michael c barlas

Hey all, So the shoot day passed and everything went off perfectly. Thanks to all of your help and a bit of luck. We set up the Arri T5 bare on spot. Unsure of Calvin setting on the Amira maybe 4300?. You you were right Dave it didn't look overly saturated. The natural sunlight at first of course was overpowering, When the angle of the direct sun light changed hitting the edge of the window frame before creeping over the house, it was noticeably bluer in comparison to the T5 direct light source. Not sure if that was in the shot however. Surprisingly the T5 could mimic a low setting sun when looking straight at it. I am not sure If I added a 1/2 CTO, would it change the intensity of the T5, making it a little diffused along with light loss and color temp change which is expected? T5 (spot) bare hitting the window at 30ft was f11 iso 640 1/30, dropping two stops at the back of the bathroom. I think it worked because it was going through a normal sized window, definitely too small to light a living room for instance. As for the fall off I mentioned before Albion, that was an error. The only thing I would change about the shoot, it would be to add a 3rd level of scaffolding. We didn't have an experienced Grip so I had to wing how to get the light up 25 ft or so. I was hoping to use a Mombo Combo extended 15 ft at the top of the scaffolding but its footprint was 6ft and wouldn't fit on the 5ft wide scaffolding. So I used a Mathews hihi overhead roller stand which has a footprint of 5ft. I had to almost max it out, I didn't calculate properly the slope of the backyard, which added another 5ft or so to the height the stand needed to go. Luckily there was no wind that day. Would one normally pull up a Crankovator on a scaffold, I know they weigh like 80lbs? The second level of the house was unusually high. Anyways thanks for all of your help Guy, David and Albion. It was most appreciated! Cheers, Michael

Hi Dave, Thanks for the replies. Yeah it could be an overcast day or cloudless. How many stops would you say you need to bring out the 5k and the ambient lighting, 2 or 3? I guess we will see on the day of when we light meter. We could always flag off some of the natural light from above. Yeah a 10k is the safer bet, luckily for us we are lighting a bathroom, not a larger living room for instance. Plus I don't want to have to make a scaffolding and put up a 10k and distro with our lonely, skinny grip. What are your opinions on using a tungsten light source rather than an HMI for a sun source? Would you say its a budgetary or personal thing. Because I have seen both and not sure I have a good enough eye to spot the difference once the film has been graded. But i do think HMIs look very strange when they are undiffused. But yeah why not just change the kelvin in camera, but I guess you would need a freshly calibrated monitor to see the difference.

Thanks Guy and Albion. Thanks Guy for the info about combining two Generators, I will definitely look into that. My apologies, I went to take precise measurements at the location, the actual distance from the window to where the DP wants the light is 34 feet NOT 20 feet. Not including the room itself, lets add 8 feet for the light to actually light the room/actors. Total 42feet. On spot the beam diameter is about 9 feet giving me 222 foot candles. After gel and diffusion that's 90 FC.(2000 LUX) Things are starting to look pretty grim for the 5k. However the DP says we can move the light in. Plus he doesn't want a nice light fall off, which you would get from a 10k Fresnel Strand or a 10k Big Eyes Fresnel Mole moved further back. How could you even find where that fall off is, other than moving the light physically or using Photometrics to find where it drops off numbers wise Albion. The DP clarified saying he wants a harsher horizontal light source, rather than from a 45 degree angle. He agreed with Dave's about the diluting natural light to blue the tungsten. But it would be nice to have some CTB on the side. Maybe add some Light Opal Frost to a 4x4 frame. Which is similar to Hampshire Frost but has a y transmission of 85%. Not sure why the Hampshire Frost doesn't have a rating. Sorry Guy I don't know what the Rosco equivalent is. Mike

Hey everybody, Thanks for the replies, every time I post a question I get great responses. Thanks Guy Holt for your in depth reply.I will be using a HondaEU7000IS and a Transformer for power for the 5k. The DP prefers a tungsten light source over HMI's for this scenario. I see your point about the lower wattage David, do you think the natural light will dilute the power as well from the 5k not just its temperature? Cancelling out its directional quality as a key light? We plan to flag some of the natural light during the day from the window. Also the 5k is going up roughly the same angle the sun will be as it rises in the morning. Hopefully mimicking the suns angle to some extent for the morning. After noon any direct natural sunlight won't be hitting the window, only bounce. If the director wants to throw up some curtains or wants the light stronger I may be in some trouble with the 5k? Maybe I should just get the 10k to be safe. However the 10k will require more hands. Or we could just open up in the camera if we need to get in more light. Am I over thinking this?

Hey everybody, My name is Mike, I am an Electric and I will be gaffing for a short film. I have to recreate late afternoon light to shine through a window. My question is do I have a strong enough light source? My main light source is an Arri Tungsten 5k. The DP wants it about 20 or so feet away from the window. We are on the second story so the light will be on a stand about 16 feet high. The DP wants afternoon light (4300k) to shine through the bathroom window. So I will gel the 5k on a 4x4 frame with 1/2 CTB (4600K). He also wants some New Hampshire Frost on it. Using Arris Photometric Calculator I calculated the Arri T5 5k light source at: 21ft. Middle flood to give me a 3914 Lux. Aperture at F13.8 ASA 800 30fps Wikepedia says Lux for a sunset/sunrise to be 400,1000 for an over cast day, 10 000 for full daylight. My 3914 Lux does not take into account my 1/2 CTB gel and Hamphire Frost. So ultimately I am asking where my light is placed right now 20ft away though 1/2CTB and Hampshire Frost, do I have enough light or Lux to recreate late afternoon sun? Yes I can lower the aperture on the camera from the 13.8. Or should I rent a 10k. Keep in mind I only have one Grip to help me. Thanks a lot for any help in advance, it is much appreciated. Cheers, Mike