These are industrial grade objectives are used in manufacturing, research and development, quality control, and inspection with measuring microscopes for making non-contact measurements of parts and electrical components.
This is the latest version of Nikons MM 5x officially known as the EDF20052 TM objective lens 5x-A. Even though I own a few of the older style Nikon 5X MM objectives, I picked up this new A type MM objective hoping to see some performance improvement but comparing images from the 5X and the 5XA the image output is absolutely identical as far as I can see in my tests.
Nikon 5X-A Measuring Microscope objective Specs
Name: EDF20052 TM objective lens 5x-A
Nikon Measuring Microscope objectives are also known as Measurescope Objectives, Toolmakers objectives, TM objectives, or just MM objectives, in this case the MM 5xA.
Type: Industrial Metrology and Inspection
Optical correction: finite correction (no tube lens is needed)
Focal length: 42.3mm
Cover glass: none
Mount: Nikon M26 x 0.75 'BD' thread
Field number or image circle: the official field number is 21.5mm but they will cover a Sony APS-C 28mm diagonal sensor.
Coverage: APS-C sensor
Working distance: 64mm
Typical price on the used market: $200-350.
There are a few important advantages of a measuring microscope objective over typical microscope objective for macro photography.
Ultra Long Working Distance: A long working distance will make lighting easier and the MM objectives are in a class of their own, the MM 5X has a huge working distance of 64mm. The LWD Mitutoyo M Plan APO 5X has a working distance only 34mm. Nikons TU, LU, Plan Fluor 5x all have just 23mm WD! More working distance will give you a lot more lighting flexibility so the MM 5X has a serious advantage here.
Shock-proof and Dust-proof Design: These are the only objectives that I know of that are designated as shock-proof.
Telecentric design: with this design perspective error is eliminated so objects farther away appear to be the same size as closer objects. This allows you to turn off scaling correction with focus-stacking software, the Nikon MM lenses eliminate parrallax for perfect alignment of photographs when stacking and/or stitching.
Image Quality: Consistent center and corner performance.
Mounting threads: standard Nikon M26 x 0.75 'BD' thread. You can find adapters on Ebay to convert the M26 to common threads for easy installation.
Easy installation: This lens has a finite optical design (the image is formed only by the objective), so no tube lens is needed to install this objective as you would be with infinity-corrected optics. You only need a M26 adapter, an extension tube or bellows, and a body mount adapter.
Coverage: up to APS-C or DX DSLR sensors with a diagonal of 26-28mm.
Overall rating: Recommended
The Nikon MM 5X is a great choice for someone that wants to photograph at 5X magnification with just extension tubes (or bellows) and and does not want to go with infinity-corrected lens that requires a tube lens .
These objectives are corrected for chromatic aberration so they do not require an eyepiece or tube lens for correction for use in photography. They are achromats, not apochromats, so they do show some Longitudinal Chromatic Aberration or LoCAs which is normal for this type of objective and they are don't cause any big issues with photography especially when focus stacking.
At 5X magnification the infinity-corrected Mitutoyo M Plan APO 5X, sells for 2-3 times the cost of the MM 5X with about half the working distance but with better CA correction. If you own a Canon DSLR you can pick up a MPE-65, a great lens, for about 3X or 4X the cost and about 1 inch less working distance and a big light blocking lens barrel.
Price and availability
The MM 5X is seems to be the most common of all the MM objectives with the MM 100X has to be the most rare.The 5X MM objectives are usually very easy to find in used condition on Ebay for reasonable prices, from $200 for one in average shape, to $350 for a clean mint condition unit.
Email me if you are interested in buying one, I can help even if you don't buy one from me, although I do usually have a few extra tested samples that are available for sale.
The MM 5xA units are very difficult to find but email me if you are interested in one. The 5xA versions of these lenses have been on the used market for a few years coming out of Asia. For some reason the used objective market in the US only has the earlier 5x versions for sale but I did manage to track one down at the end of last year.
All of the Nikon MM objectives are finite designs so installation is simple, you just need 3 additional parts, all of which can be purchased on Ebay for less than $20 each.
1. Nikon MM 5X objective - M26 x 0.75 mount.
2. Objective adapter - 26mm x 0.75 > 42mm x 1. This adapter converts the nikon M26 mount to a standard M42 mount.
3. Extension tube - 42mm mount. Extension tube (+ adapters) length of 150mm gives me 5X magnification on my Nikon D500 DSLR.
4. Camera mount adapter - 42mm female mount to male camera lens mount.
Installation notes: all of the three items in the installation diagram are listed as 42mm but you should know that the objective adapter is actually 42mm x 1mm better known as M42 thread mount, the extension tube and camera mount adapter are actually 42mm x 0.75 threads better known as T-mount threads but luckily the M42 threaded adapter screws into the T-mount tube all the way in and even bottoms out so they work together okay even though they shouldn't technically but its not surprising due to widely varying manufacturing tolerances.
M42 Studio Set-up
This is my M42 studio Set-up with a Sony A6300 body. For more details about this set-up, follow this link:https://www.closeuphotography.com/42mm-setup
Old vs New; the 5x MM vs the 5xa lens
Other than some minor cosmetic changes there is not a lot of visible difference between the old and new MM 5X lenses. I have a feeling there are some internal changes but the image quality is indistingusable between the two in my testing.
Nikon Measuring Microscope 5XA TM vs 5X TM Objective Lens Comparison Test
The newer 5xA lenses have been on the used market for a few years, but mostly in Asia. For some reason the used objective market in the US only has the earlier 5x versions for sale. Finally I have a chance to pick one up at the end of last year from a seller in China and I was optimistic about seeing some improvement in image quality.
Click on any of the images below to see the full size version in a new window.
The images above are uncropped but resized to 1500 pixels across. Click on an image to see the full size version in a new window.
I was optimistic about seeing some improvement in image quality but that was not the case. The older and newer A versions have identical image quality as far as I can see, at least the newer A version was not any worse than the older version.
Both the new and old versions of the Nikon Measuring Microscope 5x and 5xA are recommended, with good consistent performance across the sensor and ease of set-up and use thanks to a super long working distance.
Links for more information:
Nikon industrial measuring microscopes: http://www.nikon.com/products/industrial-metrology/lineup/measuring_instruments/measuring_microscope/
Nikon 5X Measuring Objective test: http://coinimaging.com/nik5xmeas.html
The 1X, 3X, 5X, and 10XMM objectives are sold under a private label in Germany under the name Vision & Control MK series http://www.vision-control.com/