 8' ceilings. On this particular shot, I had a soft head behind the stuff she's sitting on, but I have some standing designs in the works where getting some kind of strobe at the edge of the set, washing up on the seamless BG would be the absolute bomb. It's easy to light the BG top and sides without fixtures being in the scene, but getting that floor-to-waist level nice and white is a pain.

So there's no room for a head and a strip light down there, you're gonna need at least 10" or so to get that out of the scene. For now I'll play with just laying some shoemounts on the floor (there's usually a chunk of wall or molding in back to hide the floor seam in compositing). As I mentioned, a bright LED tube or three could work, but then - shutter speeds must drop. (LED tubes are great for greenscreen for this same use, get the bottom of the screen evenly lit to match the sides and top, but we're at ISO 400 and 1/60th in that realm).

I don't know if such a device is realistic, but OTOH I imagine someone could look at what I need and say "yeah, we need a dozen of these tubes, these caps and this power supply". I could use the heck out of such a light, even beyond this specific "get the bottom of the BG lit!"

AgX · Jan 31, 2022

M Carter said:
It's not for more power, it's for a wider coverage. I have piles of Speedo packs and heads, but the projects I'm doing could use a very long and narrow, low-profile strobe head. Like my comparison to an LED tube, but not continuous light.

I understood this, but you also had it about more power to my understanding of your wording.

But as I also indicated at my last sentence above, one cannot just substitute one flash tube on same generator by a bunch of tubes.

wiltw · Jan 31, 2022

M Carter said:
So basically a very low-profile "strip light" flash. (I'll spare you the "Why's" unless interested, but no, a row of strobe heads with strip softboxes would be too bulky by a mile).

If one stripbox is, for example Godox 9" x 35", and that is 'too bulky by a mile'...what dimensions are you looking for?! Without better characterization, your complaint is somewhat vague.

Pieter12 · Jan 31, 2022

M Carter said:
Or that a row of heads with strip lights is too bulky.

A 4ft or even 6ft long strip box with a compact flash head like a dynalite doesn't seem too bulky to me. But you could probable rig a bunch of speed lights to a metal bar, maybe having one synced to the camera and the others as slaves. It is going to weigh more than the head & strip box and be harder to put on a light stand if necessary.

Looking at you example, I don't see why you can't light the background with some lights (you might net even need strip boxes) off to either side as long as the background is maybe 6' behind the model. It is done all the time.

M Carter · Jan 31, 2022

wiltw said:
If one stripbox is, for example 9" x 35", and that is 'too bulky by a mile'...what dimensions are you looking for?!

Per the original post, 3"x3" x 5 or 6 feet? 4"? Seems like the components (the actual strip of tubes) could fit in something even smaller. I'd sit it on the floor, hardware to angle it would be simple. I'd probably come up with a way to get it vertical on a stand, a super-narrow but long strip like that could really have some cool uses.

My 30"-ish strip lights, including the smaller Speedo head (I have 103's and 102's) is about 18" front-to-back, it's not just the width of the light face I'm dealing with.

This isn't really "pie in the sky" for me, I would be awesome to have.

Years ago someone posted some custom Speedo heads on eBay, they used flash tubes that were maybe 8-10" long, in a narrow box. Wish I'd bought 'em!

Don_ih · Jan 31, 2022

What about one powerful flash in a contraption that diffuses the light over your required area, like a reflector and lens from a fluorescent light fixture?

M Carter · Jan 31, 2022

Pieter12 said:
A 4ft or even 6ft long strip box with a compact flash head like a dynalite doesn't seem too bulky to me. But you could probable rig a bunch of speed lights to a metal bar, maybe having one synced to the camera and the others as slaves. It is going to weigh more than the head & strip box and be harder to put on a light stand if necessary.

Looking at you example, I don't see why you can't light the background with some lights (you might net even need strip boxes) off to either side as long as the background is maybe 6' behind the model. It is done all the time.

I've got maybe 2-3 feet available behind the model for the next several projects; at some point I may make my sets modular and rent studio space. The issue is getting the BG lit evenly behind a figure, without hitting her with the lights. It's easy to get the sides and top, but the falloff behind the figure is where it gets rough. I can't hang a light from the ceiling in most cases, it drops too low. Maybe I should just have the attic torn open...

This is why I didn't get into the "why" of it - I know just what I'd optimally need. I could lay a few 285's on the floor, but getting back there and powering them up and so on, pain, and diffusing them and so on, getting AC for all of 'em or swapping batteries, etc. As I mentioned, LED tubes would give the same style of illumination, but then there's the issues of constant light, shutting down modeling and focusing lights. I'd rather shoot 1/250th-400th (this is all 4x5) and not mess with that.

I've been shooting commercial products and fashion since the 90's, I know how to light and control the light - this is a specific situation where I need a specific shape to the light - as I said in the first post, "imagine a row of 285's", that level of power and control would do it.

M Carter · Jan 31, 2022

Don Heisz said:
What about one powerful flash in a contraption that diffuses the light over your required area, like a reflector and lens from a fluorescent light fixture?

I've thought about something like those "ring flashes" that direct a shoemount up and into a ring, seen those? To get a good 5' wash of light, you could maybe have three or four speedlight-sized lights firing horizontally against a long white surface the bounces them upwards. If they were covered and were 2 feet to 3 feet from the reflecting surface, that might give enough spread so that the reflected-up light and some diffusion would make it fairly even. The extra travel will east some lumens though, and then you're back to some kind of rig that's got multiple items to power and sync. You can run 285's off of transformers, but they have to have batteries in 'em as I understand it. (I bring those up because they're 20 bucks a pop all day long and have some output control). I'd like something i could just switch on and get to work.

Craig75 · Jan 31, 2022

There's a load of replacement flash tubes for yongou flash guns on the bay for $5 each.

Could you not just do something with those?

wiltw · Jan 31, 2022

Just found some linear flash tubes that are 232mm long (including conductive pins), 400V, 1000 Joules.
https://www.xenonflashtubes.com/lin...tube-high-power-striplight_162.html#techsheet
Assuming you found existing flash circuitry with same Voltage output and sufficient stored energy, you could wire one tube to one power storage module, to create a custom configured 'strip light'

Just as tricky would be the physical 'enclosure' of a string of flash tubes that protects each one from breakage, while allowing a bit of flex of the entire string of xenon tubes to suit the set design.

M Carter · Jan 31, 2022

Craig75 said:
There's a load of replacement flash tubes for yongou flash guns on the bay for $5 each.

Could you not just do something with those?

wiltw said:
Just found some linear flash tubes that are 232mm long (including conductive pins), 400V, 1000 Joules.
https://www.xenonflashtubes.com/lin...tube-high-power-striplight_162.html#techsheet
Assuming you found existing flash circuitry with same Voltage output and sufficient stored energy, you could wire one tube to one power storage module, to create a custom configured 'strip light'

Just as tricky would be the physical 'enclosure' of a string of flash tubes that protects each one from breakage, while allowing a bit of flex of the entire string of xenon tubes to suit the set design.

That's the thing - "I" can't do it, I have really zero electronics know-how, but I assume someone who knew this stuff could slap something together that's safe and effective.

And I'm picturing something like a thin plywood box, I don't need it like a flexible LED strip or anything. Just a "bar" of light to get the lower end of backgrounds lit that's very low profile.

Craig75 · Jan 31, 2022

Something like this not going to be powerful enough using continuous light?

https://www.amazon.co.uk/YONGNUO-YN...t=&hvlocphy=1006864&hvtargid=pla-857611459634

wiltw · Jan 31, 2022

Craig75 said:
Something like this not going to be powerful enough using continuous light?

https://www.amazon.co.uk/YONGNUO-YN...t=&hvlocphy=1006864&hvtargid=pla-857611459634

About equivalent to 150W bulb
and then purchasers complain that no power supply is provided, yet the warranty is void if not used with the appropriate power supply.

Pieter12 · Jan 31, 2022

How about stacking a bunch of LED wands to get enough light to match your strobes? You will probably need quite a few, but they don't generate much heat and I would think they would be less perilous than some hacked strobe tubes. Those things can be dangerous just from sitting and not being used (the condensers, that is). You need a lot of electricity to fire a strobe tube.

Craig75 · Jan 31, 2022

wiltw said:
About equivalent to 150W bulb
and then purchasers complain that no power supply is provided, yet the warranty is void if not used with the appropriate power supply.

Oh yeah not in conjunction with Flash. Just wondering if there is anyway to light whole thing with video lighting at all or whether it's just completely off the table

Dirb9 · Jan 31, 2022

I'm assuming a Kino Flo Diva is too dim? Broncolor makes some narrow strip lights; Litestick, Striplight, and Lightbar, but they're all pretty spendy for a single project unless you can find a rental house that carries them. Frankly, a custom linear light made from xenon strobes is likely to be much more expensive than a bunch of Vivitar 285s, the high voltage circuitry involved isn't something to be toyed with. A bottom firing softbox could be made pretty narrow, this is the only one I found, I think you'd have to make something yourself (plywood box with white plexiglass maybe), but in that case you could use a couple speedotron heads to get more light (maybe one at each end?). Another option for continuous lighting could be to use some led tape, and just make a box (cover three sides with the tape, and leave the fourth for the diffuser). There's some pretty powerful led strips out there and they're very easy to wire up.

Helge · Jan 31, 2022

Just fire a regular flash into the end of an opal or sanded acrylic tube. A lightsaber basically.
You could probably also use a fluorescent light armature protector and some diffusing gel on the inside.
Use metallic tape as a reflector, if need be.

Flash/electronics nerds... how possible is this idea?

Privacy & Transparency

Privacy & Transparency