Whats the dif? CCD vx Megapixel

[rick65000]

I notice that Megapixel is refernced as storage in product descriptions. But I read previously that at 7 megapixels digital photography surpasses film photography.

So my question is which is better
Optical Sensor Size 1/2.5, CCD with 4 megapixels (DiMAGE G400, Minolta)
or
1/1.8, CCD with 5 megapixels (DSC-P92 CyberShot, Sony)

I'm not really asking if Minolta is better than Sony or vice versa. I'm just asking about the various combinations of CCD size/number of megapixels that are offered. From what I've read I understand that the CCD numbers are inch measurements and (using the Minolta numbers above) may mean either 1 and 2.5 inch square (which sounds wierd) or 1 CCD at 2.5 inches. So is a .7 CCD difference greater than a 1 megapixel difference?

Thanks for any response.


Oh and here is an odd thought. If a digital camera focuses on a CCD can a drop in cartridge with a CCD and some miniture electronics that interface with existing SLR digital controls be made? That way old SLR bodies could remain useful after they quit making film, and all the film in the warehouses runs out, like is happening with 16mm.

(post was previously missing: y , and out)

[Michael Fanelli]

This is a lot to cover so I'll give you the short version.

The prefix "mega" is used in science to designate "million." Storage is measured in megabytes, "millions of bytes" not megapixels. Another common prefix is "giga" meaning 10^9 (1000000000) as in 2 gigabytes.

Sensors are measured in megapixels, millions of pixels. The more megapixels, the more "grains" to register light. Unfortunately, it takes a lot more than megapixels to determine quality. The size of the each pixel means much more. For example, my 6 MP Canon 300D blows away the 8MP Sony 828. The Sony's pixels are very tiny to get them to fit on the sensor. The noise is very high and the chromatic abberation is awful. The 6MP on the 300D are much bigger and of much better quality.

As for "7 megapixels digital photograph surpasses film photography", I don't know where you got that from. My old Canon G1 with 3 MP easily matched 35mm film quality up 8x10. The Canon 300D with 6MP surpasses 35mm film quality at any size. The more expensive Canon 1Ds and Kodak 14n at least match, if not surpass, medium format film.

The "slip in" sensor was an idea that has been tossed around for years.Nobody has ever come up with a viable way to do this for 35mm film cameras. There is a lot more than just a sensor that is needed. Medium format do have digital backs. That works because the cameras were designed for replacable backs in the first place.

The bottom line is that you have to evaluate these cameras as a package. Megapixel alone is meaningless. Take a look at the technical test reports located on

http://www.dpreview.com/reviews/

to get a good idea as to what is involved in rating cameras.

[jcitsog1]

Thanks for this information. I did not know that the glossary was even there so thanks for the link. I learned alot about my new camera.