Please allow me to use a self-interview format for explanation of the star review ratings on the site ...
Why are there now star ratings available on the site?
With great reluctance, I have succumbed to external pressures (and many requests) to add product ratings to the reviews on this site.
Why the reluctance?
Well, the word reluctance is being kind – the phrase "kicking and screaming" would probably better describe my feeling on this topic. How can a single number/rating reflect all aspects of a product? I feel that a single number is inadequate to describe even one aspect of image quality at a single point in the image circle at a single focal length, let alone describing overall image quality, build quality, usefulness and/or value of a product. There are too many reasons an item may be good or bad to be described in a single, arbitrary number (note that I do hope to provide slightly more granular ratings in the future). And not everyone values the same product attributes equally. For example, some people don't need sharp full frame corner image quality with a wide open aperture while others must have it. Also, some of us have tighter budgets than others.
So, what does the rating number, represented by stars, mean?
The ratings represent, on a 1-5 scale, what I think about the item and my anxiousness/likeliness to recommend that item to a friend or family member (that includes you). And my arbitrary rating can perhaps be most-swayed by image quality, performance, usefulness and price.
A 5-star rating means a perfect camera or lens, right?
No, there are no perfect cameras or lenses. Compromises are made in the design of nearly all photography products. Reasons for photo gear design compromises often include cost, size and weight.
Then why are there so many 5-star ratings?
A 5-star rating can mean that the product is the best or near-best available, it performs very well overall, it is a great value and/or it has characteristics that make it worth highly recommending (such as a low price).
What about ratings for older models?
New models replacing older models are *usually* better. I will try to keep the ratings of older models updated to reflect this.
Are all of the ratings perfect?
To get the ratings live, I had to beat back the perfectionist in me. You will probably find a specific comparison showing an imperfection in the ratings of one or both items. I'll be working on those issues.
Should purchase decisions be made based on the rating alone?
No! Hopefully that answer was clear.
While I fear that decisions may be made based solely on the overall rating, it is my hope that you will use this number as a rough guide and that you will dig deep enough into the review and/or test results to be certain that a product is right or wrong for your specific want/need.