Dynamax sensor

[Josh Mitchell Frey]

I may be tripping.. but I could've sworn I've read that Panavision's Dynamax sensor uses photosites with varying shutter speeds to capture greater dynamic range. Eg, some of the photosites would be capturing light at 1/50th, while some would capture at 1/500th in order to recover highlight details that would otherwise be lost, etc. Am I out of my mind? I've been searching the internet to find the place where I read this, but I can't find any mention of it. And in addition, you'd think there'd be strange motion blur problems introduced by capturing at 1/50th and 1/500th simulataneously.. etc, so maybe I dreamt all of this up.

 

In any case, does anyone know how the "HDR"-ness of the dynamax sensor is meant to work?

[Phil Rhodes]

You could probably do that, but wouldn't you end up with strange blur artifacts? I mean, you would, but I wonder if it would look unpleasant.

 

P

[Mei Lewis]

On one of the fxguide shows they mentioned this (think it was this camera they were talking about).

 

It's not the exposure time that's varied but the sensitivity I think. Each pixel has two analogue amplifiers or outputs, a high gain and a low gain.

[Josh Mitchell Frey]

Thanks for your replies guys.

 

Could it have been the Alexa cameras that have the varied gain outputs? I was reading about this last night

 

“The key to the increased performance is what we call ‘Dual Read Out’ – we have on the sensor 32 output channels and we read every pixel twice through a normal gain and through a high gain. Each of these read outs happens in 14 bit depth. We then combine them and get 16 bit pixel depth for every pixel element. So that results in a very quiet image with very low noise. This is a philosophy which is similar to our scanner with its double flashing, however these read outs are happening at the same time.”

 

http://www.definitionmagazine.com/journal/2010/5/13/the-story-behind-the-launch-of-alexa.html

 

You're probably right though, it makes more sense to vary sensitivity rather than shutter speed to capture a high dynamic range

[David Williams]

Hiya Josh :)

 

There was an interview with John Galt from PV sometime ago, and he mentioned the Dynamax HDR mode. He used the term exposure when he described it, so you'd think that means shutter speed.

 

The Dynamax has up to six sets of RGB per pixel, so that's six exposures combined into one frame.

[James Martin]

If you are referring to the Genesis' sensor, I believe I read here on cinematography.com some time ago that half of the photosites are ND'd.

 

That seems like a logical, simple way of achieving what you're talking about.

 

In the stills world, Fuji had a SuperCCD sensor which used some photosites that were I believe smaller than the rest to achieve a similar thing.

[David Williams]

This isn't the Genesis, it's a new sensor not yet in a production camera.

[Matthew French]

"In the still photography world, what is going on is that people are taking multiple exposures and combining them. Let's say I do an exposure at a stop of 2.8. The next one is at 4, then 5.6, then 8, and 11. Depending on what I'm shooting, the 2.8 exposure could completely blow out the highlights, but it would have lots of shadow detail. And the f11 exposure would retain the highlights, but there would be no detail in the mid tones and the shadows. If we were to combine them, we'd have a single image with the most possible detail across the widest possible range.

 

Today, that's only available in the still photography world. DynaMax is designed to do that for moving images. With those 6 red, 6 green and 6 blue photosites for each output pixel, you'll have the equivalent of shooting 6 images with different exposures at once, and blend them together to create a single high dynamic range image. You'll be able to capture extreme highlights, the near highlights, the mid highlights....

 

Today, that's only available in the still photography world. DynaMax is designed to do that for moving images. With those 6 red, 6 green and 6 blue photosites for each output pixel, you'll have the equivalent of shooting 6 images with different exposures at once, and blend them together to create a single high dynamic range image. You'll be able to capture extreme highlights, the near highlights, the mid highlights...."

 

Read more here:

 

http://magazine.creativecow.net/article/the-truth-about-2k-4k-the-future-of-pixels

 

:ph34r:

[Brian Drysdale]

 

Today, that's only available in the still photography world.

 

 

The Epic sort of combines two exposures when using HDRx, using two exposure times.

[Charles Zuzak]

Any other news regarding this sensor or a successor to the Genesis? It's a bit long in the tooth at this point and is outclassed by the Alexa and Epic.

[Keith Walters]

Any other news regarding this sensor or a successor to the Genesis? It's a bit long in the tooth at this point and is outclassed by the Alexa and Epic.

Today I heard that Panavision were bringing out some sort of revolutionary camera around the end of this year. Unfortunately the person who told me this doesn't really know much about cameras, it was just something they were told.

Panavision Imaging (a company they bought a few years back) does make some interesting high-performance sensors, but up until now, they've all been fairly low resolution types, mostly designed for money-is-no-oblect military and surveillance projects.

I heard they were working on some new high-performance "Backside Illumination" CMOS sensors for digital cinematography applications.

If they can pull that off, it will get Panavision more or less back into the situation they used to enjoy, where they made the best film cameras, and only rented, not sold.

If they can make something with the imaging performance of the Alexa, but in 4K, after 30-odd years of piss-farting around with endless generations of "indistinguishable from film" second-rate video formats, they might finally be onto something. :rolleyes:

Or will this be another magic bullet that never quite makes it out of the barrel....