So What Does It Mean?
There are no stupid questions. But there are stupid comments on forums. I will try not to make those.
For practical photography not much really, other than just to make you more aware of reality. Here are the few takeaway messages for photographers:
- A great zoom is not as good as a good prime at comparable apertures, but it’s plenty good, especially in the center of the image.
- Zooms have more variation, and most copies of a given zoom will vary at different focal lengths. If someone asks me for the best copy of a zoom, my first response would always be ‘at which focal length?’ In this case, the sharpest copy at 200mm is not the sharpest at 70mm.
But for measurebating, there is a very pertinent point that needs to be made: Measurebating zooms is a fool’s errand. These differences may not be huge in your photographs, but they are very significant on a test. The reviewer who got lens #6 is going to have different conclusions and present you with different numbers than the reviewer who tested #1 or #8.
Some reviewer somewhere tested a single copy of a zoom lens and gave it their highest rating ever. Some people actually argued online about that, and then asked my opinion about that argument. So I wrote this post to explain why I thought it was all meaningless. When someone compresses something as complex as the multi-focal length performance of a zoom lens into a single number after testing a single copy, I don’t really care if their number is 3.1415926, 2.718281828 or 1.61803398; it doesn’t have any scientific value at all. Unless the rating is 42. Then it would have a meaning.
