Indoor interviews - exposure

[Thomas Kaufman]

Hi everyone,

I've been using the F3 for a few months now, and have the PP set to AB_CINE2 which I downloaded from Abelcine.

What I notice is, because the camera is so sensitive, I wind up using behind-the-lens ND and shoot with the shutter at 180 and ISO set to 800.

It would be nice to use a lower ISO and go without the ND, but I'm also setting the aperture of my 75mm prime at 1.4, so I get massive overexposure this way. Even reducing the ISO to around 280 doesn't reduce the overexposure enough.

I think there ought to be a way to do this, probably very simple, but I can't think what it is. Anyone have an answer? Can you set the camera lower than ISO 280? Or should I just go with ND and ISO 800 and forget about it? The venues for this footage are TV and web, so no transition to the big screen.

thanks,

Tom

[Thomas Kaufman]

I did notice that the ND has an adjustment, and a previous thread mentioned using a light meter/waveform monitor to adjust the amount of ND. Maybe this is part of the solution?

thanks

[Douglas Villalba]

Originally Posted by Thomas Kaufman

What I notice is, because the camera is so sensitive, I wind up using behind-the-lens ND and shoot with the shutter at 180 and ISO set to 800.
Tom

Using ND is the way to do it. Using shutter speeds faster than twice the frame rate is not recommended unless it is for effects like slowmo or Saving Private Ryan.
When you use the internal ND1 your effective ISO is ∼ 100. With ND2 ISO is ∼ 12.

[Chris Medico]

That adjustment doesn't change the cameras sensitivity.

Why is using ND a problem? If you are shooting at ISO800 is the native sensitivity for the camera. ISO800 offers you the best image quality from the camera.

If the internal NDs are not the right values for your application you have choices such as using a matte box with ND filters in steps smaller than the internal ND filters. You can also use one of the variable ND filters (not my first choice) to tune the exposure to what you want.

[Mark Kenfield]

I'd suggest stopping down a little, even if it's just a stop or two. f/1.4 at 75mm must give you a razor-thin DoF - i.e. only one eye in focus if the person turns their head even slightly).

Do you not have issues with people falling in and out of focus as they shuffle about on their feet or chairs?

[Dennis Hingsberg]

Under gain settings you can go to -3db and electronically come down a bit from 800ISO. The two built in ND filters offer 3 and 6 stops of reduction.

If you are still over exposed you will have no choice but to use additional ND filters in front of your lens or lower the lighting in the room.

As for F1.4 I don't want to criticize your choice on that f-stop as you may have specific reasons for wanting to shoot that wide open, but I don't recommend ever shooting people lower than f5.6. More commonly in portrait photography values of f11 or higher are used.

If you want a background out of focus you need to put more distance between your subject and the background. If you can't because you can not get far away enough from your subject then you should try a 50mm lens.

[Thomas Kaufman]

Thanks, guys.

Another question - in the menu is a selection for giving the ND filter a numeric value. Any idea what that is for?

Tom

[Dennis Hingsberg]

Sorry just to add to my previous post I do shoot lower than f5.6, such as f4 or f2.8 but it depends on background distances mainly. That is my deciding factor.

I've noticed the numeric value on the menu for a year and never inquired what purpose it serves. My guess is it might do something useful when the kit lenses are installed of cookies with electronic data passing back to camera. Or maybe the values are purely for reference when metadata is recorded? No idea. I bet its in the manual though.

[Alister Chapman]

It's a trim adjustment for the camera gain to ensure that when using the ND's the sensitivity reduction is exactly 3 stops or 6 stops.

[Dennis Hingsberg]

Ah yes subtle electronic gain control. Brilliant. Absolutely brilliant.

I wonder now if all this time I could have used it to adjust my exposure in smaller increments than db gain increments. ??

[Leonard Levy]

All my lenses are 77mm or have adapters to 77mm . I always carry a pouch with a 77mm ND 3, 6 & 9 for exactly this purpose and its very valuable especially if you are trying to get that low DOF look and get stuck in between the cameras large ND jumps. With mattebox I just carry 4x4's. Its a good habit.
Some cameras have 3 internal ND's and its easier to manipulate.

[Bill Thomas]

I use a Nikon 85mm 1.4 ais for almost all of my interviews with the F3. Between adjusting the lights and ND(internal or external) I try to always land around f4 in the lenses sweet spot while giving me a bit of a focus buffer in case the subject moves. To put the amount of DOF in perspective; using a 85mm @ 10' @ 1.4 gives you 3.5" of DOF, at f2.8 = 7", at f4 you'll have 9.8" and at f5.6 =14".

[Leonard Levy]

Everybody shoots their own way. My clients like low depth of field and I have never shot an interview above f2.8 in years. In small rooms I've gone to f1.4 often. Got to be damn careful on the focus though and it can bite you.

[Dennis Hingsberg]

I think 3.5" is way too shallow to shoot people with. That leaves some portion of the subject (human) out of focus, ie. Tips of nose, back of eats, shoulders, etc..

While a client might like it, it doesn't make it "right".

[Steve Cocklin]

I'm using Zeiss ZF.2's with the cine conversion from Duclos, I've found 4, 4-5.6 to be the safest place to be with an 85mm, even though I'm checking red peak on the F3 VF if I'm lower than f4 I see some softness in the edit. More than once and once is too much I've had to drop a BCC sharpening effect over a scene. There has been a good discussion going on in another forum on the differences between Zeiss super speeds and Cooke lens with the emphasis on sharpness.