Tamron 90mm macro F/2.8

DeadEnd · 6th January 2007

Can the above lens shoot at F/2.8 at the min focus distance of 0.29m?

As I understand that the Nikkor 105mm f/2.8 micro is f/5.0 at 0.314m.

ortega · 6th January 2007

i am not sure of that
but why do you want to shoot at f2.8 at the minimum focusing distance (magnification 1:1) ?

gooseberry · 6th January 2007

The lens may be wide open at it's maximum at f/2.8, but the effective aperture of the lens reduces as you focus closer - IIRC this lens becomes an effective f/5.6 aperture at minimum focus distance. Some camera bodies (like the Nikon AF cameras) will report the correct effective aperture.

Hein · 14th January 2007

Why do you want to shoot at f/2.8 at few mm from the object???? You will need to go down to at least f/11 to have a nice sharp shot with decent DOF at 1:1......

If you concern is AF speed, then, this lens has crazily slow AF speed, and you will need to MF....

However, it's still a very sharp lens, and I still love it...

6th January 2007	#1
DeadEnd Member Join Date: Nov 2006 Location: Ang Mo Kio Posts: 740	Tamron 90mm macro F/2.8 Can the above lens shoot at F/2.8 at the min focus distance of 0.29m? As I understand that the Nikkor 105mm f/2.8 micro is f/5.0 at 0.314m. Last edited by DeadEnd; 6th January 2007 at 06:02 PM.

6th January 2007	#2
ortega Moderator Join Date: Nov 2004 Location: NorthEast Posts: 16,507	Re: Tamron 90mm macro F/2.8 i am not sure of that but why do you want to shoot at f2.8 at the minimum focusing distance (magnification 1:1) ? __________________ The Law

6th January 2007	#3
gooseberry Senior Member Join Date: Mar 2004 Location: Central West Posts: 1,913	Re: Tamron 90mm macro F/2.8 The lens may be wide open at it's maximum at f/2.8, but the effective aperture of the lens reduces as you focus closer - IIRC this lens becomes an effective f/5.6 aperture at minimum focus distance. Some camera bodies (like the Nikon AF cameras) will report the correct effective aperture.

14th January 2007	#4
Hein Member Join Date: Jun 2003 Location: Singapore Posts: 711	Re: Tamron 90mm macro F/2.8 Why do you want to shoot at f/2.8 at few mm from the object???? You will need to go down to at least f/11 to have a nice sharp shot with decent DOF at 1:1...... If you concern is AF speed, then, this lens has crazily slow AF speed, and you will need to MF.... However, it's still a very sharp lens, and I still love it...