Definite Image Circle Size for Epic 5K Sensor

[Andrew Rieger]

A couple of quick questions.

1. What is the exact minimum image circle necessary to cover the new 5K sensor. I have seen a host of answers including 28mm, 30mm, 32mm and even 34mm. Which is it?

2. Some people have mentioned that the 5K sensor's recorded image is slightly smaller than the size of the sensor, allowing for some unrecorded pixels to provide a viewing area outside the frame on monitors and EVF's. Is this true? Does this mean that the image circle of the lens does not have to cover the whole sensor but only the area of the recorded image?

3. Is the 4K mode of the Epic a windowed frame on the sensor? How does the 4K mode of the Epic compare to the 4.5K of the upgraded R1's in terms of image size?

 

[Jeff Kilgroe]

The S35 Mysterium-X sensor is 30mm x 15mm. So to cover the entire sensor, you would need an image circle of 33.54mm or call it 34mm.

The pixel or photosite size of the new sensor is the same as the original Mysterium sensor, which is 5.4um or 0.0054mm. So format sizes are the same as they are on the RED One or RED One w/ M-X upgrade. Of course, we can now record up to 5K -- or will be able to on the Epic, which I think most of us are expecting to be 5120x2540. So figuring that, 5K is smaller than the full 30x15 sensor dimensions. Which suggests the ability to have a look-around area as we do on the RED One.

So we have the following formats, their sizes and image circle coverage:

M-X Sensor - 30mm x 15mm - 34mm circle
5K = 5120x2540 - 27.65 x 13.83mm - 31mm circle

Everything smaller pretty much falls in line with what we have on the RED One currently. The M-X sensor being used to upgrade the RED One is also the same sensor that will be in the Epic-X, Epic-S35 and Scarlet S35.

 

[Andrew Rieger]

Thanks Jeff.

 

[Evin Grant]

Also the Epic sensor is a 2:1 aspect ratio, which is a beautiful ratio but less commonly used than 1.77, 1.85 and 2.35:1. So all of these ratios will require smaller image circles than 2:1. I'd guess once you factor engineering space, lookaround and aspect ratio you can probably call it 30mm for 2:1 and 28mm for 16x9, 1.85:1 and 2.35:1.

 

[David Mutchler]

I'm hoping the red 18-85 lens will cover the epic M-X.

 

[Humberto Rivera]

Image Circle

Image Circle

The FULL AREA OF THE SENSOR of the S35 frame is 5556 mm X 2780 mm with 15.4 megapixels of coverage and with a 33.55mm image diagonal with look around within the FULL AREA OF THE SENSOR.

However the ACTIVE PIXEL ARRAY itself, what is recorded in the camera sensor is 5120 mm X 2700 mm with a 13.8 megapixels and a 31.26 mm Image Diagonal, with the strange Aspect Ratio of 1.896:1 that some have called the X-35 Aspect Ratio.

So let’s say that the ACTIVE PIXEL ARRAY of 31.26 mm is the maximum area that is required to cover the Lens Image Circle outline by Matthew Duclos in his Diameter Database. Of course never going over the 31.26 mm Diameter of the S35 or S35-X.

Now the 1.85:1 could be cut off from the top of the frame (just slightly) and take it to the edge of the 5120 mm frame area leaving just a bit more for the lenses to go wider on its coverage, the megapixels should be similar from leaving the 2700 mm of the top (possibly with a slight change, but not much).

Now for the smaller 2.40:1 or the 2:1 frame area it’s just a matter of cutting the top of the 2700 mm frame area, but keeping the width of 5120 mm area active. The 16.9:1 can be arranged according to fit within the ACTIVE PIXEL ARRAY.

So it can actually work with existing High Quality Cine Lenses. All the Aspect Ratio fit well within the Red Pro Primes (25 mm at 34 mm of diagonal size and bigger) and the Arri/Zeiss Master Primes (16mm at 34 mm of diagonal size and bigger). It’s all about how far the Cine lenses can go out to cover the 5120 mm frame area, and that’s where Matthew Duclos Lens Image Diagonal Circle Chart of the Diagonal Database comes in.

The more I think about it, the more convincing this option it’s the better of two worlds. I was just thinking out loud. One more stop of ISO/ASA, a larger sensor still at 5.4 microns, and the new technology of modular assembly all wrap into one package. It’s like the Red One evolved into the S35 with all of its evolutionary advancements, but the lenses, tripods, lighting and all the other things remained the same, just pull the Red One out and put in the S35 or S35-X. It continues to evolve with Jim announcement of the new Color Science, his New Big Resolution News (at REDCODE 42), and God only know what waits in the wings, or in the imagination Graeme, Jim or whoever at RED.
Of course as Jim likes to say; "Everything in life changes... includes our camera specs and delivery dates..."

Humberto Rivera