Matte Box advantage?

[John Fitzpatrick]

I'm sure that I'm missing something, but what is the advantage of a matte box vs. just screwing a filter on the front of the lens? I was looking at the cost of the Century matte box which had a street price of around $600 plus the cost of the filters and was having a hard time wondering how to justify the cost.

Fitz

[Chris Hurd]

There are several advantages that come to mind, two of which are: with a matte box that has rotating stages, you can put in a graduated filter (where the filter is more intense toward one edge than the other) and rotate it to a certain degree for your particular needs; and you can stack filters much better with a matte box than with screw-ons. The screw-on filters will vignette if you have too many of 'em, one in front of the other. Of course there's also the "wow" factor, since a matte box just looks so darn cool on the front of the camera it proves you must be serious and you must know what you're doing if you show up with one on your camera. No one has to know that there aren't really any filters in it. Hope this helps,

;-)

[Martin Munthe]

A good matte box keep unwanted flares away (if used properly). Get a french flag with the matte box and you're set to go. The real pro boxes have matte cut outs for all lenses (cine style). This way it's virtually impossible to get flares.

[Charles Papert]

C>>>This way it's virtually impossible to get flares.

Cripes, I only wish it were so. Many times a hard backlight just can't be eliminated entirely by an eyebrow or sideflap, it takes a flag or a teaser some distance from the camera to get all of it--and then if the camera is moving... oy.

Diffusion or contrast filters require the most attention; light hitting the filter even outside the part that covers the lens itself can spread through the filter and affect the image. Promist users beware! You'll rarely see it through the color viewfinder on the XL1. It's not just the obvious "sunspot" flares that can bone you!

[Martin Munthe]

Charles,

of course flares are a constant pain in the b***. But sure the greatest way to eliminate them is by the old style bellow boxes and cut out mattes (wide angle becomes a problem). And there is no way to protect against flares if the light hits the lens straight on. But...ok...I admit "virtually impossible" is a bit strong...

One of the things that is great with video is that you never miss a flare i your viewfinder. When shooting film flares can appear like magic after processing (yikes).

Put your trust in multi coating ;-)

Can you use a matte box to block out flares, and use screw on filters?

[Justin Chin]

Yeah, any light that's within the angle of the lens to matte will be hard to cut. You'll need to cut it with a flag away from the camera.

The funny thing is that most new matte boxes out there can't really accept actual hard mattes. Some smaller hard mattes take as much as a stop as well.

[Charles Papert]

<<Some smaller hard mattes take as much as a stop as well.

Justin, this is one of the great mysteries of life. How many years now have I had this discussion, of whether or not the long focal length hard mattes rob exposure?

I suppose we should explain what we are referring to here for those unfamiliar with the hardware involved: hard mattes are flat plastic trays that snap over the open end of the mattebox, and have a rectangular hole cut out that varies with the focal length in use. For a wider lens, the hole is bigger, for a telephoto lens it is smaller. The idea is to help eliminate flares by effectively closing the mattebox in around the lens. It's a fast easy trick.

The potential problem is when the size of the hole is actually smaller than the front element of the lens. Potentially, the lens is being robbed of its light-gathering effectiveness. This is not the same as vignetting, where you can see the solid in the image--this is more of a question of whether the overal efficiency of the lens is being compromised.

Justin, I have worked with scores of DP's who feel it isn't a problem, and others who are fastidious about not using them on focal lengths longer than 50mm (35mm format). But no-one I know has ever shot or seen tests to prove one way or another if there is in fact light loss!

I think for the diameter of stock DV zooms, this is probably a moot point--but with your P+S Technik setup and say, a 25-250 Angeniux, it would be relevant again, huh?

If you have the opportunity to do some scientific testing (or maybe you have already!) please let me know the results.

Cheers,

[Justin Chin]

Hi Charles,

Yeah, it's probably over stating to say 1 stop is taken away. 35mm long fast lenses might suffer from it the most, and may really only be a 1/4 of a stop.

I had this effect when I shot the other day. Since we had a 4x4 mirror to kick up the hair close to the angle of the lens I had to cut it with my side wing. The interesting thing is that BEFORE the wings got into the shot, I could see a change in light properties AND a dark "ghost" edge on the same side of the frame that I was cutting. It was like a warping effect.

In this case it could very well been the property of:

- Blurred wing entering frame
- Light physics

Since I was at T1.8 the wings were severly blurred. But the ghosting happened way before the wing entered the shot.

Also, light when pushed through a "small" space can get affected and warped causing "banding" or bouncing wave lengths. Forgive me I don't know the technical terms. Try bringing two fingers together really close to your eye while looking at a fairly bight location. As the fingers come closer together you will see ribbons of dark lines floating between your fingers. I found this example in an old physics book.

The same "properties" are exhibited with hard mattes in glamor photography. You can create star shaped glows from light sources that are in the frame with a star cut into a hard matte. Or even hearts. My Zeiss' have 3 arced blades that can shape bright highlights into triangles.

I'm running on less sleep than usual. So If this doesn't make sense, I blame that.

Loved the season finale of Scrubs, BTW.

[Martin Munthe]

Charles,

"How many years now have I had this discussion"

...on of the biggest frustrations of the internet. Knowledge just goes around. It never seems to stay. There are two new people born every second. In twenty years they will be asking the same questions that you and I have been reading over and over. Don't we just love this brave new world?

:)

[Justin Chin]

If anyone is interested I found this on the net. Take it or leave it.

http://www.cinematography.net/mattes.htm

The first post is not me BTW.

I apologize if I bring up things that have been discussed time and time again. I am personally more frustrated with people who get cranky with others who just ask questions. Perhaps one should leave the intellectuals to ramble on as the peons try and gleam knowledge as they read through their ugly disagreements and rants.

Yeah, that's a great system.

Thank goodness Ken Tanaka and Chris Hurd have some patience with the less than worthy.

[Charles Papert]

*sigh* I probably need to make my intentions clear here, although I'm sure that Justin knew where I was coming from--just don't want anyone else to misunderstand me.

When I said "how many years now have I had this discussion", it had nothing to do with the internet, or people asking questions, or even frustration. It is literally that it is one of those subjects that has a bit of voodoo to it, that everyone has a different opinion, and the funny thing is that it could easily be proved for once and for all with some simple tests. The reality is, I could take that proof and wave it in a given DP's face and have him say, "oh really? Huh. Well, I still don't like to use hard mattes, so don't use them". That is part of the way this business goes, for one reason or another--be it a function of habit, ego or otherwise.

I personally welcome questions from all as long as they are intelligently and respectfully posed, just as I made painstakingly sure to ask them when I was starting out. Otherwise I wouldn't participate on this board, where there is genuine respect and civility undertaken by almost all involved, far more so than on most boards.

The only part of Martin's thoughts that I think I can relate to is that there are many people on the Internet who seem to be too lazy to search a board before asking a question that has been covered before. That is a bit of a shame. I've probably done it myself, so who am I to throw stones, but I try not to, honest I do!

[Chris Hurd]

Some folks just don't know to search. That's simply a matter of re-education, I think, and around here we should all endeavor to teach people how to fish in a gentle, patient and accomodating way.

Say Charles, Adam Brooks and I are in town for ShowBiz Expo. Are you coming by sometime perhaps, from Saturday through Monday? At the LACC South Hall downtown. We'll be at the Canon booth. It would be great to see you again!

[Charles Papert]

I'll see you there Chris. If you can get to Cinegear & especially the crane expo on Saturday, definitely check it out--all the cool toys are there!

[Justin Chin]

Wish I could meet you guys at the expo. I registered a while a ago but unfortunately, I have shooting tests this weekend...

Have fun guys.