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Your thread got me to wondering what the equivalent magnifying power of my telephoto lens and camera combination was and how cropping an image increases magnification.

Here, for example, is a photo of some coots taken with a Canon EOS 7d and a 100-400mm lens set at 400mm. The Canon EOS 7d multiplies the focal length by 1.6, so the effective focal length of this photo is 640mm. I've read that you can divide the focal length by 50mm to tell how magnified the image is compared to a picture taken with a 50mm lens. By doing that I get a magnification of 12.8 compared to a 50mm lens of a full frame camera that doesn't multiply the focal length. A 1000mm lens like that Nikon camera you posted about would give a magnification of 20 compared to a 50mm lens.

Here's the photo:

I noticed that the coot in the middle was more or less in focus, so I cropped the image such that it was about 1/9th of the area of the original 640mm picture. Here is the resulting image blown up to the same size as the picture above:

If my calculatons are correct (always questionable), the magnification on this cropped image is 9 times 12.8, or 115 times that that a 50mm lens would give. Keep in mind I'm dealing with area of the image here, not its height or width, which would both be multiplied by a lower adjustment figure than I used in the area calculations above.

The figures released with point and shoots usually don’t correlate with DSLR ratings, there is some hype involved. To find out how this Nikon really rates you’d have to compare it side by side with a known lens and see which one gets “closer”.

Re:41.
What lens did you use. Was it an ‘L’ lens?
I have a 55-250IS that takes nice ‘snapshot’ pics. But wildlife, cropped shots are soft.
My son has a huge L lens that takes razor sharp pics and I’m trying to justify dropping $1300 on an L lens.
Canon Ti DSLR.