IES - High Values?

[jujubee]

Is anyone else experiencing having to really raise the values of the VrayIES lights very high in order to see them?

For instance, I have a dusk scene that has a bunch of uplights - and I'm finding myself having to take them up to 50k power in order to be seen. I'm just wondering if that's normal or if I'm doing something wrong.

[vlado]

It would be best to adjust the camera exposure rather than changing the lights. In any case, when using photometric lights, you have to make sure that your scene is modeled in the correct scale for the chosen scene units.

Best regards,
Vlado

[jujubee]

I've had my scene modeled to US scale - system set to Imperial Feet and Inches. Also Lighting Units: American.

Usually, I set my cameras to around 8 f-Number and leave the rest default for exteriors (other than focal length.)

For interiors I usually set it 4.5 F-Number.

I also usually turn off the white balance and set it to neutral.

I think that's pretty standard still camera settings. Is there something else I'm missing? I also use baked-in LWF.

Is it because I have "Use 3dsmax Photometric Scale" checked on?

[jujubee]

Well it's working fine for interiors with Use 3dsmax Photometric Scale checked on.

I just had a client that wanted the exterior lit up during daylight/dusk settings for a portion of the building that was in the shadows and I had to boost the IES power substantially.

[plastic_]

I didn't test hard, and I'm not an expert of light energy values, but I also thought that the IES values are much too high to be physically correct, as I would expect it, in order to get close to what i'm used to in real world.
Like, when I tried to match 35W spots I had to use like 3000W to see anything.

Of course I model with real physical scale (that's a given with archviz), and I don't have problems with VraySky in combination with the VRayPhysicalCam. When the Sky is at 1.0 the camera values are about the same as I'm used to in real world, with a real camera.

But I also don't fully get the IES lights.

[Morne]

Jip. I also noticed that the deafult values inside an IES doesn't seems to be bright enough. Or should I say they are, but something is up with my exposure? (depends on how you look at it)

[HAWF]

I got the same problem here, sometimes I need to increase the power value to something like 80000 or even more. The model´s scale is correct too.

[jujubee]

Is everyone using the IES also burning in LWF (VrayFB)? Perhaps the lights "behave" properly with normal or other methods...

I also noticed that the deafult values inside an IES doesn't seems to be bright enough. Or should I say they are, but something is up with my exposure? (depends on how you look at it)

No, because if I set up a camera for let's say F8.0 on an outdoor shot, a Vray Sun/Sky will appear to expose properly, but any Vray IES that is in the shadows needs to get taken up to something ridiculous like 50,000+.

Personally (and I could be wrong), I think something is not getting translated properly between different rendering methods when it comes to VrayIES and LWF (not using the sRGB button.)

[vlado]

It might also depend on what IES files you are using; for many IES profiles, the prescribed power is different than what the web distribution actually contains.

Best regards,
Vlado

[pixela]

I have a question for you guys.

I have put some photometric lights (without ies files. just free circular ones) in my interior scene- adjusted intensity etc. And render is taking too much time.
So I thought I should use Vraylights instead.
Should I replace them with normal Vraylights as spheres, with same lumen value as in the photometric light? Is this how to make it?
Thanks a lot.

[voltron7]

Is everyone using the IES also burning in LWF (VrayFB)? Perhaps the lights "behave" properly with normal or other methods...

No, because if I set up a camera for let's say F8.0 on an outdoor shot, a Vray Sun/Sky will appear to expose properly, but any Vray IES that is in the shadows needs to get taken up to something ridiculous like 50,000+.

Personally (and I could be wrong), I think something is not getting translated properly between different rendering methods when it comes to VrayIES and LWF (not using the sRGB button.)

I have also noticed this with most all IES files I've tried.
If I expose the phys cam for exterior, ies lights need to be cranked up a LOT. If I render the vrayIES lights with no exposure and keep their default intensities, I get more proper (or at least expected) results...
not a big deal, but a little annoying, at least.