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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

4K Projector chips from JVC??

Along with the 4K projector, JVC has been showing around a prototype 4K camera, although it seems to be something leftover from a military contract, not intended for cinema use.

It has three CMOS sensors in a prism block. Each sensor is 3840 x 2048 (1.875 : 1 aspect ratio) and is 28.8mm across, making the sensor closer to the size and shape of the Dalsa sensor, oversized compared to a 35mm movie frame / RED sensor.

It only shoots at 30 fps and uses four HD-SDI-outs to send the signal to a recorder.
 
correct me if I am wrong but doesn't a three sensor design not have 35mm dof ?
Aloha
-A
 
You positive about that Gavin ?
Aloha
-A
 
It's the size of the sensor that determines the field of view characteristics, which in turn determines what focal lengths you choose, which affect depth of field.

It doesn't matter whether there are three sensors or one sensor -- a 1/3" CCD consumer camera has the same depth of field characteristics whether it is a single-sensor Bayer-filtered design or a three-CCD prism-block design.

Same goes for a 2/3" CCD camera and in this case, a 35mm-sized CMOS camera. There are now some 2/3" Bayer-filtered single-sensor cameras on the market -- they would have the same FOV and therefore DOF issues as their 3-CCD counterparts.

A prism-block design does affect other issues, like flange depth (which may affect what lenses you can put on the camera) and there are limitations in the speed of the lens (usually there is too much flare to allow a f/1.4 lens, hence why most 3-CCD lenses are limited to f/1.6 or so.)

The 3-strip Technicolor camera had a prism block which split the light in two directions, going to two 35mm gates (one had two pieces of film bipacked together for the second and third color record.) The depth of field was that for 35mm cine frame, only affected by the slow speed of the process and the inability to put short focal lengths on the camera due to flange depth problems.
 
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