
https://www.closeuphotography.com/3x-lens-test
Lenses:
Canon 35MM f/2.8 Macrophoto Lens
Canon-MP-E 65mm f/2.8 1-5x Macro Photo Lens
Minolta DiMAGE Scan Elite 5400 Scanner Lens
Schneider Kreuznach Componon S 50mm f/3.5 Fixed Aperture lens
Tominon 35mm f/4.5 Lens
Last minute addition to the test and not in the group picture:
Olympus Zuiko Auto-Macro 38mm f2.8
Objectives:
Mitutoyo M Plan Apo 5X 0.14 objective @ 3x
Nikon 3x Measuring Microscopes Objective
Qioptiq Mag.x LD Plan APO 5x / 0.20 Objective @ 3x

This was an interesting test and I do hope that a few people out there that aren't too tired of looking at silicon wafer crops to actually look over the test results

The standouts were the Tominon 35mm due to the low cost and chromatic correction, and the Minolta Elite 5400 with APO correction and edge to edge sharpness. These two lenses when compared side-by-side next to some of the popular older well regarded lenses like the Canon 35mm MP, the Canon MP-E 65 and the Olympus 38mm f/2.8 with a target like the wafer were disappointing and not exactly as I like to remember since I have owned probably 6 or more Canon MP 35s and maybe 3 Olympus 38 f2.8s over the years.
Here are a couple of comparisons. Corner on the left, center on the right.
Be sure to click on an image for the full-size 2500 version.
Minolta 5400 vs Canon 35mm MP.

The Canon MP35 was my favorite 3x lens for years but now the Minolta 5400 has replaced it as my new favorite lens from 2-3x.
Tominon vs Olympus 38mm

The 38mm Olympus vs the Tominon comparison is tight. The Tominon performance is amazing for the cost, I think I paid $35 maybe, and it has much better CA suppression.
The Minolta Elite 5400 lens image quality proved to be best out of all the lenses and was surprisingly close to the pushed down Mitutoyo 5x M Plan.
Amazing performance. The Mitutoyo is better but the Minolta is surprisingly good at 3x.
Minolta 5400 vs Mitutoyo 5x M Plan

Camera: Sony A6300, model # ILCE-6300
Sensor size: APS-C. 23.5 × 15.6 mm. 28.21 mm diagonal. 3.92 micron sensor pitch
Flash: Godox TT350s wireless flash x 2 with one Godox X1s 2.4G wireless flash transmitter
Vertical stand: Nikon MM-11 with a Nikon focus block
A series of images was made with each lens in 5 micron steps. This was repeated for each aperture. Then the sharpest frame was then chosen using Photoshop at 100% actual pixel view. Separate images were selected for center, edge, and corner if needed. Each image was processed in PS CC with identical settings with all noise reduction and lens correction turned off, all settings were zeroed out (true zero) and the same settings were used for all of the images. All of the images shown here are single files.
Questions comments welcome.
Thanks for looking.