Stuff I probably shouldn't mess with?

Tim Tyler · November 10, 2004

On the 100 and 100a, two additional menus can be accessed by depressing the Audio Dub, Rewind, Menu button (in that order) simultaneously.

In the "Adjust Menu" there's are some options. Anybody know what they are?

ATF Gain (seems unchangable)

Linearity (seems unchangable)

Y Level (default A5)

C Level (default 71)

Defect Comp - 0

EEProm Version 1.02

There's also a 'door' in the battery slot under the viewfinder that can be opened by removing a single screw. Inside is a "EVR Connector".

I realize that without service manuals this stuff is probably useless, but I'm curious. :unsure:

Noah Kadner · November 10, 2004

That's the service menu. Not meant to be adjusted outside of the service bench. Offers no benefit and could void the warranty if something gets messed. Dig?

Annie Wengenroth · November 11, 2004

Oh boy, I'm sure glad I didn't mess with any of that stuff today when I was shooting. Good to know. Maybe I should tell my boss about this menu too, as we have 10 of these cameras and it would be terrible if somebody pressed the wrong buttons...

It's kind of like those secret codes in video games, only...bad!

Phil Rhodes · November 11, 2004

Hi,

> ATF Gain (seems unchangable)

Probably the Automatic Tracking Focus servo amp controller - do not mess with it if you want the autofocus to ever work again! I could be wrong here, it's just what it sounds like.

> Linearity (seems unchangable)

Depends what it's the linearity of.

> Y Level (default A5)

> C Level (default 71)

Clearly luminance and chrominance signal levels, but you'd need to put the camera on a picture and waveform monitor to find out what they're doing.

> Defect Comp - 0

Possibly something to do with bad pixel masking on the CCD (although I would then expect it to be something other than zero) or maybe a dropout counter (ditto).

> EEProm Version 1.02

That's just the revision of the software that runs the camera.

> There's also a 'door' in the battery slot under the viewfinder that can be opened by removing a

> single screw. Inside is a "EVR Connector".

Probably a service info port. If you're interested in this stuff, see if you can get the service manual.

Phil

Tim Tyler · November 12, 2004

Probably the Automatic Tracking Focus servo amp controller - do not mess with it if you want the autofocus to ever work again!

Interesting. One of the 'issues' I have with the DVX is a focus problem. With a typical zoom lens the operator can zoom into an object, find sharp focus, and zoom out expecting the object to remain in focus.

On several DVX100a's I've used I have found that the depth of field 'moves' further and further behind the object the more you zoom out from 100%. It's a PITA.

Phil Rhodes · November 12, 2004

Hi,

Possibly another artifact of those servo-tracked zooms. I'd have to examine the camera to be sure. There may even be software adjustments for it, but good luck finding out how.

Phil

Annie Wengenroth · November 13, 2004

Well, I have had the same problem with the focus on some DVX100's (but not all). I thought I was just going crazy or something. They make a funny rattling noise too, which I just looked up and found out that it's entirely normal. Very strange. I like the DVX100 but they have their quirks. I almost find myself wishing they were a little bit heavier; they seem so wimpy and "cheap plastic that could break".

What exactly is a servo-tracked zoom anyway? Is it just a chip that tells the camera when/how to zoom in or out?

Tim Tyler · November 13, 2004

What exactly is a servo-tracked zoom anyway? Is it just a chip that tells the camera when/how to zoom in or out?

I recall Phil mentioned in a post a while back that the unconventional lens design on the DVX is such that the focus may be adjusted internally automatically while the focal length is being changed.

I wish a Panasonic tech could comment on this and give us some real info.

Jan Crittenden · November 14, 2004

Hi,

Possibly another artifact of those servo-tracked zooms. I'd have to examine the camera to be sure. There may even be software adjustments for it, but good luck finding out how.

Phil

<{POST_SNAPBACK}>

This is best done by someone who understands the mechanism and the adjustment. Take the camera to an authorized repair facility. They should be able to help.

Best,

Jan

Phil Rhodes · November 14, 2004

Hi,

It's a completely conventional lens design - unfortunately - and is present on a lot of handycams. This workaround is actually the reason why it's cheaper for them to put servoactuated zoom and focus controls on the lens rather than a mechanical interface, simply because it avoids the manufacturer having to make a zoom which is mechanically accurate enough to track focus throughout its range.

When you zoom in on a broadcast lens, the lens has to move parts of the focus group to maintain focus with varying focal length. This allows it to combine the front element of the focus group and the rear element of the zoom. Otherwise you'd end up with essentially a prime lens with a variable wide-angle adaptor on the front, which means more glass and more aberration - we all know how much those wide angle adaptors suck.

Normally there's a helical guide slot milled into the interior body of the lens which controls the relative position of various pieces of glass as others move. The position and orientation of this slot combined with other mechanical links and the position of the back-focus alignment group controls how well the lens holds focus as you zoom. These precision mechanical components are difficult to manufacture - it's much cheaper to have servoactuated lens groups and a position sensor setup which tells the camera where everything is, so the camera can just shift everything around and make it right.

This has three problems: first off, no manual control. There cannot be manual control over both focus and zoom, although presumably you could have one or the other manual and the other servoactuated. There's nothing stopping you doing an indexed servo control, though, which I believe they've actually done on the DVX. Well done, Panny, go to the top of the class. Secondly, if you get into a situation where one group can move faster than the other, you find that there may be a delay in focus being right - apparently snap zooms on the DVX can show this up. And third, what we see here - the whole servo control loop which keeps the focus right on the DVX-100 as you zoom in and out is apparently software adjustable, and Mr. Tyler's appears to be out of true.

Phil