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Lens review

Tamron 17-70 mm f/2.8 Di III-A VC RXD

25 February 2022
Maciej Lata││o

8. Vignetting

Let's check the vignetting performance on uncorrected JPEG files produced with the help of the Sony A7R III in the APS-C mode. Appropriate thumbnails can be found below.

A7R III, APS-C, JPEG, 17ámm, f/2.8 A7R III, APS-C, JPEG, 17ámm, f/4.0
Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting
A7R III, APS-C, JPEG, 30ámm, f/2.8 A7R III, APS-C, JPEG, 30ámm, f/4.0
Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting
A7R III, APS-C, JPEG, 50ámm, f/2.8 A7R III, APS-C, JPEG, 50ámm, f/4.0
Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting
A7R III, APS-C, JPEG, 70ámm, f/2.8 A7R III, APS-C, JPEG, 70ámm, f/4.0
Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting


Of course the widest angle of view and the maximum relative aperture constitute the most difficult combination. In its case vignetting amounts to as much as 61% (−2.71 EV). Traditionally stopping down the lens helps to fight that – by f/4.0 we got a result of 45% (−1.74 EV), by f/5.6 it decreases to 33% (−1.18 EV), and by f/8.0 you are able to reduce it to 27% (−0.92 EV). Only by f/11.0 and f/16.0 you deal with low level, with the results being, respectively 22% (−0.70 EV), and 18% (−0.59 EV).


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At the 30 mm focal lenght the performance improves noticeably. By f/2.8 vignetting is 34% (−1.18 EV), by f/4.0 it decreases to a moderate level of 20% (−0.63 EV), and by f/5.6 it drops to 14% (−0.44 EV). Further stopping down of the aperture doesn't have any measureable influence on the aberration, described here.

A bit higher values can be observed at the 50 mm focal length. At the maximum relative aperture brightness loss in the frame corners amounts to 52% (−2.14 EV), and it decreases to 33% (−1.16 EV) on stopping down the aperture to f/4.0. By next three aperture values we got the following results: 22% (−0.71 EV), 16% (−0.50 EV) and 13% (−0.40 EV).

At the maximum focal length the lens returns to very high vignetting levels. By f/2.8 this aberration amounts to 57% (−2.44 EV) but, fortunately, it decreases pretty quickly on stopping down the aperture, by f/4.0 being just 36% (−1.30 EV), by f/5.6 reaching 22% (−0.73 EV), by f/8.0 dropping to 15% (−0.47 EV), and by f/11.0 amounting to 11% (−0.35 EV).

Sony A7R III, APS-C, 17ámm, JPEG, f/2.8
Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting
Sony A7R III, APS-C, 30ámm, JPEG, f/2.8
Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting
Sony A7R III, APS-C, 50ámm, JPEG, f/2.8
Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting
Sony A7R III, APS-C, 70ámm, JPEG, f/2.8
Tamron 17-70 mm f/2.8 Di III-A VC RXD - Vignetting