More megapixels, better photos: Fact or fiction?

Started Feb 7, 2008 | Discussions thread
Jay Turberville Forum Pro • Posts: 12,917
Well Chato ... here is a good comparison...

Hey, why argue with me? Play my game yourself -

Now let's play my game. In my game I take basically the same picture at nearly the same time with three different cameras. In this case, a Coolpix 5000 with a 5Mp 2/3" sensor, a Coolpix 8400 with an 8Mp 2/3" sensor and an E-330 with a 7.5Mp 4/3" sensor. I used approximately f/4 on the two 2/3" cameras. The E-330 image was shot at f/8. All were shot at the camera's lowest ISO - hence the highest quality. That's ISO 50 for the CP8400 and ISO 100 for the other two. All images were shot with raw, developed in dcraw as 48 bit non-gammma adjusted TIFFs and color adjusted in Photoshop 7. No noise reduction was applied at any step. Sharpening was done to the luminance channel in Lab color space and 48 bit color depth. The 5Mp and 7.5Mp images were uprezzed to 8Mp.

I'm only posting two images. One is a small picture of the full scene. The other shows an image crop at 100% pixels. I'll provide links to other crops as well as links to full rez final copies. But this way, this page won't take forever to load.

BTW, I could have pulled more detail out of the CP5000 image by sharpening a bit more, but that would have further increased the noise and exaggerated some of the aliasing

The summary here is that the CP5000 has less detail and more noise than the CP8400 - the camera with smaller pixels. The E-330 has the least amount of noise, but also is a bit less sharp. A better lens might help the E-330 a bit or it might just be that the E-330 has a more agressive AA filter. I don't know.

But anyway, this demonstrates my point - and the camera makers' point rather well. Increasing pixel count on the same sized sensor can improve overall image quality. In this case, it improves resolution and noise - though it probably gives up a little on the DR front. Of course, improvement may not always be the case. Another comparison with different cameras might give a different result. The lesson here is that you can't just assume. You need to actually do some checking.

Now, from the standpoint of making an 8x10 or 11x14 print, all of these cameras can give very nice output. The practical differences really aren't that large. But overall image quality improved with the CP8400 and its smaller pixels. It didn't get worse. In good light, I don't hesitate to use the CP8400 if the situation warrants it. Its images don't look plastic (take a look at the 4 comparison images) and though it has a tad more noise than my DSLRs, it isn't enough to hardly ever matter.

The image order is:

Coolpix 5000................Coolpix 8400 ....................E-330

These are around 450kb.

These files are 6-7Mb and my server runs off of my DSL connection. So don't expect fast uploads.

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