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Matching brightness between shots (1 reply and 6 comments)

Andrew Pohribnyi
2 months ago
Andrew Pohribnyi 2 months ago

Hello Roger and other cinematographers,

I'm a beginner and I want to learn how to match brightness between shots in one scene (and maybe in film overall).

Should I light the scene for the closed aperture initially, so if I change (open) T-stop value I can compensate it by ND filters? Or not change the aperture value through the whole scene and only change lenses if I want another depth of field?

I would like to know the most practical and correct way to do it.

Sorry, if you already answered this, could't find it

Thanks 🙂

dmullenasc
2 months ago
dmullenasc 2 months ago

General practice is to light a scene to a certain f-stop and maintain that in coverage because you often aren't relighting from scratch, maybe the background lighting and the practical lamp levels stay the same, so even if you relit the face, you match the levels you had on the wider shots.

There are exceptions of course, you may want to have a certain special set-up to have a visible change in depth of field. If all you want is less depth of field, then the easiest thing would be keep the light levels the same but add an ND filter.  Sometimes if you knew that one shot in the scene had to be done at 96 fps, for example, you might light the scene for two extra stops and then use an ND.60 until you need to change from 24 fps to 96 fps.

Some cinematographers will try to shoot a whole movie at the same f-stop because they think it will make things more consistent, but as you know, the depth of field drops more in close-ups, etc. (It probably mattered more with older lens optics to try and use a consistent f-stop purely from a sharpness issue.)  But a shallow-focus look might be less distracting for a night scene than a day exterior scene; your eye expects to see a bit deeper in daytime.

Al Duffield
2 months ago

Now then David, as per usual, a comprehensive and clear answer.. it begs the question; when are you releasing a book?

Andrew C
2 months ago

Insightful answer David, thank you for sharing your knowledge!

In the video below Shane Hurlbut explains his process for depth of field and pulling NDs so he could stop the lens down for closeups.

I’m wondering if this is a common technique and if you find yourself stopping the lens down for closeups to get closer to the DOF of the wider shots. Or are there certain f stops you tend to shoot at for day exteriors for example. I’ve noticed a shallow depth of field trend where some DPs shoot everything wide open, but I think that deeper depth of field shots have their place too. Thoughts?

https://m.youtube.com/watch?v=O7WkJXRcxqk»

dmullenasc
2 months ago

Deep focus is a storytelling tool just like shallow focus so I'd hate for it to be tossed out as an option. The problem with very deep focus is that cinematography is about directing the eye and controlling information, and color is one more layer of information. In b&w movies, you only have tone and texture, so the challenge with deep focus is mainly compositional and staging, designing a shot that uses deep focus effectively. But add color to the mix and you have to control the frame so that the extra information isn't distracting. Easier to do in a period story where most elements are created, or a landscape story, but in a modern urban environment with a riot of advertising, etc. it can be hard to avoid visual ugliness, though it can be argued that shallow focus is a rather easy way in color to achieve "prettiness".

dmullenasc
2 months ago

I don't know if it is commonplace to light to a higher stop for interiors and then use ND filters, but it has become more common due to the rise of high ISO cameras. If you come from a film background and are used to lighting a set to f/2.8 at ISO 500, or even ISO 200, then you find yourself adding an ND when you are done because you're rating your camera above ISO 1000, let's say. But for people who started out with high ISO cameras, I don't know if they naturally tend to light sets to an f/4, let's say, and then can use NDs.
On my current show, we don't shoot close-ups on longer lenses, our close-up is often a waist-up single on a 30mm, so I have the opposite problem, the depth of field doesn't drop off enough in our singles to isolate the actor. So in a busy location like a diner, I might add an ND.30 on the singles to drop from an f/2.8 to an f/2.0 just so that the background is less distracting. But once I did a police drama for TV where we were out on the streets of Chicago and the director wanted to use a big 10:1 zoom and often our coverage ended up near 250mm, so on the tighter shots, I dropped some ND to increase depth of field so that the city would remain a presence around the police officer characters.

Baudelaire
2 months ago

I love this nitty gritty information, many thanks

Andrew Pohribnyi
1 month ago

Thanks a lot, very useful and helpful information! 🙂

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