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Brook Willard
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Alright, let's talk about sensors here. Not Monstro... because we know nothing about it and it won't be around for at least a year after Epic arrives. Just Epic and the "X" sensor it'll ship with.
The place to start is with the RED ONE. Here's what we know:
The RED ONE full active pixel array is 4,900 x 2,580. The extra pixels on the sensor were originally specced to be used for black calibration, etc.
The maximum useful sensor area of the RED ONE is 4,520 x 2,540, sized 24.4mm x 13.7mm.
The maximum CURRENT recording resolution is 4K: 4,096 x 2,304. This was always specced as the primary shooting resolution of the camera: 4K. It is what we all think of when we think of 4K these days and is what I will base most of my calculations off of. The 4K recording area of the sensor is 22.11mm x 12.44mm.
To compare, three-perforation Super 35mm film gates are 24.89mm x 14.0mm. Granted, there are multiple gates available... but this will be the figure I use for the sake of this thread.
There is, of course, four-perforation Super 35mm film - sized at 24.89mm x 18.66mm.
When all relevant formats are put into a diagram, this is what it looks like:
There are a few things to take away from this:
First, the RED ONE 4K recording area is significantly smaller than a normal three-perforation Super 35mm film gate. While there is generally some cropping applied to a film negative before it reaches final distribution, that figure changes and is not measurable for the sake of this discussion.
So, for the sake of this discussion, the RED ONE 4K we've all become so familiar with is only 78.93% the size of a normal three-perforation film gate. This will surprise some, but there is indeed a subtle field of view conversion factor with the RED ONE when shooting 4K. A 50mm lens on a RED ONE in 4K will have the apparent FOV of a 63mm lens on a standard three-perforation gate.
This will surprise some, but it is the nature of the beast. It has not bothered many over nearly a year of field production. That's not to say I like it, just that I accept it.
Another thing to note is the relation between the 4.5K look-around area of the RED ONE versus the 4K recording area. The look-around area is 21.65% larger than the recorded area. Something to remember.
The amount of "look-around" on a film camera varies on the viewfinder optics, ground glass and position of the moon in relation to the sun. Regardless, just know that that area is indeed outside of the size of the film gate.
So this is how it all stands today. There are good things and bad things about all of this... but it is what we have with the RED ONE. The great thing about the Epic is that it's an opportunity to improve upon the RED ONE with all of the lessons we [and RED] have learned along the way.
So, Epic.
The only sensor specification we have for Epic at this point is that its 5K recording resolution is planned at 5,120 x 2,880. Since RED will not put an optical viewfinder with spinning mirror shutter on the camera, one must assume that there will be a look-around area to this camera as well.
Since Epic is a thoroughly professional camera specifically designed for film production [not ENG/EFP, not to replace a video camera, not to be a great upgrade from an HVX, etc], I personally feel that every opportunity to make it the best cinema-style camera possible should be taken. Since we're only talking about the sensor in this thread, that's where we'll start.
While the RED ONE 4K FOV has not bothered many in 16:9 shooting, that is not to say that it isn't perfect. For the Epic, the actual 5K recording area absolutely should be the full size of a Super 35mm film gate - no more and no less.
That would mean that the 5K recording area in 16:9 mode should be 24.89 x 14mm.
Based on the RED ONE's look-around area's size in relation to the recorded area, Epic's look-around area should be 21.65% larger than the recorded area. That means that the sensor's look around area should be 27.47 x 15.45mm. By the same math, its resolution should be 5.6K: 5,650 x 3,178 pixels.
Having a sensor that large will result in vignetting in the look-around area... just as the "look-around" area in an optical viewfinder on a film camera will vignette on certain lenses. Regardless, the sensor must be that large in order to be the same size as Super 35mm film while still retaining the look-around area that people love so much.
When all of these dimensions get put down onto the same diagram, this is what we get:
Epic is yellow. I was too lazy to add labels.
With Epic added, it's still very clear that RED is lacking something that film still has: a four-perforation frame. While it may seem old fashioned, many commercials still shoot 4:3. More importantly, many projects shoot anamorphic.
Now obviously one can shoot a 4:3 extract out of a RED ONE 4K frame for the sake of anamorphic. There is a conversion, of course, but many people are accepting of it. Ever see that put down on paper?
For those playing at home, shooting a 4:3 extract on a RED ONE in 4K is 44.43% the size of a four-perforation film gate. That's a 225% conversion factor. Ouch. Think 16mm film.
Now when RED enables the inevitable 4.5K anamorphic mode, the size will be 53.88%. Relative to the Arri D-21, the RED ONE 4:3 extract is 59% the size. So this will get better... but it'll never be good.
Accordingly, since the Epic is a truly professional cinema camera, it needs to have a real 4:3 four-perforation sensor. No more conversion factors, no more nonsense, just a real film-sized sensor.
Besides, one cannot help but to point out the irony of a camera named "Epic" that can't shoot anamorphic properly.
To match a four-perforation film gate, the Epic's 5K recording area should be 24.89 x 18.66mm. By this math, the resolution would be 5,120 x 3,840.
Next, the sensor still needs to be large enough to have a proper look-around area. By the 21.65% conversion used on the RED ONE, the Epic's sensor should be 27.47 x 20.61mm with a full resolution of 5,650 x 4,238. That's 23.9 megapixels, kids.
Put into our favorite diagram, here are the final formats:
Nice. Now that's how it should be.
That said, it's only a 23.14% pixel density increase. If the Epic's 5K sensor was exactly the same size as the RED ONE's 4.5K sensor, there would be a 28.43% pixel density increase. So not only should this size and resolution increase make the sensor more comparable to film, it would also result in a lower pixel density which means higher sensitivity and lower noise. We're not talking about shoehorning a zillion pixels into a small space... just making the space larger.
Those are my thoughts on the sensor. Obviously RED has their lips zipped about any specifications beyond the marketing materials we received at NAB, so it's hard to know where things stand on the camera's development.
Regardless, this is what I want out of this sensor. I may have buggered up some math here, but I think that the logic is sound. I just want a properly film-sized recording area with look-around. I'd prefer the sensor to be four-perforation instead of three-perforation as well.
Thoughts? Anybody from RED care to comment?
The place to start is with the RED ONE. Here's what we know:
The RED ONE full active pixel array is 4,900 x 2,580. The extra pixels on the sensor were originally specced to be used for black calibration, etc.
The maximum useful sensor area of the RED ONE is 4,520 x 2,540, sized 24.4mm x 13.7mm.
The maximum CURRENT recording resolution is 4K: 4,096 x 2,304. This was always specced as the primary shooting resolution of the camera: 4K. It is what we all think of when we think of 4K these days and is what I will base most of my calculations off of. The 4K recording area of the sensor is 22.11mm x 12.44mm.
To compare, three-perforation Super 35mm film gates are 24.89mm x 14.0mm. Granted, there are multiple gates available... but this will be the figure I use for the sake of this thread.
There is, of course, four-perforation Super 35mm film - sized at 24.89mm x 18.66mm.
When all relevant formats are put into a diagram, this is what it looks like:
There are a few things to take away from this:
First, the RED ONE 4K recording area is significantly smaller than a normal three-perforation Super 35mm film gate. While there is generally some cropping applied to a film negative before it reaches final distribution, that figure changes and is not measurable for the sake of this discussion.
So, for the sake of this discussion, the RED ONE 4K we've all become so familiar with is only 78.93% the size of a normal three-perforation film gate. This will surprise some, but there is indeed a subtle field of view conversion factor with the RED ONE when shooting 4K. A 50mm lens on a RED ONE in 4K will have the apparent FOV of a 63mm lens on a standard three-perforation gate.
This will surprise some, but it is the nature of the beast. It has not bothered many over nearly a year of field production. That's not to say I like it, just that I accept it.
Another thing to note is the relation between the 4.5K look-around area of the RED ONE versus the 4K recording area. The look-around area is 21.65% larger than the recorded area. Something to remember.
The amount of "look-around" on a film camera varies on the viewfinder optics, ground glass and position of the moon in relation to the sun. Regardless, just know that that area is indeed outside of the size of the film gate.
So this is how it all stands today. There are good things and bad things about all of this... but it is what we have with the RED ONE. The great thing about the Epic is that it's an opportunity to improve upon the RED ONE with all of the lessons we [and RED] have learned along the way.
So, Epic.
The only sensor specification we have for Epic at this point is that its 5K recording resolution is planned at 5,120 x 2,880. Since RED will not put an optical viewfinder with spinning mirror shutter on the camera, one must assume that there will be a look-around area to this camera as well.
Since Epic is a thoroughly professional camera specifically designed for film production [not ENG/EFP, not to replace a video camera, not to be a great upgrade from an HVX, etc], I personally feel that every opportunity to make it the best cinema-style camera possible should be taken. Since we're only talking about the sensor in this thread, that's where we'll start.
While the RED ONE 4K FOV has not bothered many in 16:9 shooting, that is not to say that it isn't perfect. For the Epic, the actual 5K recording area absolutely should be the full size of a Super 35mm film gate - no more and no less.
That would mean that the 5K recording area in 16:9 mode should be 24.89 x 14mm.
Based on the RED ONE's look-around area's size in relation to the recorded area, Epic's look-around area should be 21.65% larger than the recorded area. That means that the sensor's look around area should be 27.47 x 15.45mm. By the same math, its resolution should be 5.6K: 5,650 x 3,178 pixels.
Having a sensor that large will result in vignetting in the look-around area... just as the "look-around" area in an optical viewfinder on a film camera will vignette on certain lenses. Regardless, the sensor must be that large in order to be the same size as Super 35mm film while still retaining the look-around area that people love so much.
When all of these dimensions get put down onto the same diagram, this is what we get:
Epic is yellow. I was too lazy to add labels.
With Epic added, it's still very clear that RED is lacking something that film still has: a four-perforation frame. While it may seem old fashioned, many commercials still shoot 4:3. More importantly, many projects shoot anamorphic.
Now obviously one can shoot a 4:3 extract out of a RED ONE 4K frame for the sake of anamorphic. There is a conversion, of course, but many people are accepting of it. Ever see that put down on paper?
For those playing at home, shooting a 4:3 extract on a RED ONE in 4K is 44.43% the size of a four-perforation film gate. That's a 225% conversion factor. Ouch. Think 16mm film.
Now when RED enables the inevitable 4.5K anamorphic mode, the size will be 53.88%. Relative to the Arri D-21, the RED ONE 4:3 extract is 59% the size. So this will get better... but it'll never be good.
Accordingly, since the Epic is a truly professional cinema camera, it needs to have a real 4:3 four-perforation sensor. No more conversion factors, no more nonsense, just a real film-sized sensor.
Besides, one cannot help but to point out the irony of a camera named "Epic" that can't shoot anamorphic properly.
To match a four-perforation film gate, the Epic's 5K recording area should be 24.89 x 18.66mm. By this math, the resolution would be 5,120 x 3,840.
Next, the sensor still needs to be large enough to have a proper look-around area. By the 21.65% conversion used on the RED ONE, the Epic's sensor should be 27.47 x 20.61mm with a full resolution of 5,650 x 4,238. That's 23.9 megapixels, kids.
Put into our favorite diagram, here are the final formats:
Nice. Now that's how it should be.
That said, it's only a 23.14% pixel density increase. If the Epic's 5K sensor was exactly the same size as the RED ONE's 4.5K sensor, there would be a 28.43% pixel density increase. So not only should this size and resolution increase make the sensor more comparable to film, it would also result in a lower pixel density which means higher sensitivity and lower noise. We're not talking about shoehorning a zillion pixels into a small space... just making the space larger.
Those are my thoughts on the sensor. Obviously RED has their lips zipped about any specifications beyond the marketing materials we received at NAB, so it's hard to know where things stand on the camera's development.
Regardless, this is what I want out of this sensor. I may have buggered up some math here, but I think that the logic is sound. I just want a properly film-sized recording area with look-around. I'd prefer the sensor to be four-perforation instead of three-perforation as well.
Thoughts? Anybody from RED care to comment?
