Cinematography Mailing List - CML
    advanced

Infrared Black and White

 

I am using Kodak's HIE infrared black and white stock on an upcoming shoot.

Does anyone have any experience exposing this type of film with anything besides sunlight?

250 watt IR lamps are available, but they burn very hot- I would need to use a bank of them to get a decent exposure with this very slow (EI 10 to 25) stock. I'm afraid the actors will get scorched.

Does anyone know of instruments that emit LOTS of "cool" IR light?

Any other tips, caveats or war-stories on working with infrared stocks would be appreciated.

Thanks in advance!

Isaac Mathes DP NYC


>Does anyone know of instruments that emit LOTS of "cool" IR light?

Even tungsten lights emit IR, you can filter out the visible wavelengths.

Sam Wells


> Does anyone know of instruments that emit LOTS of "cool" IR light?

Hmmm... I was looking at the Litepanels website last night after reading some comments on CML-lighting and noticed this:

http://www.litepanels.com/IR.html

Technical description was pretty vague, nowhere does it mention that it requires IR film or modified video cameras to operate, so I'm assuming that the wavelength is one that is "visible" to ordinary video cameras / film stocks ??

George Hupka
Director/DP
Downstream Pictures
Saskatoon, Canada


> Even tungsten lights emit IR, you can filter out the visible wavelengths.

What kind of gels would you use on your instruments and/or camera filters?

Marty Hamrick
Shooter
Jax.,Fl.


>What kind of gels would you use on your instruments and/or camera >filters?

If it were me, I'd use a #25 red filter on the camera. This gives you a reasonably strong IR effect, while still letting through enough red light for you to be able to see through a reflex finder. That additional red light gives you a considerable advantage in exposure too.

You can get progressively stronger IR effects with a #29 and #70 deep red, at the expense of needing to open the lens up. It is _very_ hard to see through the finder with these.

You can get still stronger effects with #87, #88A, and #87C filters, with still wider apertures and the total inability to use a reflex finder.

I don't see any reason to gel the instruments unless they are interfering with the talent by being uncomfortably bright.

The bible for all of this stuff is Kodak Publication M-28, "Applied Infrared Photography." It used to be available for free back in the seventies from Dept. 412L, but it's probably going to cost a few bucks these days. It gives a bunch of fudge factors to allow you to use a standard meter to estimate your exposure given the colour temperature and the filter.

Scott Dorsey
Kludge Audio
Williamsburg VA.


Many thanks. What would you recommend as a start point for metering? What's an approximate ASA rating to start with?

Marty Hamrick
Shooter
Jax.,Fl


>Does anyone know of instruments that emit LOTS of "cool" IR light?

Panasonic makes a video camera with real infrared sensitivity, DVC 30 that they have aimed at the law enforcement market..

They have some infrared battery powered lights to work with the camera, I’ve seen them and they are led based. Search the Panasonic site for DVC 30 accessories and you might find them.

Mark Smith
DP NYC


>The bible for all of this stuff is Kodak Publication M-28, "Applied Infrared >Photography."

Top Tip. A quick bit of Goggling(sp?) came up with the ISBN :
0-879-850-051 Kodak Technical Publication # M-27/28-H

This page has a pretty comprehensive list of publications on IR photography (inc' ISBNs) :

http://www.atsf.co.uk/ilight/ilightbooks.html

Tom Townend,
Cinematographer/London.


Why even? Tungsten light's curve maximum at IR, its giving IR more than visible light. You are right, you can use IR filter like Tiffen 87 which is cutting all visible radiation.

I couldn’t understand what he meant with "cool" IR light.

All CCD's (CMOS too) sensors are sensibility to IR light. Silicons up to 1100nm, germanium made up to 1500nm. All digital video and photo cameras coming with IR CUTOFF filters which is cutting IR light 700<
Also light meters have sensitivity to IR lights because of this. (if they aren’t filtered with IRCUTOFF or diffusion layer which is used for reflected light meters)

Sony uses this way long time ago, this lights are not really gives IR waves. They are small diodes which is filtered with plastic IR filter.

When you using NIGHTMODE or NIGHTSHOT; ircutoff filter goes out and CCD becoming to see IR radiation usually up to 1100nm and much more faster than negatives. Kodak HIE negative sensitivity 900nm, and fast as videos but it is very high grainy (I think that’s why it is fast)

Biggest difference between sensors and negative that negative have two curves on blue wavelengths because of AgBr, and 700< ... AgBr sensibility is 2 times more than IR sensibilizators sensitivity. So red filter is enough to cut all visible lights.

Sensors starting from 400 to 1100, so red filter will not enough to see clean IR light. You have to use 87a or something like that which is cutting all(!) visible light.

Yusuf Aslanyurek
Student Cinematographer
All Russian State institute of Cinematography (VGIK)


I have a couple infrared illuminators that I got at an electronics place.

These are LED units whose original purpose is to accompany security cameras, allowing for observation of areas in complete darkness. They're similar technology to the LED LitePanel IR, but they use mains power with a built in transformer. Those 250w tungsten versions, or 'heat lamps', are really just that - heat lamps. There's lots of visible light coming from them too.

I'm not sure how to meter for pure infrared light when shooting film, as there is almost no visible light from an IR illuminator. Video is easy of course - you can judge from the monitor. I'd say a test would be in order (a perfect opportunity for still film), as IR photography can be tricky.

Instead of looking for an IR light meter (which would be great - I'd love to know where to find one), I might design a test of multiple still exposures, and place the IR illuminators at several measured physical distances from the test subject, and determine the ideal distance for a specific t-stop. That way, since the only way to vary the illuminators output is via distance, I'd be sure of my exposure on the shoot day by placing the units at those specific distances culled from the test results. You could also bring along a video camera that has IR sensitivity (aka NightShot if you're using Sony) in order to preview the scene, or even better, modify the video tap camera, removing the IR cut filter from it, and replacing it with an IR pass filter. Just some ideas...

Make sure your gaffer brings a measuring tape....

I'm sure there's more in the archives.

Ted Hayash
Los Angeles, CA


Buy Asashi Pentax V about 300$
Put Tiffen 87a filter and measure light.
Will not be exactly correct but it will work

Yusuf Aslanyurek
Student Cinematographer
All Russian State institute of Cinematography (VGIK)


I haven't been following this thread too closely, but IR meters do exist.

One specifically designed for B&W IR is available from David Romano.

http://www.davidromano.com

I believe list member Anders Uhl may handle this meter or something similar (Quantum?).

Also, I'm told that there is a great deal of IR info on still photo sites.

Brian Heller
IA 600 DP


>I'd say a test would be in order (a perfect opportunity for still film)

I have a roll of HIE 35mm B&W negative still film in my fridge and will gladly send it to the original poster to test(but please share your results!)

The Kodak literature lists a few filters to experiment with: 25, 29, 89B, 87, 87C, and no filter.

Exact speed recommendations are not possible because the ratio of infrared to visible radiation is variable and because exposure meters are calibrated only for visible radiation. So do some bracketing and find out the best exposure for your conditions.

Daylight exposures, distant scenes, w/ 25 filter, Kodak recommends 1/125 sec at f/11, and nearby scenes 1/30 sec at f/11 with no filters, Distant scenes, 1/125 sec at f/16

Also recommended is shooting at the smallest possible lens to deal with focusing-a basis for trial is the extension of the lens by 0.0025% of its focal length beyond the correct focusing for visible light.

EX: 200 mm lens would require a 0.50mm extension

There are also pressure plate issues w/ motion picture cameras as I recall from previous discussions. Also, I believe led perf counters in some cameras (435, 535?) will be a problem and you should use older cameras

Have fun and please post your results...

Best regards,

John Babl
DP
Miami


Brian Heller wrote:

>I believe list member Anders Uhl may handle this meter or something >similar

Yep, I sell David's True IR meter.

http://www.thedopshop.com/item.cfm?itemid=256

Anders Uhl
Cinematographer, NY
The DoP Shop
http://www.thedopshop.com


>Does anyone know of instruments that emit LOTS of "cool" IR light?

Infra Red is heat, I doubt if there is such a thing as "cool" IR light.

Behzad Olia-Rosenkranz
European based Cameraman / Assistant
Luzern


>Infra Red is heat, I doubt if there is such a thing as "cool" IR light.

Actually heat (radiated heat, not conducted or convected heat) is actinic IR light, which is very long wavelength. The IR that film is sensitive to is non-actinic IR, which is much closer to the visible range. This is why you can't detect heat leakage through a building, for instance, with IR film.

There is a very nice discussion of this in the Kodak pamphlet referenced earlier. There's also a photo taken with two steam irons as illumination and a couple-hour long exposure on High Speed Infrared.

Scott Dorsey


>Does anyone know of instruments that emit LOTS of "cool" IR light? >Infra Red is heat, I doubt if there is such a thing as "cool" IR light.

Actually infrared is not in itself heat anymore than red light is heat. It's important to distinguish "near infrared light" (the kind we use in photography) from the longer waves of " far infrared light" both of which are created in abundance by our sun. If all infrared light was heat, you'd burn your hand when changing the remote on your TV set which uses a near infrared LED to send a pulsation to your TV. Actually, NIR light is a tiny portion of the infrared spectrum which in as a whole is larger than the entire spectrum of visible light and ultraviolet spectrum combined. Interestingly enough, IR light contains the least amount of energy per photon than any part of the electromagnetic spectrum. But it's the far infrared energy that we feel as heat, not the larger molecules of near infrared light.

>This is why you can't detect heat leakage through a building, for >instance, with IR film.

You can if the IR energy is reflected. Hence why leaves make for great IR photography but not the limbs of the trees. After many years of IR photography, I learned that good IR is finding material that reflects IR energy and balancing it with material that doesn't. Most folks think it has something to do with heat.

Disclaimer : My opinions, thoughts, and beliefs are my own and may not reflect yours. The use of the pronouns "you, "some", and "many" to name a few are generalizations and without a proper name attached to them are not references to anyone reading my posts.

Walter Graff
BlueSky Media, Inc.
www.bluesky-web.com


>...Actually heat (radiated heat, not conducted or convected heat) is >actinic IR light, which is very long wavelength. The IR that film is >sensitive to is non-actinic IR, which is much closer to the visible range...

That's curious, in view of the fact that "actinic" means capable of producing photochemical results.

Wade K. Ramsey, DP
Dept. of Cinema & Video Production
Bob Jones University
Greenville, SC 29614



Copyright © CML. All rights reserved.