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Tokina AF 100-300mm f/4 AT-X II - Review / Lab Test Report - Analysis |
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Lens Reviews -
Canon EOS (APS-C)
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Page 2 of 2
Distortion
The level of distortion is very low throughout the zoom range. At 100mm
the lens is free of distortion changing to very slight pincushion distortion
at 200mm and 300mm.
100mm:
200mm:
300mm:
Vignetting
Oan APS-C DSLR the lens can take advantage of
the sweet spot effect so the vignetting isn't overly pronounced. At 100mm and 200mm
the issue is basically negligible. At 300mm the situation deteriorates somewhat
but even at f/4 it requires quite critical scenes to see some vignetting and
stopping down a little resolves the issue completely.
MTF (resolution)
Regarding the pro grade AT-X designation the lens performed a little worse
than expected in the lab. At 100mm and 200mm the Tokina was able to deliver
very good results at wide-open aperture increasing to excellent results at f/8.
Unfortunately there´s a quite pronounced drop in quality at the 300mm setting
to only good figures at f/4. There´s a gradual improvement towards
f/8 where the performance is in very good territory again. While not formally
measured the lens also suffered from reduced contrast at 300mm and large
aperture settings.
Please note that the MTF results are not directly comparable across the different systems!
Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure for sharpness.
If you want to know more about the MTF50 figures you may check out the corresponding Imatest Explanations
Chromatic Aberrations
The lens produced a varying degree of chromatic aberrations (color shadows at
harsh contrast transitions) at the image borders. At 100mm and 200mm CAs are
no big problem. The situation changes at 300mm where the average CA pixel width
exceeds 1.5 pixels which is very pronounced for a tele lens.
Sample Shots
Due to network bandwidth limitations I can't provide any sample images at this stage.
Verdict
The Tokina AF 100-300mm f/4 AT-X II is an engineering masterpiece regarding
construction quality and it is a joy to use. Optically you have to recognize
that the design is a little dated. This doesn´t mean that it is a bad lens -
at 100mm and 200mm it is very good indeed - but at 300mm @ f/4 it falls a little
short of the expectations with just good sharpness, pronounced CAs and
reduced contrast at large aperture settings (very good at f/8). As mentioned
the lens is discontinued now and on the used market it is a rare but very
affordable item (around 350 EUR locall) in mint condition). In this price
scope it remains a highly attractive lens.
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