Red One FOV

[teamgoo]

I have a few questions regarding the FOV of the RED.

Is the RED's sensor FOV the same as a 35mm cinema film camera? If I mount a 50mm Ultra Prime on an Arri film camera will it have the same FOV as mounting the same lens on the RED?

In addition then will a SLR lens, FF35mm, have a magnification factor going to the slightly smaller sized RED sensor, in the same way Nikon makes DX lenses which are a smaller barrel size than the regular 35mm lenses are.

Ben

 

[Vigen Vartanov]

Check this link : http://reduser.net/forum/showthread.php?t=23770

 

[Alberto Caprioglio]

I'd say in proportion

 

[Simma]

Does anyone know what chip-size (in mm) RED One uses for 4K 16:9 and 2K 16:9? I need this to calculate my FOV, but I haven't found any official numbers.

Thank you in advance

 

[Dominic Jones]

Is the RED's sensor FOV the same as a 35mm cinema film camera? If I mount a 50mm Ultra Prime on an Arri film camera will it have the same FOV as mounting the same lens on the RED?

Well, that depends on what gate/glass you've got installed in the Arri camera! ;-)

Red's sensor is essentially 3-perf 35mm in size (it's actually a wee touch smaller, giving you a very slightly tighter FoV than you would get on 3-perf, but nothing you'd particularly notice without shooting a framing chart)

Hope that helps mate,
Dom.

 

[David Mullen ASC]

The RED ONE sensor is 24.4mm x 13.7mm at 4520 x 2540 pixels.

So it's not hard to calculate the size of the area used on the sensor for an image that is 4096 x 2304 (4K 16x9).

Just using a calculator, it comes out to be about 22.11mm x 12.44mm.

Just divide everything by half to get the 2K measurements.

In comparison, a 16x9 extraction for HDTV from 3-perf Super-35 is 23.10mm x 12.98mm.

Generally though you can consider Super-35 width to be 24mm and Academy (sound) width to be 22mm.

 

[Simma]

Thank you David! Do you mind showing me the math you did to come up with those numbers?

 

[David Mullen ASC]

... divide 24.4mm by 4520 pixels and then multiply the results by 4096 to get the horizontal dimensions for that many pixels...

16x9 or 16:9 is the same ratio as 1.77777... : 1 (just divide 16 by 9.)

This can be useful when using a calculator to figure out sizes if you know the ratio of width to height.

Hence 4096 divided by 1.7777777... gets you about 2304, so 4K 16x9 (given that "4K" means 4096 and "2K" means 2048) comes out to be 4096 x 2304. Now I don't know if that is the "official" dimension or not, these numbers are just what comes out of my calculator. You never know what official standards are being used because some numbers are rounded up or down.

 

[Alexander Christ]

For direct calculations, you can use 5.4u (0.0054mm) for the pixel size. 4096 x 0.0054 = 22.1184

 

[teamgoo]

Thanks alot for the great info David and everyone. So then it is safe to say that the FOV for Cine glass will be pretty close when used on the RED.

Cheers,

Ben

 

[shaneholloman]

The RED ONE sensor is 24.4mm x 13.7mm at 4520 x 2540 pixels.

So it's not hard to calculate the size of the area used on the sensor for an image that is 4096 x 2304 (4K 16x9).

Just using a calculator, it comes out to be about 22.11mm x 12.44mm.

Just divide everything by half to get the 2K measurements.

In comparison, a 16x9 extraction for HDTV from 3-perf Super-35 is 23.10mm x 12.98mm.

Generally though you can consider Super-35 width to be 24mm and Academy (sound) width to be 22mm.

This is brilliant info David - How do we extrapolate these calculations to a lens multiplier factors (Sensor Crop)?

Example:
footage shot at 3840x2160 makes a sensor to:
5.4u x 3840 = 20.7292mm in X
5.4u x 2160 = 11.6601mm in Y

A 18mm film lens would equal: ??mm. Also does the full Red One sensor (4520x2540) perfectly match an 18mm lens? Still getting my head around it - I feel close - I hope! lol

 

[Maciej Orman]

http://www.abelcine.com/fov/