Teacher: Kenji Tachibana Digital Photography I. Sensor Chip 8 slides Copyright © 2003 – 2009 Kenji Tachibana

Teacher: Kenji TachibanaDigital Photography IDigital Photography I.

Sensor ChipSensor Chip

8 slides8 slides

Copyright © 2003 – 2009 Kenji Tachibana

Teacher: Kenji TachibanaDigital Photography IDigital Photography ISensor Chip: Compact DigitalSensor Chip: Compact Digital

EEvolving Technology:volving Technology:

1.1. Next to the lens, the chip is the heart andNext to the lens, the chip is the heart andthe most expensive part of all compactthe most expensive part of all compactdigitals.digitals.

2.2. The compact digital sensor chip is aboutThe compact digital sensor chip is aboutthe size and weight of a postage stamp.the size and weight of a postage stamp.

4.4. Imagine dividing the stamp into 10 partsImagine dividing the stamp into 10 partsas shown to the right. Divide it 10 moreas shown to the right. Divide it 10 moretimes vertically creating 100 discrete parts.times vertically creating 100 discrete parts.

5.5. Dividing it into 1,000 sections and seeing it would Dividing it into 1,000 sections and seeing it would take a microscope, which I can still imagine. take a microscope, which I can still imagine.

6.6. Today’s chips have 10 million discrete light sensitive Today’s chips have 10 million discrete light sensitive pixels on a postage stamp size area. That’s totally pixels on a postage stamp size area. That’s totally unimaginable!unimaginable!


EEnough Already:nough Already:

7.7. 10 million means over crowding which results in 10 million means over crowding which results in excessive heat. And heat is the enemy of all excessive heat. And heat is the enemy of all electronic devices.electronic devices.

8.8. 5 megapixel ran a lot cooler and it is more than 5 megapixel ran a lot cooler and it is more than adequate for most practical purposes. So, many adequate for most practical purposes. So, many photographers would rather see R&D put into photographers would rather see R&D put into getting more real image quality improvements.getting more real image quality improvements.

For the camera maker, selling bigger numbers is For the camera maker, selling bigger numbers is an easy-sell.an easy-sell.


PPractical Size: 5 MPractical Size: 5 MP

9.9. The 5 MP is capable of producing an excellent The 5 MP is capable of producing an excellent 8x10 or a good 11x14 print. 8x10 or a good 11x14 print.

10.10. It’s the bases for the assignment required 2547 It’s the bases for the assignment required 2547 x 1955 image size.x 1955 image size.

11.11. It produces approximately 2 to 2.5 MP file size It produces approximately 2 to 2.5 MP file size which is easy to process and store.which is easy to process and store.

12.12. Larger file sizes becomes harder to handle, Larger file sizes becomes harder to handle, slower to process, and storage space can slower to process, and storage space can easily become as issue even with current easily become as issue even with current cheaper storage devices.cheaper storage devices.

Teacher: Kenji TachibanaDigital Photography IDigital Photography ISensor Chip: DSLRSensor Chip: DSLR

DSLRDSLR: Pro & Con: Pro & Con

1.1. DSLR sensor chips are about 5x larger. And DSLR sensor chips are about 5x larger. And even the pixels are larger.even the pixels are larger.

2.2. The larger chip size helps to reduce over The larger chip size helps to reduce over crowding, which also reduces the over heating crowding, which also reduces the over heating problem. For the DSLR’s, the 10 MP doesn’t problem. For the DSLR’s, the 10 MP doesn’t does not means over crowding.does not means over crowding.

3.3. Besides heat, dust is another huge enemy of the Besides heat, dust is another huge enemy of the chip. Current flock of DSLR camera bodies chip. Current flock of DSLR camera bodies comes with assortment of dust fighting comes with assortment of dust fighting mechanisms. Some work better than others.mechanisms. Some work better than others.

Compact digitals are sealed. They don’t have dust issues.

Teacher: Kenji TachibanaDigital Photography IDigital Photography I

Sensor Chip: Generic informationSensor Chip: Generic information

PPixel Arrayixel Array

1.1. Sensor chips contains a 16 pixel checker Sensor chips contains a 16 pixel checker board arrangement (Bayer Pattern) ofboard arrangement (Bayer Pattern) oflight sensitive receptors (pixels).light sensitive receptors (pixels).

2.2. Receptors are photo diode whichReceptors are photo diode whichresponds to light by producingresponds to light by producingelectricity. electricity.

Sophisticated circuitry interprets and amplifies Sophisticated circuitry interprets and amplifies the signals to ‘process’ the digital image in the signals to ‘process’ the digital image in conjunction with the camera software referred conjunction with the camera software referred to as firmware.to as firmware.

All DSLR and high end compact digitals are All DSLR and high end compact digitals are capable to updating the firmware.capable to updating the firmware.



Chip Types: 2 main types with variationsChip Types: 2 main types with variations

1.1. CCD (charged couple device) is the most popular CCD (charged couple device) is the most popular sensor type found in digital cameras.sensor type found in digital cameras.

2.2. CMOS produces less heat and is cheaper to CMOS produces less heat and is cheaper to make. For those sensible reasons, it is starting to make. For those sensible reasons, it is starting to replace CCD’s. It was first successfully used in the replace CCD’s. It was first successfully used in the Canon Rebel DSLR cameras.Canon Rebel DSLR cameras.

3.3. Sony was the first to use the CMOS chip for its Sony was the first to use the CMOS chip for its prosumer digital CyberShot R-1 with a 10 MP pixel prosumer digital CyberShot R-1 with a 10 MP pixel count on a APS size chip.count on a APS size chip.

4.4. Foveon is another kind of sensor chip design. It Foveon is another kind of sensor chip design. It sounds great on paper but only Samsung has put sounds great on paper but only Samsung has put it into a production digital camera. I am looking it into a production digital camera. I am looking forward to seeing its development.forward to seeing its development.



Sensitivity: ISOSensitivity: ISO

1.1. Most compact digitals have light sensor sensitivity Most compact digitals have light sensor sensitivity ranging from ISO 100 to 800. Some have a higher ranging from ISO 100 to 800. Some have a higher numbers such as 1200 or 1600.numbers such as 1200 or 1600.

2.2. From an image quality point of view, only the ISO From an image quality point of view, only the ISO 100 is recommended for assignment shoots. Use 100 is recommended for assignment shoots. Use the ISO 200 for a one-stop gain in aperture or the ISO 200 for a one-stop gain in aperture or shutter speed under emergency situations. shutter speed under emergency situations.

3.3. Don’t use speeds higher than 200 because of Don’t use speeds higher than 200 because of image quality loss. The ISO has also fallen prey to image quality loss. The ISO has also fallen prey to the false notion that ‘bigger numbers are better’.the false notion that ‘bigger numbers are better’.

Teacher: Kenji TachibanaDigital Photography IDigital Photography IOut take from the book: Out take from the book: One Digital Day One Digital Day byby Rick Smolan Rick Smolan

Microprocessor: BackgroundMicroprocessor: Background

The modern microprocessor contains as many as 20 The modern microprocessor contains as many as 20 million transistors, and each finished chip is the product million transistors, and each finished chip is the product of processes more complicated than those used by the of processes more complicated than those used by the Manhattan Project in building the atomic bomb.Manhattan Project in building the atomic bomb.

Yet despite an extraordinarily sophisticated Yet despite an extraordinarily sophisticated manufacturing process, microchips are produced en manufacturing process, microchips are produced en masse at the rate of more than a billion each year. To masse at the rate of more than a billion each year. To put this complexity in perspective, imagine that within put this complexity in perspective, imagine that within each tiny chip there exists a structure as complex as a each tiny chip there exists a structure as complex as a mid-sized city. Now imagine that throughout that same mid-sized city. Now imagine that throughout that same city, millions of people are racing around at light speed city, millions of people are racing around at light speed and with perfect timing in an intricately choreographed and with perfect timing in an intricately choreographed dance.dance.


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Teacher: Kenji Tachibana Digital Photography I. Sensor Chip 8 slides Copyright © 2003 – 2009 Kenji Tachibana