Tamron 60/2 review

One thing I noticed that was mentioned in this review and mentioned in more detail in another review - it is only f/2 at infinity. At something like 20 feet it is f/2.2. Getting darker and darker as you get closer. So, it is not an f/2 portrait lens nor an f/2 macro lens, IMO. One plus feature not discussed - the working distance of this lens (at 1:1) is significantly greater than that of the Canon 60 macro.

The losing light as you focus closer....isn't this a characteristic of all macro lenses although I didn't think it would start at such distances, 20 feet.

bohdank wrote in post #9510800
The losing light as you focus closer....isn't this a characteristic of all macro lenses although I didn't think it would start at such distances, 20 feet.

Yes, due to the extension of the lens/change of the optical path light has more trouble getting through, the 100 Canon macro goes to about f/4 at 1:1 for instance if my memory is right

But generally its not losing the speed that quickly..from what i heard the Tamron loses f/2 the minute it leaves infinity

All macro lenses lose 2 stops of light at 1:1 magnification. The effective focal length is computed as:
efl = F (1 + m), where F is the actual (stated) focal length at infinity and m is the magnification. At 1:1 magnification, efl = 2F, and therefore the effective f-number is reduced by a factor of 2. So a 2.8 lens at infinity becomes, in terms of light transmission, a 5.6 lens.

I don't see that. A f/2.8 macro lens is f/2.8 at infinity and maybe f/5.6 at 1:1. But, most macro lenses do not lose light until you get close, not at 20 feet like the Tamron 60. Easy to do a test. Just shoot a blank wall (wall can be any distance away) set lens to infinity, then 30 feet, then 15 feet, then 5 feet, etc. Watch the wall get darker, or, if you are in A/V watch the shutter speed change. Since I do a lot of manual exposure, it is important to test all lenses to see how fast they lose light up close so you can factor that in. Wides do not have this issue, very few normals lose light up close but many telephotos do. Especially if they are not IF.

I realize this post is pretty old but I just bought this tamron 60mm F2.0 and this thing is awesome!

The bokeh is smoooooth . I've owned the canon 100 f2.8, tokina 100 f2.8, and the canon 60mm f2.8, and I think I've finally found a macro lens for hand held shots with this tamron 60mm f2.0. The only catch... a little bit noisier than the USM on canon but still fast.