As I promised, I had taken some test shots to the ISO12233 test chart with my brand new AF-S Nikkor 24-70mm f/2.8G ED. This chart is really complete and allows not only to measure sharpness but also distortion, vignetting, etc.
Before starting the test, I dedicated some time to prepare the set-up required.
- I stuck the test chart to one of my living room walls, making sure that it stayed flat against the wall, with no bubbles or irregularities.
- I lighted the chart using two daylight lamps pointing at it from 45º angle each, and at the same height of the chart.
- I mounted the camera on my Tripod Pro Giottos MTL8361B Carbon Fibre + MH1300-621 Quick Release Ball Head.
- I fitted the original hood of the lens.
- I chose a focal length of 24 mm to start with and locate the tripod at the right distance from the wall so that all the chart fitted in the frame. Notice that aligning the camera is extremely important so that I dedicated a fairly big amount of the time to fine adjust the tripod head until I had the camera perfectly aligned.
- I switched the focusing to manual.
- I took some test shots from which I took the sharpest one.
- Once I got the perfect focus I did not move the focusing ring again until the end of the test at 24mm.
- The ISO was set at 100.
- I started with an apperture of 2.8 and went all the way up to 22 in steps of +1EV.
- After having shot with all appertures at 24mm, I chose 35mm and repositioned the tripod, the ball head to fit the chart in the frame and manual focus again. This has to be done once more on completion of all the appertures at 35mm. The last focal lenght is 70mm, the max of the lens.
The lamps were placed behind the camera, to avoid any possible flare or lack of contrast.
Once prepared, the set-up looked as follows:
Here you can see the results from the test:
At 24 mm:
Centre at 2.8
Centre at 4.0
Centre at 5.6
Centre at 8.0
Centre at 11.0
Centre at 16.0
Centre at 22.0
Corner at 2.8:
Corner at 4.0
Corner at 5.6:
Corner at 8.0:
Corner at 11.0:
Corner at 16.0:
Corner at 22.0:
Between corner and diagonal at 2.8:
Between corner and diagonal at 4.0:
Between corner and diagonal at 5.6:
Between corner and diagonal at 8.0:
Between corner and diagonal at 11.0:
Between corner and diagonal at 16.0:
Between corner and diagonal at 22.0:
At 35mm:
Centre at 2.8:
Centre at 4.0:
Centre at 5.6:
Centre at 8.0:
Centre at 11.0:
Centre at 16.0:
Centre at 22.0:
Corner at 2.8:
Corner at 4.0:
Corner at 5.6:
Corner at 8.0:
Corner at 11.0:
Corner at 16.0:
Corner at 22.0:
Between corner and centre at 2.8:
Between corner and centre at 4.0:
Between corner and centre at 5.6:
Between corner and centre at 8.0:
Between corner and centre at 11.0:
Between corner and centre at 16.0:
Between corner and centre at 22.0:
At 70mm:
Centre at 2.8:
Centre at 4.0:
Centre at 5.6:
Centre at 8.0:
Centre at 11.0:
Centre at 16.0:
Centre at 22.0:
Corner at 2.8:
Corner at 4.0:
Corner at 5.6:
Corner at 8.0:
Corner at 11.0:
Corner at 16.0:
Corner at 22.0:
Between corner and centre at 2.8:
Between corner and centre at 4.0:
Between corner and centre at 5.6:
Between corner and centre at 8.0:
Between corner and centre at 11.0:
Between corner and centre at 16.0:
Between corner and centre at 22.0:
As it can be seen from the results above, the maximum sharpness is obtained always at f8.0. In this post I have not posted all the shots that comprise the test, since I would have doubled the amount of pictures and the post would become too long (even more than now!).
For instance, I have not uploaded the pictures at diaphragm 9.6 or 13.0. For me it resulted really difficult, if not impossible to decide whether or not the 8.0 shots are sharper than the 9.6. The difference is negligible to the human eye, or at least to Mario’s eye! hehe.
I will not condition anyone with my conclusions on this test for now. This merely intends to help the reader making his own mind about the lens quality.
In the next post about this lens, I will check the vignetting at big appertures for different focal lenghts. I will also bring my own conclusion to this test at the same time.
Hope this results handy.
Good night
MARIO PHOTOGRAPHEZ BLOG 