Settings for Very Low Light Conditions

[Tim Davison]

Evening all. I typically shoot in very low light conditions (i.e. night clubs/music venues) I am currently using a Canon 50mm 1.4 and a Canon 24-70mm 2.8 L Series. My question relates to what settings are best to use to maximise the footage.

Typically I would have:

1. aperture as open as possible to get as much light in as possible (i.e. 1.4 or 2.8)
2. shutter speed as a multiple of the frame rate (I usually shoot at 60p so a shutter speed of a multiple of 1/60th usually)
3. an ISO of as low as possible but, especially when using the 24-70mm, I'm finding the ISO is right up towards the top of the scale and I'm conscious that I am losing quality as a result.

Am I missing something and would you do anything differently?

In addition, I also have a Sony HVL-20DW2 20W Battery Operated Halogen Light (previously used on my Sony FX1) which I could attach to the top of the 7d to create additional light.

Many thanks

Tim

[Perrone Ford]

Things that would improve your situation:

1. Larger sensor (5D would be more suitable).
2. Faster glass. F1.2 obviously would help, especially for the zoom lens.
3. Shooting 24p
4. Shooting 1/24 shutter if the blur isn't too bad
5. Shooting on ISO multiples of 320 (640, 1280)

But you can't beat basic physics. No light = crappy video.

[David Chapman]

Hey Tim,

You said that your ISO is towards the top of the scale. Are you using an auto ISO? If so, this may be bringing the ISO higher than you would need as the camera would be trying to compensate to your metering, especially with great difference in exposure from lights, people, etc.

Your 50mm at f/1.4 will get great results with lower ISO, but there is no IS so it's a tripod only lens in dark scenes (or camera rig). A lens that lets more light in will always get a better picture. My only thought would be to control the ISO manually here to make sure you are exposing for your subject or look instead of the camera doing it for you (and changing its mind on you). You don't want to go higher than ISO 1600 in most cases. Your f/1.4 could get some great shots at or around ISO 400.

[David Chapman]

I was going to try to explain it, but here's something on Vimeo as a reference. To me, this looks great when you see people/faces/dancing when the light hits them. Who cares if they drop to black? Really has that Michael Bay or Michael Mann (what is it with Michael's?) stylized look.

Here, if ISO was auto, it would be jumping all over the place. So really, you are manually exposing for when people are lit up. You could crush blacks in post, but try not to go too high on the ISO. There are some shots where you see highlight clipping...

This was f/1.4 with ISO no higher than 1250:

Unique Live @ Club Tao on Vimeo

[Tim Davison]

Thanks everyone. A few questions on what you have written above:

1. Why is it preferable to shoot at 24p rather than 60p? Does this make a big difference?

2. I think I was only shooting with manual iso, i.e. I was in manual mode and dialing in the settings (unless I am missing something here?)

3. Is 1600 a real upper limit for quality purposes (and other straying above this if its the only way to get the shot becuse it is simply too dark)

4. Does anyone use a fixed light source (not a flash but a constant light source as I mentioned above)?

5. As I've noticed when shooting and in David's posted video, when there is a flash of light in the club and people go from black to colour there is often a great deal of over exposure but I assume this is inevitable because of the shooting environment and can only be cleaned up in post.

Thank you all very much for your help, it's really appreciated!

Tim

[Nigel Barker]

Originally Posted by Perrone Ford

2. Faster glass. F1.2 obviously would help, especially for the zoom lens.

Does such a zoom lens exist? I don't think that I have seen any zoom lens with an aperture larger than F2.8 certainly not one from Canon.

[Jon Fairhurst]

Even if such a zoom exists, I wouldn't be able to afford it!

[David Chapman]

You know, 1.4 to 1.2 is only 1/3 stop. Not a huge difference. Now 2.8 to 1.4 is 2 full stops of light. From what I have seen, the fastest zooms are 2.8, though.

@Tim,
To answer your question about fps, the only reason a majority of people shoot 60p is to capture 60 frames a second and then reconform the footage to play at 24p or 30p giving a natural slow motion (without frame blending in post). The reason people shoot 24p is because film is shot at 24p and the goal of most is to have a "film look" to their work. There is no 30p other than computer screens. Broadcast is 29.97 (or 60i). But then we get into a progressive vs interlaced conversation.

If you shoot 24p, you can have your shutter at 1/50th (close to double the frame rate) and let more light in that way (vs 60p and 1/125th). This will help give some motion blur where it should be with people moving instead of that video camera look that tends to come with 30p or 60p.

Yes, if you were dialing in specific settings for ISO, it wasn't in manual mode.

[Daniel Browning]

Originally Posted by Tim Davison

3. an ISO of as low as possible

That could be bad. As your post said, you already increased exposure as much as possible, so the next step is you should set the ISO as high as you can without blowing highlights (or making too much work for yourself in post). For example, try this comparison in a low contrast scene (e.g. dark gray wall).

• f/2.8 1/60 ISO 800
• f/2.8 1/60 ISO 3200

In post, reduce the brightness of the ISO 3200 shot so that it matches the ISO 800. You will see that it has less noise. Of course you should not blow any highlights that you care about, nor should you make the image too bright unless you're planning to reduce brightness in post (it's extra work). But above all, do not use low ISO and then increase brightness in post.

[Perrone Ford]

Originally Posted by David Chapman

You know, 1.4 to 1.2 is only 1/3 stop. Not a huge difference. Now 2.8 to 1.4 is 2 full stops of light. From what I have seen, the fastest zooms are 2.8, though.

Yes, I was speaking of the zoom... I forget that photography zoom generally stop at 2.8. Not so with cinema glass which goes right down to about F1.2 or so. At commensurate prices though. :) Probably best to stay on primes with this kind of light. A nice 85mm F1.4 ought to do.

[David Chapman]

Originally Posted by Daniel Browning

In post, reduce the brightness of the ISO 3200 shot so that it matches the ISO 800. You will see that it has less noise. Of course you should not blow any highlights that you care about, nor should you make the image too bright unless you're planning to reduce brightness in post (it's extra work). But above all, do not use low ISO and then increase brightness in post.

You are saying that exposing in camera at a higher ISO has less noise than a lower ISO with an exposure boost in post, right? Not that lower ISO has more noise in general over high ISO. Just when you boost it after it's shot. If your ISO 800 is perfectly exposed, then another shot at 1600 brought down to a visible similarity in post shows more noise on the high ISO. But, any time you brighten a jpg you see noise (bad noise).

[Daniel Browning]

Originally Posted by David Chapman

You are saying that exposing in camera at a higher ISO has less noise than a lower ISO with an exposure boost in post, right?

Yes, that was the central point of my post: the emphasize the importance of erring on the side of too bright (but not clipping) to always avoid boosting in post.

Originally Posted by David Chapman

Not that lower ISO has more noise in general over high ISO.

Correct -- as long as "in general" means "with floating exposure". When exposure is fixed (such as when you're shooting in low light), then it is indeed true that lower ISO has more noise than high ISO.

Originally Posted by David Chapman

If your ISO 800 is perfectly exposed, then another shot at 1600 brought down to a visible similarity in post shows more noise on the high ISO.

Actually, I do indeed mean that 1600 brought down to a visible similarity in post shows slightly *less* noise than ISO 800, when both have the same exposure. (In a 3-stop comparison, ISO 1600 has a *lot* less noise than ISO 200 when both have the same exposure.)

Originally Posted by David Chapman

But, any time you brighten a jpg you see noise (bad noise).

Agreed -- same with h.264, and my main point is that it's better to increase ISO than to boost in post.

[Jon Fairhurst]

It's important to expose properly, but not necessarily because of linear noise and gain levels.

Keep in mind that the camera performs an S-curve function on the video when it goes from RAW to 8-bits. You want to expose your subjects properly (especially faces) so they are in the linear part of the curve. If you over or under expose, you give very few bit levels to the subject. It's better to have noise in the shadows than on the faces.

[Tim Davison]

So presumably having a light source fixed to the top of my camera would assist with this?