Hi Vivian again!
I love macro too and have a 100mm on my D80. It's a fantastic lens (and can also be used on FF-bodies) but some butterflies don't let you come close enough for 1:1 (=31cm from sensor to butterfly, = 15cm
So if your object of desire is a little shy you should go for a 200mm that should give you (theoretically) 80cm from the sensor and 40cm from the front-lens for 1:1.
There is the Tamron AF 180mm f/3.5 SP Di LD [IF] macro going to 1:1 at 25cm working-distance. See test here
The test for the Canon 180mm macro is there
Both lenses seem to be very good but have one serious problem: No anti-shake. I love my 100mm Nikon because I seldom shoot with tripod - the VR is invaluable in the field as large magnification also means a heavy shake
The Sigma 150mm has a focus distance of 46cm. I suspect that leaves not much more than 23cm working distance. Tested here
. And also no OS...
But if you're content with 1:3 then you should end up with at least 0.5-0.6m working distance.
B.t.w.: That the working distance of the lenses is less than the theoretic one (=2x focal-lenght @ 1:1) is a clear sign that the focal lenght of these macros does not stay constant when going macro. I assume e.g. that the real optical focal length of the 180mm lenses is more like 130mm @ 1:1. Funny effect, but has to do with internal focussing.
In my favorite price-search the Tamron registers at 630EUR, the Sigma at 700EUR and the Canon at 1400EUR. I think the Tamron is a clearwinner here
(although as a Nikon-fanboy I dare say my excellent 105mm is "only" 700EUR including VR(!)
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