Pixelation question.

[mike62]

I currently have a Minolta with a 4X optical and 4MP and would like to buy either the Sony H1 with 12X optical and 5.1MP or the new Panasonic FZ30 with the 12X optical and 8MP.

My question is if I can make sense.....if I zoom to lets say maximum length to take a picture with the 8MP at the full focal length do I still have the full 8MP's that will allow me to crop and zoom in on my PC thus bringing the picture in even closer? I mean zoom does not have anything to do with the pixels in this scenario does it? Essentially, if I take a pic at 10 feet I can then crop with the full 8MP's but if I take a pic at lets say 100 feet using the zoom will my ability to crop be the same at 100 feet verse 10 feet since I used the zoom at 100 feet?

Sorry for the confluted question.

[TheObiJuan]

Well, normally, I would say yes, at full zoom, the MP count is the same.
But, lately, camera manufacturers are increasing zoom by decreasing the capture on sensor. This, essentially crops the photo.
The nikon d2x does this. It normally has a 1.5 crop factor, because it's sensor is .5x smaller than 35mm frame. The camera can crop to 2x, by only using a smaller portion of the cmos sensor, giving an equivalent field of view, of 2x focal length.
This, though causes the camera to give a maximum MP capture of 6mp, instead of 12MP.

A 50mm lens on a d2x gives a field of view similar to a 75mm lens, with the 2x crop activated, it is similar to 100mm.

The new lumix cameras, like the LX1 do this too.
It goes down from 8mp to 3mp, but you get a pretty good zoom.
You don't have to use this, though if you don't want to. But with the LX1, you will be limited to 3x zoom.
This is not to be confused with digital zoom, which captures a part of the image and blows it up. Really, the digital crop is just not 'zooming' in on the image, so you get no pixelation, but you do get less MP. Oh well....

[TartanPirate]

Surely a digital crop as you describe is just the same as a slight digital zoom. You are throwing away some of the pixels around the outer edge - just not so many so not such a drastic reduction in quality. That is my understanding of the information capture process.
:confused:
If I'm wrong can you clarify more?

Thanks,

TP.

[Geoff Chandler]

Cropping after the photo may be slightly better - if only because you can select exactly how you want to frame the crop. I don't like digital zoom, but a very small amount at higher MP levels is possibly acceptable - it does mean that the effective MP quality is reduced a bit. Provided you don't use much digital zoom it could be ok. Some cameras - like mine - will use interpolation in digital zoom - which gives a marginally better result - though I don't like the deterioration above 2x digital. If I am set at 5mp I believe the camera will make use of the remaining 3 available, as far as possible, to assist when digitally zooming.
Additional comment - when taking macro shots - I have found that a crop of an 8mp item taken not so close, has better depth of field than the same item taken at the closest possible - the same image but better dof (I posted an example somewhere back in the flower thread).