claudermilk said:
Most of the review sites are at least mostly based on subjective reviews. I've found Steve's to be pretty accurate & he is thorough in going over the camera. I use his site over DPR (and avoid the DPR forums).
But the sites I referenced have lot of objective/measured data, that can be processes/analyzed, and a conclusion can be made on performance aspects that are not subjective. I don't pay much attention to the actual opinion review text...
You mean depth of field? That's determined by you apeture & should be set by you. Slower lenses won't be able to narrow the depth of field as much as faster--that's the big drawback of P&S cameras: their little bitty lenses are all very slow comared to SLRs.
Actually, the lenses that most buy[like the typical stuff found in your local mall camera shop or circuite city, for example] for their SLRs are 'slow', and usually have rather poor MTF when weighted across the entire frame, especially with telephoto lenses of low cost. Many of the integrated cameras have very 'fast' lenses, and some of them even have superb quality zoom lenses[tack sharp from edge to edge, very little CA, etc.]. The greater DOF of the P&S cameras has to do with the focal length vs. aperature, and the same calculations are used as with SLR lenses to find DOF. But please realize that, for example, a '35 mm' 'effective' focal length on a small integrated cameras is really about 7mm, and the marked or advertised focal length is usually just a SLR equivalent magnification factor. Of course, a true 35mm focal length is going to have a shallower DOF as compared to 7mm, given the same aperature value. The image capture area of the integrated cameras is much smaller than a standard SLR, therefor you effectively magnify the smaller area relative to the focal length, as the image area becomes smaller[imagine it as a cropping effect, to put it roughly]. But in reality, you are using a much shorter focal length with this small 'cropped' area, as would be required to get the equivalent FOV with a SLR's capture area.
Here is a crude example:
35mm full frame capture area:
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2/3 standard integrated digital camera capture sensor area:
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Now imagine printing both of the area examples above on an 8" x 10" sheet, so that each fills the entire area of the sheet. The bottom example is going to be greatly magnified, if both used the same actual focal length; a cropping effect.
So, in effect, the small capture area is 'cropping' to get a magnified effect, making a shorter lens act as a much longer one so far as magnfication. The benefit is that a shorter and lower cost lens can get great reach, and with very bright optics, the con is that it can be more difficult to get the bokeh desired in some cases. Of course, some people prefer the greater DOF, just like some prefer less DOF, so for some it might be a plus.
-Chris
