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Gate masks and captured area


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I'm studying about masks and i'm a bit confused .. the shape of the masks is not a perfect rectangle  ... it has round edges .. and so the image on the hard matte frame has the same shape (like this original negative from Clockwork Orange outtake) 

So .. how you compose a frame ? On the viewfinder or the monitor you see the whole shape or a (cropped) perfect rectangle ...

that means that you MUST have also a groundglass to see where the margins are ?? 

Thanks !!

 

 

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typically with film projection one has a little smaller matte in the projector gate so that it actually crops the image a little bit MORE to get rid of the original camera aperture framing. Sometimes hard matting was done in the film printing as well, for example when doing blowups. 

If you are doing digital finishing you will typically scan the whole picture area you got including the original frame edges and maybe even more extra like some of the perforations and adjacent frames as well. Then you will crop the image later digitally to get the aspect ratio you want and to get perfect digitally made frame lines. As long as you can know the approximate final framing when shooting this will be totally fine and the camera gate aperture can be whatever can capture AT LEAST the area you need in the final image.

So the original camera aperture is not used very often for actual framing. One can of course use 2.39 or 1.85 mask in the camera aperture and do for example contact prints out of that negative and then project it with 1.37 or 1.66 gate for example so that the original camera aperture framing can be seen. But most often one wants to shoot a little wider and introduce the framelines in post to get more precise framelines AND to get better contrast to them (better blacks to the frame bars) . 

You can for example shoot 4-perf 35mm for digital finishing with spherical lenses for 2.39 final ratio and use 1.85 mask in the aperture. then either crop the image after the digital post is done (for 2.39 DCP formats) or to introduce 2.39 black bars to it (when doing TV and VOD release formats which are typically native 16:9 files with black bars if they allow the movie to not be pan-scan) . OR you can again introduce bars to fit the 2.39 image to the "spherical" DCP formats which are 1.85:1 natively. 

You will always want to introduce bars in the latest post production stage possible, no matter whether doing digital or film production and independent of the other workflow. With digital you will get soft and crappy looking bars too if you introduce them early on and then try to live with them throughout the post pipeline. Typically you need to add NEW bars in the end which are couple of pixels smaller than the original ones were to get rid of the soft and low contrast and possible compressed original bars. 

So typically NO final cropping added until you absolutely have to. Always in the latest stage possible. One additional reason for this is that intercutting different cameras would not be seamless if the original camera gate would be seen because every camera has a little bit different gate aperture (sometimes so clearly different that you can recognise which specific camera serial number it was if you have used it before)

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one important thing is that you can't grade an image which already has black bars in it (for example if having the 2.39 matte in your camera and wanting to keep those "original cropping bars" to the end but your image needs grading before release.  

If you would grade this type of image the bars would change colour as well. And you can't live with this so you would then later add NEW bars over the image which hide the original ones. The end result is the same than shooting originally with larger aperture and adding the bars later in post, BUT you will lose all the reframing possibilities and your aspect ratio changes a little (your originally planned 2.39 is now something like 2.41 ratio for example). So there is very rarely any reason to try to do final framing in the camera because you typically can't use that framing anyway in the end and you don't want the extra hassle of needing to get rid of of some useless black bars in the original image.  

So most often one shoots with the maximum frame area the film format allows and then crops in post, OR one uses a little bit larger aperture in camera to get for example 1.85 original image for 2.39 final image and, again, crops the image in post to the final dimensions. 

The only reason I can think of one would want to use original camera aperture would be if one would shoot reversal film for direct film projection of the original camera film and would want certain aspect ratio. THEN one could use for example 2.39 mask in the camera and project with 1.37 or 1.66 or 1.85 mask to show the original camera aperture framing in the final film. This is a very rare case though, making a single copy reversal silent film for direct projection. Some kind of arts piece maybe? not very practical in any case :) 

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1 hour ago, panagiotis agapitou said:

So .. how you compose a frame ? On the viewfinder or the monitor you see the whole shape or a (cropped) perfect rectangle ...

that means that you MUST have also a groundglass to see where the margins are ?? 

 


Yes with film cameras you must have a groundglass for framing and eye focussing. 

If you look at the Arri Groundglass catalogue
https://www.fdtimes.com/pdfs/howtos/ARRI_Groundglass_and_format_guide.pdf

each ground glass has the format mask outline just outside the frame lines, sometimes with a bit of extra look around room. The mask has no function in terms of operator framing, that is only done via the ground glass marks. The gate mask crops the exposed area down to just outside the framed area, which in previous times presumably prevented the wrong aspect ratio mask being used during projection of a direct print. Any monitors on set would be relaying the groundglass image.

When I worked at rental houses from the late 90s into the 00s hardly anyone used gate masks anymore, they just exposed the full aperture. 

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Allen Daviau used to use a 1.66 camera matte for his 1.85 movies, until he shot "Van Helsing" and ILM wanted the whole negative to be exposed in case they could use it for visual effects.  Today with processes like image stabilization, there is even more demand for recording a larger picture area than the composed area.

If shooting in 35mm, if you do use a camera matte, at least make it larger than the projection matte.

My early 35mm 1.85 films were shot with a 1.37 Academy matte, a bit wimpy, yes, but I got tired trying to get telecine operators to transfer dailies correctly with the image centered for sound, not silent.

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