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Measuring Lux


Adam M Smith
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Long time follower, first time poster.

I'm Cinematographer on a Western Film. We are shooting on a period accurate train with Super16mm SR3 500 stock with Zeiss Super Speeds. We searched the train tracks and found the perfect location to stop the train so we can have as much control/continuity of lighting as possible during the day. It's between 2 huge rock formations and has plenty of tree coverage. The rock formations are very close to the train (average 4-8 feet away on both sides). 

These are the readings I get:

Standing in the middle of the tracks between two formations with lots of tree coverage above and full sun: ISO500, f/s48, f 5.6-11, CCT 6460, Lux 1800-2000 average

Sitting on the train in the same exact location with skylight (cloud coverage): ISO500, f/s48, f No reading, CCT3700, Lux 5-10!! (I knew it was going to be very dark but even this was surprising to me)

My question is more geared towards shooting the interiors on the train....when measuring for Lux in a situation like this should I be more concerned about the readings outside or inside the train? My initial thought was to use an M90 as that would be more than ample in this situation from a distance creating a wonderful falloff; but we don't have the budget. Now I am constrained to at most a few 1.2 Arri HMI's combined that I own, or maybe going the route of renting a few Aputure 600d's and using battery power instead of a genny (We are finding out if we can use a genny on the tracks very soon).

My plan was to key talent from upstage outside the train looking in, probably using at least 1/4 CTS and some type of diffusion, then bouncing from inside of train to same key side wrapping a bit to get a bit more level to create the Rembrandt style of lighting, shooting into the shadows; and adding negative fill all behind camera as much as possible. The scene is meant to be dark as the audience knows we are between two rock formations and it is a train robbery. Probably going for an 8:1 at least or even darker ratio on faces.

I like the readings inside the train to an extent because we have almost full control of light. I plan to rig Astera AX1 Tubes in the ceiling to bring level up inside, we have old practicals in the ceiling as well I will most likely outfit with B7C's and try a warm flicker effect. If my 1.2's are used @ flood 23ft through 1/4 CTS and Opal I should be in the 380 Lux area. Or even better IMO if I opt for Aputure 600d with F10 Fresnel Flood 45deg @ 15ft through the same modifiers gives me in the area of 2400 Lux. I still feel I should at least double up on Aputures, and maybe triple up on 1.2's.

This is where my brain is. I haven't shot much film so I don't want to show up, look at monitor and see no levels to work with. And keying from inside of the train just wont look natural IMO.

Ultimately does the key play inside the train if the Lux outside from ambient is higher or the same?

 

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Some of the numbers don't sound right to me. I shoot on film exclusively and 500T never works in broad daylight without substantial filtering. I have a 1.5ND and even then at 180 deg shutter, we're stopped nearly all the way down.

If your shooting inside the train with lots of light coming in the windows, I would just use a few bounces. I would not try to augment with lights unless there is literally no sunlight. You'd need something HUGE in order to make it work the way you're thinking, like you said, M90 or something like that. It would stick out like a sore thumb even if you could afford it. 

Personally, I'd shoot 250D, get some metal reflectors and some diffusion and be done with it. 

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Thanks for the input Tyler. With your 250D approach we'd have to pull the train into direct sunlight (which we may end up doing.) I could then as you say bounce my hard reflectors through diff.

We chose the dense canopy location so we could have more continuity of lighting and in the end the director liked it because the formations made a nice backdrop and the darker feel fit the story. (photos would help a lot but I can't upload right now.) With less than a footcandle of a reading on the train in the center at the desired location and very little area to bounce/diffuse on either side (I envision we'd have to use at least 12x12 in our darker location if were not using lights), combined with the fact that there is very little if at all direct sunlight available to bounce, led my thinking to keying through windows. I know film has a decent dynamic range but getting enough light into the high ceiling train car seems to be our hurdle if we choose to shoot in this particular location I suppose.

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Ah got ya, makes sense. But even in the shade, 250D would be ideal, don't need to filter it really. 

You'll have to key through the windows for sure. You may not need a huge source if it's just augmenting what already exists. I wouldn't worry about lighting the inside of the car unless it's really dark. You can toss a source in the windows on the back or other side of the car to help fill it up. I've shot a lot in trains being a railfan and all, lots of options for lighting for sure! 

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Those light levels are very low.  It seems the skylight isn't reaching into the car.

Tube lights in the ceiling would work for modern cars, but it wont sell old western by themselves. Perhaps have the characters light lamps to motivate the ceiling lights. As for exterior, the skylight may not matter if you're trying to play it as it really is: a dark rock canyon under trees. But if you are trying to pretend that the treecover doesn't exist and it is really skylight (which is at 10,000 lux), then you've got to lift it up more.

Did you spot meter the rock? If the rock exposes at an acceptable stop, then I'd just play is as a dark canyon and not lift the skylight anymore.

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Ahhh Stephen, for some reason never thought of spot metering the rock. That makes a lot of sense.

Yes, you are correct at less than a foot candle inside of car in the desired location I was really taken back. Didn't expect it to be that low. I planned to bring up the foot candle of ambient inside of car with tubes out of frame obviously and a bit of the upstage key.

Tyler is making me 2nd guessing my decision on the 500 stock. I didn't want to get stuck and not have any acceptable level in the car at an already ambient 1 foot candle. If we were shooting digital with the Mini like the rest of the film I wouldn't be as concerned going in. More research needed on my part with exposing the Super16.

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It sounds like you could treat your train car basically like it’s in a stage, but with natural backgrounds out of the windows. 
 

Taking a spot reading of what the backgrounds are outside the window would be smart to see where key levels should be inside to keep some detail, (maybe 4 or 5 stops over max? Someone who shoots more film in extreme situations would know.) If they blow out, they do, but at least you’ll be emotionally prepared. 
 

To light the train car itself, you have options, the following are just my instincts, your mileage may vary. Ideally, ambient would be created with a soft push through windows on both sides of the car, or at least the one with most exposure to the sky, maybe giving you 2 stops or less under in the middle of the car. A few HMIs into ultra bounce would do. If you want to then add sun, you could do hmi’s at each bank of windows, hard with some warmth added or that M90 with 1/2 CTS far away hitting the side of the car, let it be at key or a little hotter (creative decision) Several smaller heads can work too, and wouldn't have to be so high and far away. 

Another approach would be a semi-soft push as key, like 4x4 frames of 250 in front of each bank if windows with your 1200s behind them, as if it’s skylight but more contrasty and aggressive than a general push, shaped by the windows, exposed at the shooting stop. Could possibly use skypanels or geminis if the frames are a problem in the wind. Ambience could be made inside the car with tubes and diff, maybe move it around to key side for close ups and use a bounce for return.  
 

Anyhow, a million ways to skin a cat. Trust the meter and make sure something important is exposed correctly. 

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22 minutes ago, Tristan Noelle said:

It sounds like you could treat your train car basically like it’s in a stage, but with natural backgrounds out of the windows. 
 

Taking a spot reading of what the backgrounds are outside the window would be smart to see where key levels should be inside to keep some detail, (maybe 4 or 5 stops over max? Someone who shoots more film in extreme situations would know.) If they blow out, they do, but at least you’ll be emotionally prepared. 
 

To light the train car itself, you have options, the following are just my instincts, your mileage may vary. Ideally, ambient would be created with a soft push through windows on both sides of the car, or at least the one with most exposure to the sky, maybe giving you 2 stops or less under in the middle of the car. A few HMIs into ultra bounce would do. If you want to then add sun, you could do hmi’s at each bank of windows, hard with some warmth added or that M90 with 1/2 CTS far away hitting the side of the car, let it be at key or a little hotter (creative decision) Several smaller heads can work too, and wouldn't have to be so high and far away. 

Another approach would be a semi-soft push as key, like 4x4 frames of 250 in front of each bank if windows with your 1200s behind them, as if it’s skylight but more contrasty and aggressive than a general push, shaped by the windows, exposed at the shooting stop. Could possibly use skypanels or geminis if the frames are a problem in the wind. Ambience could be made inside the car with tubes and diff, maybe move it around to key side for close ups and use a bounce for return.  
 

Anyhow, a million ways to skin a cat. Trust the meter and make sure something important is exposed correctly. 

I think you are right on Tristan, treating it like a stage almost.

I plan to possibly overexpose the key side by 1 or 2 stops and then crush it back down in post. At least that is currently my approach from what I am finding in my research for exposing the Super16 stocks. It's better to go over than under. At the age of 43 this is my first rodeo with Super16 so I am both pysched and fearful.

I like the idea of the 4x4 frames with 1200's behind. I've done that before with 1/4 CTS and Opal yet it was through window shears and we sold the "dawn" look very well. Here I don't have that option of shears. But I think that is OK cause we are going for that old Western semi-hard look instead of super soft. I think we may opt for the Aputure's though as they have more punch and less footprint in what is already a very confined space.

Thanks for chiming in. It's super helpful to get different points of view.

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15 minutes ago, Tyler Purcell said:

Oh that's plenty of light for 250D, PLENTY! 

Well for the exteriors yes. But I don't think so for the interiors. In the train car if my C-800 was right it was less than a foot candle!! Most likely cause the car is so close to the rock formation there is very little spill of ambient into it. Plus in correlation to the single foot candle reading, I would think the black rock was almost providing negative fill. I still cant wrap my head around it. But I took the readings multiple times so I doubt they were off.

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4 hours ago, Adam M Smith said:

I think you are right on Tristan, treating it like a stage almost.

I plan to possibly overexpose the key side by 1 or 2 stops and then crush it back down in post. At least that is currently my approach from what I am finding in my research for exposing the Super16 stocks. It's better to go over than under. At the age of 43 this is my first rodeo with Super16 so I am both pysched and fearful.

I like the idea of the 4x4 frames with 1200's behind. I've done that before with 1/4 CTS and Opal yet it was through window shears and we sold the "dawn" look very well. Here I don't have that option of shears. But I think that is OK cause we are going for that old Western semi-hard look instead of super soft. I think we may opt for the Aputure's though as they have more punch and less footprint in what is already a very confined space.

Thanks for chiming in. It's super helpful to get different points of view.

Thanks, Adam. I do want to apologize  however. After I posted I reread your initial post and realized I was kinda off on my own lighting tangent, not terribly helpful. 
 

I think you have it covered. Getting more 600D’s  is a good idea, they have a lot of punch and will prob be more consistent than mixing and matching HMIs.  It’s good you know the style you’re going for. You may not have to worry about negative fill very much if your key is strong enough and you have solid ratios. The shadows fall off quicker on film than modern digital. Your meter will tell you that though. 
 

FWIW I think 500T is fine, but you could also prob handle 250D with the light’s you’re getting; dealer’s choice really.  Regardless, I’ve shot 7219 in full sun exteriors before and it’s doable, your situation isn’t as extreme and will be okay. Just overexpose a bit too, you’ll have the room and print down. 
 

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3 hours ago, Adam M Smith said:

Well for the exteriors yes. But I don't think so for the interiors. In the train car if my C-800 was right it was less than a foot candle!!

But you're going to have to augment with lighting anyway. You aren't going to run 3200K, you're going to do 6500k or something like that, so having tungsten balanced stock, kinda doesn't make any sense anyway. 

I shoot a lot with 250D and artificial light, it's fine. It's basically 1 stop slower than 500T, not a big deal and getting the proper balance and lower noise floor, is more important unless you're shooting for a specific stop. But with 16mm, wide open is where you wanna be anyway.

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