The best replacement for 100mm is 135mm.

The best alternatives to 100mm are rated as following:
★★★★★  135mm
★★★★★  85mm
★★★★  60mm macro
★★★  80mm fork
★★★  50mm
★★  85mm canon
★★  180mm macro canon
★  180mm macro
★  135mm canon
★  tamron 90mm
★  50mm macro
★  60mm macro lens
★  nikon 105mm
★  50mm lens
★  60mm
★  canon 100mm
  150mm macro
  sigma 105mm
  100m
  180mm
  tamron 90mm macro

Your alternative for 100mm is not listed? Suggest!
Speaking about 100mm, one probably shouldn't forget about raynox.

Other search terms related to 100mm and their ratings are:
★★★★★ raynox
You have in mind a companion for 100mm and it is not yet here? Propose!



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100mm
135mm
85mm