"Av" and "Tv" Explanation?

[Jack Barker]

I guess I should have figured this out by now, but in the past I always felt my main setting choices were Manual or Automatic. (Notice I said "felt".) Anyway, here's the question:

On the XL2, there is are two settings on the main dial - one is "Av" and the other, "Tv".

Av (Aperture value) allows the user to set a fixed aperture and the XL2 automatically compensates by altering the shutter speed. Tv (Time value) allows the user to set a fixed shutter speed and the XL2 automatically compensates by altering the aperture.

In simple terms, could someone tell me how it would automatically compensate for either, and when these settings might be useful?

Thanks

[Alan James]

It compensates the same way any automatic setting would, by using the light meter and trying to get the correct exposure.

You would only use this setting if you are shooting run and gun style. If you shoot 24p and want it to look filmish then you HAVE to use a 1/48 shutter speed (or higher). Most of the time in automatic mode in low light the camera will lower your shutter to 1/24 of a second, making it look like video.

If you want to control your DOF then you would use the other setting so your F-stop doesn’t change.

I personally don’t like any sort of automatic mode, even if its partial automatic. I use full manual all the time and it seems to work best, for me, but everyone is different.

[Jack Barker]

Thanks Alan - so, if I want to control shutter and iris, my original assumption to use only manual was correct. I do shoot 24p mostly (if not, 30p), so I do want 1/48 shutter and I also try to generate shallow DOF using the long lens and controlling iris, which actually ain't bad, if you're careful.

Run 'n gun isn't for me either. Most of my stuff is locked down, with very little SLOW panning, and no zoom, if I can help it, and I usually can.

[Julian Fox]

I use the XL2 to film soccer in a small stadium, and on a sunny day, half the pitch is in bright sunshine, while the other half is shaded by the stand.

I therefore use "TV" mode with a fixed shutter speed and have found it adjusts to the change in brightness quite well.

Is this the best solution when you are following play and constantly the shot moves in and out of the shade or does anyone have a better idea?

[Bill Zens]

My problem is I keep bumping the shutter speed and changing it, usually to a lower speed like 1/30th. I usually catch it pretty quickly, but it does mess up the shots. So, when I'm doing handheld, I have gone over to the semi-automatic side, and shoot Tv.

[Michele Coser]

Thanx for the tip, Alan. Sometimes i lower the shutter to 1/24 due to low light reasons. I gain more light, but at the price of being not filmic anymore.

[Dale Guthormsen]

Here are a couple of thoughts sense you arre interrested in the depth of field issue.

If you are going to shoot a slow shutter speed then you will have a small aperature which is actually creating greater depth of field.
I shoot mostly at 1/60 in 30 p. If I want less depth of field I will put on my polizer or two and haze filter. Usually this with using some zoom you can make the depth of field more to your liking where using a rack focus actually looks proper. What you are trying to do is have as wide of an aperature as you can with your slower shutter speed.