Megapixel

[Theo Tan]

I know a lot of people who are bragging about their digital camera with 6 or more megapixels. But to my understading the number of megapixels is not the only factor that determines good digital image. The quality and size of the sensor (chip), bit and of course the lens has more to do than the number of the megapixels alone. Am I right?
Thanks for your input.

[Bill_1856]

Nope.

[David R Munson]

There are a lot of factors that come into play. Short answer, though, is that there is more to it than simply resolution. How much more is a matter of opinion.

[paulr]

Knowing the number of megapixels is like knowing a number for the theoretical maximum resolution of the film in a film camera. It doesn't tell you anything else.

[ronald moravec]

Don`t do digital, but I have read a little.

Size of the pixels is important as are the number of them. If memory is correct, the bigger the pixel, the better. Counter intuitive though.

Irwin Putts talked about chip size as it relates to 35mm work, and he concluded a bigger chip was not necessarily better for that application. He has a website easily found.

[Larry Mendenhall]

IMHO, what's more important than megapixels at this point is the algorithms (sp?) that process the image as it's captured. So, in theory, a 6-megapixel camera with great processing may equal or even better an 8-megapixel camera with lousy processing.

[David Van Gosen]

Here's an essay that might be helpful:

http://www.luminous-landscape.com/tutorials/understanding-series/res-demyst.shtml

Michael Reichmann has spent a lot of time researching and writing about digital imaging. You should give the rest of his site a good look as well.

[David Luttmann]

Larry,

That's correct. The latest point and shoot cameras that boast 7MP come nowhere near to matching even a 6MP DSLR. The point and shoots are plagued by smaller sensors that have significantly higher noise and lower dynamic range. That is why digital cameras with large sensors end up outputting results that exceed what people expect for the pixel count. Because of digitals lower noise, edge effects can be increased significantly when compared to film. The human eyes notices high accutance over detail to a great extent.

That is why it takes a lot less MP to equal MF and LF than most people would think.

[Ken Lee]

One helpful thing to do, is look at actual results and see what you like and don't like. Often, sample images are more revealing than the technical specs.



One camera may capture more detail, but the colors tend to be off. Some give larger files, but no more useable data. Some lenses introduce certain kinds of distortions and aberrations at different focal lengths: chromatic abberation (color fringing) barell/pincushion distortion, etc. Some cameras introduce noise in the shadows. Others can only accomodate a narrow range of subject brightness... it goes on and on - and it all helps determine image quality.



Here's one place (http://www.dpreview.com/reviews/" target="_blank) that I have visited to see some sample images. Choose a camera, and then find the samples . There are probably many such sites, but since this fellow shoots the same subjects all the time, you get a pretty good feel for what the various cameras can do.

[Janko Belaj]

Generally speaking, you could say "bigger is better", but... "bigger" number of pixels will only allow you to enlarge more, "bigger" size of pixel will only made your dynamic range better, and "bigger" in-camera software (and "bigger" raw converter) will give you only more finishing choice.



Although not the same problem as comparing analog vs digital, there is still lot of traps with comparing snapshot 8 (for example) with pro 8 Mpixels...I had opportunity to test several professional digital backs (leaf, kodak, imacon...) and I think that Canon is giving right now (with 20D, 5D and all those markII cameras) the same "kind"(!) of result as Leaf was giving several years ago with their 6Mpixels Cantare. And that is hard to explain with limited english as is mine, but the "strength" of picture was on the side of those old pro CCDs. And nothing can be compared to scanback... but, there is always some "but" - every assignment needs its kind of equipment. While you can somehow create architectural shot with 35mm-like dSLR, you can't take your scanback on fashion show. O.K., you can, but what will you shoot? ;-)) And, of course, for architecture you will "always*" get better results with 4x5" slide than with any of todays* dSLR's...



(*-how long will that "always" and "today" last? I don't know. So far, I can't see when we will have d-oneshot-LF. but for sure, the date is closer and closer...)

[Craig Wactor]

There is also the pixel size, and bit depth is just as important as # of pixels. Lens, exposure, and all those things that are common to analog cameras make a huge difference too.