Arri Amira goes 4K?

It's definitely using a larger sensor area than the standard 16x9 2880x1620. It's using exactly 3200x1800 pixels, which is easy to figure out from the math (3840/1.2 x 2160/1.2) and Abelcine confirmed it as well in the link posted earlier.

Open gate on the Alexa allows a max of 3414x2198 (3414x1.2=4096). This is taking a crop from that (the 3200x1800) and then doing the 1.2x for you in cam out to UHD ProRes. Nice workflow, and, as someone mentioned before, helpful for those who would freak if you said it wasn't exactly UHD.

Since the Alexa (and Amira) have a pixel pitch of 8.25um, the 3200x1800 would give you a sensor size of 26.4mm x 14.85mm, which would equal an image diagonal of 30.29mm. Larger than Super 35mm, but just a hair bigger than the Red Dragon at 5.5k HD (30.24mm).

Most lenses (including the Cabrio's) should have enough coverage for that (lots of testing here since Dragon's sensor is so big: http://www.reduser.net/forum/showthread.php?103766-Dragon-Lens-Coverage-Information).
 
Also, Arri can't do true 4K with the current sensor tech they're using without making the sensor way too big. A 4096x2160 sensor with the same large, light sucking pixels would have a diagonal of 38.20mm using the full frame (or 36.35mm UHD). Much bigger than the 34.53mm FF diagonal of Dragon.

There's a reason why Arri's probably going to go with a 70mm format sensor. Using the frame size of 52.48mm x 23.01mm with 8.25um pixels would give a resolution of about 6362x2789, and 6K is in fact what's rumored (https://twitter.com/OFFHOLLYWOOD/statuses/447499743368085504).
 
harddrive said:
It's difficult to give an exact figure as to "how much" the effect will be, not least because it tends to be a roll off of resolution, but the generally accepted figure is something like max luminance resolution being about 75% - maybe 80% - of sensor resolution. And chrominance resolution will be less still.
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The rule of thumb for chrominance resolution for a Bayer sensor is to divide by the square root of two (1.414). So, for 2880x1600, you're at 2036x1131 in chrominance resolution. To have full DCI 2.39 4K chrominance resolution, you'd need 5793x2427, or 6K (imagine that! :) )

That being said, I still think you have to look at the total package, including the color rendition of the system as a whole (which even includes the dyes used for the color filter array.) 6K color isn't going to look great if the green dye in the color filter array isn't held to tight standards, or if the OLPF has a brown cast to it, or if you neglect to use an IR filter, or if the sensor doesn't respond well to the temperature of light you're capturing.

Basically, while color can easily be measured in terms of resolution, the parts that can't easily be measured will probably have a greater impact.

Same for overall resolution, as well.
 
Last bastion has fallen. Interesting times and hopefully when everyone/everything will be 4K they'll start competing by bit depth, codecs, compression.
 
Bayer-Schmayer my a... - unless you have glass that performs at 300-350 LP/mm, no way the sensor even sees anything close to 4k.
 
Postmaster said:
Bayer-Schmayer my a... - unless you have glass that performs at 300-350 LP/mm, no way the sensor even sees anything close to 4k.
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LP is line pairs, so for 16x9 Super 35 (24.89mm x 14.00mm = 28.56mm diagonal) you'd only need about 75 lp/mm to resolve UHD 4K (3840/24.89/2 & 2160/14/2 = 77).

That being said, I would agree that resolution is overrated.
 
Give me a camera that renders that dreamy suspension of disbelief that film delivers and it can record to VHS for all I care. I'll take one of those over any 4K super sharp pro video-y looking camera any day of the week.
 
Joshua Cadmium said:
LP is line pairs, so for 16x9 Super 35 (24.89mm x 14.00mm = 28.56mm diagonal) you'd only need about 75 lp/mm to resolve UHD 4K (3840/24.89/2 & 2160/14/2 = 77).

.
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Well it's not THAT easy, you need to look at the whole picture (pun intended).
Let's say we have a typical S35 sensor with a pixel size of 6,4 µ.
The diffraction at the red channel @ f 2.8 is 4,4 µ, but @ f 4 it reaches already 8,9 µ

So unless you shoot mostly wide open, you could as well shoot in HD,
since more than one pixel gets the same image information, cutting your actual resolution in half.
Also there is an OLPF in front of the sensor, that makes things even worse (regarding true resolution and image information),
but prevents aliasing and moire.
And don't get me into, what compression does to your resolution.
 
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There are two aspects to this whole discussion, how good will the images be, and the marketing etc aspect. (Both by Arri and the end user.)

As regards the former, I'm sure we're all agreed the images will look very good. Straightforward 1080 images from the Alexa and Amira are widely regarded on some very high end programming, and this is likely to be even better. There shouldn't be any debate on that.

But..... there is a school that (with justification) claims that a 4k Bayer sensor doesn't give a "true" 4k image (completely true) and therefore shouldn't be called 4k..... Which is where it becomes a matter of opinion and wording. The general acceptance today seems to be that a 4k Bayer sensor is the MINIMUM needed to be able to use terms such as "4k" or "UHD", and I'd tend to go along with that.

So whilst I don't doubt the images here will look very good - and better than HD - it's wrong to refer to them as "4k" or "UHD". I'm sure that doesn't go down very well with the marketing people at Arri, but sorry, it's really stretching a definition if they're marketing this feature as UHD. If any cameraman was contracted to provide a 4k output and delivered what we're talking about here without making the situation clear to the client, they could be in breach of contract - no matter how good it may be.

I'm reminded of a recent legal case where someone advertised "free range eggs" at their farm gate. In practice they'd been buying eggs from the local supermarket and passing them off as such. Nobody claimed anything actually wrong with the eggs, nobody fell ill as a result, and I don't believe anybody have even noticed any difference in taste, but as far as the case went the charge was of misrepresentation - if you claim something about a product you're selling, you have to deliver exactly that to stay within the law.

It's also worth saying that it's impossible to give any single resolution figure for a lens - it will depend on iris setting etc, and (importantly) will likely vary across the frame - expect edge definition to be less than at the centre, especially at wide apertures. And if they are using a bigger than normal area, to get more than standard 16x9 2880x1620, that's a factor that could easily come into play here. Obviously it will vary lens to lens, but a potential user needs to aware that they may not be able to use all their lenses successfully. And factors such as outside of image viewfinding (which have been hailed as a winning feature) presumably get lost?

The scheme certainly has merit - but I'm just left with the feeling that it's driven far more by marketing than other factors. Arri are finally waking up to the fact that in the market they're in (high end!) 4k has taken off far faster than they predicted. And this is their best response at the moment.
 
harddrive said:
Arri are finally waking up to the fact that in the market they're in (high end!) 4k has taken off far faster than they predicted. And this is their best response at the moment.
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I think most people buying this update will understand it's a workflow update for what Arri considers a broadcast style camera. So its less about the resolution than it is about quickly conforming to a new 4k workflow. I seriously doubt most people could tell the difference between 3.2K and 4K anyway.
 
roxics said:
I seriously doubt most people could tell the difference between 3.2K and 4K anyway.
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We have a project at work where people shooting with the Epic were constantly missing focus. Funny how much sharpening they have to apply to 5k material to make it look even remotely sharp-ish.

If you don't nail your focus, it's not gonna be even SD.
 
maarek said:
We have a project at work where people shooting with the Epic were constantly missing focus. Funny how much sharpening they have to apply to 5k material to make it look even remotely sharp-ish.

If you don't nail your focus, it's not gonna be even SD.
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Sounds like you need some better camera operators. I know tons of shooters who run around with the Epic hand held constantly and nail their focus using so-so Canon still glass.

With that said, its a raw file, so you have the choice to add Sharpening or not. Thats the beauty.

In regards to the Arri 4K. Sounds like they're trying to scrape the bottom of the barrel to keep up. Having to up-scale in camera thats already out dated based on what the rest of the market is doing? And to have to pay for it? The image may be beautiful, but so many other cameras out there that offer similar features and more control with higher resolution at a much lower cost.

Love Arri's accessories but their camera department is a mess between hacking RED's emails and releasing something you have to pay for just to get 4K that isn't real 4K.
 
harddrive said:
The scheme certainly has merit - but I'm just left with the feeling that it's driven far more by marketing than other factors. Arri are finally waking up to the fact that in the market they're in (high end!) 4k has taken off far faster than they predicted. And this is their best response at the moment.
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Agreed. Some networks and studios are starting to require shows in 4k. Arri needed to do something quickly to stay competitive. I'm sure they will follow this with a "proper" 4k camera as soon as they're able.
 
electricjib said:
Love Arri's accessories but their camera department is a mess between hacking RED's emails and releasing something you have to pay for just to get 4K that isn't real 4K.
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Ok fanboy. You should get back to reduser, I'm sure they miss you - misinformation like this is easier to spread there.

Way to telegraph your bias so I know I can safely disregard anything you say - thank you.

(The Red era is over, btw - nobody who doesn't own one shoots with a Red anymore, they are dead in the rental market yet Alexas still go out every day.)
 
Postmaster said:
So unless you shoot mostly wide open, you could as well shoot in HD,
since more than one pixel gets the same image information, cutting your actual resolution in half.
Also there is an OLPF in front of the sensor, that makes things even worse (regarding true resolution and image information),
but prevents aliasing and moire.
Click to expand...

It's actually not as bad as you think. On a Bayer sensor with an OLPF, "an airy disk can have a diameter of about 2-3 pixels before diffraction limits resolution" - http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm .

Check out the calculator at the bottom of this page: http://www.cambridgeincolour.com/tutorials/diffraction-photography-2.htm . It factors in a Bayer sensor, an OLPF, and varying color diffraction. Plugging in a 1.5x crop and 5.8 megapixels (close to the Amira 3200 x 1800) resolution robbing diffraction doesn't begin to become an issue until f/12.
 
electricjib said:
In regards to the Arri 4K. Sounds like they're trying to scrape the bottom of the barrel to keep up. Having to up-scale in camera thats already out dated based on what the rest of the market is doing? And to have to pay for it? The image may be beautiful, but so many other cameras out there that offer similar features and more control with higher resolution at a much lower cost.
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It's amateur-hour... "keep up"? Are you are joking or just another 22yo wannabe? Arri is the last film related company that has anything to worry about, unlike just about every other one. Seen any big movies or major TV shows lately kid? Arri completely rules high-end capture in film and digital. It's not even close. Red will shut down one day because the thrill is gone and even their boss is bored with his baby. Canon will take their market, if they haven't already.

WHO GIVES A SH** WHAT RESOLUTION A CAMERA SHOOTS AT ANYMORE??? Grow the F up everyone. You are going on ten years of this uselss disussion.
 
VinceinLA said:
It's amateur-hour... "keep up"? Are you are joking or just another 22yo wannabe? Arri is the last film related company that has anything to worry about, unlike just about every other one.
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I took electricjib's comments as little to do with what the images may look like in their totality - everything to do with what is increasingly being requested by clients at the top end. And that's 4k - at least for acquisition. I'm not saying it's right or wrong - but it's what is happening.

OK, still relatively early days, but the likelihood is that the trend will accelerate. Increasingly, if a camera isn't 4K, it won't get hired for top end work - that's what I understand electricjib to mean by "keeping up". And it's wrong to look at this as an "Arri v Red" battle. Pretty well all the other major camera manufacturers are selling a lot of 4k gear.
VinceinLA said:
WHO GIVES A SH** WHAT RESOLUTION A CAMERA SHOOTS AT ANYMORE??? Grow the F up everyone. You are going on ten years of this uselss disussion.
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Everybody needs to be aware of it - and as I tried to say before, it's as much a matter of marketing as anything else. Like it or not, "4k" is being promoted in the public eye as "best quality!" and if you're any doubt of that, just go into any large TV retailer. That induces the likes of Netflix and Amazon to make sure that all their prime are 4k. Not because of any factors that you or I may hold most dear - purely so they can emblazon "4K!!!" on their advertising.

And no matter how good (in ways other than resolution) Arri images may be, what is being talked about here is simply not 4k.
 
IndyFilmPhreak2013 said:
Ok fanboy. You should get back to reduser, I'm sure they miss you - misinformation like this is easier to spread there.

Way to telegraph your bias so I know I can safely disregard anything you say - thank you.

(The Red era is over, btw - nobody who doesn't own one shoots with a Red anymore, they are dead in the rental market yet Alexas still go out every day.)
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VinceinLA said:
It's amateur-hour... "keep up"? Are you are joking or just another 22yo wannabe? Arri is the last film related company that has anything to worry about, unlike just about every other one. Seen any big movies or major TV shows lately kid? Arri completely rules high-end capture in film and digital. It's not even close. Red will shut down one day because the thrill is gone and even their boss is bored with his baby. Canon will take their market, if they haven't already.

WHO GIVES A SH** WHAT RESOLUTION A CAMERA SHOOTS AT ANYMORE??? Grow the F up everyone. You are going on ten years of this uselss disussion.
Click to expand...

Real class acts here guys.
 
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