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Startup InVisage's CEO: Why Image Sensor Revolution Is Upon Us

3/14/2016 01:31 PM EDT
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David_Ashton_EC
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Re: Comparing film to CMOS
David_Ashton_EC   3/17/2016 7:45:11 PM
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You're all right above, and reading the Kodachrome Wikipedia page reminded me about sending the film off for processing in those little orange envelopes.  And I had some BAAAD experiences (think pink clouds...) with the processing centre in Johannesburg, South Africa (closest one to me in Zimbabwe at the time) and used to send them to Frankfurt instead, even though there was about a 4-6 week turnaround.  In terms of size, ease of use, speed of getting results, digital is far ahead of what film ever was (and I have shot Ektachrome in the morning, processed it in the afternoon, and printed it in the evening).  Quality has pretty much caught up, as you've all pointed out, though it's taken 30 years.  And yet.....I quote from the Wikipedia article....

"Steve McCurry told Vanity Fair magazine:"

"If you have good light and you're at a fairly high shutter speed, it's going to be a brilliant color photograph. It had a great color palette. It wasn't too garish. Some films are like you're on a drug or something. Velvia made everything so saturated and wildly over-the-top, too electric. Kodachrome had more poetry in it, a softness, an elegance. With digital photography, you gain many benefits [but] you have to put in post-production. [With Kodachrome,] you take it out of the box and the pictures are already brilliant."


 

realjjj
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Re: Comparing film to CMOS
realjjj   3/17/2016 12:29:29 PM
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Image quality is not my thing and was trying to stay away but the convo got a bit offtrack. If you compare digital with film, digital wins in pretty much all metrics. Resolution, dynamic range, noise, film speed. If you compare film with mobile phone cameras, that's a bit unfair as you have huge size constrains in phones. The 12MP back cam module in the Galaxy S7 is 12.1 mm x 12.1 mm x 5.4 mm and a comparison with any film based device seems forced. The 13MP Quantum13 from InVisage fits in a 8.5 x 8.5mm module. In phones the pixels got too small (as low as 1 micron), there is no room for optics and breakthroughs are needed (InVisage could be one) All in all they are rather extraordinary as they are., even more so when you factor in the price- as per IHS the back cam in the Galazy S7 is 13.7$ and the front 5MP module is 1.95.

traneus
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Kodachrome
traneus   3/17/2016 10:45:05 AM
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Wikipedia's page about Kodachrome, states that Kodachrome had 12 stops of dynamic range. Since one stop, like one bit, is a factor of two, this is 12 bits of dynamic range. This is two bits better than Ektar 100.

JamesM951
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Re: Comparing film to CMOS
JamesM951   3/17/2016 2:57:49 AM
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Consider this. Is artificial orange flavors equal or better than real orange flavors ? If you or a group of people did a blind taste test & picked the artificial orange flavor as being better than the real orange flavor would you want to switch to the artificial orange flavor ?

That's the essence of digital vs analog, neural networks vs organic. 

David_Ashton_EC
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CEO
Re: Comparing film to CMOS
David_Ashton_EC   3/16/2016 11:43:53 PM
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I wonder how Kodachrome 25 film would stack up.  I loved that film, if you could get used to the slow speed.  And that was 30+ years ago.   I reckon that still can't be beaten.  I'm beginning to sound like one of those guys who reckons Vinyl is better than CDs.... :-)

traneus
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Comparing film to CMOS
traneus   3/16/2016 10:47:38 PM
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I downloaded the technical data sheet for Kodak Alaris Ektar 100 color-negative film, and converted the specs to image-sensor language.

Ektar 100 film density versus log_exposure curves, show that Ektar 100 has 1000:1 dynamic range, corresponding to 10 bits of ADC (analog-to-digital conversion).

Ektar 100 film modulation transfer function curves show that Ektar 100 has 14% response (i.e. down 17 dB) at 80 cycles/mm. This corresponds to 6.25 uM per half-cycle. To get pixels of all three colors in the usual Bayer pattern, takes a 2x2 block of four image-sensor pixels, so 80 cycles/mm corresponds to 3.125 uM image-sensor pixels.

In image sensors, one pixel is defined as one pixel of one color (red, green, or blue). This is different from the definition of pixels in monitors, where each pixel has three sub-pixels for (red, green, blue).

Note that film modulation transfer functions are made using alternating light and dark lines, not dots, to eliminate the noise due to the film grain.

I haven't yet figured out the subjective graininess measure Kodak uses, but film is generally a lot noisier than image sensors are. Avoiding the grain (noise) is one reason why film uses larger image sizes.

CMOS color image sensors with 3 to 4 uM pixels and 10-bit ADCs are common. Of course, film offers much larger image area.

The article ignores the existing HDR (high dynamic range) software techniques, where images are taken at multiple exposure times, and combined into a single HDR image. This already gives better dynamic range than film has.

realjjj
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Re: What's the advantage again ?
realjjj   3/16/2016 5:34:27 AM
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The pics are 1024x717,just copy/paste each one into your image viewer or right click/view image. As for advantages, don't forget costs.

David_Ashton_EC
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Re: What's the advantage again ?
David_Ashton_EC   3/16/2016 2:55:44 AM
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@James... "Actually I think there is no way quantum dot can ever beat kodachrome."

I'm with you.  It would be nice to see bigger photos but the Kodak ones are better even at that size.  That's the human race for you.  Convenience wins every time.  That's progress.....

JamesM951
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Re: What's the advantage again ?
JamesM951   3/16/2016 2:22:05 AM
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"See the photo comparison - Kodak film vs. trandional CMOS vs. Quantum Dot, here:

http://www.invisage.com/quantumcinema/"

 

The comparison would have a lot more credibility if I could click on each photo & pop up to at least a 4k x 4k size. As it is, the tiny photos don't prove a thing. Actually I think there is no way quantum dot can ever beat kodachrome. 

rodneyreid
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Re: What's the advantage again ?
rodneyreid   3/15/2016 11:43:40 PM
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Of course it's really needed, precisely because those videos/photos are so terrible.

See the photo comparison - Kodak film vs. trandional CMOS vs. Quantum Dot, here:

http://www.invisage.com/quantumcinema/

Most of the blur issue with security cams comes from compressing the data for storage --- people will always always want to do this as frugally as possible, and that's the kind of output they get from their systems.

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