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 p.2 #9 · Best way to choose the best copy? | |
gdanmitchell wrote:
By the way, in many cases in which we think we perceive a difference between two things, one or more of the following might be in play:
- The mind works in curious ways sometimes. In cases where two things are literally identical, some people will come to prefer one over the other and perceive that there are differences that actually don't exist. There is a type of comparison test that I have heard referred to as an "ABX" test. A subject is asked to express a preference between the "A" sample and the "B" sample, which are different. The subject is also asked to determine whether a third "X" sample is the same as "A" or "B". (And, indeed, "X" is one of the other two.) In one case I read about some years ago, a number of smart and knowledgable test subjects (and others) said that they could identify clear differences between A and B, but their ability to tell whether X was A or B was no better than if they had guessed. (To put in bluntly in this case, which involved an assessment of audio equipment quality, the experts who claimed that they could hear clear and quantifiable differences between A and B were basically fooling themselves. ;-)
- In other cases when a difference can arguably or objectively be seen (e.g. A and B are not identical), in cases where neither of the two different samples can objectively be said to be better (e.g. - they are merely "different"), those who are asked to compare both samples more often than not attempt to go beyond "they are different" and decide that one or the other is "better." But if you ask a group of people who say that one is better than the other to also tell you which is better, there will be no consistency in the choice. In some cases in which two things are different, both are good.
(To be clear, I am not at all suggesting that people can never reliably determine differences between things. That would be an absurd argument.)
Specific to cameras and lenses, there are a whole range of variables that mess with our ability to be objective about these things. (Though you can certainly argue that if you feel that one thing is better than the other you should be free to pick the one that feels better.) In many cases a perfectly fine lens might not focus as well as a less optimal lens if the adjustment of the camera body is off in a direction that favors out-of-adjustment AF. Or a lens that is objectively capable of slightly (though probably immaterially) better resolution in the center of the frame might test slightly worse in AF if it needs MA. Or a lens that is great in the center at f/4 might not be as good in the corner at f/11 as another one. And on and on and on.
And on top of that, the differences that we may obsess over when doing micro-comparisons of side-by-side or alternating 100% crops of clinical test images often turn out to be utterly invisible against the background noise* of real shooting. I suppose that one could argue that it is important to have "the best," but a) maybe it isn't all that important when the second, third... 25th... etc best works the same, and b) when all of the factors mentioned above are part of the determination of what is "best."
(*not the literal noise of sensors, etc, but the environmental noise of using a camera in the real world where things are never perfect.)
In the end, it seems to me that testing individual copies of new gear that is the product of industrial manufacturing is usually not worth the time, though I can't deny that doing so might catch some of the very rare manufacturing defects a bit sooner... but that is what warranties are for.
YMMV.
Dan...Show more →
Dan, it is not the manufacturing defects that I look for. These are very obvious under normal use. It is the tolerances or variances the "non defective" lenses exhibit that I am trying to reduce or steer to the higher end. Why do you think advanced lens testing facilities test multiple copies and come out with varying results, yet each lens is NOT defective.
If I am going to be shooting using the best techniques I know to produce large fine detailed photos, you bet I want the highest quality lens I can get rather than the one at the bottom of the barrel. If this means testing my lens to determine if my copy is top notch, I'll do that as it really does not take much effort and the possible rewards can be quite noticeable in large prints.
I spend thousands of dollars on a photo trip, practice the best photography techniques, best post processing I know...I am not going to circumvent all this by not knowing my lens is the best it could be. Sort of defeats care in other areas of the photography process if you don't care or understand the quality and limitations of your gear.
Sure, you can just go out and shoot with your gear and produce god results...but are you producing the best results you can..and how do you know without testing your gear? Maybe I am too anal about this, but I like to know the weakest links in my process so I know where I can improve. Sometimes the weakest link is me and I have to improve my process being my skills with taking the photo or my post processing skills and sometimes the weakness is the gear and knowing this allows you to know what to improve if you want to improve your photos.
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Good luck. You should do that with memory cards, cameras and printers also..........