Nikon Rayfact VF 0.5x - 3.0x Line Scan Lens

The Nikon Rayfact VF lens is a variable magnification float ring lens designed for use with a line scan camera for industrial inspection to identify flaws directly within the production process of semiconductors, FPDs (flat panel displays), and PCBs (printed circuit boards) in industrial applications. Float ring refers to the aberration correction ring that controls a floating element group. The float ring does exactly as advertised, images made with this lens are free from lateral chromatic aberrations (LaCA) and longitudinal chromatic aberrations (LoCAs) from 0.5x to 3.0x. These lenses are rare on the used market, in fact I’ve only seen one for sale used over the years but the lens is still available as new in early 2020.

This test, like all the content on my site, is completely independent and free from industry influence. I will not benefit from your purchases. Most photo sites in the web today are run by corporations for profit. I do not show ads, use any affiliate links, track your web history, sell products or take money from anyone in the photo industry. I create content for this site for fun in my free time. Instead of making a few dollars from this site, I'm far more concerned about teaching people to learn to use what they already have, rather than waste time and money buying the wrong equipment. Most of us, myself included, would make far better pictures if we'd stop buying new equipment and spend that time learning how to use what we already have instead.

Asian ladybeetle on Verbena at 1.5x Rayfact VF Float lens with Nikon D850 at 1/80th sec at f/5.6 manual mode at ISO 64 with Godox TT350 flash and diffuser.

Key Features of the VF lens

Ultra wide 0.5x to 3.0x magnification range!
Big 64mm image circle means the lens the lens can cover medium format sensors
Magnification correction float ring, for CA suppression
Bright f/4 maximum aperture
Flat image field with minimal corner shading
Lockable aperture and float rings (always great to see on a lens)
Aperture and float rings are geared so they can set by external power drives
Iris opens slightly past the maximum aperture (this is common for Rayfact lenses)
No trace of CA or LoCAs were seen during testing
Each VF lens is individually marked for best azimuth position to achieve the lens’s absolute highest resolution and contrast
The VF lens lens mount can be rotated for optimal alignment with the camera’s sensor (best azimuth)

The most well known float ring lens today has to be the Macro Varon CAS (MV) lens from Schneider Optics. The Rayfact VF lens has better specs than the MV, the maximum aperture is a little over 1/3rd stop faster; f/3.9 vs f/4.5, a wider magnification range; 0.5x-3x vs 0.5x - 2x, for about $1K USD less, $4600 vs $3600. The Linos Inspec.x L float lens is another variable magnification lens, also sold labeled as the Rodenstock Digaron, and Alpa Macro Switar. All of the Inspec.x L versions share the same optics. This Inspec.x Float lens is a full stop slower than the Rayfact VF with a longer focal length which will need more extension. I should mention that I did try to borrow the Inspec.x Float lens for this test but the US distributor did not respond. To be honest a full stop would keep the Inspec.x Float from the top of the heap but it would have been interesting to see image quality first hand. The Mejiro Etendue 4/110 matches the VF closely but this older model has been replaced by the Mejiro 95mm 1-3x Floating lens which is unusual in that the lens aperture is wider at 3x than 1x (f/4.3 vs f/2.5). I did attempt to contact Mejiro Japan for more info on the new 1-3x Float lens, but they did not respond.

Variable magnification lens	Focal length	Max aperture	Image circle	Mag range	Lens mount	Filter mount
Rayfact VF Float lens	91.7mm	f/4.0	64mm	0.5 - 3.0x	M45 x 0.75	M49 x 0.75
Schneider Macro Varon CAS 4.5/85	85mm	f/4.5	62mm	0.5 - 2.0x	V38	M37 x 0.75
Inspec.x L Float 5.6/105 lens	105mm	f/5.6	64mm	0.3 - 3.0x	V46	M43 x 0.75
HR Digaron 5.6/105 Float lens	105mm	f/5.6	64mm	0.3 - 3.0x	V46	M43 x 0.75
Alpa Macro Switar 5.6/105 Float lens	105mm	f/5.6	64mm	0.3 - 3.0x	V46	M43 x 0.75
Etendue Mejiro M-Zoom 4/110 Float lens	110mm	f/4.0	62mm	0.5 - 3.0x	V38	M49 x 0.75

Notes: The Inspec.x and Alpa float ring has settings for 0.3-3x but the lens scales are expanded to the 0.24-4.0x range. Rayfact also offers VF models optimized for 1x, 1.4x, 2.0x, 2.5x and 3.0x, all rated for sensors down to 5μm pixel pitch and image circles from 64mm to 86mm. Schneider offers set magnification versions of the Macro Varon also.

image quality test at 0.5x: Rayfact VF Vs Schneider Macro Varon CAS vs Mejiro M-Zoom

Camera: Nikon D850
Sensor size: 35.9 mm x 23.9 mm full frame BSI CMOS sensor. 43.3 mm diagonal. 4.35 μm 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 VF was designed for large sensor down to 5 μm pixel pitch so the D850 is a good match with a 4.35 μm sensor. The Nikon D850 sensor is only 8,256 × 5,504 pixels, 35.9 mm x 23.9 mm across with a 43.3 mm diagonal. The VF lens is designed to cover the 64mm image circle of a 12,000 or 12K pixel, line scan sensor camera.

A series of images was shot with each lens in 10 micron steps, and the sharpest image was chosen at Photoshop at 100% view. The single RAW file was processed in PS CC 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 test image crops are taken from single images. All test image crops are taken from single images that have been processed identically, with similar sharpening, unless noted.

Mejiro Etendue M-Zoom line scan lens at f/4
Rayfact VF line scan lens at f/4
Schneider Macro Varon CAS line scan lens at f/4.5

0.5x test: Center area crops at 100% view

For this section of this test I used a vintage 1980s Xerox silicon wafer is a perfect target for this range with lots of fine high contrast details and lettering.

Excellent results from all three lenses here at 0.5x, the level of fine detail and sharpness surprised me. The Rayfact image looks to be the sharpest of the three. The Mejiro has a tiny amount of additional resolution, see the tiny group of micro-dots on the left side, but slightly less sharpness and contrast than the other two. The blacks in the Macro Varon crop show slightly less contrast than the other two, even though all lenses used the same flocked lens tubes and all three lenses used a lens hood for the test. All the images were free of chromatic aberrations. You couldn’t go wrong with either 3 of these lenses for work at half life-size.

0.5x test: corner crops at 100% view

All three lenses are excellent performers in the far corners on the D850, with excellent chromatic aberration suppression. The Rayfact and MV are very close in contrast and sharpness here, maybe the Schneider lens is slightly sharper? The Mejiro has slightly more resolution than the others, see the micro-dots again, but slightly less contrast and sharpness overall. The Macro Varon seems to be sharper in the corner than the center!

100 percent view crop section comparison

0.5x Test Results

Looking at sections of the crop areas makes slight differences easier to see. The Mejiro gets the award for sharpness consistency from center to corner but is slightly less sharp overall. The Rayfact has a very very slight drop off in corner sharpness where the Macro Varon corner crop seems sharper than the center. Remember all 3 of these lenses cover a much larger area than the D850 sensor. Note that the Mejiro was inadvertently set to slightly lower magnification for the test.

Excellent performance at 0.5x from all three, it will be interesting to see what happens at 2x and 3x!

Nikon-Rayfact-VF-0.5x-3x-line-Scan-Lens-Closeup-Photography-com-15005.jpg

image quality test at 2x: Rayfact VF Vs Schneider Macro Varon CAS vs Mejiro M-Zoom vs Schneider lens Stack

Camera: Nikon D850
Sensor size: 35.9 mm x 23.9 mm full frame BSI CMOS sensor. 43.3 mm diagonal. 4.35 μm 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 shot with each lens in 4 micron steps, and the sharpest image was chosen at Photoshop at 100% view. The single RAW file was processed in PS CC 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 test image crops are taken from single images. All test image crops are taken from single images that have been processed identically, with similar sharpening, unless noted.

Mejiro Etendue M-Zoom line scan lens at f/4 (effective aperture: f/12)
Rayfact VF line scan lens at f/4 (effective aperture: f/12)
Schneider Macro Varon CAS line scan lens at f/4.5 (effective aperture: f/13.5)
Schneider Componon stack at f/4 (effective aperture: f/8)

Front lens: Schneider Kreuznach 4/60 APO-Componon lens reverse mounted
Rear lens: Schneider Kreuznach 5.6/120 Makro-Symmar lens mounted normally and focused at infinity

2x test: Center area crops at 100% view

The Mejiro seems to be just slightly softer than the Rayfact. The VF and the Macro Varon (MV) are extremely close, I gave up trying to see any differences, amazing performance from these lenses! Lots of fine details with zero lateral CAs, a really amazing performance.

For fun I thought it would be interesting to include a stacked lens setup at 2x, I chose the APO-Componon 4/60 makro-iris lens stacked on the Makro-Symmar 120. Center sharpness was good but the level of lateral CAs is not. This is the only lens in this test labeled as APO and it is the only one that is definitely not APO corrected. I own 3 samples of this lens and this performance is typical. Just FYI, the APO-Componon HM 4/60, APO-Componon 4/60 and APO-Digitar 4/60 have identical optics, only the price tags and barrels differ, see more here: https://www.closeuphotography.com/schneider-apo-componon-60mm-f4-test.

2x test: Corner area crops at 100% view

The corner results at 2x on the D850 are exactly the same as the center. The Mejiro is slightly weaker, the Rayfact VF and MV are both excellent with zero traces of CAs. I cannot tell the difference from the VF and MV! Both are just about perfect here. The fact that the Rayfact can match the MV at 2x is impressive since the VF design is more demanding due to the wider range. Excellent job Rayfact! The APO-Componon 4/60 + Makro-Symmar 5.6/120 lens stack falls apart in the corners on the D850 (corners are okay on APS-C).

This really is a demanding test target, if you have a few minutes, take a quick look at what normal consumer lens output looks like with this wafer, see my 5x test from 2018: https://www.closeuphotography.com/5x-lens-test

Note: in 2018 I tested the MV against 10 other lenses, and it came out overall best for large sensors, take a quick look: https://www.closeuphotography.com/2x-lens-test-2018

2x test: Longitudinal chromatic aberrations

Longitudinal chromatic aberrations or LoCAs are ugly purple and green fringing seen in the out of focus areas in front of and behind the focus point of an image. The images below are all jpegs converted from Nikon Raw files with all lens correction disabled in Photoshop CC ACR. All four lenses control LoCAs very well, impressive.

Mejiro-Etendue-M-Zoom-110mm-Float-line-scan-lens-Rayfact-VF-line-scan-lens-www-Closeuphotography-com.jpg

image quality test at 3x: Rayfact VF Vs Mejiro M-Zoom Vs Schneider Componon 2.8/35

Camera: Nikon D850
Sensor size: 35.9 mm x 23.9 mm full frame BSI CMOS sensor. 43.3 mm diagonal. 4.35 μm 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 shot with each lens in 3 micron steps, and the sharpest image was chosen at Photoshop at 100% view. The single RAW file was processed in PS CC 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 test image crops are taken from single images that have been processed identically, with similar sharpening, unless noted.

Mejiro M-Zoom line scan lens at f/4 (effective aperture: f/16)
Rayfact VF line scan lens at f/4 (effective aperture: f/16)
Schneider Componon 2.8/35 lens stack at f/2.8 (effective aperture: f/8.4)

Front lens: Schneider Kreuznach 2.8/35 Componon lens reverse mounted infinity focus
Rear lens: Scitex S-3 5/110 scanner lens reverse mounted infinity focus

Note: The Macro Varon was left out of this section of the test since 3x is out of its range, and including it would have not made in difference in the results anyway due to the final outcome, which you can read below.

3x test: Center area crops at 100% view

Since I decided not to run the Macro Varon at 3x I decided to include a ringer; a stacked lens setup, one of my all time favorites: the excellent SK Componon 2.8/35 line scan lens stacked with one of the best tube lenses I own, the Scitex S-3 5.0/110. Check out the results below, astounding!

The Mejiro center crop shows a bit less sharpness compared to the Rayfact. The Rayfact file, 3rd from the right, looks sharp, clean, and contrasty, very good overall and no performance drop from 0.5x to 3x, an excellent performance overall. Now compare the Rayfact to the image second from the left, the Componon 2.8/35, it’s a little sharper naturally since it was shot at f/2.8. Now here is the amazing part of these results, the Componon file has not been sharpened after being converted from RAW, while the Rayfact and Mejiro have had two additional light sharpening passes! That is amazing. The Componon is sharper than both the Mejiro and Rayfact without sharpening! To be fair I added an example from the Componon with sharpening on the far right side.

Below you can see the 100% center crops side by side in a single 2500 pixel file. Click on the file and right or 2 finger click and save as or open in a new tab.

Center-crop-3x-Float-lens-test-www-Closeuphotography-com-15986.JPG

3x test: Corner area crops at 100% view

In the far corner on the D850 the Mejiro now looks very slightly better in some areas than the Rayfact, but its almost too close to call. Both are excellent, zero CAs, sharp, with lots of details in the corner on the Nikon D850. The Mejiro might be sharper here than the center! The Componon 2.8/35 crop without any sharpening is close to the Mejiro and Rayfact with a very slight touch of blue/purple lateral CAs. With normal sharpening added the Componon is sharper and more detailed than the two float lenses thanks to the faster effective aperture.

Below you can see the 100% corner crops side by side in a single 2500 pixel file. Click on the file and right or 2 finger click and save as or open in a new tab.

Corner-crop-3x-Float-lens-test-www-Closeuphotography-com-15986.jpg

3X test: Final Results

It’s great to see the Mejiro and Rayfact easily cover the Nikon D850 sensor with sharp, detailed and CA free images. The lack of lateral CAs is really impressive in my eyes. The performance out of the Componon + Scitex lens stack shouldn’t have been a surprise, after all the 2.8/35 Componon and S-3 110 are two of my best stacking lenses, seeing the performance on a full frame DSLR compared to the two high-end lenses was still nice to see.

How is a Componon sharper than A Rayfact?

3x is right around the magnification level where stacked lenses have an advantage over focusing with extension due to sharpness loss from diffraction. The Mejiro and Rayfact VF lens have an effective aperture of f/16, the Componon on the other hand, is using an effective aperture f/8.4! A wider aperture = higher potential resolution.

Not all lenses will perform as well as the Componon (CPN) 35 wide open, I’ve covered it extensively on this site, for a general overview of the CPN 35 lineup follow this link: https://www.closeuphotography.com/schneider-componon-35mm-f4-lens-test.

NIKON-RAYFACT-VF-lens-dims-www-closeuphotography-com.jpg

TECHNICAL SPECIFICATIONS

Nikon Rayfact VF Lens
Part Number: L-OVM30093MN
Type: Industrial Large format 12K Line-scan
Focal length: 91.7mm
Maximum aperture: f/3.9
Sharpest Aperture: f/3.9
Aperture range: f/4 - f/8
Coverage: 64mm image circle. This lens will cover medium format digital camera like Phase One IQ3 100MP (11608 x 8708 pixel, 53.7 x 40.4mm sensor, 4.63 μm sensor with a 67mm diagonal).
Manufacturers recommended magnification range: 0.5x - 3.0x
Reference wavelength: 546.07nm (e line)
Wavelength range: 400nm - 700nm
Lens mount: M45 P= 0.75mm
Filter thread: M49 P= 0.75mm
Source: Lens made in Japan

Nikon Rayfact VF 0.5x - 3.0x lens L-OVM30093MN

PROS AND CONS

What I really like:

Extremely consistent image quality over the entire magnification range
Locking aperture and float rings
Awesome 0.5x - 3x range
Consistent image quality and huge image circle
Lens iris opens past the f/4 mark
Super apochromat chromatic aberration suppression
Short focal length (less extension needed)

What I dislike:

The Shiny satin black finish is a finger print and dust magnet
Bare uncoated mounting flange will cause veiling glare
Lens should be engraved, not labeled with a thin decal
The VF lens takes a couple of months to deliver from Japan

THE Rayfact VF BOTTOM LINE

The Nikon Rayfact VF lens has amazing sharpness and contrast over a wide magnification range free from chromatic aberrations. The balance of features on the VF is unique. The wide magnification range beats the popular SK Macro Varon while meeting or exceeding the image quality at the same time. The VF is a full stop faster than the Inspec.x Float 5.6/105 lens. All for a lower price point (about $1000 less than the Macro Varon. The Nikon Rayfact VF is very highly recommended.

This is a massive, heavy, and very well-made lens that was designed for the industrial market. For the price of this lens, the thin information decal is just silly, you would expect the lens information to be engraved on the barrel like other high-end lenses, but since it's for industrial use, maybe the thinking is that it only needs to be handled once for installation, so it’s not designed for repeated handling.

Nikon Rayfact VF horizontal setup with hood at 1.5x with Nikon D850

RAYFACT Vf installation setup notes

The VF lens uses a standard M45 P= 0.75mm Rayfact lens mount and adapters from RafCamera are available so mounting is straight forward. Above is the VF lens setup using my standard studio setup using Thorlabs SM2 components: https://www.closeuphotography.com/52mm-setup. The lens hood in the above photo is an SM2 lens tube.

Note: mounting the Raf adapter on the VF lens leaves the rear surface of the lens exposed, the problem is the rear flange of the VF lens is non-coated and not finished. This surface will cause veiling glare so it needs to be flocked. I made a simple flat disk out of flocking material to cover the uncoated area of the mount. You can see the problem with the Raf M45 adapter mounted below, this is before flocking or course. Rayfact offered to make a custom 52mm mount adapter for the VF for $4,000 USD, just for the mount adapter, not including a VF lens, the owner decided to pass on the custom adapter.

Rayfact is not alone, a lot of manufacturers ignore basic flocking, Schneider Kreuznach engineers really love shiny interior surfaces inside their adapters, unifocs, and tubes!

Rayfact-VF-91mm-Float-line-scan-lens-rear-mount-closeup-www-closeuphotographycom.jpg

Rayfact and TOCHIGI NIKON

Rayfact is a brand name for high-precision, high-quality industrial-use lenses made in Japan by the Tochigi Nikon Corporation. The name Rayfact is not very well known outside of the macro photography world but they are probably most famous for producing the Eco-Glass versions of the very well known Printing Nikkor 105mm F2.8, and Printing Nikkor 95mm F2.8 lenses. Rayfact lenses, especially the Printing Nikkor lenses, are some of the best image quality producing lenses ever made. Tochigi Nikon is a Japanese company that develops, designs, and markets optical devices for semiconductor/FPD lithography systems. In 2017 all functions related to the manufacturing technology of optical components, which were previously owned by Nikon Corporation and subsidiaries, have now been brought together as the Tochigi Nikon Corporation. More on the Nikon Group Companies: https://www.nikon.com/about/corporate/profile/group/. On April 1st 2020 Tochigi Nikon Corporation, makers of Rayfact lenses, folded the Rayfact products business into Nikon Corporation Business solutions (https://www.tochigi-nikon.co.jp/en/20200401.pdf). Quite a few Rayfact lenses were discontinued in May 2019, you can see the list here: https://www.tochigi-nikon.co.jp/whatsnew/bn2019/20190521.htm.