01-16-2012, 06:28 PM
[quote name='Brightcolours' timestamp='1326731124' post='14911']
As he states, the closer you focus, you just will lose light. The focal length-aperture size ratio changes. I believe this is referred to as the bellows effect?
[/quote]
Effective Aperture. Which is a given on any macro lens. But on Canon cameras, the physical aperture is displayed (so a macro lens seems to "keep" its aperture up to its minimum focus distance) while on Nikon cameras macro lenses (all macro lenses!) display the effective aperture.
So, the Tamron 90 will also change the aperture (the effective aperture!) with closer focus distance.
-- Markus
As he states, the closer you focus, you just will lose light. The focal length-aperture size ratio changes. I believe this is referred to as the bellows effect?
[/quote]
Effective Aperture. Which is a given on any macro lens. But on Canon cameras, the physical aperture is displayed (so a macro lens seems to "keep" its aperture up to its minimum focus distance) while on Nikon cameras macro lenses (all macro lenses!) display the effective aperture.
So, the Tamron 90 will also change the aperture (the effective aperture!) with closer focus distance.
-- Markus
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