Why would I use the “Film Emulation” feature?

From what I can tell, this setting alters the exposure and other parameters to simulate a specific film, however why is this any better than exporting a file format that supports high dynamic range (.exr or .hdr) and then editing in post?

It would seem that using a raw file format would give you much greater flexibility.

• Good question! I think the big thing is that you can edit it while looking in the viewport. So you could build your lighting off of it. – TARDIS Maker Dec 14 '15 at 2:22
• I've often wondered why we don't have a film emulation node in the compositor.. – gandalf3 Dec 14 '15 at 2:22
• Can the two be combined? – MicroMachine Feb 11 '17 at 1:41

There are a number of reasons, as @tardis-maker suggested in the other answer.

Here are a few more:

• Grading. As stated, it can be beneficial to be looking at a display referred view of your final output that covers any number of stops above middle range, properly mapped to the display referred viewing transform
• Proper desaturation. Rendering in a scene referred model extends primaries off to infinity. This means that they do not desaturate nor reach the display referred white in any way that is familiar nor correct. Consider the case of RGB 0.001 0.001 and 3.6. In this case, the only means to have blue blow out to diffuse white is via a forced intensity shift of 1000x to bring the other primaries up past the display referred ceiling of 1.0. Consider the following demonstration of primaries, that exacerbates the issue:

In both instances, the render of intensities is identical, but only in the latter does it resemble a "photorealistic" result because of the response of the display referred view transform. Notice how the pure primaries never desaturate / converge toward the hull established by the display referred primaries limitation, and instead carry on extending toward infinity, at their identical primaries chromaticity. While the above images show the flaws of a strictly 1D viewing transform, every colour is mangled in precisely the same way, to lessening degrees as a colour's luminance draws near achromatic. If you examine the achromatic cubes, it is clear how adjacent colours should converge to display referred white.

• Related to the above point, the default sRGB output view transform captures a mere two and a bit stops of light above middle grey from a Cycles render. This is entirely unnatural when compared to our learned response of examining photographic-like reproductions, which maps anywhere from six or more stops of light above middle grey to the display / output referred transform. The above images encode approximately six and a half stops of light to the display referred view, and as such, the scene properly reflects the lighting with respect to influence of bounces and other radiometric responses without cheats or hacks to bring the result into the display referred domain.

• Congruent with what @tardis-maker states above, all View transforms operate strictly on the one-way output of the viewing transform. That is, it is a means of viewing a baseline look without adversely impacting your scene referred internal values. It is entirely non-destructive in terms of evaluating an image as compared against a node chain, which corrupts and mangles values as the data flows along the chain.

It should be noted that the film emulations in Blender, although based off of solid data, are not implemented in a manner that makes them useful in the terms above. The breadth of why is beyond this post. Instead, they should be considered as nothing more than Instagram filters as a random creative dice roll.

Further viewing: https://youtu.be/vKtF2S7WEv0

Further reading: http://cinematiccolor.com http://www.oscars.org/aces/spotlight-aces-vfx Pay attention to where he discusses cheating values.

• – user1853 Feb 13 '16 at 7:06
• This is very interesting but also pretty technical. Sorry I didn't understand a good part of it. Can you clarify some things for me : • what intensity do you shift by 1000x ? • Does the second image have film emulation enabled ? If not, do you mean that with film emulation, you wouldn't need to do this intensity shift ? • does "view transform" mean the same thing as "color space conversion" ? • does the RRT mode (which apparently uses ACES) offer the same advantages ? – ChameleonScales Dec 9 '16 at 4:31
• @Gamnamno Many questions. Better served by another question. I can try to answer each if you ask it. – troy_s Dec 9 '16 at 5:00
• I found some answers myself. The only 2 left are too related to your answer to be independant questions : what intensity do you shift by 1000 and does the second image have film emulation enabled ? – ChameleonScales Dec 13 '16 at 23:14
• @Gamnamno Regarding 1000x, it relates to how a non desaturate transform would artificially desaturate; the lower values aren't converging on the display referred maximum, but rather relying on the ratios being cut. You can spot it typically in sRGB EOTF scenes on hot walls etc. where you see a very odd blue posterization band. The second image was the demo transform that evolved into the Filmic Blender set. Try them. – troy_s Dec 14 '16 at 1:10

The key advantage is that it works real-time in the view-port. Of course all color manipulation could be done once the file is saved.

However having this apply to previews while you're setting up your scene means you can setup a a rough grade, and then build the lighting off of that. This allows you to get a really good idea of where you need more detail in the render, and also gives you a more accurate representation of how your lighting will look once everything is color graded.

The look settings can also help give a rough grade without much work. There's also the plus that they're based off of real life film types.

There's also a log setting. According to the manual, this is intended more as a way to trouble shoot the image, but it can also be used to get a nice flat image for use when grading.

• Could you add a little more depth to your answer please? I think you have a good point. – VRM Dec 14 '15 at 2:28