Senser size, Image Size, Mega Pixle HELP!!!!

[sgreenman]

Ok how do I not sound to stupide. Maybe I spell stupied right to start. No really, I need someone to PLEASE explain to me like a child the answer to this Question/Thought....

I was asked and not able to answer the following. Why is my 1D mark 3 better then a P&S of the same Mega Pixle? In the context to making big 20x30 prints & The crop effect of say a 1d mark 3 vs a 40D vs a P&S... how does that effect prints?

Ok I know lens choice has a lot to do with it. I run mainly Ls. But what really stumped me was why or how is a picture from a 40D and a 1D mark 3 different when it comes to the crop? I know one is 1.3 and the other 1.6. But they both make the same size Jpeg. Yet they are a different picture when shot off the same lens.Is that the crop thing I thought I had a handle on this but have seem to lose my way. Can someone please help

[Nikonfreak]

Simply put, not all megapixels are created equal. The size of the sensor makes a difference as does the size of the photosites on the sensor, as does it's ability to gather information... and as you've already pointed out, higher quality lenses can and do help the process along. If those little point and shoots could do what the professional level DSLR's do, there'd be no market for the pro gear... There are other problems as well. Packing more and more megapixels onto smaller sensors (over simplification here but you'll understand the message) means smaller points getting the information which means a lot more chances for errors and noise to become a factor in the smaller sensors. Take a look at some of the reviews on the smaller point and shoots. You'll note that at ISO 400 -800 folks talk a lot about the noise and how much it's pushing the limits of the sensor, how much noise is in the images and such in quite a few models. The newest pro DSLR's from Nikon and Canon can shoot perfectly useable images at ISO 1600 and beyond with very very clean images.

Do a google search on the phrase "not all megapixels are created equal" and you'll get a host of articles.

Here's a few articles for you to get started.

The Online Photographer: All Pixels are Not Created Equal

Pixels vs. Pixels

Not All Digital Camera“Think” Alike

Julio

[Mr. Pickles]

In addition to what was answered above, it is "roughly" simple. The size of the sensor itself, and the size of the individual pixels is most of it. Also, given that, the size of the empty space in between those pixels is another. As the pixels "glow" with image data during exposure, neighboring pixels can "absorb" residual data. This can produce "negative' effects like purple fringing (purple halos where bright and dark meet) or other chromatic aberrations.

So "packing" pixels onto a sensor doesn't really mean the image is better. As technology improves, the negative effects are lessened.

[badpickev]

this may help.

Digital Camera Sensor Sizes: How it Influences Your Photography

[Latinbob]

You can also use a film analogy. 35mm prints looked better than 110 cameras, or disc cameras. And the shots you got at Olan Mills looked even better, because they used at least medium format. The bigger the sensor, the better looking the picture. The smaller the sensor, the less detail you can capture.

Bob

[jfrancho]

Simply, the quality of the components that make up the system are of superior quality and therefore the results are of superior quality. There are also more opportunities for creative expression using an SLR, and these subjective decisions can lead to better looking pictures. Things like shutter speed, focal length, bounce/raised/diffused flash, depth of field, etc. come to mind. An iPod sounds great, but a nice tube amp through a set of reference speakers sounds better.