Quote - Here is the tricky part.

What I see towards the end of that video is a scene with a time of 6:30pm.

Then when he applies gamma correction I see a 8:30am in the morning on a slightly foggy day.

If you use gamma correction to portray "daytime" your scene, FINE.

But instead of using gamma correction you could of just done the lighting correctly in the first place which will give better results since you're shooting for a realistic lighting position instead of a bandaid/quick fix aka Gamma correction.

That's my opinion. 

Instead of applying gamma correction to the end scene he should of just increased the lighting right?

Every rendering has it's own demands. Bright lighting, deep shadows, the artist makes the final decisions. It's true, you could correct the lights and not worry with Gamma. Very possible that method would have good results. Here's the important feature of correcting the Gamma at the "end" as mentioned in the Video. When you render to HDR or EXR you can then take the 32-bit image into PhotoshopCS4, 5, or 6 and make some incredible adjustments using the Gamma setting. I urge everyone to try rendering an image in either HDR or EXR and then take it into Photoshop or any software that supports these two formats. I use Photoshop CS5 and have upgraded the plugin to the new "OpenEXRalpha" version available free from Adobe. You can take a rendering that has given you some trouble getting the right FireFly settings and easily tweak it to look perfect. Also there are some amazing special effects available but for now we're focusing on Gamma.

Here I have loaded an .EXR file rendering into Photoshop CS5.

**You can adjust Gamma on jpg's, png's, etc but you'll get the best results using HDR or EXR as they are high quality industry standard filetypes.
**

Follow the menu and open the HDR Toning Window.

 

Now you can begin Gamma Correction on your rendering. When you "Save" your final image choose which filetype you want and now you have a corrected Gamma image.

Note: To keep your image in 32-bit format you will have to use the "Save as" feature and keep it either as an HDR or EXR. If you use "SAVE" (even though it's already in 32-bits) you will loose the 32-bits.

 

Enjoy!

-TOM-