Nikon 105mm 2.8 micro

R

renu

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Hi

i bought this lens to try some micro photography.I am struggling to understand why the aperture keeps changing when i focus on things despite trying to use in Aperture mode and manual mode as well.Pl help me. to understand what am i doing wrong:help:
 
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As you focus closer, the brightness of the light reaching the sensor reduces. The f/number is only valid at infinity focus, and at 1:2 it is one stop down on that, and two stops at 1:1. Laws of physics and all that (actually related to the inverse square law).

Nikon cameras report this, Canons do not. They are both equally correct/incorrect in different ways. But it makes no odds, the exposure is the same either way.
 
As Richard says it is the same with all macro lenses ... it is just basic physics, nothing wrong with your lens or what you are doing.

It will only happen at close up distances, where I would not want to be shooting wide open anyway because of the lack of depth of field.
 
As everybody's said, it's perfectly normal. It caught me out first time as well. I couldn't understand for the life of me why a 2.8 lens wouldn't go any wider than 3.5 - until I read the accompanying manual ;)
 
thanks for all the information.I feel better now as i was worried if the lens had a fault.
 
renu said:
i have changed it to no prefix.What does it mean by NFSW?.I am sorry, i dont have any idea which one to use.:thinking:
Click to expand...

I think there was a typo earlier. Should have read 'NSFW' which usually stands for 'not safe for work'.
 
NSFW means Not Safe For Work. You'd put it up if you had something in your thread that isn't safe to look at in a public area, like pornographic images or violence etc etc.

:thumbs:
 
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