FORUMS: list search recent posts

Need some advice on which fixture to use for a night scene.

COW Forums : Lighting Design

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Jason Flor
Need some advice on which fixture to use for a night scene.
on May 23, 2014 at 2:46:03 am

Just need a bit of advice for what kind of fixture I need to get the following light output at night.

The fixture will reproduce the effect of a street lamp above the location area. I need a ground beam spread of about 30 in diameter (with sharp well defined edges) from a fixture that is above the road on a scissor lift about 25-30 ft up. I am working at iso 320 and need an fstop of about f4.

I take it the HMI's are more efficient size-wise compared to fresnels?

What wattage of HMI lamp do you recommend and what kind of volts/ amps do i need as far a a generator goes?

Thanks
Post a Message.


Return to posts index

Bill Davis
Re: Need some advice on which fixture to use for a night scene.
on May 26, 2014 at 8:18:10 pm
Last Edited By Bill Davis on May 26, 2014 at 8:19:32 pm

If you truly want " sharp, well defined edges" you need a light that can focus properly.

I think a theatrical elipsoidal spot (Leko) would be a better option.

Plus that would enable you to adjust the diameter properly.

YMMV

Know someone who teaches video editing in elementary school, high school or college? Tell them to check out http://www.StartEditingNow.com - video editing curriculum complete with licensed practice content.


Return to posts index

Craig Alan
Re: Need some advice on which fixture to use for a night scene.
on Jun 1, 2014 at 6:02:33 am

Bill, can you get the spot to be 30 in diameter from a fixture that is above the road about 25-30 ft up? We have some Lekos mounted about 15 feet up and it can certainly get the look described but not sure what would happen at twice that distance in terms of the diameter. 30 in is a pretty small diameter. Or am I misunderstanding and we are talking about a 30 degree beam spread? Lekos are really good for a spot effect and work great with gobo patterns. Most street lamps produce a pattern of sorts since they are rarely clean.

Mac Pro, macbook pro, Imacs (i7); Canon 5D Mark III/70D, Panasonic AG-HPX170/AG-HPX250P, Canon HV40, Sony Z7U/VX2000/PD170; FCP 6 certified; FCP X write professionally for a variety of media; teach video production in L.A.


Return to posts index


Bill Davis
Re: Need some advice on which fixture to use for a night scene.
on Jun 3, 2014 at 9:20:38 pm

if you need smaller, just add a snoot.

And it THATs too big, embed a washer in blackwrap ON the snoot holder and use that.

This is field production. You do what works. Period.

Know someone who teaches video editing in elementary school, high school or college? Tell them to check out http://www.StartEditingNow.com - video editing curriculum complete with licensed practice content.


Return to posts index

Dennis Size
Re: Need some advice on which fixture to use for a night scene.
on Jun 4, 2014 at 12:18:35 am

A 10 degree Source 4 ellipsoidal with a 750w lamp will give you the exposure you want (have a dimmer available also in case you need less intensity) along with the narrow beam width.
Have a 5 degree lens barrel available in case you want a narrower beam width ... and a 14 degree barrel if you want a bit bigger beam width. Use a 1/2 CTB color correction to cool down the light (or a 1/2 CTO with 1/4 Plusgreen if you want the effect of a Sodium vapor streetlamp).
30" seems a bit bizarre however. What are you shooting that requires such little space?
I've also never seen a streetlamp yield a perfectly defined, sharp focused circle -- especially that small.
If you trully want the effect of a mercury vapor streetlamp, I would use a 1.8kw HMI PAR with a very narrow lens. That would yield a bigger softer diameter -- but would look correct.
Good luck,
Dennis



Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]