footcandle calculation?

[Jeff B]

Feeling kinda dumb... I thought I remembered the illustrious michaelk showing me a way to chart foot-candles over an area being lit - sort of like a topo map -but I can't seem to find hide nor hair of such a thing in Help or on this Forum... am I imaging things? (again?)

Thanks

[rDesign]

I think you're imagining things.

I believe you're looking for the Photometric grid tool in Spotlight, but from what I've read this tool has limited real-world calculation usage and I wouldn't rely on its foot-candle calculations. I think it's meant to be used only as a rough guideline of lighting levels for theatrical productions.

Some old threads on this long-requested wish list item:

ies distribution and photogrid

Calculation of Lighting Levels?

Can the Photogrid work with Custom Lights?

Quote from michalek in one of those threads:

You are correct. The photo grid tool works w/ spotlight instruments ONLY.

It calculates light from each instrument using the beam and field angles and inverse square law along the focus vector. (and an arccosine function for the falloff.)

It is a calculated value. If you put a brick wall between the light and the focus point, the foot candle value remains unchanged.

The light object w/ the ies data will render correctly, but the light level can't be calculated in VW.

This has been a frequent wish list item.

michaelk

[Jeff B]

Thanks much Tim. Thanks too for realizing I meant "imagining" where I wrote "imaging..." Like we don't spend enough time 'imaging' stuff...

The photometric grid is what I remembered and was looking for, I'm feeling even more dumb now I know it was a simple tool in Spotlight. That said, you might think a Help search on "footcandle calculation" might bring up said tool, but it didn't seem to for me anyway.

At the moment thankfully I am using Spotlight fixtures so I will play with it and see if it serves my needs. It does seem that this would be a great feature to add for other kinds of light fixtures (and ambient/daylight too) but given that on one of the threads you highlighted for me, VW was talking about "looking into it" in what was it, '07 or '08? it doesn't seem like it's on any kind of fast track.

Thanks again.

[rDesign]

You're welcome. It wasn't my intent to correct your use of 'imaging': I misread it as 'imagining'.

TIP ON SEARCHING: Until Nemetschek replaces this User Forum's search (which JimW has said is happening - just not soon enough), the best way to have success searching is to use the Advanced Search, put your search term in quotations, and be sure to change the Date Range to something other than 'Newer than 1 Week'.

[michaelk]

Feeling kinda dumb... I thought I remembered the illustrious michaelk showing me a way to chart foot-candles over an area being lit - sort of like a topo map -but I can't seem to find hide nor hair of such a thing in Help or on this Forum... am I imaging things? (again?)

Thanks

I remember that day very well. It was in your dining room many many years ago!

mk