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...meaning, can anyone?

There's no shutter speed, and I assume f-stop, ISO, and 'exposure' are all just accumulated into the same multiplier, or very similar.

I wonder about:

Why is the Linear/Off response-curve so much darker than any profile - I'd guess that any of those curves would create their effect by reduction, not amplification.

Why are material preview scenes so bright? If I adjust exposure for them then my scene is underexposed by 4 stops at least, even in daylight.

Is there any reason for the daylight environment to have a power > 1.0 ? (Assuming one isn't trying to render a scene on another planet)

Since the material preview scene was made by OR-team, I assume they know The Right Way. My exposure is usually something like Exp=1, ISO=200, f=2.8 -- which makes the material-preview scene blown out completely -- I assume they would not intend for users to adjust their camera when flipping between a scene and a preview, or how useful would they be.


And if each of those factors are just multiplied together, then what reason is there to have all three? Maybe I should just set ISO=1, f=1(or whatever gets x1.0 as it's inverse) and only adjust 'exposure.'

Discuss.

benjamin9999 wrote: Why are material preview scenes so bright? If I adjust exposure for them then my scene is underexposed by 4 stops at least, even in daylight.

As you said, this is especially annoying if you are setting your materials up on the ball and need to jump back & forth between the ball & actual scene. The reason its brighter is that the preview scene contains a fixed emitter, which lighting gets added to the environment lighting set by the user. Maybe we should have an option to toggle off this emitter. Anyway, I got accustomed to not use the ball at all, and just set the materials on the actual model.

About the tonemapping: I never touch ISO or fstop, just exposure, cause it seems to me that those parameters do exactly the same thing. But I don't have much photographic background, so this discrepancies with real photo camera settings never really bothered me.

this is especially annoying if you are setting your materials up on the ball and need to jump back & forth between the ball & actual scene.

- For my own, I never use the ball as well. I prefer adjusting the material directly in the real scene.

- In an actual camera, the F-stop value has an effect on the depth of field. In Octane, it hasn't. Curiously, this parameter is adjusted by the Aperture slider... which has no effect on the brightness ! I already asked the reason why a long time a go, and I have to say that I don't remember the answer !

These two parameters must be adjusted separately to fake the proper setting. It may allow more flexibility/control from an artistic point of view, but doesn't match the behaviour of an actual hardware camera.

Well, I've been experimenting some more.

I built my room piece by piece, roof last...

Trying to imagine what the space would look like (given the same exposure settings in a camera) when the roof was removed in the summer - and I decided that the Daylight Environment must not be calibrated to 1.0 ? Or maybe it isn't even expected to be a physical reference in that way.

If I push the d.env power up to 30-40 then I feel like I get the intensity I'd expect in real life.

Put another way:
A small 40w tungsten bulb, uplighting an interior wall would be barely noticeable in daylight, but this isn't the case until d.env is at those levels.

I originally assumed that 1.0 was a calibrated value of some kind.

I thought to mess with it after loading my scene in the Thea Render demo and noticed right away that sunlight entering the space was far more intense than in Octane.

>Aperture in Octane is f-stop/DOF.
Something that has always seemed to me quite odd or incorrect in the way its done.
I think this should be changed to be logical for those who are familiar with cameras.
The aperture and f-stop should be realistically linked/combined.
If people don't want to balance/trade off playing with ISO/shutter etc as they would with a real camera then it should be simplified ie f-stop should be the DOF control and the other stuff removed.
If people do want to play photographer then they should add shutter and make everything work as expected.
IMHO

It may be coincidence, but....

With the Day-Env power @ 100.0, it seems to me that everything works in a reasonable way.

For example - The Sunny-16 Rule "works" @ f/16, ISO 100, Exp=1.0 ....

...and the difference between interior & exterior (and lighting) all seems much more like I would expect.


Maybe it's all been handled very well by the developers and it's just a documentation failure. (although, the default Day-Env is initialized at 1.0... perhaps there is a pwr/=100.0f; that needs to be removed somewhere)