HV20/Brevis + Snow, Ice, Sun :-)
 

Here are some shots done with the HV20, Brevis35 (CF1), 50mm Minolta f1.4 lens (f2.8 to f5). I had an ND .9 and polarizer (4x4's in mattebox) out in front. Clips were captured using HDVsplit, and 2:3 pull down removal done in AE7.0. I found that unless the clips were captured seperately and each analyzed for pull down sequence individually, pull down removal would not work. HDVsplit (free) captures, splits and logs all clips from tape unattended. Other than adjusting brightness on two of the shots, there was no cc done.

The HV20 was in shutter priority mode, 1/48s shutter, with aperture locked at f 4.8

720p (24fps)...107MB wmv right-click/save

620x360, 48MB, mov right-click/save

Wow, fantastic!

What music is that?

Oh my goodness. That was the sharpest outdoor stuff I have *ever* seen from a 35mm adapter. Exposure was spot on Dennis. You are the man! That's the best advert I've seen - the Brevis speaks for itself! ;)

EDIT: And on an (consumer) HV20 no less!

Great looking stuff Dennis (looks like the little girl was going for the camera on that one shot - my worst fear with three toddler-age nieces - LOL)

Two questions:
1. how are you "locking" the apeture on the HV20 in Tv mode?
2. how are you monitoring the video on location since I assume the Brevis results in a flipped image.

Thanks guys :-) Music is edited from a track done by the Vulcan Dub Squad. My daughter has had a camera on her from pretty much day 1, so I just keep a lens-pen on hand for smudges and consider collisions a hazard of the workplace. I'll likely keep the HV20 around so she can start actually learning how to use it.

Peter, I just used the HV20 LCD for these shots. I do have a 7" Marshall HD but it's useless without a hood in strong sunlight. The HV20 LCD is bright enough so that if it's shaded from direct sunlight...it's actually pretty good. The image is indeed upside down (flip module almost done though) but like most adapter users, once you've done it a few times, your brain figures it out. I had a follow focus mounted so basically I would stop recording, frame the shot, hit focus assist to determine the focus points, then used the ff and focus marks on the lens as a reference to rack.

For aperture management I followed a workflow based on a few initial hours of testing with the camera. Playing the HV20 tapes back on the XHA1 you can view aperture, shutter and gain (although not ND filters deployed). After doing similar testing with a GS400 several years ago, the HV20 wasn't much different. You can zoom out completely and with the right angle of light observe the iris closing and ND filters sliding into place as you play with exposure. Here's what I've been doing for 24p adapter use:

1. Zoom out completely.
2. Set up zebras to display 70%
3. Set camera in 24p mode.
3. Place cam in TV mode (shutter priority) and set shutter to 1/48s
4. Frame a shot so about 30% of the frame is displaying zebras, then toggle exposure on using the joystick.
5. You should see +- 11db on the scale. 0 db corresponds to f4 to f5 when using this technique. f4 is usually a good estimate for the lens sweet spot.

Once the camera was set, I controlled overall exposure with only small tweaks on the HV20. The balance of light management was done with the two 4x4 filters, and the 50mm aperture. The Brevis/HV20 combination dictates that in these conditions, you need to lose something like 16.5 stops:

50mm at f5.6 = - 6 stops
ND.9 = - 3 stops
Polarizer = - 2 stops
HV20 at f4.8 = - 5.5 stops

the letus footage from the other thread seems lot more sharper

http://dvinfo.net/conf/showthread.php?t=91465

the girl is sharp like a pic, but in this brevis footage theres always some softness

I believe you have to keep Exposure toggled on as you shoot -- correct me if I'm wrong Dennis.

Thank you Dennis for taking the time to answer our questions.

Did you rotate the polarier to darken the sky?

When I look at some of the shots (like at 23seconds) I thought you were using a grad on the sky because it's so dark on such an obviously sunny day.


I'm also curious about what's happening at 8seconds.

You pull focus to, and then go past "infinity" as the mountains miles away in the distance are brought into focus... and then go out of focus as you focus past them. Is this a byproduct of 35mm adapters due to backfocus issues or is it something else?

You can see the relative effect of the polarizer as relative solar angle changes...so yes I did have one on there, and rotated to cut exposure as much as possible. The snow was so blinding and foreground so bright...it gave an interesting effect. Going past infinity on focus likely reflects a slight collimation error on my part. The test unit in question typically hosts about six different lens mounts for testing. We are currently integrating an updated front mount design that incorporates a micro-adjustable collimation feature...making adjustment in the field a snap...and obviously this unit does not have it :-)

I don't know. Dennis Wood's footage looks pretty darn good to me. The smooth rack focus is great.

Good luck.

Dennis

It looks AMAZING!

I am anxiously awaiting my Brevis35 and can't wait to get the DOF that 35mm lenses offer without paying a small forture for a higher-end 2/3" CCD video camera!

Thanks Dennis for the footage - seeing is believing!

Rob Robinson

I was just playing with the camera this morning (haven't had a chance to shoot much with it yet - I'm stil working on two DVX100 projects) but I discovered in Tv mode you can manually adjust (and thus "lock") the apeture! (I'm sure others already figured this out but I guess I'm a bit slow.) Yes, Rob, by using the joystick to select "EXP" you toggle between manual and auto exposure. Manual let's you adjust exposure in +/- 11 increments (probably equivalent of 1/3 stop increments?) Brilliant!

Full manual apeture and shutter (in increments at least) control, mic input, headphone output, 24p in HDV, decent autofocus - all for $900. Thank you Canon!

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.

Dude... that is SICK good color/sharpness. I have an HV20 and it doesn't look like that! Too bad it will set me back as much as the camera.

Will that work with my Canon 50mm 1.4?

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.

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

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.)

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.

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.**

Very nice!

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.

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? ;)

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.

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

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.

Brevis and EOS mount -- lens controls?
 

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.

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.

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

Hmmm... you mean on the still camera. Still a bit of a hassle but might work.

a test
 

Canon EOS lenses don't actually stop-down the aperture except during an exposure or when the depth-of-field preview button is pressed. So I set my RebelXT to manual exposure mode, set the lens to f32, and removed the lens while holding the depth-of-field preview button. The lens did stay stopped-down to f32.

This would be awfully cumbersome though. I'd prefer if the Brevis EOS lens adapter connected to the lens contacts and passed the connection out to some pins on the back. Then I could wire up one of my EOS camera bodies directly to those pins and control the lens. To keep it from being such a cumbersome combination, maybe I could strip down the EOS camera body to become just a couple of buttons, a display, and the control dial... That would probably be easier than reverse-engineering the EOS lens communication protocol and programming it into a microcontroller, and old EOS bodies are getting cheaper and cheaper.

Of course, if the lens communication protocol were reverse-engineered, it might be possible to control the lens motors and for follow-focus, although I'm not sure if they move in small enough steps to rack smoothly.