Which HMI or Tungsten light? -> Window of a hotel room

see-mann

see-mann

Active member
Hi
For a shooting in a hotel room with a balcony i plan to put a keylight from the balcony and some diffusion on the window/door.
I did a test with a 800W Tungsten and CTB foil. With the foil and diffusion it became to dark.
What would you suggest? A 575HMI, a 1.2 HMI or a 1K Tungsten with CTB foil?

Thanks,
Rainer
 
Trying to match any tungsten light to daylight with full CTB already loses a lot of output. Couple that with diffusion and you're much better off with an HMI. A 1.2K HMI would be ideal (5k tungsten equivalent) since you can double up on the diffusion if you need to and/or pan the light on/off to dial in the exposure inside the room.

Depending on what you want to see, though, you could use that light inside the room to bring up the levels enough so that you don't lose detail outside of the window.
 
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PeopleCanFly said:
Trying to match any tungsten light to daylight with full CTB already loses a lot of output. Couple that with diffusion and you're much better off with an HMI. A 1.2K HMI would be ideal (5k tungsten equivalent) since you can double up on the diffusion if you need to and/or pan the light on/off to dial in the exposure inside the room.

Depending on what you want to see, though, you could use that light inside the room to bring up the levels enough so that you don't lose detail outside of the window.
Click to expand...
1.2K HMI 5K equivalent seems to be a lot... the room is about 4m x 4m, the light will be max. 50cm in front of the window. On the window will be a diffusion foil. The actor will walk around the room and i guess standing 1m in front of the 1.2K HMI will burn his face like a steak...(?) ;-)
It will be the keylight, a lot of contrast, rest just some reflectors, not too strong.
The 800W Tungsten without CTB and without the diffusion foil on the windows was almost perfect in our test, with foil it was too dark.
I just don't know, if a 575HMI would match the level better than a 1.2HMI. But with your information about the 5K Tungsten equivalent i guess the 575HMI will be the better choice... (?). Another thing is the budget. Shooting will be around 10 days. An HMI is about 55,- /day here in Germany.
Would fit a 1K or 2K Tungsten with CTB and the diffusion foil on the window? That's about 16,- / day... It will be a reel for potential produers, all paid by private money.
 
Considerations..

Are you after a diffused look or sun shadows/shafts through the window ?

Shafts?

It is important to remember the sun is some millions of miles away and rays from it are effectively parrallel

A point source close to the window the shadows will not be paralle but triangular and will not give the impression of sun.

Therefore one would want the fixture as far back as possible from the window.

On a balcony the fixture could be jibbed away from the building clearly an operation for a skilled gaffer.

Once the light is far back a 1.2 would probably be the thing.

Diffused?

Because of the physical limitations of the balcony you would want a fixture that has a wide beam angle, enabling placement without 'jibbing' the fixture.

My tests show that a big kino or two (or maybe 4 lightpanels in a square) will give the same illuminance as a small HMI like a Joker when fired through diffussion.

On that basis I feel you could broaden your search into the panels/skypanels/kino realm

I think I would go for a skypanel and a semi diffuse look which gives you more space to 'cheat' the light around the room on a shot by shot basis.

(or of course a huge light far away on a crane!)
 
I don't really understand what you're trying to achieve but be careful if you're pointing a tungsten or HMIs through windows for extended periods. If they're too close the glass can heat up and break.

There are heat shields you can get - the rental house should know about them.
 
I wouldn't use tungsten, as you're just throwing away 2/3rds of it's output by putting a full CTB on there. Whatever you do choose though, make sure it is secure on that balcony - it sounds like a recipe for disaster to me...
 
@morgan_moore
thanks for your considerations - indeed, that's an interesting point with the parallel sunbeam. Yes, i have to think about that! The balcony is on the 2nd floor and budget wise i am limited to light from that balcony. A 1.2HMI on a crane, a few meters away from the window is not possible. So i will think about a diffuse look...
@rob norton
-> Hotel room is in Germany, outside the window are typical german buildings. The film plays in Arizona (..), so we cannot show the outside, although the window will be in the frame from time to time. Therefore i plan to put some diffusion foil on the window with a jalousie. The whole film will be in that room, that's why i want to work with contrasts, highlights, shadows to make it more interesting. We will shoot 10 days and to be independent of the weather, we have to work with artificial light (unfortunately Germany is not like Arizona where you have sun most of the time...)
Budget is very low, it will be a sizzle reel for producers, it's all private money from the director. But all those limitations could give an interesting look - i thought about something like the hotel room scene in Apocalypse Now. Here are some good examples to see: http://cnelkurtz.blogspot.de/2011/08/apocalypse-now-el-argumento-i.html
 
I was thinking about the parrallel thing. Having used various hard lights outside windows.

It seems not to be a problem when using the light as a projector.. eg to put shadows on a far wall (ive shot light - branches - wall to put interesting shadows on a boring far wall)

Using as a sidelight it is probably marginal

And when used as a pure backlight (say 'prison cell with bars window and haze') it very becomes apparent.

Personally I think I would be looking for a mid point where there is some texture/shadows but avoiding hard beams.

--

You may also need to consider some black to keep the real sun undercontrol, and your shoot may be more varied if you provide plans for 'night' and also 'morning/evening' (same light set lower with straw)

S
 
My thoughts..... You can always scrim a 1.2K HMI and drop the level as needed. But you can't make a 575w any brighter if the output level is too low for the desired shot.
 
would you do it with ND foil or with a dimmer? I seldom work with HMI, so it may be a "stupid" question... of course, that's a good argument.
@morgan_moore: yes, i want to simulate the time of day with the position and color of the light. Morning deep, hard shadows, midday white, position high, afternoon little bit more orange, position deeper, evening ¼ - ½ CTB and some tungsten lights in the room, practicals. Night 1 CTB (?), hard shadows, high position and so on :)
 
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see-mann said:
would you do it with ND foil or with a dimmer? I seldom work with HMI, so it may be a "stupid" question... of course, that's a good argument.
Click to expand...

Some HMI's have a built-in dimming feature, others don't. For example my Kobold HMI's do.

If I were renting I would want a wire scrim set for the light included in the rental.
 
Hi there, just an update to my post:
we're in the middle of the shooting. Ok, i use a 575 hmi and it is more than bright enough to get the artificial sun. Unfortunately it's a very low budget thing, i would love to have more time on set for the lightning but i do my best... enclosed a first still - i just tried something in FCPX with Color Finale, a lut and some manual grading.
I guess i will try to get even more contrast the next shooting days. The room darker, some extra light just on the faces.. but how to do in a short time, no assistant available.. well, we will see. I guess i will have to create some "tunnel" lightning just for the faces.. i have a small LED and a bigger one...
hotelroom-first-still.jpg
 
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