New Nikon Lens...Defective or Normal Operation??

[RawHope]

Just unboxed my new Nikon 105mm F2.8 Macro lens. My husband noticed in Aperature Priority, lens would not go down to 2.8 in all situations...in my D70 or on his D90. In different lighting, it would go down to 2.8. Sometimes in other lighting though, it would only go down to a maximum of f3.2. Wondering is this normal or is this something wrong with this lens I just purchased?? Hoping nothing is wrong.

Thanks,
Carolyn

 

[Overread]

As part of how macro lenses (at least most modern ones it seems) achive close focus they effectivly stop down as you focus closer on a subject. So at macro distances your wide open aperture might very well effectivly be smaller than f2.8.
Canon cameras don't report this change in effective aperture, but it appears Nikon cameras do report the effective aperture.

 

[kundalini]

This is normal when you're getting down in the macro settings. Did you try fosucing on something at a "normal" shooting distance? I don't have mine handy, but look at the charts in the last few pages of your owners manual.

 

[itznfb]

It's normal.

As kundalini said though your manual will go into more detail if you wish to know.

 

[DScience]

What? So you can't use your macro lens at 2.8??? What's the freaking point?

 

[itznfb]

What? So you can't use your macro lens at 2.8??? What's the freaking point?

I don't think you understand how ridiculously shallow the dof gets at min focus distance. f/2.8 is pretty useless in a lot of situations.

 

[kundalini]

What's the freaking point?

The ability to get a 1:1 ratio. You're normally going to be shooting from f/8 to f/18 anyway when doing macro.

 

[KmH]

This is normal when you're getting down in the macro settings. Did you try fosucing on something at a "normal" shooting distance? I don't have mine handy, but look at the charts in the last few pages of your owners manual.

Ah, the old read the users manual trick. Pity more people don't do so.

 

[kundalini]

Being they only have 3 posts so far, I didn't want to run them off with RTFM. :lmao:

 

[Wolverinepwnes]

totally normal!

 

[DScience]

What's the freaking point?

The ability to get a 1:1 ratio. You're normally going to be shooting from f/8 to f/18 anyway when doing macro.

LOL no i meant what's the point of making an expensive f2.8 lens when you can make it an affordable f3.5 lens?

 

[RawHope]

Thank you for all the replies. I'm so relieved there's nothing wrong with my lens! Guess I better read the manual. I will but I can't seem to put my camera down right now!

 

[Overread]

What's the freaking point?

The ability to get a 1:1 ratio. You're normally going to be shooting from f/8 to f/18 anyway when doing macro.

LOL no i meant what's the point of making an expensive f2.8 lens when you can make it an affordable f3.5 lens?

Because (as I understand it) the aperture change is constant due to the design of the way the lens focuses closer. So if you had an f3.5 macro lens it would still lose a stop or so of light as it focuses closer - thus the viewfinder image would be far darker than on an f2.8 lens.
The f2.8 is really there for the light gathering during focusing, its use at macro distances for shooting is far more restricted (you have to not only perfect your focus but also your angle of shooting to maximise the wafer thin depth of field you will have).