# Unlimited DR Camera invented by students at MIT...



## PureClassA (Aug 19, 2015)

http://petapixel.com/2015/08/18/mit-created-a-camera-that-will-never-overexpose-a-photograph/

Feast your eyes DRones ;-) How cool is this?!


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## neuroanatomist (Aug 19, 2015)

Kewl.


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## 3kramd5 (Aug 19, 2015)

I wonder how easy it is to implement in consumer-type electronics.


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## Random Orbits (Aug 19, 2015)

I'm hoping this can be implemented soon. So many of the technologies that work in the lab don't work or aren't economical enough to work in the end product that consumers use.


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## AcutancePhotography (Aug 19, 2015)

I am glad we have smart people researching this. Who knows what this may result in after a while.


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## Neutral (Aug 19, 2015)

I like this , very smart indeed and extremely simple. 
I believe this is something that had been used for very long time in math, encryption and numbers hashing.
Just applied to completely different domain.
Actually this is method of compressing big numbers to much smaller ones.
I remember that from very very long time back when I was a student.

More interesting that is does not seem to be very difficult to implement.
Just add reset counter for each pixel and use its data for further signal processing. 
Circuit diagram is very simple. 
Reset counter before ADC and DSP using its values to recalculate number at the output of ADC.
Kind of forward signal correction.
For BSI sensor and especially for stacked BSI one this would be very easy as there could be enough 3D space behind photocell to add additional circuitry for that.
Could be implemented for next sensors generation next year.
Will see who will do this first.


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## PureClassA (Aug 19, 2015)

To me it seems so simple an idea it's almost silly no one has tried it before. Then again, I don't know the feasability of mass manufacturing. This is the sort of thing a company like Canon should be writing a blank check to MIT to buy the rights to even if just to keep it out of competitor's hands until they can figure out a way to produce it for consumer uses.

Just imagine setting the perfect exposure for the shadows with total disregard for the highlights as they can be infinitely blown out and still fully recoverable. Holy cow.


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## anthonyd (Aug 19, 2015)

Well, our screens and printers are LDR, so even if this technology manages to perfectly capture all the HDR of a scene, it would require tonemapping to bring it down to a usable LDR. It will take much more than a cool new sensor technology before we can stop worrying about exposure (although I do agree that having the extra room in pp is a big deal).


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## PureClassA (Aug 19, 2015)

It's not about what you can print. It's about what you can capture and RECOVER and make into a print. Exposing for shadows properly can sometimes mean clipping highlights and therefore you have totally lost some image data. This new method prevents data clipping and you can recover in post everything that was there. That's something we can't do right now with any camera made by anyone.


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## 9VIII (Aug 19, 2015)

Looks good, hopefully someone implements it soon. This would pretty much erase any advantage from one sensor to the next.
It's also interesting to think that this gives infinite DR at any ISO, and at any pixel size.

I think cell phones will be one of the first to take advantage.


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## Sporgon (Aug 19, 2015)

But...but...given how some people on here describe the Exmor I thought it did this anyway ? 

Seriously though, that really is an improvement in practical DR !


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## retroreflection (Aug 19, 2015)

This does not provide for infinite dynamic range in the final image.
The camera system includes a defined file format. This device allows for a theoretical measurement of infinity, but computers have no conception of infinity. That pesky file definition will limit the dynamic range.

Then, what this seems to do is expand the dynamic range at the high end. I see no enhancement of the signal when noise becomes the limiting factor. That is where there's the most opportunity to improve things, IMHO.

Finally, the "bucket emptying" process must take some time. For the extreme example, I wish to photograph a prickly pear blossom backlit by a nuclear blast. I really doubt the emptying process can keep up with the microsecond pace. Seriously, highlight regions equal high rates of bucket filling, thus a need for fast dumps. I could read the paper to maybe assess, but I won't. Shadows know why.


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## emko (Aug 19, 2015)

Sporgon said:


> But...but...given how some people on here describe the Exmor I thought it did this anyway ?
> 
> Seriously though, that really is an improvement in practical DR !



You don't need that DR just learn proper photography


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## R1-7D (Aug 19, 2015)

As a massive Sony/Nikon fanboi, ...if this doesn't have enough DR to fully illuminate dark matter, Exmor still wins!

;D


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## TeT (Aug 19, 2015)

Regardless its a pretty cool development... Sound a lot like P Mode if P Mode had buckets.


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## unfocused (Aug 20, 2015)

Imagine what will happen when this gets combined with light field focusing. Now that will be a disruptive technology!


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## 3kramd5 (Aug 20, 2015)

unfocused said:


> Imagine what will happen when this gets combined with light field focusing. Now that will be a disruptive technology!



Multi-lens multi-sensor UDR cameras. Just crank out a 360 degree pano wherever you go and create practically any possible final product.


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## lion rock (Aug 20, 2015)

So what is the difference between this and adding extra bits to the ADC, when each "bucketful" means another step? Or to decrease the photo site gain (dynamic gain) down with each "bucketful" advance?
Description may be fancy, but concept is not original.
-r


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## meywd (Aug 20, 2015)

lion rock said:


> So what is the difference between this and adding extra bits to the ADC, when each "bucketful" means another step? Or to decrease the photo site gain (dynamic gain) down with each "bucketful" advance?
> Description may be fancy, but concept is not original.
> -r



they don't increase the range, or include all information, if a pixel is full it is reset, meaning it records less data.


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## Lurker (Aug 20, 2015)

> So what is the difference between this and adding extra bits to the ADC, when each "bucketful" means another step? Or to decrease the photo site gain (dynamic gain) down with each "bucketful" advance?
> Description may be fancy, but concept is not original.
> -r



From the description in the article I'd say nothing. I believe the article said "created" not invented. Invented suggest new technology to me. Created seems to imply this is existing technology with a new process behind it.


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## Antono Refa (Aug 20, 2015)

The sentence "by taking into account the number of resets for each bucket, the camera can figure out the relative brightness for each pixel" means the bucket spills over into a memory cell.

That is a neat idea, but means the DR is not infinite, but rather limited by the combination of pixel capacity and per pixel memory size, which isn't infinite.


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## tron (Aug 20, 2015)

Antono Refa said:


> The sentence "by taking into account the number of resets for each bucket, the camera can figure out the relative brightness for each pixel" means the bucket spills over into a memory cell.
> 
> That is a neat idea, but means the DR is not infinite, but rather limited by the combination of pixel capacity and per pixel memory size, which isn't infinite.


OK it's not infinite but even an 8-bit counter per pixel would increase DR approximately by 8 stops (and similarly a 16 bit counter by 16 stops...)


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## K-amps (Aug 20, 2015)

A limited version can be implemented without requiring shooting the sun and expect the bucket to be reset fast enough... the example shots had a lot of color fringing... I am sure it will get better, but the same issue happens now in HDR blending... this will be only as good as the tone mapping algorithm.

exciting times.


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## tron (Aug 20, 2015)

K-amps said:


> A limited version can be implemented without requiring shooting the sun and expect the bucket to be reset fast enough... the example shots had a lot of color fringing... I am sure it will get better, but the same issue happens now in HDR blending... this will be only as good as the tone mapping algorithm.
> 
> exciting times.


Let's hope that the color finging was mostly due to the lens used... 

Exciting times indeed


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## Nelu (Aug 20, 2015)

Weird! The DR is unlimited but still, the last image still has blown-out highlights on the metal thingy...

Nelu


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## rfdesigner (Aug 20, 2015)

This is impressive to see working in any way at all, very interesting but not the only way.

One issue with this method is you can lose linearity if resets are not perfectly accounted for (i.e. you assume 50,000e / well when some are 50,100e and others are 49,920e etc., you'd need good calibration and you'd need to know it still held true over time)

One method that could solve that is the electron count per pixel method.. you get rid of the ADCs altogether and just use one comparitor per pixel, whenever an electron turns up you record that as an electrical pulse and add it to your count for that pixel.

sCMOS sensors have thousands of ADCs (one per row), so millions of simple comparators isn't out of the question.. the bandwidths on all those comparitors would be exceptionally low compared to feeding all the data out of one gate, so noise falls substantially, once it's less than about 0.1e you can count electrons (noise power is proportional to bandwidth)

I should add this isn't my idea, it's just a proposed technique.


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## jarrodeu (Aug 20, 2015)

Finally, a sensor that can match and surpass the range of film!

Jarrod


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## privatebydesign (Aug 21, 2015)

jarrodeu said:


> Finally, a sensor that can match and surpass the range of film!
> 
> Jarrod



Seriously?

According to Eastman Kodak (1) they rated one of their best general purpose films at 13 stops, many slide films that were, and still are, the preferred emulsions for film users are between 6 and 8 stops (2). All digital cameras are comfortably above the slide film and many best the 13 stops of the best non specialised scientific films (3).

(1) http://motion.kodak.com/motion/uploadedFiles/Kodak/motion/Products/Camera_Films/Color_Negative/Product_Info/5213_SS_4pgs.pdf

(2) http://www.fujifilm.com/products/professional_films/pdf/velvia_50_datasheet.pdf

(3) http://www.dxomark.com/Cameras/Ratings/Landscape

DR is a complete red herring, as is resolution, digital kicked the butt of film in every metric long ago, just look at iso performance to see how badly film really does against digital on a technical comparison. Use film if you want to, but do it because you want to, not because you think it has some magic technical superiority to digital, it doesn't.


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## stefang (Aug 21, 2015)

This is not much different from the idea to record the time after which a bucket is full, for which a patent already exists.
That idea will also lead to almost unlimited DR, because you can extrapolate the time to calculate the effective amount of light.


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## leGreve (Aug 21, 2015)

PureClassA said:


> To me it seems so simple an idea it's almost silly no one has tried it before. Then again, I don't know the feasability of mass manufacturing. This is the sort of thing a company like Canon should be writing a blank check to MIT to buy the rights to even if just to keep it out of competitor's hands until they can figure out a way to produce it for consumer uses.
> 
> Just imagine setting the perfect exposure for the shadows with total disregard for the highlights as they can be infinitely blown out and still fully recoverable. Holy cow.



Actually... one would more hope that someone like Elon Musk would buy the concept and make it open source so EVERYONE could use it, instead of a money grubbing un-innovating company like Canon.


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## leGreve (Aug 21, 2015)

Nelu said:


> Weird! The DR is unlimited but still, the last image still has blown-out highlights on the metal thingy...
> 
> Nelu



Im sure they are really sorry that this test product not even remotely ready for mass production yet is not 100% perfect.


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## Eldar (Aug 21, 2015)

I think this is intriguing and I wonder who picks it up and turns it into an industrialized product first. From a signal processing perspective, it sounds like a mouthful though ...


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## Hector1970 (Aug 21, 2015)

If Canon don't implement this in 5D Mark IV I'm refusing to buy it. ;D


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## Dylan777 (Aug 21, 2015)

Good reading. thanks for sharing


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## jarrodeu (Aug 21, 2015)

privatebydesign said:


> jarrodeu said:
> 
> 
> > Finally, a sensor that can match and surpass the range of film!
> ...


I am serious.
I'm assuming that you've been away from film for a while and are unaware of the advancements that have been made. I myself shoot almost all digital and but when I have time and I want the best, I shoot some film. 

Dynamic Range
It is true that slide film has a limited dynamic range but when it comes to negative films like the new Kodak Portra 400, there is no comparison. As can be seen here, it has around 18 stops of DR. https://www.onlandscape.co.uk/2011/05/kodaks-new-portra-400-film/

Resolution
This also really depends on the type of film being used. Kodak Ektar in 35mm compares fairly well to the 21MP 5DMk II as can be seen here. http://www.twinlenslife.com/2011/01/digital-vs-film-canon-5d-mark-ii-vs.html
There some black and white films which provide a tremendous amount of resolution such as Adox CMS 20. Here you can see an example with the truck taken with 35mm film that was scanned in at 85 megapixels and tack sharp. http://www.adox.de/Photo/adox-films-2/cms-20-ii-adotech-ii/

High ISO
Here is a realm that digital clearly is superior to film which is why so many high ISO films have been discontinued. But not every situation calls for ISO 1600+

So when it comes to convenience and cost effectiveness digital is the clear winner but when it comes to dynamic range and resolution, that's when the answer becomes dependent on what type of film is being used vs the digital sensor. Film also comes in many sizes larger than any digital sensor.
Here are further tests that have been done on larger film formats. http://www.onlandscape.co.uk/2011/12/big-camera-comparison/
Jarrod


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## kaihp (Aug 23, 2015)

rfdesigner said:


> This is impressive to see working in any way at all, very interesting but not the only way.
> 
> One issue with this method is you can lose linearity if resets are not perfectly accounted for (i.e. you assume 50,000e / well when some are 50,100e and others are 49,920e etc., you'd need good calibration and you'd need to know it still held true over time)
> 
> ...



I'm right with you. There's going to be some uncertaincy about detecting the "pixel full" condition (no matter where you set it) and the time it takes to "flush" the pixel could result in lost electrons as well.
Finally, they will need to have a counter for each pixel as well, and _those do not_ have infinite capacity either.

But definitely a novel and different idea. It will be interesting to see if they can make a product out of it.


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## lion rock (Aug 24, 2015)

> I'm right with you. There's going to be some uncertaincy about detecting the "pixel full" condition (no matter where you set it) and the time it takes to "flush" the pixel could result in lost electrons as well.
> Finally, they will need to have a counter for each pixel as well, and _those do not_ have infinite capacity either.
> 
> But definitely a novel and different idea. It will be interesting to see if they can make a product out of it.



Thus the extra bits just for keeping track of the number of "overflow" full buckets. So again, nothing special about the "invention", nor the "unlimited DR" claim. I would just say this is just an increase of bit number to give higher resolution of the photon count.
I'm *NOT excited* about the MIT claim as it stands now.
-r


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## privatebydesign (Aug 24, 2015)

jarrodeu said:


> privatebydesign said:
> 
> 
> > jarrodeu said:
> ...



You might be serious, but you are in denial.

Dynamic Range
Just taking a look at your first link that purports to prove Portra 400 has _"around 18 stops of DR"_. have you actually looked at the strip? For instance why is the fourth image darker than the fifth image when it is exposed one stop more? Maybe the fact that they were shot when the sun was being covered more and less by moving clouds!

But lets not fret over that, lets rely on Kodak themselves who state, quite clearly in their Portra 400 data sheet (1), a Log Exposure range of 3.3-3.6, or 11-12 stops. Personally I trust Kodak's own measurements over uncontrolled random 'test' hyperbole.


Resolution
Your first issue with the examples you gave is scanning, it introduces all kinds of digital irregularities, besides, anybody that has drum scans done regularly, or did, knows full well you are not resolving more detail, you are just resolving the film grain more accurately.

Personally I have many 24"x36" wet prints from 135 format Fuji Velvia 50 and 100, some of the finest grained film which @ 1000:1 contrast ratio it is supposedly good for 160 lines/mm (2), they don't hold a candle to 21MP images at the same size.

The 5DSR has a 241 lines/mm.

As for your Adox film, it is clearly not what it is claimed to be. The truck image was scanned at 8000dpi, that is 314 lines/mm, nowhere near the 800 claimed, or the farcical 800 lp/mm they also claim, and it has no more detail it is just grain. Yes it is a bigger file than a 5DSR, but does it contain more detail?

Lets look at two crops from the same area from the Adox and a 5DSR, see below. Image 12 is from a 5DSR, image 13 is a same sized crop from the Adox, I know which I'd take, and the Adox needed four times the exposure.

High ISO
We agree on.


As a final note, yes film does come in larger sizes than digital sensors, well the ones currently available at prices we can afford, but stitching is free and easy and have you seen the resolution figures for large format lenses, they are nowhere near as good as those for 135 and medium format.

So when it comes to convenience, cost effectiveness, dynamic range and resolution digital is the clear winner. Like I said, there are many reasons to shoot film, but the main one is shoot it because you want to, because of the organic nature if the process, because you love the darkroom and it's smells feel and isolation, because you are in love with your 8x10 Wista and Berlebach..........




(1) http://www.kodak.com/global/en/professional/support/techPubs/e4050/e4050.pdf
(2) http://www.fujifilm.com/products/professional_films/pdf/velvia_50_datasheet.pdf


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## Don Haines (Aug 24, 2015)

privatebydesign said:


> jarrodeu said:
> 
> 
> > Finally, a sensor that can match and surpass the range of film!
> ...


This reminds me of the audiophile arguments about tube amps and transistor amps. So many people were so adamant that tube amplifiers were better and would attack those who disagreed with them. Put them on a spectrum analyzer and it was obvious that the transistor amps were far superior, but that had no effect on the tube enthusiasts who "knew" that the tubes were far better. No amount of scientific testing could ever change their minds because their minds were already made up. The reality was that they liked the way the distortion sounded.....

Same with film.... it is a different media and it looks different.... if that's what you want, then fine, use it. You don't have to try justifying it against digital or using ridiculously concocted scenarios.... if you like it, use it!


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## privatebydesign (Aug 24, 2015)

Don Haines said:


> privatebydesign said:
> 
> 
> > jarrodeu said:
> ...



Couldn't agree more Don. That is why I still own and occasionally use my 1VHS and my Mamiya 6x9.


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## Mt Spokane Photography (Aug 24, 2015)

Camera manufacturers have been researching ways to control each pixel individually, and adjusting gain to keep them from blowing out. So far, its not been practical to produce.

This definitely seems more practical. The University would likely want to license any patent they may receive to any and all willing to pay. Usually, they setup a company that is owned by the University to do this. A number of circuitry patents with designs for actually implementing the basic idea will differentiate products in the market place.

Look for something practical in 9-15 years.


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