04-13-2011, 10:01 PM
[quote name='ben4345' timestamp='1302591721' post='7553']
I was playing with the Canons 24-105 f4 today along with Nikon 24-120 f/4 lens. I am confused on why the Canon gets 4 stars for mechanical and the Nikon gets 4 and a half.
[/quote]
[quote name='mst' timestamp='1302689007' post='7589']
I do not see why I should downrate the mechanical quality. You may not like the haptics of the outer lens tube, but the lens is no doubt very solid and well constructed.
[/quote]
[quote name='Brightcolours' timestamp='1302694372' post='7591']
I do see why, it is in no relation to the rating of the Canon EF 24-105mm f4 L IS USM rating of the same (mechanical quality).
It is not like ben4345 is imagining things, regarding construction quality differences between the lenses...
The Canon is better constructed, yet gets a lower rating.
[/quote]
Fair points... but half a star..?
Drawing a comparison with psychometric testing, this may be raising issues of validity, and of test-retest and inter-rater reliability: does a test measure what it purports to measure? If different people measure the same thing twice, do you get the same result? If the same person measures the same thing twice, on different occasions - using the same measure - do they get the same result?
The resolution, vignetting and distortion results are based on measures, so it's reasonable to expect the reliability and validity criteria to apply.
Build quality seems to be more 'impressionistic'... so the suggested level of consistency and comparison between reviews (and reviewers) may be expecting too much...
The summaries BC quotes do suggest the Canon's build quality is better, rather than the Nikon's, though.
Ian
I was playing with the Canons 24-105 f4 today along with Nikon 24-120 f/4 lens. I am confused on why the Canon gets 4 stars for mechanical and the Nikon gets 4 and a half.
[/quote]
[quote name='mst' timestamp='1302689007' post='7589']
I do not see why I should downrate the mechanical quality. You may not like the haptics of the outer lens tube, but the lens is no doubt very solid and well constructed.
[/quote]
[quote name='Brightcolours' timestamp='1302694372' post='7591']
I do see why, it is in no relation to the rating of the Canon EF 24-105mm f4 L IS USM rating of the same (mechanical quality).
It is not like ben4345 is imagining things, regarding construction quality differences between the lenses...
The Canon is better constructed, yet gets a lower rating.
[/quote]
Fair points... but half a star..?
Drawing a comparison with psychometric testing, this may be raising issues of validity, and of test-retest and inter-rater reliability: does a test measure what it purports to measure? If different people measure the same thing twice, do you get the same result? If the same person measures the same thing twice, on different occasions - using the same measure - do they get the same result?
The resolution, vignetting and distortion results are based on measures, so it's reasonable to expect the reliability and validity criteria to apply.
Build quality seems to be more 'impressionistic'... so the suggested level of consistency and comparison between reviews (and reviewers) may be expecting too much...
The summaries BC quotes do suggest the Canon's build quality is better, rather than the Nikon's, though.
Ian