Exposue -- not so simple after all

[Steve Mullen]

While it is true that at 1/30th the iris moves from 2.0 to 22 -- once the light goes higher, behavior seems unpredictable. Yes, it sometimes switches to 1/60th or even 1/125th while holding at f22. But, it may also pick another exposure combination with a lower F stop.

And, if you cycle through SA it seems to rebalance bringing speed down and the iris more closed.

If you could use the right ND and the correct amount of light you could probably stay within 1/30th S. But, I think that's going to be very hard. And since 1/30th MUST be the speed -- I think one must lock at 1/30th and use AE. This makes it far more a consumer camera than a pro camera.

JVC should -- at minimum -- have had the microcode altered to allow the AE exposure to be locked while in Shutter-priority mode. Or, simply fixed the shutter at 1/30th in HD and forced us to use ND filters! I could live with that.

Exposure is very accurate, but reflections etc. cause fluctuations in exposure that most pros will find unacceptable.

At wide angles, I found I could compose a scene and let the AE settle and then shoot. So if one is careful and tolerant, one can use the camera to shoot HD rez.

[Heath McKnight]

Now you tell us, after I decided to keep the camera...oh, well, I won't jump the ship now...

heath

[Joseph George]

If you can't lock the shutter speed and iris, this thing is useless. Any of the geniuses out there, would it be possible to build some kind of switch to bypass the camera circuit to the iris so it think that it is feeding the iris -- to change its setting, and at the same time lock up the iris that is disconnected from the circuit, or even move it remotely by some calibrated potentiometer? This should not be too hard. It may work, unless the camera does not stay locked up at its selected shutter speed once the iris can't compensate for overexposure. I believe that JVC of Japan has Service Manuals available on the web gratis; at least I know that they had them some time ago in Japanese. Now they should be available in English. Some expert should go over the schematic to see what could be done. There may also be some test points, etc., that could be used to lock the shutter and the iris -- who knows? Any electronics experts here?

[Heath McKnight]

I just want to know what the heck is going on! So far, things have been up and down, and Steve's latest reports aren't too good.

BTW, I locked everything with the exposure wheel.

Can we stop people from looking like ghosts? Can I do close-ups?

heath

[Alex Knappenberger]

Hah, I feel sorry for you guys. If I knew the person(s) who designed this camera, I would throw feces on them.

How could they not allow you to lock/manually adjust the exposure?


Hopefully JVC comes out with a firmware upgrade or whatnot to fix it......

[Heath McKnight]

<<<-- Originally posted by Alex Knappenberger : Hah, I feel sorry for you guys. If I knew the person(s) who designed this camera, I would throw feces on them.

How could they not allow you to lock/manually adjust the exposure?


Hopefully JVC comes out with a firmware upgrade or whatnot to fix it...... -->>>

Thanks for the hah...

[Joseph George]

You guys that you bought this camera should put pressure on JVC to upgrade it for you. I'm sure that various forms of firmware are available in their labs. They can't sell you merchandise that is not usable for its intended purpose. It is illegal.

[Heath McKnight]

<<<-- Originally posted by Joseph George : You guys that you bought this camera should put pressure on JVC to upgrade it for you. I'm sure that various forms of firmware are available in their labs. They can't sell you merchandise that is not usable for its intended purpose. It is illegal. -->>>

I'm going to call Ken Freed after a morning meeting (in front of Palm Beach County Commissioners to save the Palm Beach International Film Festival, hooray...) and tell him EVERYTHING on the posts, esp. what Steve just said. I was holding out hope, and feeling better after what Steve and Ken said, even if they were contradictory...

heath

[Joe Russ]

let us know how it goes....we're all getting pretty frustrated

[Mark Love]

I have had my HD1 for a month or so now. I've had far too few chances to really put it to work, but I have logged a few hours. Now that I have my complement of ND, Polarizer and contrast filters, I mostly shoot that way. However, when I use my Glidecam to follow a subject, more often than not I want to lock the exposure for the light-level most prevalent. Unless I don't understand the meaning of exposure lock, it seems like it doesn't always work.

Let's say I am following an actor through a yard which is 30% in shadow and 70% in sunlight.

1) I set up my actor at the correct distance in the sunlight.
2) Set camera to M
3) Press the exposure button until I see "+-0" and if need be adjust that number.
4) Hold the exposure button until it "L"ocks.

So then we begin shooting, we start in the sunlight, picture is nice and balanced. We move into shadow, and it's dark (which is what I want). Back into sun - still looks "okay" ish, but maybe a little brighter. Back in shadow, it's not as dark as before. Back in sunlight, and it's so GD bright that the screen is virtually white. I thought that I must have not set the "L" so I look, and sure enough, it's Locked. I unlock it and the image quickly adjusts itself.

This shouldn't happen should it?

I had a similar thing happen using a StickyPod car mount, and with a few regular handheld shots. I am able to recreate the bad shot usually, and then I can usually get a good one, too. Something seems whacked out, am I right?

[David Kennett]

Mark,

I have used the exposure lock before OK, but not for very long. I tried it now for about 5 min and OK. When the camera times out and shuts down though, all is lost!

[Heath McKnight]

I notice that if you leave either the shutter or iris option up (don't hit menu or S/A again), that will lock it fairly well.

heath

[Troy Lamont]

I notice that if you leave either the shutter or iris option up (don't hit menu or S/A again), that will lock it fairly well.

I'll have to try that also because my iris wanders as well when I supposedly lock the shutter....

Troy