I need help aligning my Chrosziel matte box

[mflo]

Hello all,

This is my first experience with a matte box of any sort, so please accept my apologies if I'm just being retarded. That being said, a search yielded no results, so I'm hoping that someone here who has experienced this can help me out directly...

This is what I've done so far, in order:
I've attached the support rods and baseplate to my HVX. I've loosened the hex bolt on the front side of the baseplate to allow the rails to move side-side/up-down. I then attached the matte box to the rails, centering the adapter ring of the matte box over the HVX lens. I re-tightened the hex bolt when the matte box + adapter ring were in place.


After adjusting and re-adjusting more, I'm still experiencing vignetting while the zoom is full wide. Is this just a normal limitation of using a matte box, or am I just missing a key step for properly aligning my mattebox?

Here is a frame grab illustrating the vignetting, as well as two photos that show how I have the matte box mounted to my HVX:

http://www.desertrides.com/~mike/vignetting01.jpg

http://www.desertrides.com/~mike/IMG_4041.jpg

http://www.desertrides.com/~mike/IMG_4045.jpg

Help/suggestions would be greatly appreciated, thanks.

-Mike

[mflo]

I spent some more time problem solving, and realized the vignetting is being caused by the 16x9 removable insert. It's just a piece of plastic, so I'm thinking I'm going to shave a bit of material off with a dremel.

[SurJones]

I cringe at your dremeling down that matte box. I would wait till someone can give you a more accurate solution. There are many people who have this. I know Barry used to, but sold it.

[mflo]

Yeah, me too. It really sucks spending that kind of money on something that just isn't right. When I pull the insert out (highlighted in red in the photo) the vignetting completely goes away, so I know that's the culprit. I'm thinking that removing a couple mm's worth of material along the portions highlighted in yellow will solve the problem. I checked with a friend of mine that has an HVX+Chrosziel matte box, and he is having the exact same issue with his. I'm just surprised no one has mentioned it here before.

http://www.desertrides.com/~mike/IMG_4049.jpg

[n8ture]

It's really hard to get the alignment perfect.
When I went to Hawaii I just yanked that 16:9 insert out and never had any issues at all. With the insert in it's a bear ( at least for me ) to get it aligned. Without it I can put it on and off in a hurry and never have to worry about the alignment.

I'd take it out and see how it works for you before I started shaving off a bit here and there.

[GrafxLvr]

From the first pix, it seems that the vignetting may be caused by an "alignment" problem; as you've obviously stated. Nonetheless, something doesn't look right from the first image, i.e., there is a lot of curvature on the image (most noticeable on the top left corner).

Anyhow, have you tried centering the mattebox prior to mounting it on the rods? Just to make sure that their isn't a spacing issue with the rods. If all else fails, you can follow n8ture's advise, i.e., yank the 16:9 insert-off.

Anyhow, I haven't had any problems with this Mattebox on the HVX200. Dunno what else to tell yah.

[mflo]

Yes, I tried centering the mattebox, I tried every adjustment I could with it. It ended up being the 16:9 insert, so I dremeled it down a hair. Problem solved. The weird curvature in the framegrab is because I didn't correct the aspect ratio in photoshop before I posted it... rookie move. For the type of shooting that I typically do, I need to have that insert mounted in the mattebox for added protection. The vignetting was only when the zoom was wide open, like 00-06 on the zoom meter. I know for a fact I'm not the only one with the same issue.

[andynick]

The weird curvature in the framegrab is because I didn't correct the aspect ratio in photoshop before I posted it... rookie move.
Correction:
The wierd curvature you see at full wideangle is called Barrell Distortion.

It's a serious optical issue with the HVX200 at full wide.
We just have to live with it unless we can afford to buy a camera with (seriously expensive) interchangeable lenses.

I try to make a point of never using a zoom setting wider than 5.5mm. That helps a bit.

Andy

[andynick]

so I dremeled it down a hair
WOW !
Drastic action or WHAT?

Did you "dremel down" the camera's mic too? There's a huge chunk missing from the front mesh - or is it an early model or something?

Remind me never to buy a used camera from you!

Andy

[GrafxLvr]

Yes, I tried centering the mattebox, I tried every adjustment I could with it. It ended up being the 16:9 insert, so I dremeled it down a hair... I know for a fact I'm not the only one with the same issue.
Dunno what to tell you then. but I'll check it in two weeks; I'll double check it!

[mflo]

GrafxLvr, I appreciate your actually taking some time to consider my problem, and actively pursue a solution. Helpful users like you are the reason I frequent this board. I'm not sure what the technical name of the part on the mattebox is, I think its called the adapter ring, but from what I found the alignment of the mattebox on the rails is pretty limited to simply centering the adapter ring over the lens on the HVX bayonet style. Once that is done there really isn't any room for further adjustment.

I was going to respond to Andynick's condescending vocabulary lesson, but my initial reaction to his posts was less than nice and I didn't want to make an ass out of myself.

Oh and Andy, from your decidedly unhelpful response and silly interpretation of my photo, I'm assuming you don't own and probably haven't used this mattebox on an HVX. The "chunk missing" from the on-board mic isn't a chunk missing... they're the handles on the filter stages. And I guess I didn't really "dremel down" the insert for my mattebox, since I actually used a Craftsman rotary tool.

[andynick]

Oh and Andy, from your decidedly unhelpful response and silly interpretation of my photo, I'm assuming you don't own and probably haven't used this mattebox on an HVX. The "chunk missing" from the on-board mic isn't a chunk missing... they're the handles on the filter stages
You're right, I've never used one (nor likely to) but I stand corrected about the mic.
Sorry if I offended you. My post was meant to be light-hearted - but it's not every day we hear about people carving bits off their camera equipment - I see that as pretty drastic, you obvioulsy don't.


And I guess I didn't really "dremel down" the insert for my mattebox, since I actually used a Craftsman rotary tool
Apologies again - I didn't realise you posted one thing and actually did another, but it makes no difference. Either way, I think what you did was impatient and silly.

If the product is faulty, most of us would send it back to the manufacturer - but it's your choice.

Andy

[GrafxLvr]

GrafxLvr, I appreciate your actually taking some time to consider my problem, and actively pursue a solution. Helpful users like you are the reason I frequent this board. I'm not sure what the technical name of the part on the mattebox is, I think its called the adapter ring, but from what I found the alignment of the mattebox on the rails is pretty limited to simply centering the adapter ring over the lens on the HVX bayonet style. Once that is done there really isn't any room for further adjustment.
mflo, Thanks...and Sorry for my delayed response. My shoot was postponed 'till this Tuesday...