Cavision mattebox vignetting

Re: Cavision mattebox vignetting

"He believes the problem is due to using a UV filter."  

I was not using a UV filter with the "new" adapter when I discovered the vignetting. Also, if you notice, with the filters so far away from the lens I was able to read the writing on the glass edge of the tiffen filter (not exactly the effect I was looking for). Perhaps if one is doing a spot for Tiffen Polarizers it would be a good thing. This distance would obviously also be a problem for slight dirt or fingerprints on the filter, nets, etc... everything becomes much more visible.

Now, I would like to point out that I don't wish to slam this matte box, for I really do think it is built well and I really do want to keep it and make it work. But I would like to find a resolution and solution to the problem.

Daveagain, if you had a UV on the "new" adapter - no question you're going to have big-time vignetting. If you use the other adapter they're talking about (the xl1 adapter) with the UV, you will get closer to the lens and the UV will just barely bring it past the mic. The question is - is it still to far from the lens to use nets or spot blemishes on the filter etc. Also, with the xl1 adapter and the UV it is still too far away to dial a polarizer. This is the whole purpose of a rotating matte box.

One more thing, can some one with this matte box please check this out for me. Now this may be a flaw in the design of the DVX100. Put the matte box on with the "new" adapter, zoom out to widest, hook it to an underscan monitor or firewire it directly into your computer with Final Cut Pro and mount under "log capture". This way you will see the underscan image. This is what I need you to check - look on the left side and see how much is vignetting. Is it more than the right side of screen? Now flip the matte box upside down and look at the left side - again, is there more vignetting on the left side? If not, I have a faulty camera. If so, it's not that I have a faulty camera - we all have a cameras with a faulty design. Wassup with that?
 
Re: Cavision mattebox vignetting

Hum! Let's wait for the next step with that Cavision matte box problem.
 
Re: Cavision mattebox vignetting

Cavision doesnt have the DVX, they take the product to a local dealer to test, and sometimes send me one (not to keep :( ) to test and find problems out... which I did in this case. They arnt shady, this is just a new product and stuff like this is bound to happen.
 
Re: Cavision mattebox vignetting

I agree Jarred, I definitely don't think they're shady. In fact I really like the build of this unit. But I can live without the 'tude when I contact a company looking for a solution for both myself and them.

Here's the solution: Put the 3x3 matte box on to the XL1 adapter. This brings the matte box and filters nice and close to the lens. So close that I am now even able to dial the polarizer without vignetting. The problem is the levers for the rear filter bumps into the onboard mic - solution, keep your rear (rotating) filter oriented to a 45 degree (sideways) position. It's perfectly square only now you access it from the side. To pull this rear tray out, simply angle it up slightly and Bob's your uncle.

The matte box is working very well with this strategy. As for the 40+ hours I've already shot with the vignetting... guess this human guinea pig/crash test dummy is **** out of luck.
 
Re: Cavision mattebox vignetting

That was my original work around exactly,, angle the tray so it can move. I just didnt think it was a good solution and was hoping there would be a better fix, which I guess because of the size of the 3x3 opening there may not be.

And bear with Jason, he is a young yipper snapper and has quite the workload, but is a nice guy on the bottom line.
 
Re: Cavision mattebox vignetting

here is the 4x4 in case anyone is wondering:

4x4solid.jpg
 
Re: Cavision mattebox vignetting

Looks nice. Any vignetting with or without a UV filter?

What is the price as seen above?... (minus camera, of course)

Is that your homemade cheeseplate? Do you plan to manufacture and sell any? I'll buy!
 
Re: Cavision mattebox vignetting

A little retraction on my "solution" for the 3x3:

After doing some tests last night, I slipped the camera into the camera bag. The first thing I came to realize is that with the rear filter rotated to the side (for it doesn't fit under the onboard mic when positioned upright) it sticks out further than the matte box. As a result it is easyly knocked inward by touching up against the side of the bag and may end up being slid into frame. So one needs to be very careful that it is properly centered each time you take it out of the bag and begin shooting again.

A better "solution" might be for Cavision to customize the rear tray. Grind down the handle used to pull the tray out and shorten the filter release pin. This would allow the tray to be seated upright and avoid being bumped in the side position.

Also, there are small little machined holes where the internal spring-pressured bearings set into certain positions when rotating the filter (ie when it is perfectly upright it sort of locks into the right spot) one of these machined guide holes would be good when in the side position as well.
 
Re: Cavision mattebox vignetting

Damn, I thought the Cavision was my answer.

Looks like it is riddled with problems for DVX users. :-/
 
Re: Cavision mattebox vignetting

What is everyone trippin on?

I tested out the DVX and 3 X 3 Cavision and am having ZERO problems.  Usually shoot in LETTERBOX but even tried it in 4:3 and NADA; no vignetting.

My set-up is by attaching the threaded stepout adapter that comes with the 3 X 3 Cavision, then adding the HMC UV Sky...

No problems.  The first (rotating) stage clears the onboard mic; it's a close call but works unless you have big fat awkward fingers.  What I am saying is, it works.  It clears it without incident.

Just thought I'd report my findings.  
 
Re: Cavision mattebox vignetting

Thanks, John.

I was curious if you were having the same connection problem with your 3x3 Cavision mattebox.

How long have you owned your mattebox? Is the problem people seem to have due to a newer design element?
 
Re: Cavision mattebox vignetting

I have mine about 5 or 6 weeks now. I specifically requested the newer FILTER holders (don't know if that's a mandatory request). I did have the MIC issue prior to attaching the HMC UV Filter, but all is good now.
 
Re: Cavision mattebox vignetting

And is the mattebox on there sturdy?? as if I can take the cam in n' out of my bag without need to ginger it?
 
Re: Cavision mattebox vignetting

John,

What are the "newer" filter holders?

Also, with the UV on as you mentioned, did you try rotating the filter/filter holder and was all okay that way too? I seem to get edges dipping in the corner (4:3) when rotating the filter (while UV is on), not just in underscan, but when looking through the veiwfinder.
 
Re: Cavision mattebox vignetting

Hi dale (damn boy! register already! :P)

I did not rotate but will do so tomorrow after work and report back. Again, I shoot letterbox always and will crop anyway if 4:3.

booggerg

It is clamped on very nice. I always treat my DVX like ginger :P as it stands but I have had it mounted on cam ever since I got it and it has not at all come off, come loose.
 
Re: Cavision mattebox vignetting

I just bought the 4x4 bellows version and had some difficulty getting it set up initially but CAVision makes everything (and I mean everything) on this unit adjustable. I got it to where it fits fine and even with the bellows out a good bit, there is no sign of vignetting in the captured footage.

On top of that, the camera looks wicked, more like a 16mm or 35mm camera than a video camera.

The construction is very good for this unit and I would highly recommend this to anyone considering it. I would go with the version I bought, though, it seems to be more compatable with the camera.
 
Re: Cavision mattebox vignetting

Test's are in and the verdict is...

There is definate vignetting when ROTATING the 1st Stage. >:( I'm not usre how pissed off I am. I confess, I have not ran into a siution yet that warrants a rotation of a GRAD or POLORIZER but whats the point of having a ROTATING stage if it will vignette.

Sigh....

What to do, what to do...

I'm not going to die without it because OTHER THAN THIS DETAIL it is a rocking set-up. Can I live with it? Can I live without it?

I'll contact Jason at Cavision and figure it out.
 
Re: Cavision mattebox vignetting

Steve, how much did the 4x4 setup run you?
 
Re: Cavision mattebox vignetting

Boogger,

This is Steven again (just became a member). The total cost of the package including shipping for the 4x4 system is $680. Now while this may sound like a lot, consider the cost of the (inferior, in my opinion) Chroszeil equivalent.

It's completely rigid on camera. In fact, it feels like part of the camera when it's secured properly. I have also used a UV filter with it (between the adapter ring and the camera lens) with no vignetting whatsoever.

I can't recommend this enough. I love it.

Steven
 
Re: Cavision mattebox vignetting

so are there any updates to the problems of the 3x3? i'd like to buy one asap but not until the issues are resolved. thanks!
 
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