AeroPhotographer
Senior Member
I have a superb Sigma 105mm macro lens which I use to photograph bees. But sometimes I want to get closer. An example would be bees near the ground. So I've tried telephoto lenses with both diopter lenses screwed into the front and with extension tubes between the body and the telephoto lens.
The diopter lenses have not worked well with autofocus, which I like for fast moving bees.
But the extension tubes autofocus well and deliver sharpness which generally equals the Sigma after moderate sharpening. I shoot at f11, which works best with the Sigma and with the telephoto lenses.
I mostly use a 16mm extension tube, but 21mm works well with my 70-300 and my 70-350, at long zoom.
I have found success with all of the following:
Tamron 28-200, 70-180 and 70-300. I bought the 70-180 because it was reputed to focus faster. But I don't notice a difference.
Sony 70-350 and 100-400. The 70-350 is APS-C but I always use a small crop out of the center.
I have used these lenses with Sony A6400, A7RIV and A1. Results are similar because they all have relatively close pixels per mm. The A1 "finds" the bees (eye) best and is the fastest.
I test for closest focus on a ruler and it's in the ballpark of a 3" subject width, which is magnification = 2:1 (subject:sensor), and 4" subject width (2.7:1).
Here are some examples. They are not necessarily the sharpest example from each lens.

Sigma 105 macro

Sony 100-400

Tamron 28-200

Tamron 70-180

Tamron 70-300

Sony 70-350
The diopter lenses have not worked well with autofocus, which I like for fast moving bees.
But the extension tubes autofocus well and deliver sharpness which generally equals the Sigma after moderate sharpening. I shoot at f11, which works best with the Sigma and with the telephoto lenses.
I mostly use a 16mm extension tube, but 21mm works well with my 70-300 and my 70-350, at long zoom.
I have found success with all of the following:
Tamron 28-200, 70-180 and 70-300. I bought the 70-180 because it was reputed to focus faster. But I don't notice a difference.
Sony 70-350 and 100-400. The 70-350 is APS-C but I always use a small crop out of the center.
I have used these lenses with Sony A6400, A7RIV and A1. Results are similar because they all have relatively close pixels per mm. The A1 "finds" the bees (eye) best and is the fastest.
I test for closest focus on a ruler and it's in the ballpark of a 3" subject width, which is magnification = 2:1 (subject:sensor), and 4" subject width (2.7:1).
Here are some examples. They are not necessarily the sharpest example from each lens.

Sigma 105 macro

Sony 100-400

Tamron 28-200

Tamron 70-180

Tamron 70-300

Sony 70-350