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New Arri HD camera?


Guest Stephen Murphy

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You find more details here:

http://www.arri.de/fileadmin/media/arri.co...9_ARRI_News.pdf

 

As far as I understood it, there will be three different cameras. The entry model (50k€) won't record ARRIRAW and has only an EVF, the second one records also ARRIRAW, the big one (130k€) is the D-21 successor with ARRIRAW, usable 4:3 aspect ratio for anamorphics and OVF.

 

The electronics seem to be entirely new (I wonder if it's still a cypress-sensor) and it has some unique features as well:

 

- it records uncompressed RAW sufficient for 2k (downsampled from 3072 horizontal pixels)

 

- it shots up to 60fps

 

- it has the highest-res EVF (1280x720) with larger image area (the sensor has 3392x2200 pixels) than recorded

 

- it has a base sensitivity of 800ISO

 

- 16bit color depth

 

But they also mention the problems with a real, uncompressed 4k-workflow and the problems with smaller pixels (they would need to go down from 8,25µm to 4,125µm - increasing noise and decreasing DR) and therefore don't call it a replacement for 35mm. Panavision created a sensor with 2,95µm-pixel-pitch, a fill-rate of 70% with microlenses, the result is: high dynamic range OR high resolution, but not both... I don't think we will see 4k so soon.

 

 

I wonder what is the "competitor A"-camera in the ARRINEWS, such noise and banding with 500ASA? Such a camera is sold?

Edited by georg lamshöft
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I still think developing digital mags for the Arricam and 435 cameras would have been a better way to go at it. That is what Aaton is reportedly doing.

 

On the plus side for digital mags, there is still an optical viewfinder and mirror shutter involved, the latter could help to give the image a bit more of a"filmic" look, and as for the former, well, operators and DPs will be happy they can look into the viewfinder whether the camera is on or not.

 

I cannot find any reasons why not to develop digital mags for proven camera workhorses . . .

 

But, hey, who am I to question "superior German engineering?" ;)

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I'm not 100% sure, but at least in the still photography world these digital mags cause lots of trouble. Even the modular systems in the medium/large-format sector have to deal with complex issues regarding mechanical calibration and electrical communication between back and camera. Leica was the only producer which actually created some kind of "digital mag" for a "normal" SLR, the Digital-Modul-R. You had to be really careful to keep the contacts clean, the mechanical film transport components weren't designed for a digital back but the biggest issue was the frame window. The sensor-"board" itself is quite large (you can even see it in the images in arridigital.com) due to circuitry and the mechanical housing while the sensor has to penetrate deep into the camera-window. They weren't able to achieve a full-frame sensor (the 15digital SR Mag also has a crop) because it didn't fit into the film-body.

 

So you end up with a compromise that uses a smaller sensor, is more complex, larger and heavier... and I don't think ARRI loves compromises...

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The reasons that digital mags for film cameras are a bad idea....

 

1. The parts of the film camera that you need are at most the lens mount and optical viewfinder. You're carrying around -- and paying for -- a lot of stuff that you don't need. Weight, size, battery consumption, expense....

 

2. While you're shooting digital, you're putting wear and tear on the high precision pulldown and pin registration mechanisms that you're not using. Anything little thing that goes wrong with them won't show up in the digital image, but it'll be there all of a sudden if you use it for film again. Anything that goes very wrong with the stuff you don't need stops you from shooting until you get another body.

 

3. Film doesn't need an optical low pass filter, but digital does. The aperture of the film camera is where the focal plane is and where the surface of the chip needs to be. It gets in the way of the OLPF, as does the mirror shutter. The OLPF would have to somehow extend thru the aperture without its means of attachment covering any of the image. The OLPF of the Red, for instance, looks to be about 3/8" in front of the chip, where it would get clobbered by any film camera shutter. So, you have to design an OLPF with a severe limit on how far it can be from the focal plane. When you pull the digital mag, the delicate OLPF and chip would be exposed to damage.

 

Those are just a few off the top of my head, there are probably more.

 

The best approach is to grab a few of the parts you need from your film camera factory, and build your digital camera using those few things that it makes sense to have in common with the film camera line. You get some economies of scale on the high precision mechanical and optical parts that way, which appears to be what Arri has done. Those Arri guys are plenty smart, and they made the right decision.

 

 

 

 

 

-- J.S.

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The best approach is to grab a few of the parts you need from your film camera factory, and build your digital camera using those few things that it makes sense to have in common with the film camera line. You get some economies of scale on the high precision mechanical and optical parts that way, which appears to be what Arri has done. Those Arri guys are plenty smart, and they made the right decision.

 

 

-- J.S.

 

Interesting. I wonder how Joe Dunton (who came up with the SR3 digi mag a few years back) and Aaton are negotiating the OPLF issues. Not because it is not easy to do, it doesn't mean that it cannot be succesfully done.

 

As far as power consumption, electronics suck more power than just the electric motors for cameras, I do know that. Of course, electronics and electric motors suck more power than just electronics.

The weight, 2/3" chip cameras are pretty heavy, and I imagine the HD Arri offerings are not super lightweight. The cost, these cameras are going to be in the $50,000 to $150,00 range (if what the arri folks said is true), plus accesories. So they are not RED One cheap, but they are also not Panavision expensive.

 

I do see the point about the pull down mechanism and registration pin wear.

 

The biggest issue for me as a camera operator is the optical viewfinder. It seems Arri, RED, etc are staying away from HD cameras with optical viewfinders. I am sure they are not technically easy to incorporate to their HD camera designs, but it is an engineering problem and as such some one out there will eventually figure out how to get it done.

 

Again, not because I can't figure out a solution to these problems, it doesn't mean they are impossible to figure out either.

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I don't think ARRI loves compromises...

 

Right. To me, the electronic viewfinder-only on HD cameras is a compromise though. If I have my choice between shooting film (optical viewfinder and video tap) vs purely electronic image display (HD), I will always choose film, even if I end up transferring the film to HD. And that is not even considering that film is still a superior choice in terms of exposure latitude, etc.

 

But I am just a pain, I guess.

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The biggest issue for me as a camera operator is the optical viewfinder. It seems Arri, RED, etc are staying away from HD cameras with optical viewfinders. I am sure they are not technically easy to incorporate to their HD camera designs, but it is an engineering problem and as such some one out there will eventually figure out how to get it done.

 

Certainly it can be done -- Arri already does it. Because of the precision required, it's a feature that adds a lot to the price of the camera. You can have the electronic finder only model for $50K, or add the mirror shutter finder and add $100K. Arri are sending both price performance points to the market. We'll all get to decide if it's worth the price.

 

 

 

 

-- J.S.

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John; while I agree with most of your points RE digimag, I wonder if one cold just attach it to the back of the camera and then leave the camera off with the mirror shutter in the open position. Just my rough though (and pipe dream).

For example, on the SR3, one inches the mirror shutter away and open, and then doesn't turn on the camera at all, but rather just runs the digi-mag. Though, i suppose then you loose the optical viewfinder :/

I'm sure the Aaton camera might have some form of disengage between the shutter and the film transport mechanism(s) when the digi mag is on, so that only the shutter spins, and nothing else does (makes sense to me to do something like that). Such thing are impossible, of course on my SR3, or other such cameras 'round now; but I think Arri would be well served to make a hybrid camera system one of these days.

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Hi,

 

Niether Leica on their DMR,M8 & M9,or Phase One on their medium format backs use a OLPF.I'm no techie,but to my eye,these camera's produce a more acceptable digital image than the current crop of Canon's & Nikons etc.

 

Tom.

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The OLPF isn't such a big problem regarding mechanical properties (fitting the sensor in a film-camera), even without it, you'll have to squetch a complex optoelectronical device (sensor, coverglass...) into the aperture.

 

"Camera aperture" is the correct English term instead of "window" ?

 

The still photography cameras without OLPF (M9, S2, MFDBs) are designed for max. IQ, the OLPF always reduces resolution close below nyquist which cannot be restored with any kind of sharpening - despite common believe.

The problem is moire which has to be removed manually in post. This works in still photography, but all these filters/algorithms are extremely problematic in moving pictures - they would change the "look" every single frame!

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Thank you Georg,that's one of best explanations I've read.

Do you know if anybody is working on a solution to the problems.If we could achieve the same kind of image quality that these camera's produce for moving pictures,it would go a long way to making digital acquisition more acceptable.

 

Tom.

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We're experiencing two major issues in digital cinematography:

 

Dynamic range and establishing a real 4k workflow.

 

Dynamic range is mostly a product of the active photodiode size while 4k needs smaller photodiodes to stay within Super35-size (or do you want a 65mm-sized-sensor? ;-). A 4k (4096x2048 given a 2:1 aspect-ratio)-signal would need a sensor with at least 24 million photodiodes (or pixels - 4096 x 2048 x red x green x blue) on a sensor which is three times smaller (24x12mm instead of 36x24mm) than 35mm-full-frame in still-photography! At 4k the signal would contain zero contrast/information - to increase MTF (achieveable contrast over resolution) up to higher resolutions/frequencies, to avoid alaising/moire and make an OLPF unnecessary you would have to oversample the signal. ARRI does that already with their digital systems (D-21 and Arriscan with 1.5x the linear resolution) - they scan/film with 3k to create a high-quality 2k-signal!

So what do we need for a real 4k-digital-camera with a Super35-sized sensor without alaising, high contrast up to high frequencies and no color interpolation? A sensor with 6144x3072 (1.5x linear oversampling) photodiodes for RGB-colors (one color pixel is created out of three filtered photodiodes) = 56 million photodiodes, such a sensor would have 168MP on 35mm-full-frame! the pixel-pitch (and therefore the max. pixel-size) would be 1.3µm x 3.9µm (assuming that three of them combined create one square "color-pixel") so about 13 times smaller than in the new digital ARRIs!

 

What does that mean? Well, no 800ASA, no 12 stops DR...

 

That would be the "perfect" 4k-solution (the ARRISCAN pretty much does that when scanning at 6k, combining 24 (two exposeres for 16bit, 4x pixel-shift for 6k, 3x for RGB-color) images per frame to one oversampled 4k-scan) and I don't think we can see one of those in near future...

It will propably a compromise (just 1.5x oversampling or only three subpixels for every color) but it would still mean tiny photodiodes with problematic DR and sensitivity and about 1.2GB/s @24fps! Panavision has such a sensor already (www.panavisionimaging.com) and it has 33MP at Super35-size with 2.9µm pixel-pitch. But still, high DR OR 4k - not both...

 

CCD-based-still-photography cameras like the S2/M9 or P40+/P65+ use full-frame-CCDs with very large photodiodes (due to a high fill-rate, much of the sensor area is actually light-sensitive - the big advantage over CMOS) but they are slow (also to keep DR up and noise down due to slow read-out) and power-consuming (they get really hot when used with live-view) and have little to do with digital cinematography.

 

Digital has hopefully a great future but companies like ARRI and Panavision have good reasons to be careful and offering "only" 2k and still offering 35mm-film-systems.

 

I for myself am impressed with the technology incorporated in the D-21 or the new system (oversampling, custom CMOS, mechanical shutter, uncompressed...) but we shouldn't overestimate it's possibilites, it's really not difficult to see that it's not film at all and even on my tiny PAL-80cm-TV I much prefer well-done 35mm in TV-series (like House M.D.)...

Edited by georg lamshöft
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Georg,

 

thank you for taking the time to explain.

I totally agree with you regarding 35mm film.I attended the screening of the BSC Film & Digital evaluation,and while some of the images that digital can produce are very impressive,especially the D21,it's clear that digital has a way to go before being able to equal film. I've no doubt that it'll get there,eventually.

 

Tom.

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For example, on the SR3, one inches the mirror shutter away and open, and then doesn't turn on the camera at all, but rather just runs the digi-mag. Though, i suppose then you loose the optical viewfinder :/

 

That would work, but you'd be carrying the entire film camera around just to make use of its lens mount. Better to leave the SR3 safe in its case on the shelf, and put a lens mount onto the digimag, turning it into a digital camera. Or you could rent the SR out to another production.... There's a substantial opportunity cost in having its value tied up while you're shooting digtial.

 

 

 

 

-- J.S.

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Talking of an SR

 

That would work, but you'd be carrying the entire film camera around just to make use of its lens mount. Better to leave the SR3 safe in its case on the shelf, and put a lens mount onto the digimag, turning it into a digital camera. Or you could rent the SR out to another production.... There's a substantial opportunity cost in having its value tied up while you're shooting digtial.

 

 

 

 

-- J.S.

post-3524-1253564230.jpg

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