Question on Origin, D20 and Genesis

[Guest Jennifer Pun]

Hello,

 

I'm currently conducting some research on the comparisons between the Dalsa Origin, Arriflex D20 and the Panavision Genesis. My knowledge is fairly limited so please bear with me. If someone can please clarify the following points for me that would be greatly appreciated! Thanks!

 

1) The Origin states that it is 4K digital capture, is the Genesis and D20 2K digital capture only?

 

2) The origin notes 4:4:4 bayer pattern - what is the equivalent for D20 and Genesis? Is the Genesis then 4:4:4 HDSDI?

 

3) What are the key specs that you would look for when comparing the three cameras? I have noted the Lenses, lens mount, depth of field, sensor, weight, fps.

 

4) The Genesis promotes that it is a true RBG sensor and not Bayer pattern. What does this mean? What does D20 use?

 

Thanks for your assistance!

 

Best regards.

[Ilmari Reitmaa]

1) The Origin states that it is 4K digital capture, is the Genesis and D20 2K digital capture only?

 

2) The origin notes 4:4:4 bayer pattern - what is the equivalent for D20 and Genesis?  Is the Genesis then 4:4:4 HDSDI?

 

3) What are the key specs that you would look for when comparing the three cameras?  I have noted the Lenses, lens mount, depth of field, sensor, weight, fps. 

 

4) The Genesis promotes that it is a true RBG sensor and not Bayer pattern.  What does this mean?  What does D20 use?

<{POST_SNAPBACK}>

 

1 & 2) For D-20, the technical specs are available online at http://www.arri.com/prod/cam/d_20/tech_spec.htm

 

There are different modes of operation for D-20, in "Film Mode" the camera is more or less 3k 12-bit raw Bayer-data, in "Video Mode" the capture is HD-resolution x 1.5 (to make up for information lost in Bayer-interpolation) and the output 1920x1080, either 4:2:2 YCbCr or 4:4:4 RGB.

 

For Genesis, see http://www.panavision.com/product_detail.p...de=c0,c202,c203

 

Genesis is single-sensor 5760x2160 (non-square pixels) which is then downsampled to 1920x1080 10-bit logarithmic 4:4:4 Dual HD-SDI.

 

Incidentally, strictly speaking 4:4:4 is not applicable to Bayer-pattern images as such, since full resolution color information isn't available before interpolation. Furthermore 4:4:4 gives an impression that the resolution for each is color channel is the same, which is not true for Bayer-pattern images.

 

3) I might add at least viewfinders (optical on Origin and D-20; electronic on Genesis) and data recorders (external on Origin and D-20, need cabling; dockable Sony SRW-1 on Genesis, extra cables not necessary). Perhaps available aspect ratios, too (D-20 is, in my opinion, the most sensible construction in this particular sense).

 

4) There's been a lot of speculation what "true RGB not Bayer-pattern" actually means. Probably it means just some other sort of colour filter pattern, possibly RGBRGB instead of GRGB; search earlier Genesis-threads on this forum for further discussion. D-20 uses a Bayer-pattern CMOS sensor.

Edited April 15, 2005 by Ilmari Reitmaa

[Guest Jennifer Pun]

Thanks for taking the time to assist me Ilmari. This is very helpful! Just one quick question. I know the Origin has an aspect ratio of 2:1. Do you know what the others are? Thanks!

[Ilmari Reitmaa]

I know the Origin has an aspect ratio of 2:1.  Do you know what the others are?  Thanks!

<{POST_SNAPBACK}>

 

Genesis is 16:9 (or 1.78:1). D-20 in Video Mode is 16:9, in Film Mode 4:3 (more precisely 1.37:1). Letterboxing can naturally be applied to change the aspect ratio, as well as anamorphic lenses; note however that anamorphic lenses are somewhat problematic on Origin and Genesis because the sensors are already widescreen to begin with.

 

Have a look at the tech specs for more info.

[Guest Jennifer Pun]

Genesis is 16:9 (or 1.78:1). D-20 in Video Mode is 16:9, in Film Mode 4:3 (more precisely 1.37:1). Letterboxing can naturally be applied to change the aspect ratio, as well as anamorphic lenses; note however that anamorphic lenses are somewhat problematic on Origin and Genesis because the sensors are already widescreen to begin with.

 

Have a look at the tech specs for more info.

<{POST_SNAPBACK}>

 

 

Thanks again Ilmari!

[Guest Jim Murdoch]

Hi Jennifer,

 

It's a waste of time trying to get any real information out of Panavision or Dalsa. Dalsa doggedly refer to their camera as having a "4K" sensor, which it couldn't possibly be, and Panavison don't really tell you anything at all!

 

Arri are much more forthcoming, but I don't think they take their D-20 all that seriously. Nonetheless, they have some good technical articles about it on their website/

 

However if you visit this website

Espanavision

and scroll down the "Latest News" section a bit to Feb 13, you'll probably find most of the information you're after, on the Genesis at least. (Good men died getting this information:-)

 

If you also check out the "Tech Talk" section, you'll find some useful articles on Depth of Field and other problems faced by video cameras. If that's not enough, send them an e-mail and they'll probably give you the information you're asking for or tell you where you can get it. They'll also probably give you a nice little list of all the questions that the various manufacturers would rather you didn't ask!

 

I know a lot of non-technical people here are unshakeably convinced that "Digital Cinematography" Cameras are going to be the "Next Big Thing", but old buggers like me have heard all this too many times before! The reality is, over the past ten years the Panavision management have run up massive debts, which they haven't got a hope in hell of ever paying off, so they keep churning out these "miracle" technologies in the hope of stretching out their credit a little longer!

Edited April 17, 2005 by Jim Murdoch

[Ilmari Reitmaa]

Dalsa doggedly refer to their camera as having a "4K" sensor, which it couldn't possibly be

<{POST_SNAPBACK}>

 

I recall DALSA presenting a tech paper at the IEEE AIS 1999 conference, describing a functional 4k x 2k 8.4um CCD sensor prototype with 16 x 37.125MHz outputs and a system board to go with the sensor; this being six years ago, I find it unlikely that they wouldn't have been able to work out a system to accommodate this particular sensor or a variant. Are you suggesting there are prohibitive restrictions other than the sensor itself, or could you please clarify?

 

I probably have the paper archived, I'll try to look it up.

[David Mullen ASC]

I recall DALSA presenting a tech paper at the IEEE AIS 1999 conference, describing a functional 4k x 2k 8.4um CCD sensor prototype with 16 x 37.125MHz outputs and a system board to go with the sensor; this being six years ago, I find it unlikely that they wouldn't have been able to work out a system to accommodate this particular sensor or a variant. Are you suggesting there are prohibitive restrictions other than the sensor itself, or could you please clarify?

 

I probably have the paper archived, I'll try to look it up.

<{POST_SNAPBACK}>

 

It IS a "4k" sensor (4096 x 2048 pixels I think) with a Bayer filter, so there are twice as many green pixels as there are red and blue. All of this gets "de-Bayered" and converted into 4K data for R, G, and B. So the original sensor is 4K and the final data files are 4K -- the controversy is whether this is true 4K "resolution" or not since each color was not CAPTURED at 4K individually.

 

It's a bit of a technical argument -- ultimately what matters is perceived final resolution and the ability to resolve fine details on the level of a fine-grain 35mm color negative scanned at 4K. From the tests I've seen, I'd say that it is 4K or 3K, certainly comparable to a 4K scan of 35mm (Vision-2 100T) when doing a side-by-side test (which what I saw, then both were blown-up something like 400% to compare a portion of the same image.)

 

The Genesis has a 12MP sensor with non-Bayer RGB striping but it is only designed as a path to getting a 4:4:4 HD (1920 x 1080 pixel) image off of it. Panavision will tell you that the final resolution is HD themselves.

[John Sprung]

It IS a "4k" sensor (4096 x 2048 pixels I think) with a Bayer filter,

<{POST_SNAPBACK}>

The underlying Dalsa Origin chip is 4096 x 2048, but a column 50 pixels wide is metallized over on one side as a black reference, leaving 4046 x 2048. Unfortunately, the chip is much wider than any 35mm film aperture, so existing film lenses only cover a region about 3000 pixels wide by 2048 high. Re-packaged still camera lenses would be ideal for this, as was done long ago for VistaVision.

 

Genesis uses simple RGB vertical stripes. If you look at a region on it's sensor that's three photosites wide, one set of RGB stripes, by two high, that's a square. You can think of it as having 1920 x 1080 of that kind of 3x2 squares. Of course, just averaging within 3x2 squares isn't the cleverest way to use the data. The prototype was 10 bit, but that's not carved in stone for the production units.

 

Arri's D-20 is a CMOS sensor while the others are CCD. It's a Bayer pattern with pixel counts in the same ballpark as the others, exact numbers I don't remember, but they're on the Arri web site.

 

We'll be seeing them all in the same room at dinner in a couple weeks, it should be interesting. I especially want to see the look of CMOS vs. CCD.

 

 

 

-- J.S.

[Ilmari Reitmaa]

We'll be seeing them all in the same room at dinner in a couple weeks, it should be interesting.

<{POST_SNAPBACK}>

That's most interesting; if you could post your sentiments afterwards it would be greatly appreciated.