Questions about a blacklight party? Think club for children i think

bobandcar · Jan 31, 2014

I so a good friend asked if I could photograph her child's 4th birthday party so that she would be able to enjoy it more. I fullly explained to her my lack of experience in this type of shooting. She is fine with that as it is a free thing. I am to take pics and deliver a SD card to her with the pictures on it.

It's called a black light dance party. For ages 2-14. They place has a website and videos online. It will be dark but enough light that you can still see what is going on(this is for children so think dimmer switch) also glow sticks and a disco ball

Gonna be using a canon t3i(read as ISO 800-1600 MAX) a 50 1.4 and a 12-24 f4 for this. I also own a good flash unit with capability for off camera flash.

Here's the questions.
Should I use the 50 and just try and use ambient light
Should I use the 12-24 and use the flash on second curtain with my shutter around 1/20-1/60 so that I get some blur but a sharp face?

Any thoughts would help me out!! I have about a month till the event.

Designer · Jan 31, 2014

A flash will absolutely kill the glowing things. Beyond that, I have no idea how to shoot this.

bobandcar · Jan 31, 2014

That was my thought to but I gotta get light somehow.
What if I turn my flash as low as it can go, then ambient light would still be everything but my subject?
If I am thinking correctly.

Designer · Jan 31, 2014

Definitely take it along and try it. Low power, bounced off the ceiling or a wall. Good luck!

Braineack · Jan 31, 2014

8:45 - Broncolor UV Light adapter?

only $1,400 - Broncolor UV Attachment B-33.626.00 B&H Photo Video

Bossy · Jan 31, 2014

Flash is going to kill it. I wonder if you could layer blue saran wrap or something over the flash to dim it too?

DanielLewis76 · Jan 31, 2014

So much opportunity for light painting!!

bobandcar · Jan 31, 2014

We're can I buy a black light at? Anyone know so I can test some stuff

I don't have sound on that video. Will check it out on my tablet later.

bobandcar · Jan 31, 2014

Just checked out there video again. Here
http://www.dance-parties.com/videos.html

Seems it's less blacklights and more regular type lights but dark

bobandcar · Feb 1, 2014

Any other thoughts?

bobandcar · Feb 6, 2014

Gavjenks · Feb 6, 2014

A regular speedlight flash puts out plenty of UV light. All you need is a simple UV-pass filtering gel, for example
Rosco Permacolor Glass UV Pass Woods-type Filter - 120336507508

Though I feel like you might be able to do cheaper somewhere. Then affix to the front of your flash (tape, or whatever) so that only light goes through that filter. Ta Da! You now have a UV flash, which will light the scene more brightly, but only in the same ways that a blacklight does (will light up all the fluorescent stuff more, but not as much the rest of the scene). You still want to modify the light as normal, such as by bouncing it off walls, or by using an umbrella or whatever. Jack your flash up to full strength / higher than you normally would and have at it. You will probably not get faces very bright, more so whatever weird neon clothes they're wearing. But that's sort of the point of a black light party isnt it?

UV flash will also slightly light everything else in the scene, since your camera is a bit sensitive to UV. If you don't like that, you can just use one of those cheap UV-block clear lens filters to cut out that light, while still passing all of the fluouresced light.

TCampbell · Feb 6, 2014

Which flash do you have?

If the light is low, the camera is going to struggle to lock focus. But if you have a flash with a focus-assist beam (e.g. a Canon Speedlite 430EX II for example) then the camera will be able to lock focus even in completely darkness. You can actually use the focus-assist beam and tell the flash NOT to fire if you want.

You can also get some creative flash gels. For example: Amazon.com: ExpoImaging ROGUEGELS-U Rogue Photographic Design Rogue Gels Universal Lighting Filter Kit: Camera & Photo

The kit is basically a rubber band that goes on your flash head and notice that the gels have "wings" or tabs ... you just wrap the tabs around the flash so the rubber bands hold them.

But here's a cool twist on the basic winged gels... the MagMod: https://www.kickstarter.com/project...d-magnetic-speedlite-modifiers-for-hot-shoe-f

I just noticed Scott Kelby showing this off on Google+ and I gotta admit it's a very reasonable priced and they sell a creative-gel option. These look best when you use multiple flash guns and gel each with a different color... e.g. putting one color on your subject and a different color on the background.

As for "black light" -- black light happens when you block most of the visible spectrum (light from 400nm to 700nm wavelengths) and only allow the shorter wavelengths through (e.g. wavelengths with values lower than 400nm).

A Xenon flash strobe (common in most flashes) puts out quite a bit of light in the 200-300nm range (far UV) and a bit less in the 300-400nm range (near UV). Black lights usually put out light in the 350-400nm range (near UV) and these wavelengths will "fluoresce" off when they hit fluorescent colored dyes. I think a Xenon flash strobe is probably putting out the bulk of it's light in a wavelength a bit too far to actually work on the subjects in a meaningful way. You could use the deepest violet flash gel you can possibly find and it will probably have a mild fluorescing effect.

A Lee filter #181 Congo Blue or a Roscolux #59 Indigo will both block most visible light and create a black light look if the light source behind them pumps out enough in the near UV spectrum. A typical florescent light would do this.

If you have enough black light in the room then you could probably get away with just using the focus-assist beam on the flash but not bother with the flash at all. You'll need to test it before the party.

Gavjenks · Feb 6, 2014

? Xenon drops off quite smoothly, dunno what you're talking about. The amount in 300-400nm UV to my eye is about 1/5-1/4 as much as the output in visible range. Which would imply you should start out with your flash about 2 stops higher than normal with a UV or maybe violet gel on it, to get the beginnings of an impressive effect. Then go up from there, since who knows how efficient the fluorescence is.

A deep violet filter looks from the graphs like it would be about 20% violet 20% far UV and 60% near UV roughly