The Mitutoyo M Plan APO 5x 0.14 objective is one of the most popular, if not the most popular objective in the macro photography world, and is very well-known for having an unbeatable balance of performance, sensor coverage, excellent availability, and low cost. This test compares the image quality produced by different tube lenses with the Mitutoyo M Plan APO 5x 0.14 on a full frame sensor using the Sony α7R IV body. What is the best possible tube lens for use with the Mitutoyo M Plan APO 5x on a smaller sensor body? This question has already been addressed in 2018, with a 28mm diagonal APS-C sensor camera: https://www.closeuphotography.com/tube-lens-test
Lenses in this test
Fuji EBC Fujinon GX 210mm f/5.6 medium format lens
Raynox DCR-150 +4.8 208mm add-on close-up lens
Rodenstock Rodagon 210mm f/5.6 enlarger lens
Schneider Kreuznach Componon-S 210mm f/5.6 enlarger lens
Schneider Kreuznach G-Claron 210mm f/9 process lens
Thorlabs ITL200 f=200 tube lens
Each lens in this test is standard issue and easy-to-find on the used market. Expect to pay $50 - 150 USD on eBay for each, except for the ITL200, which can be hard to find on the used market but is known to sell for less than $200 although I have no idea if the ITL200 labeled lens sold right now on eBay from China is really an ITL200. Be wary of counterfeit units from China.
It has been my experience that the microscope manufacturers’ own tube lenses high cost do not match their performance. The gains in image quality from expensive APO telephoto lenses are typically not worth the extra cost or the more difficult installation these require.
spoiler alert
Mitutoyo’s M Plan objectives officially have a 30mm OFN (Optical Field Number) or image circle Ø (I’ve also seen this listed as small as 24). To cover Sony APS-C sensors a lens would need a 28mm OFN or image circle Ø (Sony APS-C is 23.6mm x 15.6mm = 28.3mm diagonal). The full frame Sony A7R4 used in this test would need at least a 43mm OFN or image circle Ø for perfect coverage (35.7 length x 23.8mm width = 42.9mm). How close will the Mitutoyo M Plan 5x 0,14 get to covering the Sony full frame sensor?
Nikon and Olympus wide-field objectives are designed with a Ø26mm field, which sounds good, but unfortunately in practice using Nikon and Olympus they don’t come close to covering 26.5mm with a sharp image, so they wont cover an APS-C sensor with a 28mm diagonal. A 26mm field objective will cover a Micro Four Thirds (MFT or M4/3) sensor but in my experience that is about it the maximum.
About This Test
All of the lenses tested here were purchased by closeuphotography.com, without any discount or commission from any person. We don’t sell anything or use affiliate links that generate a commission when the visitor clicks on a link to buy something. This is not a fan page either, this product was not given to me, I was not paid to write this, nor did the manufacturer or distributor loan me this lens for this review.
What is a Tube Lens?
The tube lens is an integral part of all infinity-corrected microscope system. The best tube lens should form an image as sharp as possible while introducing minimal aberrations, especially chromatic aberration, all the way to the very edge of the corners without any corner shading.
The tube lens is a relatively simple multi-element optic used to focus the parallel light coming through an objective onto the image plane or sensor. For photography, the tube lens is installed between the objective and the sensor. The tube lens is designed for a microscope system but a telephoto lens, or even a close-up lens can work equally well or even better. To find out if you need to use a tube lens with an objective, it's easy to check, infinity-corrected objectives are identified with the infinite mark (∞) on the side of the lens barrel.
Correction for optical aberration in an infinity-corrected microscope is accomplished in the tube lens design or in the design of the objective. Mitutoyo, Qioptiq, Thorlabs and Nikon correct for spherical and chromatic aberrations in the objective lens itself using very low dispersion glass so no other aberration compensation is needed, like eyepieces or tube lenses (also no coverslip needed). Zeiss for one example, uses a combination of correction in the tube lens and the objective.
TUBE LENS FOCAL LENGTH
With infinity-corrected objectives you can easily change the tube lens focal length to create a different magnification ratio at the camera sensor, without compromising the color correction. To calculate the system magnification for different tube lens and objective combinations, you can use this simple formula: Effective magnification = Marked magnification X the new tube lens focal length / the system tube lens focal length.
Manufacturers design their infinity-corrected microscope system with just a few standard tube lens focal lengths. Qioptiq uses a 250mm focal length. Thorlabs, Nikon, Leica, and Mitutoyo use 200mm. Olympus 180mm, and Zeiss 165mm.
What about the Factory Mitutoyo MT-1 Tube Lens?
Mitutoyo offers 5 tube lenses in their catalog and the MT-1 is best suited for photography, visible wavelength range, Ø 30 field (the widest of all the lenses). The MT-1 is expensive at $710 USD new, for comparison, that’s about 30% more than I paid for my Mitutoyo M Plan 5x 0.14 objective new from Mitutoyo! The list price would make sense if the performance from this lens matched the objective but in the case of the MT-1, it’s overpriced. You can find a MT-1 test here on Closeuphotography.com: https://www.closeuphotography.com/mitutoyo-mt-1-tube-lens.
Test setup
The Mitutoyo M Plan APO 5x is an excellent objective so the goal of this test is really simply to find out which tube lens adds the least aberrations and at the same time, the largest usable sharp image circle. Some M Plan magnifications have larger image circles than others, for example the 7.5x M Plan has a larger image circle than the 5x M Plan.
All of the lenses were tried mounted normally and in reverse, and with best spacing between TL and objective. All tube lenses were focused at infinity.
Raynox DCR-150 +4.8: normal mount (lens label towards objective)
Rodenstock Rodagon 210mm f/5.6: normal mount (lens label towards objective)
Schneider Kreuznach Componon-S 210mm f/5.6: normal mount (lens label towards objective)
Schneider Kreuznach G-Claron 210mm f/9 process lens: normal mount (lens label towards objective)
Thorlabs ITL200 f=200 tube lens: reverse mount (smaller diameter end towards subject)
Objective: Mitutoyo M Plan APO 5x 0.14
Camera: Sony α7R IV (A7R4), also called the Sony Alpha ILCE-A7R IV (A7R4)
Sensor size: Full Frame. 35.7mm x 23.8mm. 42.91 mm diagonal. 3.76 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
The sharpest frame was then selected out of a stack of images made in 4 micron steps. 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 have not been stacked and are single files only.
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100% Center Crops
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Fujinon GX, Raynox, Rodenstock Rodagon L to R. Sharpness and CAs are close with the Fujinon being slightly less sharp. Hopefully the Fujinon will do better in the corners?
Componon-S, G-Claron, ITL200 L to R. Thorlabs ITL200 is best, sharpest, zero CAs. Componon-S is very good. The Claron is the worst, showing CAs and the least details.
28mm Image Circle (APS-C) corner Crops
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Fujinon GX, Raynox, Rodenstock Rodagon L to R. Rodagon is sharpest here with great CA control. Zero CAs out of the Fujinon but not as sharp. Raynox is not as sharp as the Rodagon has a warmer rendering than the other two. All images processed identically.
Componon-S, G-Claron, ITL200 L to R. ITL200 is excellent, easily the best. Componon-S makes a nice image. G-Claron is worst with red fringing around the 209 222.
43mm image circle Full frame corner Crops
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There is quite a drop off in sharpness, R to L, with the lenses here especially the Fujinon and the Raynox. The Fujinon is poor. Stacking did not help at all. Rodagon is disappointing. Raynox is good into the corner but there is lots of field curvature here, this is 9 frames from the center crop. The Rodagon image plane is almost flat by comparison.
Componon-S, G-Claron, ITL200 L to R. Componon-S corners are soft, same with the G-Claron. The ITL200 is closer to the Raynox but is not as sharp.
Result
Best of the test: Raynox DCR-150 +4.8 208mm
The 3 element Raynox lens delivered a sharper image, even outside the factory rated image circle, than all the other lenses tested including the excellent ITL200. Glad to see the Raynox results even though I’ve wasted hundreds and hundreds of dollars on tube lenses and huge chunks of my time just to find out that my first and oldest tube lens is the best on a full frame sensor? At least the test results will save others from wasting their money and valuable time.
Runner up: Thorlabs ITL200
The ITL200 gave us fantastic APS-C coverage, even better than the Raynox, but the full frame coverage was poor. It’s interesting that Thorlabs does not list the image circle Ø or OFN (optical field number), they refer to this as Field Size at Image Plane number and the spec is not available. Sources say the ITL200 is a private label Nikon Super Fluor tube lens and if that’s the case then it’s made to cover only a 26mm image circle!
Update Oct 20th 2021
The ITL200 might have been designed to cover a 26-28mm image circle but doesn’t mean it cannot cover a larger full frame sensor. New testing has shown that with at least one objective the ITL200 will cover a full frame sensor but this is new and I will post more on this when the test is ready to publish.
additional Tube Lens Information
Fuji EBC Fujinon GX 5.6/210
Made for the Fuji GX680 MF camera system
Optical design: 5 element 5 groups
Accessory threads: M82 x 0.75
Rear threads: M50 x 0.75
Mounting threads: none
Pros: low cost
Cons: huge size, no rear mount threads, no manual iris control
Setup notes:
Normal mount (lens label towards objective)
Minimal objective spacing (objective was placed inside the shroud)
More info: https://fujifilm.jp/personal/filmandcamera/lens/gx680iii/gxm210mm.html
Raynox DCR-150 +4.8 208mm
Optical design: 3 elements 2 groups, Hi-Index Optical Glass
Accessory threads: M49 x 0.75
Mounting threads: M43 x 0.75
Pros: low cost, optical correction
Cons: none
Setup notes:
Normal mount was best (lens label facing objective)
Minimal objective spacing was best
More info: http://www.raynox.co.jp/english/dcr/dcr150/indexdcr150eg.htm
Rodenstock Rodagon 5.6/210
Optical design: 6 element 4 groups
Accessory threads: M67 x 0.75
Mounting threads: M58 x 0.75
Pros: low cost, easy to find used
Cons: corner performance (when used as a tube lens)
Setup notes:
Normal mount was best (lens label towards objective)
Minimal objective spacing
Notes: Latest model
Schneider Kreuznach Componon-S 5.6/210
Optical design: 6 element 4 groups
Accessory threads: M72 x 0.75
Mounting threads: M55 x 0.75
Pros: low cost, easy to find used
Cons: corner performance (when used as a tube lens)
Setup notes:
Normal mount was best (lens label towards objective)
Minimal objective spacing was best
Notes: this is the latest model with BL-1a iris mount with blue aperture window
Schneider Kreuznach G-Claron 9/210
BK-1 iris mount and 207.5 effective FL
Optical design: 6 element 4 groups
Accessory threads: M49 x 0.75
Mounting threads: M39 x 0.75 (Not standard M39 x 26TPI)
Pros: low cost
Cons: lack of CA correction (when used as a tube lens)
Setup notes:
Minimal objective spacing was best
Normal mount (lens label towards objective)
Notes: later type
ITL200 - Tube Lens, f = 200 mm, External M38 x 0.5 Threads
Optical design: unknown
Front mounting threads: none
Rear mounting threads: M38 x 0.5 (Standard Nikon tube lens threads)
Front mounting threads with SM2A20 adapter: SM2 (2.035"-40)
Rear mounting threads with SM2A20 adapter: SM2 (2.035"-40)
Pros: performance on APS-C image circle
Cons: can be hard to find used
Setup notes:
Reverse mount (threads towards sensor) best
Normal 70mm objective spacing was best
More info: https://www.thorlabs.com/thorproduct.cfm?partnumber=ITL200
More test results here on Closeuphotography.com: https://www.closeuphotography.com/thorlabs-itl200
tests in progress
Work has already begun on the 240mm tube lens test for the Qioptiq Mag.x 5x LD Plan. The APO-Gerogon is an excellent lens and the favorite going into the test but looking at the results so far, this test might also result in an upset where the most expensive/complex lens is not the top performer.
Century - Schneider Optics (Century Precision) +4 close-up lens
Rodenstock Rodagon 240mm f5.6 enlarging lens
Rodenstock Rodagon-G 5.6/240 enlarging lens
Rodenstock APO-Gerogon 9/240 process lens
Rodenstock Ysaron 9/240 industrial lens
Rodenstock Apo-Ronar 9/240 LF lens
You can find the 240mm test here: https://www.closeuphotography.com/240-tube-lens-test
Whats next?
2021 Mitutoyo QV HR Objective Test,
2021 Mitutoyo 5x HR Objective Test
Lenses That Did Not Make This Test
Raynox DCR-5320PRO: this might be a great performer but I would need two of these since I would need two plus two lenses, +2+2 = +4, and that would cost over $600 USD which would be more expensive than a new Mitutoyo M Plan APO 5x + new Raynox DCR-150.
EL-Nikkor 5.6/210: hard to find on the used market
APO EL-Nikkor 5.6/210: very expensive on the used market
Mitutoyo MT-1 Tube Lens: CA issues. See the test: https://www.closeuphotography.com/mitutoyo-mt-1-tube-lens
Nikon MXA20696 Tube Lens: CA issues. Tested here - https://www.closeuphotography.com/tube-lens-test