Yelvertoft said:
Mick,
7MP is overkill. I was quite shocked the other day when I took the attached photo of a swan. I looked at the picture on the PC screen and thought "there's a speck of dirt on this shot". Then I thought, "no, it's a mosquito on the swan's back". Then I looked at the shot at full 1:1 scale 5MP resolution. I found I could count the legs on a mosquito on the back of a swan with a picture taken from about 25 metres away. Just how much more resolution do you need?
.
Need? That's hardly the question. The question is how much do I want. And for me, that's about as much as I can get and afford.
I like making prints. I especially like making big prints. I don't think a camera can deliver too much resolution. I recently bought a 4x5 view camera because I know it will be quite a few years before digital can affordably resolve as much detail. I scan the transparencies at 2400 Dpi and get 90Mp images. I'll also stitch digital images together to get even larger pictures.
Detail and resolution are good things, IMO. 7Mp overkill?!? I don't think so. I want much more.
http://www.jayandwanda.com/birds/cwren_zoom.html
The nice thing about digitals is they almost always allow you to choose shooting in a lower resolution if you prefer. So you lose littlle by having the capability to shoot with a greater resolution.
Of course, everybody has somewhat different needs. If all you do is look at images on your screen, email photos and make the occasional 5x7 or 8x10, then certainly, a 2 or 3mp camera is completely sufficient and perhaps even too much resolution. But from a print quality quality standpoint, you probably need 5Mp or better (conventional sensor design - megapixels to NOT equal resolution BTW) to get print image quality that approaches 35mm film. 3Mp is nice, but it doesn't provide the overall image quality that a good 35mm camera provides.
'm sure there are people chasing after megapixels that won't really benefit from them and consequently they are wasting their money. So for some people, the chase is silly. You just have to define what it is you want to do with your images before you can know.
BTW, its nice that you can count the legs on the mosquito, but by my eyes, that is only because I happen to know to expect six legs. The mosquito is quite indistinct. This level of fuzziness would limit how far this image could be successfully enlarged. Furthermore, mosquitos can easily be over an inch long. So I'm not sure that seeing this mosquito this says a lot about the detail resolved in the image.
The megapixel counts rise much faster than the actual increase in resolution because the megapixel count is an indication of the number of sensors in the picture area. Twice the resolution requires four times the number of pixels (assuming the same sensor design). 7Mp isn't "overkill". Its only a 20% resolution increase over 5Mp.
Personally, I''m waiting for a 10Mp Nikon DSLR at an affordable price. That should serve me well for a number of years. And then, I'd expect even more sensor design evolution and cameras capable of even greater resolution - which would be just fine for me - but not necessarily what everyone should buy.