Image Circle Database

[Steven Hilder]

Well then it'll be much less useful. There may very well be some difference in the unused area (+/- 2-3%) but without at least a 10% lookaround it's not going to do you any good because you won't be able to see mics or other elements entering your frame. After all that's the whole point of it.

I agree to some degree, but unfortunately the figures that RED has already disclosed suggest the S35's lookaround will be around 8% (depending very much on the chosen aspect ratio, of course). Any lookaround is better than none at all.

Anyway, to get back to the original topic, my calculations show that most 5K modes will require around 30-31mm coverage.

[Evin Grant]

Even assuming 8% look around and 2% unused sensor edge you would still only need the 30mm image circle coverage for the 2:1 aspect ratio which is non standard. The 16:9 (1.77) Aspect ratio will only require a 27.5mm image circle and the 2:40 aspect ratio will require 29.25mm of coverage. I think most lenses will work just fine in the standard ratios we're used to shooting. this is actually one of the key benefits of a 2:1 aspect sensor. I also think that with Epic's custom frame sizes most DP's (including myself) will choose to lose a few lines of res. rather than their favorite cinema optics.

[Steven Hilder]

The 16:9 (1.77) Aspect ratio will only require a 27.5mm image circle

A 16:9 crop from the 5120x2700 usable area will be 4800x2700, which at 5.4 microns per pixel, equates to an image circle of 29.74mm.

I also think that with Epic's custom frame sizes most DP's (including myself) will choose to lose a few lines of res. rather than their favorite cinema optics.

I don't disagree; people are free to use whatever glass and aspect ratio they choose, I'm just keen to make all the data readily available, and as accurate as possible with the information we have right now, hence the chart.

[Evin Grant]

First off the S35 Mysterium-X chip is 30x15mm, native 2:1 aspect ratio. Therefore the maximum record area would be 5120x2560. I believe the 2700 number was published earlier by Red but this would not be "active" as far as I can tell. That would give a max 16:9 resolution of 4531x2560 x 4.5 microns = 24.5x13.8mm and an image circle of 27.5mm.

If you use 2700 as your record height then I see where your numbers are coming from.
However, the pragmatic approach (especially for post) would suggest if you can't achieve 5K in 16x9 to window down to the standard format of 4096x2305. 5k will be especially useful for 2.40 and 2:1 projects but my gut feeling is the majority of 16:9 and 1.85 projects (the ratio 75% of professional media is shot in these days) will still be acquired at the 4K standard.

[Humberto Rivera]

“If I design a new lens with a 30.10mm image circle, can I market it as an 'X35'-compatible lens? Sure, it wouldn't cover the full 5K active sensor area (which is a non-standard aspect ratio of 1.896:1), but it'll comfortably cover 5K at 2.40:1 and 16:9 aspect ratios.”

My understanding of: The Chart, that Steven is referring to list the full sensor with the look around area as 5556 X 2780, with 15.4 megapixels, the active pixel array as 5120 X 2700, with 13.8 megapixels, that’s were he gets the strange aspect ratio of 1.896:1, and the 2:1 aspect ratio of 5120 X 2560 with 13.1 megapixels.

It’s that correct?

Humberto Rivera

[Humberto Rivera]

One more thought, Matthew gets his Image Circle Diameter of 33.54 mm from the outside of the 5556 X 2780 image area. For the full Active Pixel Array it would be a diameter of 31.26.

Humberto Rivera

[Steven Hilder]

First off the S35 Mysterium-X chip is 30x15mm, native 2:1 aspect ratio. Therefore the maximum record area would be 5120x2560. I believe the 2700 number was published earlier by Red but this would not be "active" as far as I can tell. That would give a max 16:9 resolution of 4531x2560 x 4.5 microns = 24.5x13.8mm and an image circle of 27.5mm.

The maximum record area of the chip doesn't need to follow the same aspect ratio as the chip's exterior dimensions; I can't think of any requirement for a direct relationship between the two. Also remember that both horizontal and vertical pixel dimensions will generally be divisible by 4 to account for tiling in the wavelet codec.

True, the 5120x2700 area described as "Max Resolution" in the original DSMC announcement hasn't been mentioned in a while, but I'm going to assume it's still applicable until we hear otherwise. Remember the full height of the chip will be over 2700 pixels anyway - I wouldn't mind betting you'll be able to squeeze a larger 16:9 frame (ie. closer to "5K") into that area.

[Steven Hilder]

“If I design a new lens with a 30.10mm image circle, can I market it as an 'X35'-compatible lens? Sure, it wouldn't cover the full 5K active sensor area (which is a non-standard aspect ratio of 1.896:1), but it'll comfortably cover 5K at 2.40:1 and 16:9 aspect ratios.”

My understanding of: The Chart, that Steven is referring to list the full sensor with the look around area as 5556 X 2780, with 15.4 megapixels, the active pixel array as 5120 X 2700, with 13.8 megapixels, that’s were he gets the strange aspect ratio of 1.896:1, and the 2:1 aspect ratio of 5120 X 2560 with 13.1 megapixels.

It’s that correct?

Humberto Rivera

Humberto, yes, that's exactly what I'm predicting. The 5.4µm dot pitch is the spec that's least likely to change (as it's pretty fundamental to the pixel design), and Jim has referred to the 30x15mm S35 sensor several times this year, so I reckon they've finalised the physical dimensions (and therefore the full sensor's resolution), too. The only figure that might still be subject to change is the maximum recordable resolution, which was originally defined as 5120x2700 pixels. The rest is just arithmetic.

[Humberto Rivera]

Matthew, I don’t know if I getting too obnoxious with my suggestions, but they are just that, suggestions. Anyhow I was thinking that the following format might be a bit more useful, again is just a suggestion. Your web site looks great, and it will be better from week to week, thanks.

Make/Model - Focal Length
Zeiss Master Prime Dia/mm T Stop AOV

14mm T1.3 81°
16mm 34mm T1.3 70°
18mm T1.3 67°
21mm T1.3 60°
25mm 35mm T1.3 51°
27mm T1.3 48°
32mm 36mm T1.3 42°
35mm T1.3 38°
40mm T1.3 34°
50mm 40mm T1.3 27°
65mm T1.3 21°
75mm 42+mm T1.3 18°
100mm 42+mm T1.3 14°
150mm T1.3 9°
100mm Macro T2/T4.3/T32 14.02°/13.52°/12.42°

RED Pro Prime

18mm T1.8
25mm 34mm T1.8
35mm 36mm T1.8
50mm 41mm T1.8
85mm 43+mm T1.8
100mm 43+mm T1.8

Humberto Rivera

[Humberto Rivera]

Well the page I had did not translate from to what came out on the Red screen, sorry.

Humberto Rivera