Photograph Works

I looked around the prints from the P5100 and the D200 and saw that the P5100 had in fact not focused at its sharpest where the brackets were set, but rather nearer. The end of the cucumber in the shot was the point where it focused best so here is a combined shot with the P5100 above and the D200 below.

I had already junked the jpegs so this is a scan from the two shots.

OK, another test.

I set the cameras on a tripod, with an 85mm f1.8D lens on the Nikon D200, and the zoom on the P5100 set to maximum optical zoom, which brings the two cameras close to having the same field of view.

This time I remembered to turn off VR (vibration reduction) on the P5100, as I recalled that the manual suggests one should do that if the camera is fixed on a tripod.

I set the D200 to shoot jpegs at highest quality and I set the aperture to f8. I set the aperture on the P5100 to f7.3, which is the minimum possible.

I shot at ISO100 and at ISO800 and then had large prints made of all four images so I could compare the shots for myself ‘in the flesh’ as it were instead of on screen. I did this because I feel sometimes I am losing touch with what these differences mean when looking at a print. After all, if the differences do not show in a print, what is the point of drawing conclusions about how they look on screen. In fact the prints that I looked at reflect the conclusions I have come to here, very well.

Here are the four images, full frame.

I cannot distinguish differences in image quality between these shots with full-frame images at this size on-screen, so here is a comparison shot made by pasting crops at 100% into a new image.

I think that the images from the P5100 hold up reasonably well at ISO100 but fall apart at ISO800. The P5100 has vibration reduction built in to the camera, and as a rule of thumb we can say that this gives the camera a three stop advantage over a non-VR system.

I think the shots from the D200 at ISO800 are more or less as good as or maybe better than the shots from the P5100 at ISO100. That is a three stop advantage to the D200. Which means that the VR advantage is cancelled out by the loss of image quality. Or to put it another way, A Nikon dSLR with a VR lens of something around the quality of the 85mm I used on the D200 would be about six stops better than the P5100. That is a big argument for bearing the extra weight and size of a dSLR.

Now which dSLR has about the same pixel count and a decent VR lens in a small, lightweight package?

And here is a 100% crop of part of the image from the P5100 at ISO100

And here is a 100% crop of part of the image from the D200 at ISO800