Photographer - Camera Exposure, White Balance, Autofocus and Physical Lights

This is great thanks. I am also exploring using the fStop controller manually to see how many stops adjusted it takes to middle grey which works pretty well.

With regard to the EV picker, is that delta related to a constant that I could compare to the scene referred values from the stack exchange post? Perhaps then a simple numerical output could be relative to change in stops.

I did test before answering you, but as I mentioned, I also find the “auto” mode a bit obscure. I rarely render portraits in production so I haven’t personally experienced the issues you are having. I’ll investigate, but it’s a Blender problem.

Exposure value is a base-2 logarithmic scale. You double or halve the brightness by doing a 1 stop change.

Let’s set color management to sRGB with a standard view transform and look “None”.
Using a pure white environment to light your scene, your grey card will return 18% grey in the scene referred image, pre-exposure. You can see it using the sampler in Blender on your rendered image (red rectangle at the bottom).

That value in red won’t change with exposure. The other value in the green rectangle will change with exposure, as this is the color managed, after exposure, display referred value of the pixel.

To clear up any confusion, it is not returning exactly 18% nor sRGB 0.5 because the swatch on a MacBeth chart isn’t exactly 18% nor 21.40%, but it’s close enough.

So changing the EV by 1 stop will divide the pixel brightness by 2. Notice the Exposure value changing from 9.42 to 10.42.

You may say “wait, 0.344 isn’t half of 0.478!”. Remember that this color is display referred, which means that it has been transformed by the sRGB gamma.

Changing the Display Device to None will show the linear values, and there, the grey value will properly be half of the actual pixel value (0.1944 / 2 = 0.0972):

To summarize:

  • EV 9.416 means no exposure adjustment over the scene-referred pre-exposure pixel value. 2^9.416 is a 683 multiplier in order to (very inaccurately, but this seems to be an industry standard at the moment) convert radiometric energy to photometric.
  • Exposure is applied during color management, and won’t affect the RAW data of your EXR (unless you check “Apply at Compositing”).
  • +1 stop will halve the pixel brightness in linear space.
  • -1 stop will double the pixel brightness in linear space.
  • In linear space, you can calculate the value of your midgrey at any exposure value, provided that you know the brightness of your environment.
  • To calculate the display-referred value of your pixel after an exposure change, you need to know the math behind the View Transform.

Sorry if I’m talking about things you already know, but it may be of interest for other people.

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Ok,I want to make connections in the virtual and real worlds, so it’s important to me. Please let me know if you have any definite conclusions in future. thank you.

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Please no apologies necessary this is exactly what I was hoping for. Thank you so much

Hello Fabien. Is it possible to add subcategory (subfolders) for HDRi category like the ones in Simple assets?

Similarly to Simple Asset Manager, if you put your HDRI images into subfolders, it will create sub-categories automatically.

For some reason it’s not. At least in 2.93.5 ver. But, yes I’ve saw that it have created the thumbnails in subfolders. I need to check it ones again in different versions of Blender or maybe try to reinstall the addon

I’ve check it in defferent ways. And wil try to explain my current confusion better.
In Simple Asset we can choose the subfolder manualy.


While in Photographer it visually and automatically represent the subfolder without control over choosing.
.
For example - My current folder switch to Exterior. That folder is contain few subfolders (Winter\Night\Rain). Currently addon allow me to choose between them. But! This folder is locating in HDRi folder, which was by default few minutes ago. And if I switch back to it again (in addon preferences) it wouldn’t be able to let me choose the subfolders (Winter\Night\Rain), basically only Exterior folder. It will only show the exact HDRi maps that locating only in that folder (but not subfolder inside it).
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I hope I explained it better this time. Thanks for the quick reply btw =)

There is a limitation of 1 subfolder level at the moment. It’s on my list to support more, sorry about the confusion.

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No problem. Will looking forward =)

Coming soon
dollyzoom_low

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I am so excited for this!

@chafouin this is F* awesome!