Figure 3. AF area is center. Focal point is the centre block of words.
17mm at f/2.8.
Figure 4. (a) Left, 17mm at f/2.8. Focal point is the tetra-pack icon. AF area is middle top.
(b) Middle, 17mm at f/2.8. Focal point is the middle block of words. AF area is center.
(c) Right, 17mm at f/2.8. Focal point is the block of Chinese characters. AF area is middle bottom.
- From Figure 1, we can see that even the fine dust particles are visible and relatively sharp on Megatron. The face, neck, chest and Decepticon icon appeared very sharp. That is expected at f/11, which is thought to be the sharpess aperture for this lens and gives plenty of depth.
- In Figure 2, the sharpness at the focal point is compared at (a) 50mm and (b) 17mm, since the aperture is fixed at f/2.8, giving a shallow depth of field. The focal point is the tetra-pack icon and in both pictures, the icon and the Chinese characters appear sharp.
- In Figure 3, I shot a card with plenty of words at 17mm f/2.8. f2.8 was used since the card is flat and so all words should fall within a shallow depth of field. I engaged the shot at an angle, so there is some depth difference after all. However, on the whole, the focal point, which is the center block of words, appear sharp.
- In Figure 4, I compared the sharpness at f/2.8, at three different auto-focus (AF) areas in the middle. (a) The top AF area is focused on the tetra-pack icon, (b) The middle center AF area is on the middle block of Malay and French words while (c) the middle bottom is on the lower block of Chinese characters. The sharpness is there for all the three AF areas.
My copy of the Tamron 17-50mm f/2.8 is definitely sharp and accurate without any front/back-focusing issues, and there is no doubt about it. I shall heed the kind advises from nice friends and save up the money for other things.
I sincerely apologize for the members who made me excellent offers in B&S.
Is this evaluation good enough or is there other ways that I can improve?