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PL lenses and digital sensors


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Hello

 

Sorry if it's a silly question but i'm new to all that ...

 

These lenses from this RENTAL STORE are made for 35mm Film cameras ... right ?? (ARRI Master Prime , ZEISS T 1,3 , ZEISS T 2.1, Cooke S4, Cooke Zoom 20-100mm, Ultra Prime)

 

And also are compatible with Cine PL digital cameras like ALEXA, RED, Canon EOS C300PL etc ... Right ??

 

But according to this chart ... If I want to use a 18mm lens in the way Kubrick it .. it's impossible with the Digital cameras .. Right ??

 

And the CLOSEST to that is Canon C300 with 99% !! Right ??

 

So the Canon C300 is better on that point than the high end ALEXA and AMIRA ?!?!

 

And what is the solution to achieve an 100% result ???

 

Thank you !!

 

35mm_DigitalSensors_13.jpg

Edited by panagiotis agapitou
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Yes, those lenses are all cine lenses designed for S35 format, and they will work on digital cameras with S35 sized sensors. (The Cooke zoom is older but still just covers most S35 aspect ratios.)

 

Those percentages are just telling you how big the 16:9 sensor area is on various digital cameras compared to a S35 3 perf 16:9 frame. Most lenses made for S35 will cover at least a 30mm diagonal frame (see the image circle diameters needed for each camera in the circles next to the frames), often more. There are a few image circle databases around to give you a sense of how big a frame a lens will cover. There are new cameras around since that Abel Cine guide was made, like the Red Dragon, which have oversized sensors that are more problematic for some S35 lenses.

 

A slightly smaller sensor will result in a slightly smaller field of view, a slightly larger sensor will give a slightly larger field of view, but as long as the image circle created by a lens covers the sensor you don't need to worry about those pecentages. It's just a guide to get a sense of the differences in field of view on different cameras.

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Keep in mind that Kubrick used the 18mm on standard 35mm, not Super-35 (21mm width, not 24mm width) so in that sense, the cameras listed as being around 90% of Super-35 are closer to the field of view that Kubrick got with an 18mm. But that's being pretty nitpicky.

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Just comparing horizontal view, Kubrick's movies when projected in 35mm had an aperture width of 20.96mm, whether projected in Academy, 1.66, or 1.85.

 

So if 16x9 1080P on an Alexa uses a sensor width of 23.8mm, then an 18mm lens will have a wider field of view than it would for Kubrick. Divide 23.8 by 20.96 and you get a 1.1355X crop factor or conversion factor. So you'd have to use a 20.44m lens on an Alexa to match the view of an 18mm lens on a standard 35mm camera (not Super-35).

 

I wouldn't get worked up though about this small difference in field of view, not many people watching the image on the big screen are going to realize that the 18mm on the Alexa is giving a slightly wider view than it would on standard 35mm.

 

Truth is that they are using the largest possible dimensions for Super-35, 24.9mm (which they call "100%"), and compared to 20.96mm for projected standard 35mm, you'd have to use a camera listed as 84% on their chart to get closest to the view that Kubrick got when shooting!

 

Achieving "100%" is a somewhat meaningless goal.

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If you're talking about field of view of lenses, the Alexa normally uses a 2.8K area for most recordings like 2K ProRes, 1080P, etc. but can use a 3.2K area for 3.2K ProRes or 3.8K (UHD) ProRes. The max size recordable sensor area is 3.4K "Open Gate" in ARRIRAW.

 

2.8K is similar to Super-35 but beyond that, you get into slightly larger areas for 3.2K and 3.4K.

ALEXA_Classic_Recording_Areas-Surround_V

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  • 2 months later...

I want to thank you again !!! You have helped me so much !!!

If in post production i cut a centered and symmetric frame with 20.96 width (like the green one in the image) ...

6OF0g.png

  • So then I will have THE EXACTLY frame that Kubrick would have with it's 35mm FILM CAMERA ? Right ??
  • With the exactly same perspective ... Right ??

So in what MODE should the footage be recorder on ALEXA (I want in ARRIRAW) so that this "ZOOMED IN" would be lossless of quality on a 1080p export ??

 

Thanks again and Merry Christmas !!!!

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Yes, a 20.96mm sensor area would be the same as the projected width in a 35mm print of a Kubrick movie.
An ALEXA can be set to capture ARRIRAW in a 16:9 or 4:3 aspect ratio.
A 16:9 ARRIRAW frame is 2880 x 1620 pixels.
A 4:3 ARRIRAW frame is 2880 x 2160 pixels.
A 6:5 (4:3 cropped) ARRIRAW frame is 2578 x 2160 pixels.
An Open Gate ARRIRAW frame is 3414x2198 pixels.

 

ALEXA_Mini_SUP_4_-_RecordingAreas-P1.jpg

 

You can record any of these ARRIRAW formats with the right 4:3 Alexa and just create special frame lines to crop the sensor area in post to 20.96mm, but the closest RAW recording format to that width already is 6:5 (formerly called 4:3 cropped) or 2K Anamorphic.

 

However, I don't know if the 6:5 format automatically assumes you are using 2X anamorphic lenses and will be unsqueezing your monitor image, etc.

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