07-14-2015, 03:56 AM
Good grief...
For the record, I measured all of the lenses for this - in fact I've measured all 702 lenses tested so far for this project. This is what I'm at Olaf for the summer to do, other than write software to work with the 'raw' data and present it nice.
The otus lenses are manufactured by Cosina in Japan in the same facilities with the same testing equipment. The best manufactures use testing similar to a dumbed down and sped up imatest setup, which is not remotely as sensitive as an MTF bench. It is not surprising that they are hardly better than other ZE/ZF Zeiss lenses - they are built under the same capacity. The mega-kilobucks lenses made in Germany by Zeiss do fare much better. Despite being a zoom, the 28-80 is from what I can tell from the 3 I've measured, going to be as good as the Otus, despite being an enormously complex zoom. Same for the 70-200.
$4000 is a pittance for such a complicated instrument as the Otus. The price range for a lens to be tested on an MTF bench per copy is typically $10,000+ in the US at least. It is prohibitively expensive in terms of time, though I do think the software I've written for it provides the fastest method of anything available due to how hands-off it is.
The 50 STM likely does as well as it does because it is drop-dead simple and it is lightweight, so there is no large inertia to decenter it. It's also the newest Canon lens and is likely produced on an automated production line which is more accurate than humans doing drop assemblies.
Regarding the scores - the Otus vs 58mm Nikkor difference is insignificant. If we took them out to 25 copies they would likely become the same. Otus vs sigma art is a significant difference.
Dave, failure copies are pre-screened.
A true bad copy of the 24mm f/1.4G looks something like this: https://www.dropbox.com/s/c1u239jo5bjtiw...s.pdf?dl=0
While a decent one looks more like this: https://www.dropbox.com/s/xeqnnkx2oz31qh...s.pdf?dl=0
If my own standards were used, not a single copy of any rokinon model would pass inspection.
In my honest opinion no lens should be scored lower than 6-6.5 which indicates about +/- 5-10% but alas, this is too tight a tolerance.
Keep in mind that despite the Otus' similar score to the 58/1.8G, there is this massive difference present: https://www.dropbox.com/s/sfm1gkhripnsn6...O.pdf?dl=0
vs https://www.dropbox.com/s/1rk45m9s4nv38g...O.pdf?dl=0
For the record, I measured all of the lenses for this - in fact I've measured all 702 lenses tested so far for this project. This is what I'm at Olaf for the summer to do, other than write software to work with the 'raw' data and present it nice.
The otus lenses are manufactured by Cosina in Japan in the same facilities with the same testing equipment. The best manufactures use testing similar to a dumbed down and sped up imatest setup, which is not remotely as sensitive as an MTF bench. It is not surprising that they are hardly better than other ZE/ZF Zeiss lenses - they are built under the same capacity. The mega-kilobucks lenses made in Germany by Zeiss do fare much better. Despite being a zoom, the 28-80 is from what I can tell from the 3 I've measured, going to be as good as the Otus, despite being an enormously complex zoom. Same for the 70-200.
$4000 is a pittance for such a complicated instrument as the Otus. The price range for a lens to be tested on an MTF bench per copy is typically $10,000+ in the US at least. It is prohibitively expensive in terms of time, though I do think the software I've written for it provides the fastest method of anything available due to how hands-off it is.
The 50 STM likely does as well as it does because it is drop-dead simple and it is lightweight, so there is no large inertia to decenter it. It's also the newest Canon lens and is likely produced on an automated production line which is more accurate than humans doing drop assemblies.
Regarding the scores - the Otus vs 58mm Nikkor difference is insignificant. If we took them out to 25 copies they would likely become the same. Otus vs sigma art is a significant difference.
Dave, failure copies are pre-screened.
A true bad copy of the 24mm f/1.4G looks something like this: https://www.dropbox.com/s/c1u239jo5bjtiw...s.pdf?dl=0
While a decent one looks more like this: https://www.dropbox.com/s/xeqnnkx2oz31qh...s.pdf?dl=0
If my own standards were used, not a single copy of any rokinon model would pass inspection.
In my honest opinion no lens should be scored lower than 6-6.5 which indicates about +/- 5-10% but alas, this is too tight a tolerance.
Keep in mind that despite the Otus' similar score to the 58/1.8G, there is this massive difference present: https://www.dropbox.com/s/sfm1gkhripnsn6...O.pdf?dl=0
vs https://www.dropbox.com/s/1rk45m9s4nv38g...O.pdf?dl=0