Turning Sunny Day into Cloudy Dark Day

[Filip Vandueren]

And make sure you absolutely don’t clip any highlights.
When you start to darken your frame and you have a uniform grey area where a white specular highlight used to be…
dead giveaway, and very ugly

So I would choose a good inbetween kind of lighting: where you can brighten and warm for sunshine and dull down the colors and brightness for the cloudiness

[Delete]

it may be too late for this, but keep in mind that lighting for news anchors is really bright even at night; so you may want to duplicate the layer and mask out all but your actor. This will give you the freedom to color/level correct him separately from the background elements. Keeping a shallow depth of field for your camera during shooting will help maintain the illusion and give your transition a softer, less jarring effect. If you need more emphasis on the rain, shoot a similarly angled rain over black plate later and use high intensity lights to get focus on the rain, then comp it in on top additive; or use a particle generator.

[Darby Edelen]

It sounds like you’ll be getting most of the effect you want during production and only tweaking (Color ‘Correction’) in After Effects.

If this is the case then I would recommend taking reference footage. Shoot (or borrow: https://images.gooogle.com) a still photograph of a sunny day and one of a cloudy/overcast day. Then when you’re working in After Effects use these photographs as reference when you’re making your adjustments via Levels channel by channel. Workflow to follow:

Place your ‘Sunny Day’ reference footage/photograph and your source footage side by side in a large comp (2x as wide as you need it, probably 1440 x 480)

Apply a Levels effect to your source material

Hit alt-1 (opt-1) to view the red channel of your comp

Select the Red channel in the levels effect of your source material and tweak the settings until you see no distinguishable differences in the levels between your reference’s red channel and your source footage’s red channel.

Hit alt-2 (opt-2) to view the green channel of your comp

Select the Green channel in the levels effect… etc.

When you finish this process for each channel, the color in your source footage should very closely resemble the color in your reference photograph. From here the simplest thing to do would be set a keyframe for the histogram in the Levels effect, advance to where you want it to look cloudy and repeat the above procedure. Only this time use the ‘Cloudy Day’ photograph as your reference.

Sorry if this is a little more than you bargained for getting in a forum reply =) If I left anything out or you have any questions feel free to let me know.