12-16-2010, 04:51 AM
[quote name='Klaus' timestamp='1292451337' post='5022']
So how do you rate the performance at f/1.4 then ? This cannot be ignored. If it offers f/1.4 (and priced higher) it should deliver something more than that. Just arguing that the marks aren't much worse at comparable apertures doesn't seem to be valid to me.
[/quote]
As I wrote in my closing sentence, I don't know how to reflect that consistently in the rating system. After all, the summarized ratings are just for those people looking for... well... a quick summary, so they inevitably have to abstract from the numbers. In you user lens This is most likely spam content DB I believe you have different ratings for wide-open and stopped-down performance. But even this would only be a compromise. While "wide open" is perfectly clear, the rating is of course again relative to the lens' spec. And what does "stopped down" mean? Make that "one or two stops below the lens' maximum aperture" and it is still a rating relative to the lens' spec (and might push slower lenses well beyond the system's DLA). Make it a "common aperture shared by all lenses" it becomes f5.6 (or f6.3 for certain 3rd party superzooms on their long end), making the rating meaningless for fast lenses and making it fall together with the wide open rating for f5.6 lenses.
Perhaps you could make one rating "overall optical quality" (could be basically the current rating) and another one relative to the lens' competition. So the Canon would fall into the "ultra-fast UWA (for FF, make that WA in the APS-C scope) prime" for full frame, while the Zeiss would only be "fast". But even here I don't know if it makes sense to separate the two lenses into two categories... f2 is still quite fast, after all. But at least with a relative rating you could express that while "superzoom X stinks optically", it is actually "as good as superzooms get these days". With the relatively new rating for "field quality" which you use for some lenses (as it seems, you use it especially for fast lenses that are not totally flawless but have some unique capabilities) you have something that goes into that direction.
So, sorry, no, I don't have a conclusive answer, and I wonder if there is one that doesn't involve significantly extending the current rating system, which I understand is not desirable.
Since I guess anyone having a real interest in a lens will not make his purchasing decision based solely on the star ratings, but will have a look at the numbers, anyway.
The sole purpose of my posting was that I find the rating for the 24s not to be fully fair. And I don't even own that lens (nor a full-frame body), so I am not a over-defensive owner that tries to justify and confirm his purchase. But I am a Canonist, if you didn't already guess that. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />
Anyway, to make this not sound too negative, I really like your site, it is one of the best lens review sites on the web, and I based many lens purchasing decisions on your measurements (and I always look at the star ratings as well, but do not use them alone <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
' />). So, please keep up the good work.
Grummbeerbauer
PS: Oh, and if I ever have an inspiration for a simple-yet-more-precise rating system that solves the dilemma, I will tell you.
So how do you rate the performance at f/1.4 then ? This cannot be ignored. If it offers f/1.4 (and priced higher) it should deliver something more than that. Just arguing that the marks aren't much worse at comparable apertures doesn't seem to be valid to me.
[/quote]
As I wrote in my closing sentence, I don't know how to reflect that consistently in the rating system. After all, the summarized ratings are just for those people looking for... well... a quick summary, so they inevitably have to abstract from the numbers. In you user lens This is most likely spam content DB I believe you have different ratings for wide-open and stopped-down performance. But even this would only be a compromise. While "wide open" is perfectly clear, the rating is of course again relative to the lens' spec. And what does "stopped down" mean? Make that "one or two stops below the lens' maximum aperture" and it is still a rating relative to the lens' spec (and might push slower lenses well beyond the system's DLA). Make it a "common aperture shared by all lenses" it becomes f5.6 (or f6.3 for certain 3rd party superzooms on their long end), making the rating meaningless for fast lenses and making it fall together with the wide open rating for f5.6 lenses.
Perhaps you could make one rating "overall optical quality" (could be basically the current rating) and another one relative to the lens' competition. So the Canon would fall into the "ultra-fast UWA (for FF, make that WA in the APS-C scope) prime" for full frame, while the Zeiss would only be "fast". But even here I don't know if it makes sense to separate the two lenses into two categories... f2 is still quite fast, after all. But at least with a relative rating you could express that while "superzoom X stinks optically", it is actually "as good as superzooms get these days". With the relatively new rating for "field quality" which you use for some lenses (as it seems, you use it especially for fast lenses that are not totally flawless but have some unique capabilities) you have something that goes into that direction.
So, sorry, no, I don't have a conclusive answer, and I wonder if there is one that doesn't involve significantly extending the current rating system, which I understand is not desirable.
Since I guess anyone having a real interest in a lens will not make his purchasing decision based solely on the star ratings, but will have a look at the numbers, anyway.
The sole purpose of my posting was that I find the rating for the 24s not to be fully fair. And I don't even own that lens (nor a full-frame body), so I am not a over-defensive owner that tries to justify and confirm his purchase. But I am a Canonist, if you didn't already guess that. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' /> Anyway, to make this not sound too negative, I really like your site, it is one of the best lens review sites on the web, and I based many lens purchasing decisions on your measurements (and I always look at the star ratings as well, but do not use them alone <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
' />). So, please keep up the good work.Grummbeerbauer
PS: Oh, and if I ever have an inspiration for a simple-yet-more-precise rating system that solves the dilemma, I will tell you.