Current RED Scarlet can't cover Super 35 area @ 4K???

[dean tsolakis]

Thanks Gavin,
based on 4k only using 89% of the 3 perf S35 area, and your AOV variances i guess its safe to conclude a 1.1x crop factor case closed!

 

[Gavin Greenwalt]

Ok that Duclos chart is either so poorly labeled that it's inaccurate or it is flat out inaccurate.

Something to keep in mind with the Arri Alexa is that while the sensor is s35 you don't record all of it when recording in pro-res... Which with the Alexa is synonymous with filming. It's actually right in between MX 4k and s35 @ 23.76mm. The Duclos chart is accurate on some values and wildly off on others so I can only assume it's simply wrong.

It's charts like that which inspired me to actually figure out the real numbers. (http://www.vfxnation.com/showthread.php/220-Camera-Specs-and-Resources)

 

[Eric Lange]

I think the information you want is here.

Thanks for posting that. That’s very handy.


The EPIC chip is 30 mm wide.

So again 30mm horizontal dimension = 5120 (photosites).

4k crop in is 4096 (photosites).

Therefore 30 * 4096/5120 = 24 mm (Horizontal width of 4k crop in).

From Fuller’s posted chart on the Abel Cine’s website…

The ARRI ALEXA is 23.8mm by 13.4mm [The usable diagonal is 27.8 mm].

There is negligible difference between 24mm (4k width on Scarlet) Vs. ALEXA 23.8mm horizontal dimension.

For comparing apples with apples I tend to use the horizontal field of view as a basis so that the different aspect ratios do not skew the comparison. Of course the image diagonal is crucial to figuring out whether the lens you choose has a sufficiently large image circle or whether or not the optical performance of the lens starts to break down in the corners of the image (in terms of distortion, light fall off, fringing and radial and tangential resolvability/MTF).

So the idea is that the Primes are designed for S-35…

According to ZEISS S-35 could be of the form

Normal 35 Academy aperture (aspect ratio 1.37:1. 22mm x 16 mm)
Or
DIN Super 35 Silent camera aperture (aspect ratio 1.33:1, 24mm x 18)
Or
ANSI Super 35 Silent camera aperture (aspect ratio 1.33:1, 24.9 x 18.7)

There seem to be various S-35 formats that are smidge smaller than 24mm (in Width, just like what Gavin is saying) and there are some standards and formats that are a smidge larger.

So in terms of function and apparent dimensionality and perceived angle of view you are not going to experience significantly different (if you like) angular projections from 4k Scarlet cropped in and a notional S-35.

Depending on your basis of comparison that you will have as notional "S-35" there will be a range of angular differences; an angular difference that tends basical to zero (i.e. no difference) to so something of the order of a +/- a couple of degress. In terms of look and feel that is really negligible.

In other words everything should work out just fine and you should not get any "Wow... that looks like an unexpectedly long lens..." effect. I.e. really surprising angular mis matches are not going to happen.

Just out of interest what primes are you wanting to use and at what focal lengths?

Cheers,

Eric

PS. The actual performance of the lens through the focusing range is going to make a bigger difference to how things appear and how close you want to focus for particular shots. Also don’t forget some primes have different floating elements and strategies for focusing and compensation of breathing. So I think it boils down more to the particular individual lenses you are fixin to use.

 

[James Stone]

Forgive my ignorance, but if I have to get an image close to 35mm which lens on Scarlet would be most appropriate.

Thanks
J

 

[Gavin Greenwalt]

Thanks for posting that. That’s very handy.


The EPIC chip is 30 mm wide.

So again 30mm horizontal dimension = 5120 (photosites).

4k crop in is 4096 (photosites).

Therefore 30 * 4096/5120 = 24 mm (Horizontal width of 4k crop in).

From Fuller’s posted chart on the Abel Cine’s website…

Except that it isn't. It's 27.65

The first thing I discovered when creating my format/spec list is that 90% of the information even from otherwise knowledgeable sources is wrong and shouldn't be trusted.

 

[Eric Lange]

Except that it isn't. It's 27.65

The first thing I discovered when creating my format/spec list is that 90% of the information even from otherwise knowledgeable sources is wrong and shouldn't be trusted.

Ok when RED.com says 30mm for Epic its actually 27.65

Gavin is that what you mean?

I guess when I wrote "Epic is 30mm wide" I should have put a question mark after it? It seemed like a nominal size...

So I now say assuming Epic is 27.65 mmm wide then [27.65 * (4096/5120)] = 22.12 mm for 4k crop in width on 5k Epic sensor.

So that's very close to Normal 35 Academy aperture (aspect ratio 1.37:1. 22mm x 16 mm)? At least in width.

That's interesting as that would influence my lense choice a bit for the applications we are pursuing (only by a couple of mms), but still a difference.

Interesting...

Ta for that Gavin.

Eric

Can anyone confirm the actual size of the Epic and Scarlet sensor aswell?

It is important.

 

[Eric Lange]

The difference in the field of view of a lens on Standard 35mm cine versus Super-35mm is minimal -- Super-35 is just 2mm wider than Standard 35mm cine!

I think on a 10mm lens, it's the difference between a 102 degree view versus a 96 degree view, which in practical terms, is not much.

Really, this is much ado about nothing... it's not like a wide-angle lens becomes a medium focal length because you've cropped a 24mm wide frame to 22mm.

If you had a 50mm lens on a Super-35 camera, you'd need a 45mm lens on a Standard 35mm cine camera to match the field of view. It's the sort of difference that can be accommodated in any number of ways, like backing the camera up a foot...

Basically what's being said here by David.

Cheers,

E.

 

[Eric Lange]

It's more like the difference between a 11.5 film camera and a 12 for the RED. Unless you've been shooting s35 digitally magically for the last 10 years your film has been getting cropped slightly from the maximum dimensions of the format. Most people you know are right. It's a microscopic difference between a format that is relatively new and almost identical to MX 4k.

The variation on projection/curtains from theater to theater will probably be greater than the difference between the two.

EDIT Ok I did the actual FOV calculations and an 10mm @ 4k (22.12) == 11mm @ s35 (24.49)

...And what you have said here...

Seems pretty straight forward.

Best

Eric

 

[Mike Garrick]

i would think that too...

and yet, if lens coverage is what counts, why would the chart only show Epic/Scarlet's sensor size? (http://ducloslenses.com/ref/formatref.pdf)
i agree that as a sensor size chart it should do just that
but i think it should also have a comment added that actual lens coverage is 27.7x14.6 mm


Hector Berrebi
PrePost consulting

If you look at the Duclos document you will see that the heading beside each 'sensor" is a measurement with a zero & a line through it, This represents the the maximum(?) image circle needed to create a full image on the sensor without vignetting by a lens . Hence a lens on Epic will need to create an image circle of 33.54mm and on Alexa, a lens will need to create an image circle 22.4mm. This is independent of sprocket holes & the like. Please remember this is a lens document not a sensor document. However as others have stated & knowing the source of the document, I wouldn't for a moment question it's veracity.

 

[Alexander Ibrahim]

As your understanding of optics is so lacking you need to ask the question if you should buy a camera at all.

Don't be an a**hole.

That's my job.

 

[Alexander Ibrahim]

Another summary for photographers.

Epic is roughly equivalent to an APS-H size sensor at 5K, and so is Scarlet.

At 4K both of these cameras are roughly APS-C sensors ... like a Canon 7D or a Red One.

Roughly.

So, if I understand the question ... the lenses will be "cropped" a bit when shooting 4K compared to full frame 5K, but its very close to the standard used in motion pictures for decades.

In any case there is no reason to worry. Just about any lens that works on an APS-H camera (like the 1DMK4) will work beautifully with the Epic or Scarlet.

Now, what was written before me was more precise ... but this is the gist of the discussion I think. About right guys?

 

[Brennan Clark]

I'm wondering if you could use a HyperDeck Shuttle thing to record full frame HD if the camera was set to 5K? Like, you know you're only gonna need whatever you're shooting in HD, so hook up the HyperDeck to maximize the sensor and save some hard drive space. Anyone have any thoughts on this idea? Maybe there are other external recorders out there to take care of it. Maybe someone will invent one if not.

 

[Alexander Ibrahim]

I'm wondering if you could use a HyperDeck Shuttle thing to record full frame HD if the camera was set to 5K? Like, you know you're only gonna need whatever you're shooting in HD, so hook up the HyperDeck to maximize the sensor and save some hard drive space. Anyone have any thoughts on this idea? Maybe there are other external recorders out there to take care of it. Maybe someone will invent one if not.

Well, sort of.

Yes you can use a Hyperdeck, it will work just fine.

The Hyperdeck only records uncompressed last I checked.

That isn't going to save you space.

I recommend something like the Sound Devices PIX series if you only want 1080p and want to to save disk space.

 

[Brennan Clark]

Well, sort of.

Yes you can use a Hyperdeck, it will work just fine.

The Hyperdeck only records uncompressed last I checked.

That isn't going to save you space.

I recommend something like the Sound Devices PIX series if you only want 1080p and want to to save disk space.

Ok good point. I was just trying to think of a way to maximize the sensor. Maybe if you could capture a 1080 60p stream off the full sensor, that might come in handy, but otherwise you're not really gaining anything. You may get to use the full sensor, but you're losing redcode and resolution and not gaining anything when it comes to disk space conservation.

 

[Les C.]

For the optically/mentally challenged, is there a calculator that would show the FOV dimensions at a certain distance with a certain xx mm lens when shooting 4K?

For example, if I'm trying to pick a lens that will give me at 10 feet, a FOV 10' wide, it would be great to be able to plug some figures into a calculator (desired distance, desired visible width), and figure out what lens in mm I'd need to buy and what the FOV height would be at that distance?

 

[James Stone]

Hi Gurus,
Is there any book/source to get a basic understanding of the technicalities of framing?

 

[David Battistella]

Gavin

Your sensor chart shows the M and MX chip as exactly the same size. That clears up a bit of misinterpretation that MX and M are different size chips. I suspect it's one of those sales things where people who upgraded to MX started telling people it's a bigger better chip, when it's the same size with better noise handling and a different OLPF.

Thanks Gavin.

 

[Hector Berrebi]

If you look at the Duclos document you will see that the heading beside each 'sensor" is a measurement with a zero & a line through it, This represents the the maximum(?) image circle needed to create a full image on the sensor without vignetting by a lens . Hence a lens on Epic will need to create an image circle of 33.54mm and on Alexa, a lens will need to create an image circle 22.4mm. This is independent of sprocket holes & the like. Please remember this is a lens document not a sensor document. However as others have stated & knowing the source of the document, I wouldn't for a moment question it's veracity.

the circle with the line is angular diameter, it does what you stated.
my confusion (still) is whether the angular diameter should be derived from the sensor size (30x15) or from the lens coverage stated in the specs (27.7x14.6)

i do realize differences are minor, and will have little to no affect on my work... like someone here wrote, nothing you can't solve by slightly backing up your camera.
my interest is purely theoretical.

hector

 

[Eric Lange]

For the optically/mentally challenged, is there a calculator that would show the FOV dimensions at a certain distance with a certain xx mm lens when shooting 4K?

For example, if I'm trying to pick a lens that will give me at 10 feet, a FOV 10' wide, it would be great to be able to plug some figures into a calculator (desired distance, desired visible width), and figure out what lens in mm I'd need to buy and what the FOV height would be at that distance?

That would be a nice little app.

That has to exist somewhere… right?

I was thinking if it has a smidge of 3d rendering then you could show the “dimensionality” of each lens selection. i.e. the degree of foreshortening. Or graphically overlay the set ups and projections of different formats and lens selections.

I’m sure some of the pre-viz software that’s out there has reasonably accurate viewing frusta. No doubt there is some classic book put out by focal press that would have simple formulae and look up tables. Failing that, a pad of paper and some basic trigonometry… (twist the arm of a bright twelve year old to show you how he or she really uses the inverse tan function on his or her scientific calculator).

Very Best,

Eric

 

[Gavin Greenwalt]

Gavin

Your sensor chart shows the M and MX chip as exactly the same size. That clears up a bit of misinterpretation that MX and M are different size chips. I suspect it's one of those sales things where people who upgraded to MX started telling people it's a bigger better chip, when it's the same size with better noise handling and a different OLPF.

Thanks Gavin.

Careful at any given resolution they're the same sized chip. Important qualifier. M is only 4.5k while MX goes to 5k so it's physically larger but yes when cropped to 4k, 4.5k, 2k etc they're identical for the purposes of format size.

To quote Graeme

The M-X sensor has the same 5.4micron pixel pitch as the original in the RED One, but the active area is larger, out to 5120x2560.

To calculate RED sensor size in mm simply use:

5.4 * Resolution / 1000

So

5.4 * 5120 / 1000 = 27.648mm

Also that's what RED.com lists (but rounded up)
http://www.red.com/products/epic
27.7mm (h) x 14.6mm (v) x 31.4 mm (d)