What kind of vignetting is normal?

[chinadan]

Hi, I have a huge problem.

I just bought an Equinox ProPak8 for my DVX100 and I see unacceptable vignetting when viewed through a Firewire connection. If you view through the viewfinder, it is OK but bear in mind that the camera's viewfinder does not show the whole video image but only what is in the safe zones (I believe this is called underscanning).

This may be OK for most who use a TV as a playback device but in the NLE and if the DVD is played back on a computer you see ugly black corners.

I this normal - i.e. do other camera/housing combinations have the same problem? I would understand that a consumer camera housing may exhibit this but Equinox prides themselves to be Pro suppliers and the DVX100 is certainly pro equipment.

Needless to say that Equinox has so far ignored my requests for help...

 

[JamesD]

I'd expect that from my Minolta Xt, whoch has definate vignetting, but is a fairly cheap "point and click" camera. Until now I've been using a JVC camcorder and an Ikelite housing (not a very advanced setup) and I get no vignetting, so I would say that's bad.

To me however, your vignetting almost looks like part of the housing and not vignetting, it's too dark and doesn't fade into the picture (at least for my Minolta, it's always really dark in the corners, but fades into the main picture).

 

[ronrosa]

Hi, I have a huge problem.

I just bought an Equinox ProPak8 for my DVX100 and I see unacceptable vignetting when viewed through a Firewire connection. If you view through the viewfinder, it is OK but bear in mind that the camera's viewfinder does not show the whole video image but only what is in the safe zones (I believe this is called underscanning).

This may be OK for most who use a TV as a playback device but in the NLE and if the DVD is played back on a computer you see ugly black corners.

I this normal - i.e. do other camera/housing combinations have the same problem? I would understand that a consumer camera housing may exhibit this but Equinox prides themselves to be Pro suppliers and the DVX100 is certainly pro equipment.

Needless to say that Equinox has so far ignored my requests for help...

It's the housing. Zoom in a little....problem solved.

 

[chinadan]

Considering the money I have invested zooming in a little is only my last way out until I get a bigger dome port. Submersion in water aggrevates the whole thing, so I loose about 15% of my wide angle.

I was just wondering if people in general experience this sort of problem since it is a "hidden" problem. You will never see it in your camcorder or on an external monitor, unless it is an underscanning broadcast monitor.

You DO see it, however, in your NLE software and when you play back the DVD on a computer.

If you look at Gates housings, the especially advertise the "no vignetting" fact.

While Equinox is by far more inexpensive it can't/shouldn't be less professional. After all, they are the OEM manufacturer for the Panasonic housing for the DVX100.

It's the housing. Zoom in a little....problem solved.

 

[peterbkk]

chinadan,

I don't know the camera and housing that you have so my comment may be way off line. But, are you sure you are mouting the camcorder correctly in the housing? If it was just a millimeter or two back from its correct position, that could cause vignetting. Is there anyway you can get the lens closer to the housing port?

Regards
Peter

 

[chinadan]

The camera in this housing type is fixed in multiple locations:

- the main tripod screw
- the VHS pin to get the axis of the camcorder in line
- a rotational stop at the rear left

The camera is mounted on a tray and the tray can only be pushed in so far. Since you can't see the black corners in the viewfinder I would have to assume that the manufacturer has not taken underscanning into account when they made this housing.

I can not move the camera closer to the port, I can only machine the port hole deeper to recess the port further - thus bringing it closer to the lens.

The port is too small for this camera as you need perfect alignment to even get equal amounts of black corners. Regretfully, this barrel-type housing does not alow for precision alignment of the front plate. I can cut out tulip-shaped areas form the port protector/lens shade but then there is still a small chance that a corner will show up.

I believe the appropriate port size is available, but at a $350 premium...

I'll talk to thes manufactuere tonight and see what they have to say....

 

[shadowr69]

I've seen it on amphibico's with two different (sony)cameras. It's slightly more exagerated when you have the image stabization(IS) on...then the edges go all over the place....I ended up shooting in the faux widescreen mode that the camera could do for the ws look as well as the IS mode not being on in this mode.

I looked at the camera housing(propak 8) and noted that it had the ext color corrector, is that something that you use or do you use the manual WB? I noticed that without the ext filter on mine, I got less vignetting. The filter mount might be coming into play as well

The dvx 100 is a nice camera, it's a shame that you're having this issue. Btw, have you seen the hvx200? nice HD camera in the same size package....

-Mark

 

[chinadan]

For some reason the DVX100 never made it under water and there are only 3 housing manufacturers available. Equinox being the most prominent supplier due to their OEM ties to Panasonic, a German and a Japanese company with very nice albeit super-expensive housings.

The housing comes with a rather crappy external color corrector but I am not planning on using it.

This problem will continue to exists until I recess the whole dome port plus protector further into the 1" thick front plate, thus moving it closer to the lens and eliminating the vignetting. In the meantime I will cut out the corners on the lens shade with a Dremel tool but regretfully even the dome port (the clear acrylic plastic) can show up in the image. This housing definitely needs a larger port!

The HVX200 is indeed nice but even larger in size. If I had to do it all over again I would be getting the HDV-HC1 from Sony w/ a new housing...my current setup, due to its bulk, weighs in at 40 pounds. Add the dive gear and I have a choice of running around naked during my vacaion or plunk down beacoup bucks in excess luggage...for the sake of the Filipino islanders I guess I will pay... :05:

I just hope that other people can benefit from my experience and either

- record some footage and review it in their NLE
- hook up the camera via FireWire while in the housing
- use an underscanning broadcast monitor before byuing a housing

This I certainly did not know before and had to lear it the hard way. Gates housings apaprently know this problem and advertise specifically that their products do not have these problems (would be kinda embarassing having to explain that to NatGeo)

 

[MikeC]

Dude, that happens every now and then with $125,000 broadcast cameras. Our solution, don't zoom out all the way. A wide angle lens just makes things worse.

 

[chinadan]

but I can't accept such a flaw as it could be easily cured.

Also, a broadcast camera may show you an underscanned image. In my case, I have to - every day, as I have to remove the camera to exchange the batteries - verify the vignetting with my laptop/Firewire connection as neither the viewfinder, in-camera LCD or my 5" external LCD will show the underscanned image.

So let's say I didn't do that and everything looks clean on the LCD, as soon as you enter the water (different optical properties), a previous vignetting at the threshold of the action safe zone may now pop into view, not only ruining your footage for on-line use but now even a normal TV playback has black corners.

All they needed to do is put in a bigger port or move the current port closer to the camera. With the ridiculously thick 1" front plate there is ample material to dig into.

Then, a tulip-shaped lens hood - problem solved. After all, this is THE OEM housing for a Panasonic Broadcast-Division camera...and the changes would be so minimal in cost increase that it is almost criminal not to do them...

So, while zooming in may be a band-aid, I find it not acceptable to loose 10% of my wide end due to such a trivial problem. Almost like having a Porsche and not put high-speed tires on it...