E-M5II extreme macro for metrology

https://www.flickr.com/photos/9578475@N02/

I'm pretty certain I will be getting the E-M5 II for greater than life size photography in the near future. I've just got a move coming up, and then as soon as I've moved in a few weeks I'll be getting one. I'm specifically interested in the his res sensor shift feature. I've got a whole set of macro lenses, mainly Canon fit including an MP-E 65mm f2.8 1-5x lens I will probably use with it via a Metabones smart adapter, plus I'll probably be getting a Venus (now called ‘LAOWA’) 60mm and an Olympus 60mm macro.

http://www.venuslens.net/

One of my internet friends just did a test on one, and there are some full res comparison images he took. He compared it to the Tamron 60mm f2 macro and the Canon MP-E 65mm at equivalent magnifications. It is at least as good as these lenses. Wide open it is apparently still quite good in the centre.

http://orionmystery.blogspot.co.uk/2015/02/venus-60mm-21-macro-lens.html

Be aware though that apparently the Venus lens apparent shows some slight distortion. Not visible on insects, but possibly on engineering samples.

From what I've read the Olympus 60mm should be more than capable of resolving the detail.

However, what you need to be aware of is that as you get more into the macro region is that the effective aperture becomes smaller than the nominal one, due to the bellows factor. Already 2 f-stops smaller at 1:1. This means diffraction softening kicks in earlier. Therefore, for maximum resolution, but not necessarily for active insect shots, you need to use a wider aperture. Until at higher magnifications, for maximum resolution you will need to use the lens near wide open, and focus stack if you want more dept of field.

An alternative for higher magnification in a controlled situation like engineering photos, would be to use a reverse enlarging lens, a bellows lens, or a microscope lens on a bellows. This link below has some good tests and reviews. It also tells you the extension you will need for various magnifications. Some of the better enlarging lenses can be gotten quite cheaply secondhand.

http://coinimaging.com/Lens_tests.html

This is the best person I know for information on using various microscope, bellows and enlarging lenses. Whilst John shoots mainly insects, his technique is the best, and he produces some incredibly high magnification focus stacks. Look at the equipment sets for more information. There is a lot of technical information there.

https://www.flickr.com/photos/johnhallmen/