Do you have a favorite f stop?

[Michael Wisniewski]

Just wondering because I'm finding myself always lighting for f5.6. I don't know why, but I like the look. Anyone else doing something similar?

[Robin Davies-Rollinson]

The lower the better for me, to take advantage of ambient lighting - to which I can always add my own accents.
For example, if I have a location such as a bar, then I don't want to lose the prac lights on optics or beer pumps as well as the little lights in the booths - but I can then add specific areas of light for the actors.

[Brian Drysdale]

Shooting 2/3" video interiors with a zoom it tends to be around f2.8, the lenses tend to be performing better, but you don't have a huge DOF.

On exteriors it really depends on the subject and the type of production.

[Daniel Epstein]

Maybe I missed something but no mention of content, format, camera or lens in the question makes it pretty vague.
Brian's response is pretty good as he provides some context. Robin is also on a good track.
Personally I try to light the scene so the look is what I want which sometimes is shallow DOF and sometimes not. Knowing how your gear performs in those situations is also a guide.

[Stas Bobkov]

F5.6 indoor will likely make backdrops too dark no matter what camera is used, unless it's a very small room. Why 5.6?

[Brian Drysdale]

How dark the background looks will depend the balance of the lighting levels between the foreground and background rather than the f stop being used.

[Gary Nattrass]

F2.8 for video and F5.6 for stills!

But it all depends on the camera and lens being used.

[Allan Black]

With vid cams, generally at either end is for when you're in trouble, I try and stay around the middle.

Cheers.

[Stas Bobkov]

Originally Posted by Brian Drysdale

How dark the background looks will depend the balance of the lighting levels between the foreground and background rather than the f stop being used.

True. Even lighting is what we all wish for but in reality - gyms, ballrooms, swiming pools, theaters, etc.. - only few square feet around the subject can be properly lit, the rest, if you shoot at F5.6 with an average 1/3" camera will likely turn pich black.

[Garrett Low]

Originally Posted by Michael Wisniewski

Just wondering because I'm finding myself always lighting for f5.6. I don't know why, but I like the look. Anyone else doing something similar?

My favorite is the one that gives me the look I the scene calls for. Sometimes I want to maximize my DOF so that it gives a big wide open feel. Everything is open to you as far as your eye can see. So I close the lens as far down as I can which for my lens is around f8. If I need a shallower DOF I'll open it up. It really depends. On what the shot calls for and what your lens' sweet spot is.

Originally Posted by Stas Bobkov

True. Even lighting is what we all wish for but in reality - gyms, ballrooms, swiming pools, theaters, etc.. - only few square feet around the subject can be properly lit, the rest, if you shoot at F5.6 with an average 1/3" camera will likely turn pich black.

Actually Stas, in most cases I detest even lighting. Even lighting equates to flat shots. Shadows and differences in contrast are what brings out expression and draws our attention to the critical elements in a shot. If I'm shooting a scene where I want to portray a sterile lifeless feel, I'd try for even white light, but in most other case give me focused controlled lighting.

-Garrett

[Josh Bass]

One thing to consider that I haven't really seen mentioned here is something I learned elsewhere: if indoors, when your stop is more open, you're getting more of the ambient light already in the room from wherever (other rooms' lights, windows, bounce from your own lights) polluting the background, while, when more stopped down you're going to increasingly have to specifically light where you want things lit.

[Robin Davies-Rollinson]

Agreed, but my point earlier was that if you were in, say,a bar, then the ambient light, far from "polluting" the shot, can enhance it - as long as you control the scene by adding light on the talent for example. You can usually turn off or mask lights you don't need.
Anyway, I've been a lighting cameraman long enough to know that every situation is different and that one has to be reactive on the day...

[Josh Bass]

Perhaps polluting was not the right word. I simply meant "adding to" or "making itself known." Sometimes it's a good thing, sometimes bad.

Sometimes you simply want to supplement the environment lighting (wide open fstop), sometimes you want to overpower it (closed down fstop).

[Charles Papert]

There are situations where you may need to light to a higher level for one reason or another which has nothing to do with the desired f-stop or t-stop. Say you were planning on overcranking a section of a scene; you would need to light to the appropriate level for that situation. If you shoot other portions at 24p, you could stop down to compensate--but what if you wanted to preserve the same stop to maintain a similar look? You might add ND, which seems counterintuitive for an interior, but this would achieve the desired effect. This scenario is applicable to high speed shooting, short shutter (those two factors are generally linked when shooting video), macro tubes, snorkels or other specialty lenses etc.

On "No Ordinary Family" I had to light a storage closet for a sequence that included Phantom high speed shots, up to 360 fps. We rigged 5K fresnels and 1K pars all over the ceiling. It was brighter than hell in there. On camera it looked appropriately moody. I had to use something like an ND 1.2 on the Alexa when we went back to 24p.

[Brian Drysdale]

Originally Posted by Stas Bobkov

True. Even lighting is what we all wish for but in reality - gyms, ballrooms, swiming pools, theaters, etc.. - only few square feet around the subject can be properly lit, the rest, if you shoot at F5.6 with an average 1/3" camera will likely turn pich black.

In that situation the best way balance your foreground lighting level to the match background light levels as required (you may not want a total match) using ND, scrim or lower wattage lights.

I wouldn't categorise ambient or natural light as polluting, pretty often it can be wonderful. It really depend on what's there and what you stylistically want. I once worked with a director who wanted black walls (or at the most dark grey), even in your average white walled office, so that's the effect we lit for.