Filling a frame with small sources

[Leon Brehony]

Hello all,

I had a question regarding bouncing light. Specifically in low budget scenarios with no desk ops/DMX setups and often without a proper gaffer… Let’s say I’m making a big soft key light by bouncing multiple small sources into an 8x8 frame in a fairly cramped space (could be tungsten fresnels on dimmers or LED fixtures with their own dimmers) - I always find that it takes a while to get the balance of the different levels of the lights into the frame to get the desired look on the scene that I want. Partly cause I’m often running back and forth between the lights and the camera. Also just in terms of trying to fill the frame as much as possible with the right levels coming from the different lights, I find this takes a fair bit of tweaking to get just right and is never as simple as ‘just bounce 3 lights into that frame’.

I’ve even had this situation with gaffers, where they get it all set up but it doesn’t look right until I’ve tweaked it to within an inch of its life. I always get what I’m after eventually so maybe this is a moot point but my question is whether there is a specific standardised system for setting something like this up? E.g. setting one fixture at a time and gradually increasing the size of the source. Again, I imagine in the world of desk ops and DMX this is all a lot simpler but just wanted to check if any DOPs or gaffers had any nuggets of wisdom for this sort of thing as I see myself still having to do this sort of setup a fair bit in the future. 

P.s. I found this a lot easier when I was starting out by using something like a 2k blonde to create a single large bounce source so maybe the answer lies in using single sources for bouncing but I’ve not found many decent open face equivalents in the LED world.

[David Mullen ASC]

IF you want maximum softness you have to fill the frame evenly without hot spots, but there’s no rule that you have to achieve maximum potential softness anymore than you have to use the heaviest diffusion gel in front of a light.

[Aapo Lettinen]

Using 1 grade stronger diffusion on the big frame should make it much faster and easier. I guess the op is using something like 1/8 at the moment which indeed would make it very slow to tweak with small sources for the frame not diffusing much and the individual hotspots showing through? 

[Phil Rhodes]

I keep wondering whether I should buy a large amount of LED strip from eBay and just wind it around some 4x4 frames.

[Adrian Sierkowski]

17 hours ago, Phil Rhodes said:

I keep wondering whether I should buy a large amount of LED strip from eBay and just wind it around some 4x4 frames.

I have had issues with strip before. Here in the states, we would just rent a litemt 8 which is essentially that.

If I wanted to do it on the cheap; I'd get a few Amaram F21x or C lights (or the F22s) and zip tie them together and to the frame. But that's a lot clunkier.

I guess you could source good enough LED strip and affix it to coroplast (maybe even white coro?) with little sides and make essentially a litemat 8 type fixture.

[Phil Rhodes]

Something along those lines, yes. I just like things that are collapsible.

Also, LED strip does give up something in efficiency, with all those resistors. There may be a better way, but perhaps not so easily improvised.

[JB Earl]

a 600w COB instrument will give you about a 2K tungsen equivalent.  

when you say tweaking the bounces, is it because you're usng multiple smaller lights?  

[Leon Brehony]

On 8/13/2023 at 9:06 PM, aapo lettinen said:

Using 1 grade stronger diffusion on the big frame should make it much faster and easier. I guess the op is using something like 1/8 at the moment which indeed would make it very slow to tweak with small sources for the frame not diffusing much and the individual hotspots showing through? 

Was talking more about bouncing than projecting through diffusion. 

 

1 hour ago, JB Earl said:

a 600w COB instrument will give you about a 2K tungsen equivalent.  

when you say tweaking the bounces, is it because you're usng multiple smaller lights?  

Yes usually because I haven't had much space or a modifier that would spread a single source over the whole frame.

[Aapo Lettinen]

3 hours ago, Leon Brehony said:

Was talking more about bouncing than projecting through diffusion. 

 

Yes usually because I haven't had much space or a modifier that would spread a single source over the whole frame.

Oh ok, I thought you were first bouncing them and then diffusing the bounced light further with the frame.

So you just have a frame and bounce small lights directly from it? Maybe your bounce surface is just too shiny causing a more directional reflection than expected. If it is for example ultrabounce, you can try muslin to see if its effect is closer to what you are after.

Using softboxes or if unavailable just diffusion gel on lights might be another solution, would help with specularity of the sources bounced from too shiny surface and help to fill the frame more evenly.

[JB Earl]

...my question is whether there is a specific standardised system for setting something like this up?

you mentioned it already.  a 2K blonde into the frame will work, or a 600 LED COB.  Or as others have mentioned some large mats through difusion (even better becaause it will be more even)

Are there other limitations at play here?

 

[Adrian Sierkowski]

Generally your limitations will be space, power, and time ( also budget ). You kinda do the best you can with the time and space you get. I tend to large led sources since it's more even and generally I've already got those in the budget.

[Leon Brehony]

I always thought that projecting through diffusion renders a different quality of light that feels more source-y and I prefer the look of bounced light but maybe I'm wrong and the different is negligible.

Big litemats through a layer or two of diff sounds like a simpler and faster solution the next time I'm in this sort of situation.

[Aapo Lettinen]

17 minutes ago, Leon Brehony said:

I always thought that projecting through diffusion renders a different quality of light that feels more source-y and I prefer the look of bounced light but maybe I'm wrong and the different is negligible.

Big litemats through a layer or two of diff sounds like a simpler and faster solution the next time I'm in this sort of situation.

if it is heavy diffusion then it may be pretty uniform quality light, but weaker ones let some of the original source to shine through which create very different effect than bouncing does.

bounced light almost always has more directionality and the directionality of the source may be more asymmetrical than with diffused light depending on what kind of materials are used and what the angle is. By my experience, reflected/bounced light is "more finicky" to tune and it needs more skill and "better eye" to fully control it, one "needs to get to the zone" to fully feel how it behaves on each particular set and the rest of the crew may be unable to follow what you are doing unless they see the actual result on monitors. In comparison, using a point source and a simple diffusion frame is more predictable and easier for other people to guess what could happen if this light and that frame with that kind of material is used.  On student film shoots I often carried 2k fresnels and bounced them off the ceiling or wall or styro or kapaboard etc. and then using shinier reflectors for eyelight or fill. The rest of the crew often had difficulties to see why I wanted to move the 2k by two feets and rotate it by 10 degrees when it was "just bouncing from the white ceiling, it should be the same result" but I could fully see and predict how it would behave with the "semi-matte but a little bit glossy" which paint the ceiling had and could direct the bounce by moving the light just a little bit. Now when lighting less regularly it is difficult to do it like this anymore, "losing the flow" so to speak, but could learn it again quickly if just paying attention to the details. This is what people often miss with bounced light: the reclection is very depended on the material and it is always more or less directional and can be manipulated if just paying enough attention to it. Even with very matte surfaces like white molton or plain styrofoam it is still pretty directional, often more so than for example a 250 or 216 frame is.

As for led mats, they are pretty good if you can diffuse them a little bit to even the light and reduce the multi shadow issue. the real issue with leds for me is the often very poor light quality on low colour temperatures, usually the reasonably priced leds have issues with under 4000K or so and most are really poor, even almost unusable at around 3000 / 3200K.  For that reason I still carry up to 2K tungsten lights on shoots even when having good led kit now: the leds are really good for smaller amounts neutral and cold light but for warm light they generally suck and you would need to spend thousands per light to get usable tungsten balanced light out of a led unit, then would be really expensive to use them because leds tend to only last like from 1000 to couple of thousand hours until their phosphors go bad and the light quality and output levels start to suffer. That is why I also still have HMIs as well: with a HMI unit you can change the bulb when it goes bad, you don't need to purchase a whole need light for every couple of thousand work hours. I think the Led lights are expendables just like modern cameras are, they are not even meant to last more than couple of years before new more advanced one is purchased and the old kit is thrown to garbage with no one wanting to use it anymore ?