E-M5II extreme macro for metrology

No, I don't mean meteorology...

I'm curious if anyone has considered using the E-M5II high res mode with either a standard 1:1 macro lens, or one of the various 2:1 or higher macro systems for some ultra-extreme macro work? My specific goal here is to do measurements of some precision engineering equipment (metrology).

If I did the math right, the high resolution E-M5II mode should give a physical scale of about 2 microns/pixel. Can the Olympus 60/2.8 macro resolve that scale? Anyone have either of these and able to provide a test?

There are also a few more extreme macro lenses (Venus 60/2.8 2:1, Nanoha x5), which could provide even higher magnification, in particular when coupled with the E-M5II. Most reviews of these lenses focus on their photographic qualities, as opposed to their physical resolving power, so I'd be curious if anyone knows more.

I'm not wedded to micro 4/3 for this purpose (we currently borrow one of the engineer's D810), but it would be quite a bit cheaper and light enough that we could carry it around to use for other purposes.

parejkoj wrote:

No, I don't mean meteorology...

I'm curious if anyone has considered using the E-M5II high res mode with either a standard 1:1 macro lens, or one of the various 2:1 or higher macro systems for some ultra-extreme macro work? My specific goal here is to do measurements of some precision engineering equipment (metrology).

If I did the math right, the high resolution E-M5II mode should give a physical scale of about 2 microns/pixel. Can the Olympus 60/2.8 macro resolve that scale? Anyone have either of these and able to provide a test?

There are also a few more extreme macro lenses (Venus 60/2.8 2:1, Nanoha x5), which could provide even higher magnification, in particular when coupled with the E-M5II. Most reviews of these lenses focus on their photographic qualities, as opposed to their physical resolving power, so I'd be curious if anyone knows more.

I'm not wedded to micro 4/3 for this purpose (we currently borrow one of the engineer's D810), but it would be quite a bit cheaper and light enough that we could carry it around to use for other purposes.

I did something up on this for in here awhile ago. 2:1 is a bit low for me, so anything above a 2:1 works for what I want out of it. Generally 4:1, but not always.

http://www.dpreview.com/forums/post/55297406

No crops, I don't crop macro shots.

BTW, specialised lenses like you mention there or even the Canon M-PE -65 F/2.8, you need to be very close to the subject. I hit a 4:1 at a distance of 210mm lens to subject.

Danny.

Interesting question. Disclaimer: since this is an engineering question, you get an engineering type of answer that may not be a perfect match with a photography audience.

About diffraction: when modeling the sensor resolving power in combination with diffraction limits, the 40 Mp MFT camera will suffer a 20% impact on resolution because of diffraction around f/6. If you do not care about depth of field (flat subject), I would advise to stay at f/4 or below for MFT. This advice holds equally for the D810 to achieve the same resolution at subject plane (at magnifications larger than 1:1, the diffraction limit is at the subject side). Take also into account that the real aperture at maximum magnification is likely one or 2 stops worse than the value specified for focus at infinity. So basically, shoot wide open. If you get more resolution by stopping down, there is still significant room for resolution improvement by finding a better lens.

About lens data: I have only tried the Panasonic Leica 45/2.8. At maximum magnification (1:1) the lens is actually sharpest (in the center) wide open, which suggests very low aberration levels. At this aperture I can, on a GH4, clearly resolve a tiny "plus" sign with an overall width of 20 micron and a line width of 4 micron (chrome on glass). I do not know the performance of the Oly. Take chart measurements for comparing it to the PL45 taken from several meters with a grain of salt. They are not representative for macro lenses since they can be optimized for closer distances.

I don't know what type of structures you need to resolve, but my model of the GH4 reaches for a perfect lens an MTF50 value for repeating line/space structures at 4 micron line width. This goes down to 2.5 micron when i substitute in the same model a 40 Mp sensor with similar anti aliasing filter strength (additional blurring as a percentage of pixel size). Based on the model in combination with the measurement, I would take the bet that the PL45 in combination with the EM5ii will resolve better than 4 micron line/spaces when placed on a very sturdy tripod, but I'm not sure whether you will reach your quoted 2.

Yes, I did a quick macro test. You can see it on Flickr:

https://www.flickr.com/photos/thrumikesviewfinder/16649226955/

And I didn't even get all the way to 1:1 magnification in this image.