Down-lamping vs dimming a 1K Arrilite
 

When I bought my lights, I really didn't know how much light I would need. I bought a 650 fresnel, and a 1K open-faced Arrilite.

I use them to light drama films indoors, and I've discovered that I really did buy far too much light. Now, I can use ND gels, and I do have a couple of those popular $10 dimmers and those work great. But now I've started to think about down-lamping the Arrilite.

I figure I probably should have just bought a 300 watt fresnel instead, or even just another 650 watt fresnel.

Am I better off downlamping the Arrilite 1K to 600watts and starting the dimming slightly from there, or keeping it at 1K and just relying on dimming and ND gels.

I know that once you dim drastically you change the color temperature. But is that the worst that can happen? I'd hate to damage my lights because I want to dim a 1K all the way down simply for an edge or hair light.

You can use also scrims to reduce the light output. It's not unusual to use larger lamps on dramas and then scrim/ND down, it's a lot quicker than changing lights.

If you use CTB gels on your lights, you quickly discover that you need the bigger units, especially if you use diffusion or bounce.

Good point. I am actually using scrims instead of ND gels, though I plan to pick up some ND gels soon.

I do use diffusion gels also, so I agree that those cut down the light quite a bit as well. I guess I just worried that I would still have to dim-down quite a bit, and I was worried about damaging my lights somehow.

What's the worst that could happen, would it just break the lamp or could it damage the fixture?

Dimming will not damage your bulbs or fixtures, on the contrary your bulbs will last longer.

The cons - you're using more power than you need, which can be a problem if you have limited power service in a location. This power is being dissipated as heat by the dimmer. You have to carry the dimmer, setup is more complicated. Biggest issue to me is that you're changing the color temperature of the light (towards the warmer) with the dimmer.

A warmer color temp can be a good thing, or a bad thing, depending. For me, I'd rather lamp down (still carry the 1K lamp with me, it's small and light), so that all my lights are the same color temperature. You can always throw in some rose or cto to warm things up when you want them warmer, but most people are going neutral and cc in post.

The exception is backgrounds. If you want the background colder or warmer than the subject that is best done with gels in the bg light while shooting.

PS. what Brian said about CTB for daylight balance sucking down the light intensity is a serious consideration. Using CTB typically means needing twice the light, so, do keep that 1K bulb if you lamp down.

Hi Craig:

Dimming fixtures will not harm them but it will turn the light coming from your Arri 1k a nice orange color and you will get noise, physically from the instrument and sometimes in your audio chain.

Between barn doors, scrims and ND/Diffusion, you can take an Arri 1k down to almost nothing without resorting to a dimmer, I do it all of the time. Brian's point about having the extra horsepower when you need to CTB those lights is a really valid point. Shoot a daylight interior with an Arri 1k with full CTB through a Chimera as a key and you have about what a 300 watt fresnel does without CTB. It's easy to reduce light but impossible to increase it.

Best,

Dan

If you do want to keep using the dimmer. I have heard that as long as you don't go bellow about 50% the color temp shouldn't really change. I have no way of testing this though.

By downlamp do you mean just replacing the bulb? If so I think that would be a great idea if the ends match up, and you could keep the 1k bulb around for when you need it.

Hi Eric

Not true. I use a lot of dimmers with my tungsten lights and you can see a color shift with as little as 10% dimming. 50% dimming will radically change the color temp.

Dimming is fine when you want a warm orange BG but is really too much when keying people. If you go too orange, especially with 4:2:0 formats, you will not have enough latitude to ever color correct it back to a natural skin tone.

Just wanted to give you what I have experienced.

Dan

Thank you for the correction.

No prob Eric, just hate to see someone try that and then get backed into a corner. I have measured my tungsten instruments with a Minolta color meter and there is an almost immediate shift when dimmed and it accelerates exponentially as the lights are further dimmed.

Great for BGs and tabletop, not so healthy for skin tone unless you like all your talent to have the "Fake Bake" look. ;-)

Dan

If your lights are always too bright, it's a good idea to put in lower watt lamps (bulbs).

It is not a problem at all to use a smaller watt lamp. Using a lamp the right size saves on heat and watts pulled. The only precaution is to not touch the glass with bare fingers, leaving a bit of oil on the glass. Oil heats to a higher temperature than the glass will normally, a hot spot is created where the finger mark burns in and the glass becomes a bit milky. This greatly increases the likelihood of an explosive lamp failure. (If the glass on a lamp is touched, it should be clearned immediately with a soft cloth and maybe alcohol.)

You can carry the higher watt lamps in a small protective lamp pack in case you need them. Lowel makes some little plastic boxes with cutouts for lamps that are very good:
http://www.bhphotovideo.com/bnh/cont...arch&Q=*&bhs=t
The Lowel ones sometimes need a rubber band to keep them closed. I'm sure other companies make them, too. The Lowel lamp packs, for example, are much more protective than keeping spare lamps in their cardboard containers.

If you are using Fresnels, you can have a number of little ND filter cut that quickly go into the gel/filter holder. You can carry a combination of ND, diffusion, CTB and CTO. You can have a big range of little squares for each light and still be toting around much less than 1 dimmer.

A dimmer can be helpful on backgrounds and/or when you are using colored filters.

A gaffer in a lighting course once told me to never go below 70% with tungsten lamps because of the color temperature. I was doing my job training at the time and he said that in the final exams, dimming below 70% would be counted as a mistake with at least minus 5 points (out of hundred)

That's pretty funny--can I assume that the wording of the question precluded the concept of dimming tungsten down to warm it up, such as matching incandescent bulbs in the scene or firelight?

Well, it was pretty basic and we knew the task would be exactly this: 3-point light one person in front of a green screen for a tv presentation (note: don't be creative, just do it according to the book - it didn't say that, but it was what they meant). Dimming too low would have warmed the color temperature too much, so they wouldn't accept it...

Right, it would have been scandalous to think that you would give someone a healthy looking skin tone by warming up their key source a little...!

I'm not trying to be too judgmental (well, maybe a little) but it kills me to think that people are penalized over something like that that is simply not an absolute of right or wrong--this is lighting for the camera, it HAS to incorporate a "creative" element in order to be successful (unless the goal is simply to provide enough illumination to make the engineers happy, which is probably the case more often than not in that end of the industry). Is there a technical reason not to warm up a source by dimming it? No. Does it hurt the potential green screen key? No. Might it actually improve the look of the subject? Yes. Especially if it was the backlight.

So in this instance doing it by the "book" is to end up with footage that is potentially less pleasing, all out of principle. But then again, live TV is often marred by this sort of thinking. The idea that making a subject look good is a "creative" decision instead of the absolute priority is just baffling to me.

Sorry about the rant, Heiko!

I know exactly what you mean, but the school was pretty caught up in the bureaucracy of public television. Interestingly whenever I talked to someone there in private they were always open to creative approaches and seemed to be very capable people.

However, the rule not to dim below 70% serves the purpose of staying in a very small range of color temperature. For some purposes (exact color reproduction) this is definitely welcome, you can't say there is anything wrong with that. And they just needed to set some rules - how else would they be able to give grades for what is mostly a creative process? Let everyone do their thing and in the end say "hmm I like the looks, I give it an A"?
Considering it was a very basic lighting education, I guess setting some stupid rules was necessary. I feel free to break them whenever I like (and that is very often ;) )

No, that of course makes sense. It sounded like there was no specific reason to observe that in the given example though.

Well, yeah, that makes sense doesn't it? If it was a creative writing class, wouldn't it be appropriate for the teacher to say "I like the story, I give it an A"?

Now, had the example dictated that it needed to match the other studio lighting, or specifically that the color temperature needed to be within a specific range, then absolutely it would be appropriate to dock points for an overly dimmed unit. My point being that it is important to distinguish the purely technical side from the creative side. If one is asked on a test, "which draws more power, a 1K or a 2K?" then the answer is black and white. If the question is "which is a better key light, a hard or soft source?" there's no right or wrong answer.

I'm a film school dropout myself, so I will admit to some bias when I hear about this sort of thing. It's important for students to learn certain "rules" as long as the teachers are pointing out the entire time that they not only can be broken, in this day and age nearly all are. I myself teach Steadicam operation and outside of some basic universal guidelines, much of what I prescribe I will constantly define in terms of "there's many ways to approach this other than what I'm giving you--try a lot of them and see what works for you".

Interesting thread.

I'm gonna play devil's advocate here and suggest that the awful teacher might have had it precisely right to require their students to tow that arbitrary line. (dim below 70% and fail!)

For some odd reasons...

Not because of issues of "right or wrong" but mostly because that kind of rigid, inflexible thinking is pretty much par for the course of what you confront in much of life - particularly bureaucracies.

They just LOVE metrics based rules. Makes it easier to score stuff and give financial rewards to the players who simply score best without pondering messy less tangible stuff like "quality" or "creativity."

The reason I think those RIGID systems are really valuable is because they give two great gifts to TRUELY creative people. First, they FORCE them to confront what is wrong with the RULES - something you can hardly do if you're never actually LEARNED or been subjected to them.

And second, because when the constraints get too stupid, that's when the smart kids push them over and actually re-invent the wheels.

It's kinda a Zen take on teaching and education.

Without up you can't have down.

There's no good - unless you have bad.

Without steeping yourself in the hide-bound traditions of an industry and gaining an understanding of why those standards developed - how does anyone move on to ACTUALLY improving stuff?

If there's no scoring system, nobody's gonna decide that not only is the SCORING screwed up - but maybe the whole damn GAME is screwed up and needs to be re-invented.

If you START OUT with a free flowing system, how do you know that the teacher that gave your project an A+ didn't do so because the story, or the politics, or the clever use of sound effects didn't float his or her boat - and gave them license to overlook the fact that all the dialog floated on a sea of 60hz hum? Teacher: "Uh, Johnny, I was particularly excited by your use of sonic drone-scape to underscore the bleakness of the street life of the teen-age hooker." Johnny: "uh, oh, uh, sure....glad you liked it." (mops sweat from his brow.)

So here's to the traditional video production education where some Bozo tells you what's RIGHT and what's WRONG.

The ideal spawning ground for angst and annoyance - and the launch pad for guys like Charles - who after being dipped in that for a short while - figure out how to escape and go out and actually do something useful in the real world! Including breaking the rules they're already mastered if the situation dictates it.

Interesting points Bill.

My film school experience was possibly along the lines of what you describe--at that time NYU was pretty anti-Hollywood, and I was subjected to a stream of avant-garde cinema, from the classic (Buenuel, Maya Deren) to the obscure (a friend of my professor, whose film consisted of her standing in a shallow stream with the camera pointed straight down and zooming in and out for 10 minutes). It was after suffering through the latter film that I had had enough. I decided to make a film that thumbed its nose at this seemingly anything-goes, no-rules philosophy of filmmaking. So I made what I thought was a completely obtuse and random film, but it turned out that my aesthetic was too steeped in traditional filmmaking to be as "out there" as I thought I was being and the result was actually a pretty good piece that, while being a collection of images, did actually tell a story and was quite strong visually. The class and the professor loved it and I unwittingly became the class darling.

For my next attempt I was determined to avoid a backfire so I decided to really go for it this time. I made a film about two girls sitting in a diner talking and eating for 5 minutes; the kicker was that it was silent. I screened it and the professor seemed unsure--probably sensed I was up to something. I said that it was exactly what it appeared to be: a study of a conversation between these two people where the viewer wouldn't get caught up in the actual discussion because there was no sound, something like that. The professor said, well, if you really stand behind that film as an artistic statement, I'll go along with it. I think I pretty much lost it at that point, started laughing and said "no, it's just bulls****".

Between that and the fact that via a friendship I had forged with a very successful Steadicam operator I was spending my free time hanging out on the sets of movies like "Ghostbusters", my film school days came to a quick conclusion, a decision I have never regretted.

So what of teaching the "rules"? Again, nothing wrong with it as long as it is made clear that to be a visionary in this business it's all about invention or re-invention. Take camera blocking, specifically "the line"...it's taken me years to feel confident that I have seen just about every variation of how to observe the line and work within it with ease, but I swear that it will take me the rest of my career to understand how and when to break it (I will rewind scenes from certain current films and watch, jaw agape, as I see two actors facing each other and looking the same screen direction in their closeups, the single most blatant disregard of the line, and yet it works, somehow...). In the instance we are discussing in this thread, again, a simple mention that in for this lighting setup the color temperature should remain above 3000K would have achieved the same result without forcing a judgemental label into the mix--"creative" almost being a dirty word here, like "don't get all fancy on us now boys, we're in TV land, just blast 'em and we're good to go".

There you go.

Film school did it's job. It's excesses got you comfortable questioning EVERYTHING.

Then life on the set exposed you to TRADITIONAL PROCESS in a way that didn't make you give up, but rather encouraged you to master those traditions.

And learning the traditions while questioning them constantly and looking out for improvements sounds to me like a pretty darn good recipe for becoming really excellent at anything.

So for those considering film school, I just have one gentle suggestion.

Try to figure out, in advance, what you'll say to calm your parents down when you tell them their tuition checks financed an education that was largely BS.

That kinda stuff is pretty hard on the people footing the bills!

FWIW.

:)