LensTip.com

Lens review

Tamron AF 18-200 mm f/3.5-6.3 XR Di II LD Aspherical (IF)

12 January 2011
Arkadiusz Olech

7. Coma and astigmatism



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In the mosaic of photos, showed below, you can see quite clearly that the coma will be the least bothersome at 50 mm. The further we move from this value the more the coma level increases, reaching its maximum point at the ends of the range.

Tamron AF 18-200 mm f/3.5-6.3 XR Di II LD Aspherical (IF) - Coma and astigmatism

Astigmatism also makes itself felt in the case of the Tamron 18-200 mm. Its average value is perhaps not very high, amounting to 9%, but mainly because of a negligible level of this aberration in the middle of the range. The worst situation is at 18 mm where the astigmatism increases over 20%.