[Mihai]

using the film speed you can use an aperature that will give you desired DOF while still maintaining the lighting conditions. Oh, and to add grain if you want.
J.

But in Maxwell, ie 3D, ie not in real life, we can control that via shutterspeed only correct? So the filmspeed only becomes relevant because of the motionblur. As for simulating different film grains, I don't think the Maxwell ISO setting does that now, or if it ever will, it's just there to control the amount of motionblur.

[lluistar]

Imagine you want to animate a fly out of the concert hall with a zillion lights. You want to control the DOF and the shutter speed should be optimal for the desired motion blur. What happen if you don't have enough light. You will have to update all the lights of the scene (a zillion) if you just change the ISO you spend only one second doing it and start rendering again.

More control. perfect

[Mihai]

Yes lluistar, that is what I said A filmspeed setting in Maxwell, ONLY makes sense if you use motionblur. Otherwise it is completely redundant.

Personally I would like an option to switch completely off motionblur in some cases where you wouldn't need it. Because right now we don't know if this film speed parameter in some cases produces more noisy images, or if in terms of noise doesn't change anything, you see what I mean? It's just one more thing to take under consideration, when if you're not in need of motionblur, it becomes completely pointless.

[lluistar]

The chance we get with Maxwell is to setup an scene simulating real lights. Like a 60Watt bulb correspond an emitter X big with X properties. (I guess Tom will make a comparative table one day So you can study how many lights you need in the simulated place. To get the right render you should not change the lights as this will ruin the simulation, you can change the ISO value as you would do with a real camera. Then you can judge your render and decide if you'll need more lights in the real scene.

As for the fact that in real life different ISO have different noise we'll have to test how it translate to Maxwell render.

[j_man]

oops! when I was describing different noise techniques, I was actually referring to real life chemical photography. I don't think there is much point having Maxwell add grain to an image but I still think film speed is relevant

[smeggy]

Nope, no point at all. I have to say the iso feature was a great help to me over the weekend as i was rendering differing lighting scenario's and tweaking the iso value was a really quick and painless way to adjust my exposures. I was able to get really quick noiseless renders done on a P4 1.7 in about 10 minutes at 800x600 using only 4 bounces and it looked as good as 12 bounces.

[Mihai]

Smeggy, so in your case, why didn't you just adjust your cameras shutterspeed?

[smeggy]

because then I'd have to adjust the aperture and fiddle around a lot and my head would explode..

[Mihai]

Why would you have to adjust the aperture, when the shutterspeed controls how much light falls on the film? More light, lower shutterspeed... Just repeating again that filmspeed settings in 3D only make sense when you have motionblur involved.....

[smeggy]

Ok, good point. Let's say this is a great convenience feature then, I don't have to budge from the render dialog to adjust anything before hitting the render button