11-15-2011, 11:15 PM
[quote name='deroppi' timestamp='1321349065' post='12943']
Not sure if that could be the case with some lenses, but at least with my lenses I don't see the problem.
My AF-S 85/3.5 and AF-S 40/2.8 are both macro lenses and are both sharp even wide open at long distances. In fact the 40 seems extremely sharp for landscape shots.
On the other hand, my AF-S 16-85 does not suffer from using it at the closest possible focus distance. And even my AF-S 55-300 is usable as a kind of close-up lens when shot at 300mm and minimum focus distance. No worries.
[/quote]
Minimum focus distance normally isn't a problem. Extension tubes my cause a problem, although less so with tele-zooms than with shorter zooms.
However, using telezooms for macro generally benefit from the use of a good quality close-up lens (multi-coated doublet/achromat) of approximately the same FL or longer of the longest FL of the zoom. This will give one a WD of approximately the same distance as the FL of the close-up lens, and an extra magnification of longest zoom FL divided by close-up lens FL.
The FL of a close-up lens is equal to 1000 mm/diopter number of the close-up lens, so in the case of the 70-300, a ~300 mm or approximately 3 diopter achromatic multi-coated close-up lens would be a great, simple, effective, and fairly cheap addition to do real macro shots with that particular lens, allowing for a WD that no macrolens can provide at those magnifications <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.
Kind regards, Wim
Not sure if that could be the case with some lenses, but at least with my lenses I don't see the problem.
My AF-S 85/3.5 and AF-S 40/2.8 are both macro lenses and are both sharp even wide open at long distances. In fact the 40 seems extremely sharp for landscape shots.
On the other hand, my AF-S 16-85 does not suffer from using it at the closest possible focus distance. And even my AF-S 55-300 is usable as a kind of close-up lens when shot at 300mm and minimum focus distance. No worries.
[/quote]
Minimum focus distance normally isn't a problem. Extension tubes my cause a problem, although less so with tele-zooms than with shorter zooms.
However, using telezooms for macro generally benefit from the use of a good quality close-up lens (multi-coated doublet/achromat) of approximately the same FL or longer of the longest FL of the zoom. This will give one a WD of approximately the same distance as the FL of the close-up lens, and an extra magnification of longest zoom FL divided by close-up lens FL.
The FL of a close-up lens is equal to 1000 mm/diopter number of the close-up lens, so in the case of the 70-300, a ~300 mm or approximately 3 diopter achromatic multi-coated close-up lens would be a great, simple, effective, and fairly cheap addition to do real macro shots with that particular lens, allowing for a WD that no macrolens can provide at those magnifications <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....