How to extend sunset or dusk time (5 replies and 8 comments)
Hello Master Roger,
I'm going to shoot a short film project with a tight budget, the scene will be 95% in a convenience store. One problem I know that I will encounter is the time of the day because the dusk time fades away so fast. Most of the frames will be the time of the day will be visible (Like from the stills from the attached file) How would I be able to keep the look consistent?
As long as you have no one entering and exiting, and you have a cloudy sky, which might be a big ask, you might consider using a heavy ND on all the windows and shoot during the day. That might be expensive but nothing like shooting for an hour a day over what might be weeks. You can get hard gel NDs, which would be easy to change. For instance, a .6 and a 1.2 ND hard gel would give you three densities to play with, even more if you have enough of each. Of course, the sheer size of the windows involved could make things expensive but, if you know the camera angles, you could use black drapes for those areas that you don't see in camera. I am presuming the overhead lighting is going to be your main source and that no one enters and exits. If they do you might think about shooting that one section at the 'right' time of day but matching it in would be another challenge.
Thank you so much Roger!
Can`t you just put ND on the Lens, instead of coating the Windows with it? Sorry if that`s a stupid Question...
If you do that you will ND the light inside the store, which would, presumably a dusk, be overhead florescent fixtures. In essence, by adding ND in front of the lens you are not affecting the outside relative to the inside.
It brings up an interesting potential solution though. Using ND on the lens and then rigging extra fluorescent lights above the actors. Could this be a quick and cheaper alternative Roger?
You'd need a bigger light than extra fluorescents like an HMI bounce -- so what's more expensive, ND gel on the windows and practicals inside, or ND filter on the lens but a 4K HMI ceiling bounce inside?
Robert has re-set your wrench symbol, you should hopefully be able to edit posts.
Otherwise, you may have to change your password.
Thanks, it works!
Remember, you're trying to make daylight look like twilight, meaning you're trying to make the light levels inside brighter than outside, so if it is sunny outside the windows, you'd need to make the interior brighter than sunlight inside if you were going to add ND to the lens rather than the windows.
Yes good point David. I had forgotten that it was meant to mimic twilight.
I have a question David regarding to what you said that in twilight we try to make the interior brighter than the exterior. For hoy many stops do you recommend that the lit side of the face should be brighter than the exterior to recreate twilight?
There's no rule. The issue is how you would light and expose the interior IF it were really dusk outside. You could have a dusk interior with NO interior practical lighting on and everyone is silhouette against the windows, you could have people standing under a fluorescent practical, or they might not be under it but someone in the background is, etc. What do you want it to look like? Now if it is a store and they are standing under a practical overhead, perhaps their faces are at normal exposure but the "dusk" windows in the background are one and a half-stops or two-stops underexposed at twilight (depends on whether it is early or late twilight, etc.) Just depends on what look you want.
I just went outside where it is lightly overcast today and my meter said (at 24 fps / 180 degree shutter) that it was an f/5.6 at 100 ASA. So at 800 ASA on an Alexa, it would be f/16 outside. If you wanted to shoot at f/2.8, you'd need an ND 1.5 (5-stops). So if you wanted it to be 2-stops underexposed for a deep twilight look, that would require an ND 2.1 (7-stops). Now imagine trying to light an interior in daytime with an ND2.1 on the lens so that the window view was 2-stops underexposed. Hence the problem with faking dusk or moonlight in daytime inside with windows. Even if you put ND.9 gel on the windows, you'd still be using a lot of light inside, and since a darkened window becomes like a mirror, your gel better be very flat and neat, ideally you'd use acrylic sheets. The other problem is that ND gel looks heavier when viewed at a raking angle rather than flat-on (because at an angle, you are looking through more gel). So it always becomes a mix of techniques to pull off day-for-dusk inside, and you have to be flexible in case the light level outside changes. IF you are lucky, it's heavily overcast on that day so the light level out the window is pretty consistent for most of the day other than early morning and late afternoon.