Unformatted text preview:

Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16PhotonrateTimeEnd of exposureEnd of exposureIdealRate of incoming light is constantReal lifeRate of incoming light is fluctuatingPhotonrateTimeHow much fluctuation?√nDictated by Poisson (pwasõ) DistributionFor n total photons in exposure,standard deviation =Photons collected = n + √nIf n = 10,000 photons,Photons collected = 10,000 + √10,000 = 10,000 + 100 photons10,000 photons9,900photons10,100photons9,950photons√n, so what?Variable brightness = noise!Noise monsterOne of the photographer’s worst enemies0 1000 2000 3000 4000 5000 6000 7000 8000 9000 100000%2%4%6%8%10%12%Proportion of fluctuationProportion of Photon Fluctuation (√(n)/n)Photons0 500 1000 1500 2000 2500 3000 35000%2%4%6%8%10%12%Canon 5DNikon D300Sony H9Proportion of Photon Fluctuation (√(n)/n)Photons90 900 90000%2%4%6%8%10%12%Canon 5DNikon D300Sony H9Proportion of Photon Fluctuation (√(n)/n)Photons0 500 1000 1500 2000 2500 3000 35000%2%4%6%8%10%12%Sony H9Sony H9Proportion of Photon Fluctuation (√(n)/n)Photons0 500 1000 1500 2000 2500 3000 35000%1%2%3%4%5%6%7%8%Canon A570ISCanon A570ISISO100ISO200ISO400ISO800ISO1600Proportion of Photon Fluctuation (√(n)/n)PhotonsCanon A570IS7.1 Megapixels1/2.5” sensor5.76 x 4.29mm (24.7mm2)Density: 3.48 μm2/pixelISO100 ISO200 ISO400ISO800 ISO1600Canon A570IS7.1 Megapixels1/2.5” sensor5.74 x 4.3mm (24.7mm2)Density: 3.48 μm2/pixel0 500 1000 1500 2000 2500 3000 35000%1%2%3%4%5%6%7%8%1002004008001600images: dcresource.com0 10002000300040005000600070008000-2%0%2%4%6%8%ISO100 ISO200 ISO400ISO800 ISO1600Fuji F306.1 Megapixels1/1.7” sensor7.7 x 5.77mm (44.4mm2)Density: 7.27 μm2/pixel1002004008001600images: dcresource.com0 100002000030000400005000060000-2%0%2%4%6%8%ISO100 ISO200 ISO400ISO800 ISO1600Canon 30D8.2 MegapixelsAPS-C sensor22.5 x 15mm (337.5mm2)Density: 41.16 μm2/pixel1002004008001600images: dcresource.com30D30DF30F30A570ISA570IS8.2 Megapixels22.5 x 15mm (337.5mm2)Density: 41.16 μm2/pixel6.1 Megapixels7.7 x 5.77mm (44.4mm2)Density: 7.27 μm2/pixel7.1 Megapixels5.76 x 4.29mm (24.7mm2)Density: 3.48 μm2/pixelISO100 ISO200 ISO400 ISO800 ISO16000%1%2%3%4%5%6%7%8%Canon A570ISFuji F30Canon 30DCanon 5DProportion of Photon Fluctuation (√(n)/n)ISOMaking matters worse, circuitry must occupy some space between each photowell – the more photowells, the more space circuitry takes up.SummaryMore pixels, smaller sensor => less light per pixel => more noiseLess pixels, bigger sensor => more light per pixels => less noiseIn theory, the biggest sensor with the least pixels will give us the best image, in terms of noise.A 1-pixel sensor would be ideal. With 1 pixel, we’d have low noise but no detail.Many pixels => High detail, high noiseFew pixels => Low detail, low noiseThe “Megapixel Myth”: Detail vs. NoiseMegapixels: Detail vs. NoiseFacebook profile picture: 4x6 studio print at 300dpi: 5x7 studio print at 300dpiStandard VGA TV: 1080p HDTV: 1280x1024 19” LCD monitor: 8.5x11in, 300dpi magazine spread:8x10 inkjetprint at 200dpi:10x14in, 150dpi full-page spread in Daily Cal: Giant 20x30in poster print at 150dpi:0.03 MP2.16 MP3.15 MP0.35 MP2.07 MP1.31 MP8.42 MP3.20 MP3.15 MP13.5 MPHow many pixels do we need?:If you only look at pictures on the computer, 2-3MPIf you make non-poster-size prints (4x6, 5x7, 8x10), 3-4MPMore pixels beyond this don’t add detail, and contribute to greater


View Full Document

Berkeley ELENG 198 - Lecture Notes

Documents in this Course
Load more
Download Lecture Notes
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Lecture Notes and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Lecture Notes 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?