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S35 Frame Sizes

Charles Angus

Charles Angus

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I was wondering what the theory is behind the 30mmx15mm frame size of the new S35 cameras. S35 on film is about 25mmx19mm for 4:3. S35 film for 16x9 would be about 25mmx14mm.

So, wouldn't a 30mm wide frame just mess up people's perception of what their lenses look like, in addition to excluding the use of some lenses which don't cover the format? Why not make the active area simply ~25mmx14mm, or ~25mmx19mm?

To clarify, I'm not criticizing, just curious. I feel there must be some advantage I'm missing out on.
 
Charles Angus said:
I was wondering what the theory is behind the 30mmx15mm frame size of the new S35 cameras. S35 on film is about 25mmx19mm for 4:3. S35 film for 16x9 would be about 25mmx14mm.

So, wouldn't a 30mm wide frame just mess up people's perception of what their lenses look like, in addition to excluding the use of some lenses which don't cover the format? Why not make the active area simply ~25mmx14mm, or ~25mmx19mm?

To clarify, I'm not criticizing, just curious. I feel there must be some advantage I'm missing out on.
Click to expand...

You don't need all 30mm width for 5K. And remember that lenses are circular (sorry) and are concerned about the diagonal... not the width.

And you can choose a format that only covers S35 (and all standard lenses), but that is about 4K.

Jim
 
If we assume the same amount of look around area as the Red One then we can come to some speculative conclusions about actual recording dimensions.

R1 chip size is 24.4x13.7mm (16x9)
R1 full pixel array is 4900x2580
R1 chip active chip area 22.5x13.5mm
R1 active pixels 4520x2540
R1 Currently useable area 20.4x12.2mm
R1 currently useable pixels 4096x2304

Epic chip size is 30x15 (+18.6% horiz. Vs. R1)
Epic full pixel array (estimated) 5520x2742
Epic active pixel area 2:1 (estimated) 27.7x14.7mm
Epic active pixel array (2:1 according to brochure) is 5120x2560
Epic active pixel area 16:9 (estimated) 25.8x13.94
Epic active pixel array 16:9 (estimated) is 4779x2700
epic active pixel area 2.40:1 (estimated) is 27.7x11.6mm
Epic active pixel array 2.40:1 (estimated) is 5120x2133

I'll channel Brook here and make a chart...
EpicCoverage.jpg


Interestingly the 16x9 frame will be the most forgiving for lens coverage, followed by 2.40:1. The almost 2:1 aspect ratio chip is a nice compromise for shooting all three ratios.

Jim please feel free to check my math on this.
 
Overall package size might change a bit, but the meat of the active area is very close to what Evin has posted.

Jim
 
Häakon said:
Why would we get more height out of the sensor in 16x9 mode than 2:1?
Click to expand...

The shorter the height, the deeper you can get into the width. Full 5120 is 2:1 or 2.4:1. 16:9 is a bit less horizontal resolution as shown by Evin's chart.

We are cramming a lot of capability into a small sensor. No matter how you do it, something gives somewhere. The sensor design is locked down. Now we just have to all find our best way to use it.

Jim
 
Jim

I think it is great that the sensor is 2:1. Def the best all round compromise.

I realise frame size has an impact on potential frame rate and like the red 1, which has higher frame rates with 2:1 (smaller frame size), will Epic squeeze a little extra out with 16:9?

The closer we get to a Arri 435 replacement on frame rates the better for many. Without obviously dropping to massive FOV changing sizes.

Hopefull you'll squeeze a bit more out! Just like that extra .5 of a stop! ;-)

Michael L
 
Jannard said:
The shorter the height, the deeper you can get into the width.
Click to expand...
Ah, that clarifies things... thanks. I didn't realize that even the RPPs didn't cover Epic and Scarlet's entire sensor area. I suppose the obvious question is "why not," but that's a topic for another discussion. :)

I agree with Michael; in an age where 1.85:1 and 2.40:1 are the most common flavors of aspect choices, a 2:1 sensor is the best choice. 2:1 is also a fantastic ratio in itself.
 
They cover the entire recording area, and Jim has said the RPPs actually cover greater than 32mm (Up to 34mm) he just doesn't want to publish that because it's a little different for each lens.

As strange as this might sound I'm actually looking forward to seeing my old T2.1s on this new sensor the edge falloff/vingette may look wicked cool!
 
Evin Grant said:
They cover the entire recording area, and Jim has said the RPPs actually cover greater than 32mm (Up to 34mm) he just doesn't want to publish that because it's a little different for each lens.
Click to expand...
If that's the case, then it doesn't make sense that one can get a taller frame from a 2:1 sensor by shooting in a 16:9 mode.
 
Häakon said:
If that's the case, then it doesn't make sense that one can get a taller frame from a 2:1 sensor by shooting in a 16:9 mode.
Click to expand...

The 5K Epic sensor record area is actually 1.9:1 in aspect ratio, I assumed that the 2:1 mode would use the entire width, but actually be a true 2:1 and the 16:9 would use the full height. Hence the 16:9 frame is ever so slightly taller than the 2:1 (2560 Vs. 2700 Pixels).
 
So the old standards for sure will not cover the full 5k? When I first bought them and had them projected, I was told it should cover beyond 4k..?
 
Häakon said:
I agree with Michael; in an age where 1.85:1 and 2.40:1 are the most common flavors of aspect choices, a 2:1 sensor is the best choice. 2:1 is also a fantastic ratio in itself.
Click to expand...

Hmmm... 2:1 sensor that is larger than Super-35... sounds like the Dalsa. I remember people complaining "hey, why isn't the Dalsa sensor 16x9 and why isn't it 24mm wide?" Now that's suddenly a good thing now that RED is doing it?
 
Evin Grant said:
The 5K Epic sensor record area is actually 1.9:1 in aspect ratio, I assumed that the 2:1 mode would use the entire width, but actually be a true 2:1 and the 16:9 would use the full height. Hence the 16:9 frame is ever so slightly taller than the 2:1 (2560 Vs. 2700 Pixels).
Click to expand...
Gotcha - well that helps. I keep seeing 30x15mm being thrown around (as it is in the first post of this topic) - which is obviously a 2:1 ratio - but if that's not recordable area information, it's pretty irrelevant.

RED really should be quoting the maximum active (usable) area of the sensor for purposes of lens coverage and frame size calculations and not the "dummy area"; that would solve a lot of problems.

That being said, I think you still have some math wrong. In your list, there are more pixels in the 16:9 area height than the 2:1 (which we have now resolved), but the physical height of the 16:9 area you list is shorter than the 2:1 area. Additionally, 25.8x13.94mm is not a 16:9 ratio (it's 1.85:1 instead of 1.77:1). I think that's why I was getting confused; if both the physical height and width of the 16:9 format are smaller than 2:1, there shouldn't be more total pixels. :) It's hard to calculate the total active area if we don't know the full usable height of the sensor.

David Mullen ASC said:
Hmmm... 2:1 sensor that is larger than Super-35... sounds like the Dalsa. I remember people complaining "hey, why isn't the Dalsa sensor 16x9 and why isn't it 24mm wide?" Now that's suddenly a good thing now that RED is doing it?
Click to expand...
You can go back and find any post I have ever made on this website... I have never championed for keeping sensors constricted to a s35 size (on the contrary, I've been pretty vocal in opposing it). I just think that 2:1 is a great aspect for a sensor, regardless of size.

To be blunt, I think the 645 is where the Epic line should truly start, but I guess some revolutions take time...
 
(r)yan said:
So the old standards for sure will not cover the full 5k? When I first bought them and had them projected, I was told it should cover beyond 4k..?
Click to expand...

Unfortunately, whoever told you that was just trying to sell you a lens. They couldn't possibly know that, because metrics related to number of pixels (such as '4K') tell you nothing about the physical size of the sensor.

For example, the 3K Mysterium-X, 5K Mysterium-X, 6K Monstro, and 28K Monstro all have different sized pixels. Yet the 9K Monstro uses the same sized pixels as the 6K Monstro!

Or that 36x24mm Monstro could have been 2K or 8K instead of 6K if they'd felt like it!
 
They weren't selling them, I had just bought them (pending projection). Bought them 3500 was a steal. Looks like I will be windowing my scarlet.
 
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