Schneider APO-Digitar 5.6/120 M line scan lens
The APO Digitar 5.6/120 was marketed as an updated version of the already excellent Makro Symmar 5.6/120 lens. The APO Digitar 120 is supposed to offer the same apochromatic color correction but with higher resolving power over a smaller image circle to cover medium format digital backs. My job is to find out if APO Digitar 120 really is an improved, and higher resolving version of the Makro Symmar 120. Honestly I am a bit skeptical that the new lens is really an improvement over the Makro Symmar (MSR) so I will compare the APO Digitar to the Makro Symmar on extension as a macro lens, and focused at infinity as a tube lens in a stacked configuration.
Schneider sales literature states that the APO Digitar designs are all new and improved designs but you should know that not all lenses in the APO Digitar line are actually new, some of the APO Digitar actually use the same optical design as the Componon, or APO Componon lens that it supposed to update. We know this since Schneider lens gaussian optics data is identical for both lenses in some cases. This is not the case for the 5.6/120 design since the gaussian optics show that the APO Digitar is new design based on the Makro Symmar.
The Makro-symmar was designed to work with large format film cameras which do not have any glass between the rear of the lens and the film plane. APO-digitar lenses were designed to work with digital backs, which do have a IR filter stack in front of the sensor, so they should be better optimized to work with modern digital sensors that also have a filter stack in front of the sensor. I say should since Schneider fails to provide any information on whether or not the design of APO-Digitar includes sensor clover glass in their design. Rodenstock lens data sheets indicate whether each lens design includes cover glass or not. Rodenstock even includes the thickness of the cover glass used in the design of digital lenses in their brochure on digital lenses: “To avoid blurring and color fringing caused by the sensor protection glass, the calculation of the optical design includes a 2 mm thick sensor glass” Schneider marketing decided to keep this information from the public unfortunately.
Schneider APO Digitar 120mm f/5.6 M line scan lens
Apo Digitar 5/6/120 Quick Specs
High resolution lens specifically for digital backs as large as 63 x 63mm
Apochromatic color correction for good edge delineation across entire field
Designed for use at maximum aperture
Broad uniform image circle
Accepts 40.5mm threaded filters
Narrow rear barrel allows use on broad variety of cameras
SHARPNESS TEST at 1x
Front lens: Schneider APO Digitar 5.6/120 mounted normally and focused on extension
Nominal aperture: f5.6
Effective aperture at 1x: f/11.2
Camera: Sony α6300, model # ILCE-6300, also known as: A6300
Sensor size: APS-C. 23.5 × 15.6 mm. 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
Vertical stand: Nikon MM-11 with a Nikon focus block
For this test a stack of images was made with 10 micron steps, and was repeated for each aperture. The sharpest frame was then chosen using Photoshop at 100% actual pixel view. Separate images were selected for center, 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 are single files.
2500 pixel 1x sample image
Click on the image to open a larger version in a new window sized to fit your browser window. To see the full 2500px version, right or two finger click and specify to open in a new tab or window or better yet, save as, to save the image to open in the app of your choice. Either way just make sure the URL ends in 2500, if not change the number to 2500 and enter to see the full size version.
Schneider APO Digitar 5.6/120 at 1x
Sharpness Test at 3.4x Magnification
TEST SET-UP
Front lens: Schneider Componon 35mm f/2.8 lens reverse mounted
Nominal aperture: f2.8
Effective aperture at 3.4x: f/9.5!
Rear lens: Schneider APO Digitar 5.6/120 mounted normally and focused at infinity
Aperture: f5.6
Camera: Sony α6300, model # ILCE-6300, also known as: A6300
Sensor size: APS-C. 23.5 × 15.6 mm. 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
Vertical stand: Nikon MM-11 with a Nikon focus block
For this test a stack of images was made with 2 micron steps, and was repeated for each aperture. The sharpest frame was then chosen using Photoshop at 100% actual pixel view. Separate images were selected for center, 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 are single files.
2500 pixel 3.4x sample image
Click on the image to open a larger version in a new window sized to fit your browser window. To see the full 2500px version, right or two finger click and specify to open in a new tab or window or better yet, save as, to save the image to open in the app of your choice. Either way just make sure the URL ends in 2500, if not change the number to 2500 and enter to see the full size version.
Schneider Componon 35mm f/2.8 stacked with APO Digitar 5.6/120 tube lens at 3.4x
TESt results
For the 1x comparison I spent a lot of time, too much time, shooting two APO Digitar 5.6/120 samples against two 5.6/120 Makro Symmar lenses back to back. Then I compared the results at 100% view until my eyes hurt from eye strain. What did I find out? The lenses are very very close, both are excellent, and the APO Digitar is at least as good, maybe very slightly better with fine details than the Makro Symmar. I think the difference between the two is so slight that sample variation might be a greater difference in image quality than the difference between the newer APO Digitar design and the older Makro Symmar. You can’t go wrong with either lens for use at 1x.
As a tube lens stacked with the Componon 2.8/35, both lenses gave me nothing but excellent results. The Componon gave me fantastic image quality even wide open at f/2.8 at 3.4x without any visible chromatic aberrations, so both lenses, the APO Digitar and Makro Symmar are excellent tube lenses and I would recommend either without any reservations.
The last Word on the test results
For work as a macro lens at 1x or as a tube lens the APO Digitar 5.6/120 is an excellent choice, as is the Makro Symmar, that will cover full frame or medium format digital without any issues. The APO-Digitar 120 lenses were discontinued recently by Schneider in 2017, but the prices on the used market are actually lower than the Makro Symmar 120. For tube lens duty I prefer the Makro Symmar M-SR Makro Iris version since it is a lot more compact.
Not all APO-Digitar lenses perform at the same level as the 5.6/120. The Colortrac APO-Digitar 5.6/80 lens for example, is a strong under-performer compared to the 5.6/120, and is not a lens I recommended.
APO Digitar 5.6/120 Quick Review
Image Quality:
Clean and sharp, free of CAs across the entire field at 1X, with full frame sensor coverage
Like:
Image Quality
APO correction
Consistent edge to edge performance on a full frame or APS-C sensor
All metal lens and iris mount
Don't like so much:
5 blade iris
32.5mm thread mount
Iris is slightly closing down aperture at wide open setting
Schneider does not provide sensor cover glass design information with the APO Digitar.
Schneider APO-Digitar 5.6/120 M line scan lens with the B0 iris mount.
The lens as shown above is mounted in the all-metal Schneider Iris Mount Barrel B-0, the smallest mount for this lens. It is also very common to see the lens on the used market in a Copal #0 shutter mount or the Schneider Electronic Shutter mount #0.
APO-Digitar 5.6/120 M TECHNICAL DETAILS
Part number: 17964
Type: Macro lens / Technical lens / line scan lens
Focal length: 120mm at infinity
Aperture: 5 blades
Maximum aperture: Nominal f/5.6, measured f/6.2 forwards and in reverse (symmetrical design).
Magnification range: Optimized for 1X, recommended range is 1:4 to 4:1.
Coverage: 70mm at 1:1 (SK lens data PDF)
Working distance: Good.
Chromatic Aberration (CAs) control: Zero visible Lateral CAs.
B-0 Iris mount threads: M32.5 x 0.5
Front filter threads: M40.5 x 0.5
Optical design: symmetric 8 Elements in 4 Groups, ULD, ultra low dispersion glass used in the design.
Mounting the APO Digitar with the B-0 Iris Mount
The B-0 iris mount uses 32.5mm mounting threads, and thankfully, step-down adapters like the 42mm to 32.5mm that I use, are available on eBay. The 42mm to 32.5mm is stacked on a Thorlabs M42 to SM2 step-down adapter which mounts on my studio setup. You will have to remove the real cell of the lens to install the adapter since the rear cell of the Apo digitar is larger than the adapter (37mm in diameter). That’s not anything difficult though since the B-0, like the CPL #0 mount version, disassembles into two separate lens cells.
To make things even easier I prefer to use the RafCamera made lens cell adapter to mount the lens cells, as seen below. The RafCamera adapter mounts directly on my SM2 studio setup without any adapters, and has the additional advantage of being slightly faster than the B-0 or CPL#0 iris housings, f/6.2 vs f/5.2. Both the B-0 or CPL#0 iris housings are slightly closed down maybe 2mm even when set wide-open to f/5.6. The Makro-Symmar 5.6/120 in a B-0 housing is also closed down slightly even when set wide-open.
APO Digitar 120 Sensor Coverage
APO Digitar 5.6/120: 70mm at 1x
Makro Symmar 5.6/120: 90mm at 1x
Makro Symmar M-SR 5.9/120 lens: 90mm at 1x
Makro Symmar HM 5,6/120: 250mm at 1x
APO Digitar ASPH 5.6/120: 150mm at infinity
This 8 element macro lens optimized to cover medium format digital sensors with a 70mm image circle at 1X magnification. APO-Digitars are now discontinued, but they were sold and distributed by high-end camera manufacturers like Alpa, Cambo, Linhof, Rollei, Sinar, Arca-Swiss, Horseman and others. The APO-Digitar 120 M was designed to cover a smaller sensor with more resolving power than large format lenses like the Makro-Symmar, with a 90mm image circle, and APO-Componon HM, with a 250mm image circle.
APO Digitar 5.6/120 Lens Types
Lens data from Schneider indicates that the APO Digitar 120 optical design is slightly different than the Makro Symmar 120.
Schneider Apo Digitar M 5.6/120: 8 element medium format design optimized for a 1:1 reproduction ratio.
Schneider M-SR Makro-Symmar 5.6/120: 8 element large format design optimized for a 1:1 reproduction ratio.
Schneider APO Digitar N 5.6/120: 8 element design different than the M type for the range of infinity to 1:3.
Schneider APO Digitar ASPH 5.6/120: 6 element design with Aspherical Lens technology and a larger 150mm image circle designed for tilt and shift movements with technical cameras. 46mm filter threads.
Some APO Digitar lenses are not new designs, according to Schneider, some are identical to the older Componon or APO Componon lens designs. The Componon 4/80 and the APO Digitar 4/80, are the same lens, also the APO Componon 4/60, and the APO Digitar 4/60, are identical optically. Schneider re-badging lenses is common and at least they don’t hide the information.
External Links for more Info
Makro Symmar 120 + 2.8/28 Componon lens stack: https://www.closeuphotography.com/makro-symmar-120-and-componon-28-lens-stack
Makro Symmar 120 + Xenon lens stack test: https://www.closeuphotography.com/makro-symmar-xenon
Makro Symmar 120 + Lomo 3,7x test: https://www.closeuphotography.com/lomo-3-7x-and-sr120
Makro Symmar SR 5.6/120 Makro Iris: https://www.closeuphotography.com/schneider-makro-symmar-sr-120
Makro Symmar HM 5.6/120 Lens test here on Closeuphotography: https://www.closeuphotography.com/schneider-makro-symmar-120mm
1x test here on Closeuphotography.com including the Makro Symmar 5.6/120: https://www.closeuphotography.com/sharpness-test-1x