Scanner Nikkor ED 7 Element Lens

The Source

The Scanner Nikkor ED lenses were designed by Nikon for their Coolscan, and Super Coolscan scanner lines. The Coolscan ED scanners were sensational performers because of their highly corrected lenses, they were one of only a few on the market at the time, that could actually reach their advertised resolution figures in testing.

In high-grade optics, apochromatic or APO color correction is found in the very best best lenses. Designing an APO lens requires the use of ultra low dispersion glass, however this UD glass is expensive and difficult to process and fabricate so this makes APO lenses very expensive. For the Scanner Nikkor ED line, Nikon has somehow achieved the impossible, APO correction over an unheard-of-wide wavelength range, for a low price!

It's interesting that, the Scanner Nikkor ED lenses are virtually unknown in the photography world, even by Nikon experts that specialize in rare high-end industrial Nikkor lenses, yet these are some of the most highly corrected Nikkor lenses ever made.

Why a Scanner Lens for Macro Photography

Image quality. The Nikon Scanner Nikkor ED lenses were designed to be completely chromatic aberration free, sharp from the center to the corners, with a completely flat field and free from distortion.  Consumer market macro lens are not on the same level of correction as a Scanner Nikkor lens.

Nikon Coolscan scanners have been out of production for a long time, so the prices of the used scanners and replacement lenses make the price vs performance factor of these lenses just about impossible to beat.

This article will give you information you need to know about setting up this lens for photography, how to find one, and how the lens performs in some comparison tests. 

Scanner Nikkor ED 7 element lens before and after installing a Thorlabs SM1 threaded sleeve.

The Scanner Nikkor ED lenses

The Scanner Nikkor ED 7 Element lens is the smallest of the 3 versions of the Scanner Nikkor ED lenses, designed by Nikon for their 35mm format Coolscan IV and V and the Supercool Scan 4000 and 5000 ED scanners. The 14 element Scanner Nikkor lenses are found in the medium format scanners, the Super Coolscan 8000 ED and 9000 ED scanners, a detailed review of that lens is available here on Closeuphotography.com.

Scanner Nikkor ED 7 Element lens, Scanner Nikkor ED 14 element lenses from the Super CoolScan 8000 ED scanner and the Scanner Nikkor ED 14 element lenses from the Super CoolScan 9000 ED scanner on the right.

The 7 element Scanner Nikkor ED is a tiny lens, as you can see below, next to a Sigma 50mm macro lens. One of only problems with the Scanner Nikkor lenses is setting it up for photography, since there are no mounting threads!

Scanner Nikkor ED 7 Element lens, Scanner Nikkor ED 14 element lenses from the Super CoolScan 8000 ED scanner and the Sigma 50mm f/2.8 macro lens for scale.

SCANNER NIKKOR ED 7 ELEMENT LENS SPECIFICATIONS

Lens type: film scanning

Aperture: f/2.0 nominal aperture

Optical design: The 7 elements in 4 groups including 3 ED glass elements

Focal length: 40mm

 Working Distance: very good, about 58-60mm at 1.2x.

Chromatic Correction: This lens is an APO or apochromatically corrected in the range of 438 – 852nm. This correction extends into infrared range to cover the scanners LED output that is used for scratch and dust detection. The infrared light wave-length used by the scanner allows it to pass through film emulsion of negatives and slides without resistance, but the scratches and dust particles reflect it. The image is scanned two times, the first, as the normal RGB scan, and the second, captures defects like dust and scratches, preserving the important details.

An apochromatic or APO lens is corrected for chromatic aberration at the red, blue, and yellow wavelengths. This really adds to the subjective perception of sharpness. An APO objective should have correction of both types of chromatic aberrations or CAs, lateral CAs, or color fringing,  and longitudinal CAs, or LoCAs, also called Bokeh CAs. 

Resolution: Nominal optical resolution of 4,000 dpi. The site, www.filmscanner.info, found the 5000 ED scanner to have an effective resolution of horizontal 4100 dpi and vertical 3650 dpi, averaged out to about 3900 dpi. It is rare for a scanner to reach their nominal resolution.

Mounting Threads: None. This lens has no mount and no filter threads. I installed a Throlabs SM1 thread sleeve to give the lens 1.035"-40 threads. You can find more details on the set-up below.

Coverage: Full frame sensor format.

Country of origin: Japan

Scanner Nikkor ED 7 Element lens.

PRICE AND AVAILABILITY

Scanner Nikkor ED 7 Element lenses are available only on the used market, since Nikon discontinued the Coolscan some time ago. In early 2017,  the going rate for these lenses was only $25, but over time, they have become a little more well known, so the supply has tightened up, raising prices on the used market, and Ebay.

One strategy that still works well is to search ebay for non-working, parts only, Coolscan scanners. These are sometimes available for as low as $100 online, sometimes even less than that. If the scanner is in good condition, you can sell the case and spare parts to help offset the cost of the lens. 

The 7 elements Scanner Nikkor lens is found in these Nikon scanners:

Coolscan IV ED LS-40
Coolscan V ED LS-50
Super Coolscan 4000 ED LS-4000ED
Super Coolscan 5000 ED LS-5000ED

The 4000 is probably the most common Nikon scanner on the used market. But don't overpay, I have picked up a parts only condition 4000 ED scanner for as low as $40-50. You should be able to find a non-working 4000 scanner for less than $150 if you are patient.

How does the 7 ELEMENT LENS compare to the 14 element version?

The 7 element lens is a good sharp performer but the 14 element lens performs on another level. This is due to the more complex optics that allowed the designers to correct the aberrations at the very highest level possible. The 14 element lens is harder to find, more expensive and is a lot larger and heavier than the tiny 7 element lens.

Scanner Nikkor Pros and Cons

What I like
Image Sharpness
APO correction
Price vs Performance factor
No chrome or gold trim industrial design

What I could live without
Lack of mounting threads
The small size

Scanner Nikkor ED and the Canon MP-E 65 f/2.8 1-5x macro lens.

Test: SCANNER NIKKOR ED 7 ELEMENT LENS vs the Canon MP-E 65 f/2.8 1-5x macro lens at 1.3x

The 6 inch silicon wafer makes the perfect test subject. The disk is perfectly flat and has plenty of super-fine details. Best of all, a disk will not warp, bend, or twist in the middle of a test, like natural targets such as butterfly wings like to do.

Before this test I ran the Scanner Nikkor from 1x to 1.5x and it looked like the 1.3x to 1.35 x images were sharpest. The test was run at 1.3x, with the MP-E set at f/4, the sharpest and highest resolving aperture for this lens at this magnification ratio. The MP-E was shot from f/2.8 to f/5.6 for this test and the sharpest images were selected for the comparison.

Vintage 6 inch silicon wafer test target

100% crop areas shown in green.

100% center crops, Canon MP-E 65mm f/2.8 1-5x Macro Photo Lens at f/4 vs the Scanner Nikkor ED 7 Element Lens

100% edge crops, Canon MP-E 65mm f/2.8 1-5x Macro Photo Lens at f/4 vs the Scanner Nikkor ED 7 Element Lens

100% corner crops, Canon MP-E 65mm f/2.8 1-5x Macro Photo Lens at f/4 vs the Scanner Nikkor ED 7 Element Lens

TEST SUMMARY

Although the Scanner Nikkor lens certainly doesn't look impressive, the image quality is. In all of the 100% actual pixel crops, the Scanner Nikkor is sharper and more contrasty. The edge crop shows an especially large resolution difference. Honestly, I was a little surprised at the results since the MP-E is such a sharp lens.

One factor that you don't see in the above crops, is the difference in chromatic correction between the Scanner Nikkor lens and the MP-E 65. Canon claims, The (MP-E) lens design contains UD-glass elements to suppress chromatic aberrations which often become apparent at high magnifications, but in reality the lens has LoCAs, also known as Bokeh CAs.

In the examples below, the APO corrected Scanner Nikkor lens crop is completely free from CAs, the Canon MP-E is not.

Longitudinal chromatic aberration or Bokeh CA crops, Canon MP-E 65mm f/2.8 1-5x Macro Photo Lens at f/4 vs the Scanner Nikkor ED 7 Element Lens

Note: LoCAs can be reduced in the focus stacking process with software like Zerene, see: https://zerenesystems.com/cms/stacker, since the LoCAs shows more strongly in the slightly OOF regions that are mostly ignored so they do not appear in the in-focus stack. Color casts can sometimes still remain though, either through information leakage or since some of the out of focus remain in the completed stack. 

the Test Set-Up

Camera: Sony α6300, model # ILCE-6300, also known as: A6300
Sensor size: 23.5 × 15.6 mm. APS-C. 28.21 mm diagonal. 3.92 micron sensor pitch
Flash: Godox TT350s wireless flash x 2 with one Godox X1s 2.4G wireless flash transmitter

The Canon MP-E 65 was used on the Sony with a Sigma MC-11 E-mount to EOS adapter. The Scanner Nikkor ED 7 element lens was mounted on my 42mm studio set-up, for more information on the setup used for this test, follow this link: https://www.closeuphotography.com/42mm-setup 

For this test, the Sony α6300 camera was mounted on a Nikon MM-11 vertical stand. Manual mode was used at ISO 100. To avoid any sharpness loss due to vibration, I used the two Godox TT350s wireless flash, at 1/128th to 1/16th power triggered by a Godox X1s 2.4G wireless flash trigger/transmitter. The flashes remained in place for the entire test to avoid changes in light angle, the flash was mounted on a flash bracket, bolted to an optical breadboard shooting, into a 4-3/4 inch (12 cm) Godox plastic half dome diffuser, placed over the wafer.

Each lens was focus bracketed and the single sharpest image for the center and corner were chosen at 100% view in Photoshop. All images were shot as RAW Sony ARW files and 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. 

Setting up the SCANNER NIKKOR ED 7 ELEMENT LENS for macro photography

The lack of mounting threads makes mounting this lens on your camera a little bit of a challenge. I just so happened to have an extra Thorlabs SM1 threaded sleeve in my toolbox, so it was an easy choice for me. The internal diameter of the sleeve was really close, within 0.5 - 1mm, but it was too small. I tried to press-fit the sleeve after heating it, but I ended up having the lens machined down 0.5mm and the sleeve pressed on. The secret to a threaded sleeve is that you can mount the lens forwards or backwards, and make fine adjustments that would not be possible with a flat ring type adapter. The lock ring keeps the lens wobble-free, solid and secure in the mount.

Scanner Nikkor 7 element bare lens with Thorlabs SM1 parts laid out and installed.

With the SM1 sleeve in place there are lots of high-quality adapters available at Thorlabs to take it to any thread size you need, I chose M42 since my standard studio set-up is based on this thread, a detailed review of that set-up is available here on Closeuphotography.com.

With the SM1 - M42 flat adapter in place the Scanner Nikkor screws into place in my standard RAF Camera variable M42 extension tube setup, as you can see below.

Scanner Nikkor ED 7 element lens mounted on RAF camera extension tubes and Thorlabs SM1 adapters.

This is the Scanner Nikkor ED 7 element lens installed in a RAF camera M42 x 50mm variable extension tube, that will allow extension from 55mm to 90mm, mounted inside a RAF M42mm x 50mm tube. I use the variable tube to set an exact magnification rate, but you can also use it to set precise framing, or use it to focus like a focus ring on a normal lens. The use or variable tubes is not that common in macro photography. I started using this type of variable tube after purchasing a couple of industrial machine vision set-ups that were designed using this kind of tube.  The type of variable tube set-up is standard in the line-scan machine vision industry.

Thorlabs and RAF parts used in my set-up from left to right;

SM1T10 - SM1 (1.035"-40) Coupler, External Threads, 1" Long  with lock rings

https://www.thorlabs.com/thorproduct.cfm?partnumber=SM1T10

SM1A49 - Adapter with External M42 x 1.0 Threads and Internal SM1 Threads

https://www.thorlabs.com/thorproduct.cfm?partnumber=SM1A49

RAF Camera M42 x 1 x 50mm Variable Extension tube with lock ring

https://www.rafcamera.com/extender-m42x1-50mm-with-stop-ring

RAF Camera M42 x 1 x 50mm Extension tube

https://www.rafcamera.com/extender-m42x1-50mm

Scanner Nikkor ED 7 Element lens with Thorlabs SM1 threaded parts.

Once the Scanner Nikkor ED 7 element is converted to SM1 threads, there are other SM1 parts that can be useful, some are available on Ebay at great prices, thanks to the popularity of Thorlabs parts. The SM1 threaded iris was only $10 on Ebay in as-new condition. The variable SM1 threaded tubes above were only $9 each on ebay, new, and in unopened factory packages. 

As an alternative it would be easy to use SM1 tubes with the Scanner Nikkor 7 element lens, instead of the larger M42 tubes.

Scanner Nikkor ED 7 Element lens bare and with the Thorlabs SM1 iris and extension tube.

This is the Scanner Nikkor 7 element lens, mounted to a Thorlabs SM1 iris and extension tube. From here you would just need an SM1 to M42 adapter and a low cost M42 to the camera mount of your choice adapter to finish the set-up.

SM1L10 - SM1 Lens Tube, 1.00" Thread Depth, One Retaining Ring Included 

https://www.thorlabs.com/thorproduct.cfm?partnumber=SM1L10

Various thread adapters on the Thorlabs site:

https://www.thorlabs.com/navigation.cfm?guide_id=2327

Scanner Nikkor 7 and 14 element lenses next to the Minolta DiMAGE scanner lenses for scale.

LINKS FOR MORE INFO:

My favorite optical expert, Marco Cavina, offers an excellent look at the optical designs of Scanner Nikkor ED lens prototypes on his site. This PDF is in Italian, so you will need to use an online translator like google translate (https://translate.google.com/):

http://www.marcocavina.com/articoli_fotografici/articolo%20Scanner%20Nikkor%20ED.pdf

For lots of excellent Scanner Nikkor ED 7 element lens info visit my friend, Enrico Savazzi's site:

http://www.savazzi.net/photography/scanner_nikkor_40mm.html

A test of the Nikon Super Coolscan 5000 ED scanner with resolution samples: 

http://www.filmscanner.info/en/NikonSuperCoolscan5000ED.html