As on the Nex 5n it behaves as a fantastic macro lens as well.
On the Nex 5n I found f/7.1 optimum this close, with the Nex 7 it is more towards f/11.
Herb
... all my lenses that i consider sharp show a noticeable degradation in sharpness stopping down beyond f/5.6. i would think diffraction would be more evident on the NEX-7 (note i\'m using an original NEX-3).
I would agree. I\'ve been a little surprised at the f/8 and f/11 apertures used in the lens comparisions on these NEX threads.
wfrank and jimbuchanan,
I understand your worries. Some explanation.
Please note that the lenses I tested are perfectly useable from wide open to f/11.
When I investigate a lens I shoot at close / medium and infinity distance with all full aperture stops. Then I check these RAW files at 100% within Lightroom in centre, edges and corners.
The centre image is most of the time after one stop closing already very good, however for most (wide angle) lens designs it takes further stoping down for corners. Certainly in case of sensor / lens combinations that are not specifically designed for each other it can take quite some stopping down to reach the best corner sharpness. And when you have the best corner sharpness the centre image could have worsened a little due to diffraction. One has to decide for oneself which aperture is optimum. For landscape I tend to choose for better corners, for images with the main subject in the centre I choose for the best centre performance.
The optimum aperture for one lens at closest focus can be different compared to infinity.
And overruling it all; in practice I pick any aperture needed to get the picture.But I still want to know how my gear can perform.
I know only a handful (Leica M) wideangle lenses that perform almost perfect wide open and do not neet to stop down for corners on the Leica M9.
Best thing is to try it for yourself. Take a camera, pick your wide angle lens en shoot an aperture series.
Check the RAW files at 100% without noisereduction and without sharpnening. It will amaze you how much you will have to stop down for the most even performance. Please note again we are talking here about wide angle lenses. Anything from 35 mm and longer is far more easy to get sharp from corner to corner.
As on the Nex 5n it behaves as a fantastic macro lens as well.
On the Nex 5n I found f/7.1 optimum this close, with the Nex 7 it is more towards f/11.
Herb
... all my lenses that i consider sharp show a noticeable degradation in sharpness stopping down beyond f/5.6. i would think diffraction would be more evident on the NEX-7 (note i\'m using an original NEX-3).
I would agree. I\'ve been a little surprised at the f/8 and f/11 apertures used in the lens comparisions on these NEX threads.
wfrank and jimbuchanan,
I understand your worries. Some explanation.
Please note that the lenses I tested are perfectly useable from wide open to f/11.
When I investigate a lens I shoot at close / medium and infinity distance with all full aperture stops. Then I check these RAW files at 100% within Lightroom in centre, edges and corners.
The centre image is most of the time after one stop closing already very good, however for most (wide angle) lens designs it takes further stoping down for corners. Certainly in case of sensor / lens combinations that are not specifically designed for each other it can take quite some stopping down to reach the best corner sharpness. And when you have the best corner sharpness the centre image could have worsened a little due to diffraction. One has to decide for oneself which aperture is optimum. For landscape I tend to choose for better corners, for images with the main subject in the centre I choose for the best centre performance.
The optimum aperture for one lens at closest focus can be different compared to infinity.
And overruling it all; in practice I pick any aperture needed to get the picture.
I know only a handful (Leica M) wideangle lenses that perform almost perfect wide open and do not neet to stop down for corners on the Leica M9.
Best thing is to try it for yourself. Take a camera, pick your wide angle lens en shoot an aperture series.
Check the RAW files at 100% without noisereduction and without sharpnening. It will amaze you how much you will have to stop down for the most even performance. Please note again we are talking here about wide angle lenses. Anything from 35 mm and longer is far more easy to get sharp from corner to corner.
As on the Nex 5n it behaves as a fantastic macro lens as well.
On the Nex 5n I found f/7.1 optimum this close, with the Nex 7 it is more towards f/11.
Herb
... all my lenses that i consider sharp show a noticeable degradation in sharpness stopping down beyond f/5.6. i would think diffraction would be more evident on the NEX-7 (note i\'m using an original NEX-3).
I would agree. I\'ve been a little surprised at the f/8 and f/11 apertures used in the lens comparisions on these NEX threads.
jfrank and jimbuchanan,
I understand your worries.
Please note that the lenses I tested are perfectly useable from wide open to f/11.
When I investigate a lens I shoot at close / medium and infinity distance with all full aperture stops. Then I check these RAW files at 100% within Lightroom in centre, edges and corners.
The centre image is most of the time after one stop closing already very good, however for most lens designs it takes further stoping down. Certainly in case of sensor / lens combinations that are not specifically designed for each other it can take quite some stopping down to reach the best cornersharpness. And when you have the best cornersharpness the centre image could have worsened a little due to diffraction. One has to decide for oneself which aperture is optimum. For landscape I tend to choose for better corners, for images with the main subject in the centre I choose for optimum centre.
I know only a handful (Leica M) lenses that perform almost perfect wide open and do not neet to stop down for corners.
Best thing is to try it for yourself. Take a camera, pick you lens en shoot an aperture series.
Check the RAW files at 100% without noisereduction and without sharpnening. It will amaze you how much you will have to stop down for the most even performance. Please note we are talking here about wide angle lenses. Anything from 35 mm and longer is far more easy to get sharp from corner to corner.
Herb
Jan 04, 2012 at 04:27 AM
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