[waiwi0309]

Tamron SP AF90mm F/2.8 Di 1:1 Macro
Tokina AT-X M100 AF PRO D AF 100mm f/2.8
如題,即係近攝時個光圈會唔會自動孌細左

[homankop]

yes

[飛哥仔]

真係好想找一支定焦係無恆定光圈既 @@

[stanleyau]

要你買晒你都幾驚...

[waiwi0309]

飛哥仔
SIGMA 150mm F2.8呢支已經唔係恆定光圈啦
只有係無限段至3M先有F2.8,而係微距段最大只有F5.6

[Obi-Wan]

T90 (NOT fix aperture)*
Tokina 100 (have not used before, can't comment)
S150 (NOT fix aperture)*

* the aperture value f. no. increases as the distance decreases (THIS FACT IS MENTIONED IN THE LENS MANUAL GUIDE included with the lens)

[h0001244]

As mentioned by many website, they are not fixed aperture when focus at close objects though you can still see the value in viewfinder is F2.8...........

But I don't know which lens does not have the problem of reducing aperture at close objects.