HV20/Brevis + Snow, Ice, Sun :-)

[Dennis Wood]

Scott, if your Canon is an EOS or FD mount, yes it will work. The HV20 is a rather unique camera in that is the first HD cam shooting in 24p anywhere close to it's price point. This makes it very attractive IMHO as an adapter "imaging engine" where as long as the camera does a good job imaging, it's features aren't as important.

[Wes Vasher]

Originally Posted by Dennis Wood

Peter, that's correct...the procedure I outlined above for locking exposure and shutter in 24p mode describes the method to lock in aperture. Here's the catch. The exposure adjustment range depends on exposure conditions the camera is seeing when you toggle manual exposure on! There's gain to worry about (which you never see) and what looks like two ND filters that slide into play so unless you use some baseline for exposure before you lock it...you never know where 0 db is on the scale. That's why I set zebras at 70%, zoom out completely, and frame a scene with about 30% zebras showing. This method ensures that 0 db is somewhere in the f2 to f4 range.

If you zoom out completely while exposure lock is on, you can look through the HV20 lens and watch aperture change, as well as the ND filters slide in. You can't actually visualize the ND filters slide in, but you'll see reflected light from the aperture change colour. The behaviour of shutter speed/aperture/gain will vary depending on what shooting mode you're using. My tests all reflect shutter priority (TV) mode operation.

Barry has a great trick for locking exposure here...
http://www.dvinfo.net/conf/showpost....7&postcount=33

[Peter J Alessandria]

Originally Posted by Dennis Wood

Peter, that's correct...the procedure I outlined above for locking exposure and shutter in 24p mode describes the method to lock in aperture. Here's the catch. The exposure adjustment range depends on exposure conditions the camera is seeing when you toggle manual exposure on! There's gain to worry about (which you never see) and what looks like two ND filters that slide into play so unless you use some baseline for exposure before you lock it...you never know where 0 db is on the scale. That's why I set zebras at 70%, zoom out completely, and frame a scene with about 30% zebras showing. This method ensures that 0 db is somewhere in the f2 to f4 range.

If you zoom out completely while exposure lock is on, you can look through the HV20 lens and watch aperture change, as well as the ND filters slide in. You can't actually visualize the ND filters slide in, but you'll see reflected light from the aperture change colour. The behaviour of shutter speed/aperture/gain will vary depending on what shooting mode you're using. My tests all reflect shutter priority (TV) mode operation.

Hmmmm.... well now I'm confused again. If the apeture will still self adjust to changing light conditions then we're not really locking exposure. It would seem to me more troublesome if the apeture changes during a shot since that changes the focal length and thus could throw off focus in the middle of a shot, no? (Gain or ND filters wouldn't affect focal length so they shouldn't ruin a shot.)

[Peter J Alessandria]

Originally Posted by Wes Vasher

Barry has a great trick for locking exposure here...
http://www.dvinfo.net/conf/showpost....7&postcount=33

Yeah Barry's post makes a bit more sense now. I've been using Tv instead of CinemaMode to avoid a changing shutter, plus CinemaMode makes the image too soft IMO.

[Rob Unck]

Originally Posted by Peter J Alessandria

Hmmmm.... well now I'm confused again. If the apeture will still self adjust to changing light conditions then we're not really locking exposure. It would seem to me more troublesome if the apeture changes during a shot since that changes the focal length and thus could throw off focus in the middle of a shot, no? (Gain or ND filters wouldn't affect focal length so they shouldn't ruin a shot.)

The aperture won't change during a shot as long as you keep exposure toggled "on" as you shoot.

In step #4 of Dennis' original post on this topic, I'd add:
4. Frame a shot so about 30% of the frame is displaying zebras, then toggle exposure on using the joystick. **Keep exposure toggled on as you shoot the scene to ensure the camera does not self-adjust the aperture.**

[Glenn Thomas]

Very nice!

[Peter J Alessandria]

Originally Posted by Rob Unck

The aperture won't change during a shot as long as you keep exposure toggled "on" as you shoot.

In step #4 of Dennis' original post on this topic, I'd add:
4. Frame a shot so about 30% of the frame is displaying zebras, then toggle exposure on using the joystick. **Keep exposure toggled on as you shoot the scene to ensure the camera does not self-adjust the aperture.**

Yeah, that's what I thought as well. But Dennis seems to be saying something different here: "If you zoom out completely while exposure lock is on, you can look through the HV20 lens and watch aperture change..." Maybe I'm just not following him in this quote.

[David Garvin]

Originally Posted by Peter J Alessandria

But Dennis seems to be saying something different here: "If you zoom out completely while exposure lock is on, you can look through the HV20 lens and watch aperture change..."

Right, you can watch the aperture change as *you* change it. The point he was making (afaik) is that when you lock the exposure and manually adjust it *yourself* (+-11) you can see what each adjustment is physically doing in the camera.

Unless I'm completely misunderstanding your question or his explanation.

[Rob Unck]

Originally Posted by David Garvin

Right, you can watch the aperture change as *you* change it. The point he was making (afaik) is that when you lock the exposure and manually adjust it *yourself* (+-11) you can see what each adjustment is physically doing in the camera.

Unless I'm completely misunderstanding your question or his explanation.

I was just about to suggest that Dennis made a typo and that he typed "on" when he meant "off", but David's assumption above makes more sense to me.

Dennis? ;)

[Dennis Wood]

Peter, follow Rob's update a few posts back. Once you toggle exposure, as long as you see the +-11 db scale in white on the LCD, it will remain locked. If you toggle the exposure off...it will readjust and you'll have to do the 30% zebra thing again.

Zooming out to visualize the aperture/nd filters is just a way to visualize what's going on when you're playing with exposure. Once you figure out your own baseline for setting exposure, you won't look at it again. Just play back your tapes with camera data toggled on the menus, and if you want gain information, play your tapes in a camera like the XHA1. It will show shutter/aperture and gain.

[Peter J Alessandria]

Got it. Sorry if I was a little dense. :-(

[Dennis Wood]

There's no shame in a good question :-) I figured I had the exposure thing figured out and was quite surprised to see the scale "shift" depending on conditions when you engage exposure lock. This makes perfect sense as a consumer cam feature, and a firmware upgrade would likely make displaying aperture/gain in real numbers possible.

[Zach Fine]

Originally Posted by Dennis Wood

Scott, if your Canon is an EOS or FD mount, yes it will work. The HV20 is a rather unique camera in that is the first HD cam shooting in 24p anywhere close to it's price point. This makes it very attractive IMHO as an adapter "imaging engine" where as long as the camera does a good job imaging, it's features aren't as important.

Since the aperture of a Canon EOS lens is controlled electronically by the EOS camera body, would it be accurate to say that the aperture of such lenses when used with the Brevis would not be controllable? I have a large investment in Canon EOS glass, and am daydreaming about the combination of HV20 and Brevis with EOS mount, but the whole combination would be more enticing if I knew there was a way to stop down my EOS lenses -- there are likely situations in which f2.8 wouldn't be the best choice.

[Peter J Alessandria]

Originally Posted by Zach Fine

Since the aperture of a Canon EOS lens is controlled electronically by the EOS camera body, would it be accurate to say that the aperture of such lenses when used with the Brevis would not be controllable?

I'm in the same boat Zach - a few really nice Canon "L" lenses. And you are correct - for now at least, you can't control the apeture. It automatically goes wide open. Some people are working on tweaks - there was a link somewhere to a guy who had a 30D with a special adapter that ran from the 30D to the Brevis (I think) and he was adjusting apeture that way on EOS lenses on the 35mm camcorder adapter. But it looked like an unwieldy mess to me.

[Patrick Jennings]

i remember reading that you can set the aperture on your camera, disconnect the lens (while the camera is still turned on) then it's locked at that aperture.
it should work