View Full Version : Lighting and Camera question(s)

01-01-2007, 03:32 PM
I have a multitude of questions regarding light, camera, and how to match "real world gear" to "digital world gear" aside from physical xyz location and number of light instruments or camera lenses.

In the "real world":
On the set, I used 200watt fresnel "key" lights, 1000-2000watt scoop "fill or soft" lights, and a few 650watt flood "hair or rim" lights. The lighting adjustment(s) were done using spun glass for diffusion, flags for broader area style light, and rosco gels for temperature/mood adjustment.

In the "digital world":
I'm not sure if I completely understand the relationship between a digital light's settings/measurements of 1-100%, and how a light on a real world set can be measured after taking into account wattage, temperature adjustment and/or diffusion. If I have readings of incident and reflective light from the "real world" shoot, how can I translate that data into how I should set the power of my "digital lights"?

On camera things, having the ability to select lenses is great. But, when you render, does Lightwave also need data input on shutter speed and film speed? If you shoot digital video and have all the settings of gain, f stop, shutter speed, and frame rate, will they translate accurately when you take into account the light readings, or is there a chart somewhere on equivalents to help in the translation?

And now I must stop typing, as my brains are beginning to ooze out of my ear, and I can't find the cork...

01-01-2007, 05:25 PM
Something to look at for lights:
When you have your lights set up for your studio set, use a chrome ball or super wide fisheye to take several stills at various f-stops. Use HDR software to create an HDR image, use this image alongside radiosity to recreate the original environment within LW. This isn't foolproof, you'll still have to tweak your radiosity levels and add additional lights if neccessary.

Do a search on google or these forums for HDR or HDR software.

On the camera front, the current version of LW (9.0) only allows for focal length and fstops (fstops are only of use for DOF), unless you build your own camera lens model, it doesn't cater for 'out of the box' lens types etc. Unfortunately, 9.2's in beta and I can't talk about it's features here. Have a look at the last Siggraph footage from Newtek to see some vids about what I can't tell you about. :D

A quick tip here would be if you're not using 9's nodal then buy FPrime (fast radiosity previewer) from Worley labs, it'll make your job a heck of a lot easier.

To be fair, I think over the years SFX companies try to get their lighting environment as close as possible within the 3D scene, then the final render is colour matched and noise matched etc within a compositing app. Unless there's some amazing new plugin out there I'm unaware of it's all a case of making your best educated guess then tweak tweak tweak.

Best of luck :)

01-01-2007, 05:55 PM
Thanks very much for the tips!