To try to capture the new “candle” effect, I snapped a few photos of my iPhone 4. The picture qualities aren’t phenomenal because I used an iPhone 3GS but I think you can see the difference. The screen on the left shows Flux enabled.
Because the iPhone 3GS camera was attempting to adjust the lighting, I also took these shots of the Flux settings. Note that the photo with the applied “Candle” effect had to be snapped as Flux was being enabled, so that the camera would not adjust its lighting. That’s the reason for the discoloration at the top of the screen.
I’m a big fan of this tool. It should ship with iOS itself.