I love my Tamron 180mm f3.5 Macro, but it does have one fault that affects all longer tele macros and that is the depth of field at minimum focus distance is like a sliver. Even at f10, the grasshopper’s back legs and abdomen are way out of focus.
Here’s the conundrum: longer tele macro lens let you stay a distance away from flighty critters, but it means you have to shoot at a smaller aperture to get same depth of field. Compared to a 60mm macro you also have to shoot at almost 2 stops faster shutter speed to prevent camera shake; so effectively you could lose 3 or more stops of light. Even in bright daylight I am often using my D700 on ISO 3200 or 6400 just to allow decent depth of field and not let the shutter speed drop much below 1/250 second.
Would the grasshopper still be there if I used my 60mm Macro at f16; or would he have been frightened away due to being too close? Dunno. The conundrum continues.