Nikon 60mm F2.8 Macro Help!

[jgrove]

I have been lent this lens to use, but i am a bit confused, when mounted on my D2hs i can only get F2.8 when the lens is set to infinity, as you focus down through the range the aperture changes through to F5 at its macro setting.

Any ideas, (i must be missing something here)

Thanks

 

[Chris101]

Nope - sorry James, that's the way it works.

As you focus closer and closer, the open aperture gets further and further form the sensor. In other words, the aperture becomes smaller (due to distance) while the effective focal length becomes longer (due to lens extension.) So the f-number (focal length divided by the aperture diameter) gets slower (ie, a larger number.)

Bummer, but physics is physics.

 

[jgrove]

Nope - sorry James, that's the way it works.

As you focus closer and closer, the open aperture gets further and further form the sensor. In other words, the aperture becomes smaller (due to distance) while the effective focal length becomes longer (due to lens extension.) So the f-number (focal length divided by the aperture diameter) gets slower (ie, a larger number.)

Bummer, but physics is physics.

Thanks for that Chris, i had a feeling that was what it was, but didnt think it effected macro lenses, but if i think about it it has to, i suppose a 60mm F2.8 constant would be a huge lens!

Thanks

 

[MontyDog]

#1064 - You have an error in your SQL syntax;

 

[Beezle]

Seems to me that you wouldn't want to use that lens at infinity anyway. The few I've shot near inifinity looked pretty awful.

Under 10 feet or so, it's the sharpest lens I have ever used.