Updates for October 2018: Uploaded new lens data including MTFs ( ! ) from Schneider-Kreuznach european site, see the bottom of the page.
The new MV PDF at SchneiderKreuznach.com: https://schneiderkreuznach.com/application/files/9315/4115/5413/1072517_Macro_Varon_4-5_85.pdf
The Macro Varon was part of a 2x test on closeuphotography.com, to see the full test follow this link: https://www.closeuphotography.com/2x-lens-test-2018
Schneider-Kreuznach designed the Macro Varon CAS specifically for the machine vision industrial inspection systems (PCB) inspection systems for the range of 0.5x - 2.0x or half-life size to two times life-size magnification. These lenses are just about impossible to find on the used market and don't expect to see this lens at your local camera shop.
Range: Extremely large optimization range of 0.5X - 2.0X life-size! There are not very many lenses made that can offer this kind of range.
IQ: Image quality doesn't get much better than this over this kind of range. The lens was designed to meet industrial inspection systems requirements for 5 micron-pixel size sensors.
V-Mount system: Schneider's V-mount is designed to withstand the high g-forces and vibration found in an industrial environment so its rock solid.
Coverage: No problems here, the Macro Varon can easily cover a full frame DSLR.
Size: Super compact size, not much bigger than an enlarging lens.
Controls: the manual controls on this lens are lockable.
Can live with: The non-circular 6 bladed iris is standard for an industrial lens but not ideal for photography
Can live without: Schneider V-mount system hardware prices
What makes the Macro Varon and other high-end lenses like the Printing-Nikkors and others so sought after by serious macro photographers is the ultra high optical correction. Lenses like these are designed to produce superb edge-to-edge resolution over an extra large image circle with practically zero vignetting, zero distortion and ultra low longitudinal and lateral chromatic aberration.
The Macro Varon is very valuable not only for the for ultra high optical correction but for the large optimized magnification range, 0.5x - 2.0x or half-life size to two times life-size magnification, the same exact range where I do most of my macro photography! More well-known ultra high end lenses in the same image quality class like the 95mm and 105mm Printing-Nikkors or the Rodenstock APO-Rodagon D lenses are great performers but only in the narrow specific magnification range they were designed for. Outside that range the performance drops off dramatically. The MV is able to perform at the same or higher level over a wide magnification range thanks to the CAS or Continuos Aberration Suppression technology. The CAS system uses a geared beta ring that is set for the magnification level by the user that compensates the lens optical aberrations for exactly the chosen optical magnification. There are only a few other industrial lenses that I know of that are designed for a similar kind of range with a floating correction or optimization ring, the Linos Inspec.x L 5.6/105 floating at 0.3X to 3X, Nikon Rayfact VF at 0.5X to 2.0X, and the 150mm printing Nikkor at 0.25X to 4X (out of production).
Consumer macro lenses like those from Canon, Nikon, Sigma, Zeiss, and Sony on the other hand are designed for good results over a large range from infinity down to 1:2X or 1X. Over this large range its impossible for the designers to correct for all aberrations so you will see compromises especially at larger apertures. Some of the best consumer lenses like the Canon EF 100mm f/2.8 USM L IS macro and the Zeiss Makro-Planar T* 100mm f/2 ZF both have issues with vignetting and chromatic aberration (LoCA), also called Bokeh CAs, the green and purple fringing in the front and rear out of focus areas (some lenses like the Sigma macro lenses like the Sigma 150mm f/2.8 are almost completely free of LoCAs).
The ring labeled ß' is a gear that corrects for aberrations by controlling floating elements or flexibly arrayed lenses inside the lens for close range optimization that compensates the lens optical aberrations for exactly the chosen optical magnification. This is the CAS or Continuos Aberration Suppression technology is what makes this lens such a strong performer over a wide magnification range.
Each Macro Varon lens is tested and marked for the best azimuth before they leave the factory and the V-mount system makes setting the best orientation really easy.
Schneider Kreuznach Macro Varon 4.5/85 CAS Lens Specs
Type: High end Industrial high-resolution line scan and inspection applications
Focal length: 85mm
The MV focal length remains constant through the magnification range. Lenses that use internal focusing will lose focal length as they focus to the minimum focus distance.
Optimization range: 0.5X - 2.0X
Optical Design: 8 elements / 6 groups
Coverage: 62mm image circle
Working distance: 228mm @ 0.5X - 100mm @ 2.0X
Schneider went with 85mm to reduce the required working distance to save space.
Controls: Aperture and CAS setting ring have locking screws. This is to counter the high g-forces and vibration in machine vision environments.
Lens mount: Schneider V-Mount (V38)
The Schneider V-mount system is very solid and quick to set up. The male and female sides slip on and off and are secured with 3 set screws. Schneider make adapters, V mount to M42 for example, to make the MV easy to set up on a DSLR.
Filter thread: M37 x 0.75
The filter threads make it easy to install a lens hood.
Cost: $4500 new
Unfortunately this lens is almost impossible to find on the used market but they do pop-up time to time.
Aperture: f/4.5 - f/8 with a 6 bladed iris.
Note: The MV is diffraction limited so the lens performs at its best wide open.
Macro Varon Hood
A 37mm to 25mm step down ring makes a perfect hood for the Macro Varon without losing any working distance. This $1.49 step down ring is cheap flare prevention and will help prevent a bent front lip in the case of a fall.
Macro Varon Updates, May 2017:
oinimaging.com has posted a very interesting test of the Macro Varon lens:
Follow the link and select 'bellows lenses' and 'Macro Varon' in the drop down menus:
Also be sure to check out the lens comparison tool, it's excellent:
Looks like Schneider has a fixed version of the Macro Varon listed available for about half the cost of the full CAS version. Contact: http://www.schneiderkreuznach.com/en/industrial-solutions/lenses-and-accessories/products/unifoc-system/macro-varon-line-scan-lenses/
Found this interesting slide from Schnieder showing the recommended lens magnification ranges and where the Macro Varon fits in, thanks google!
This Schneider slide differs in recommending the Macro Varon from 0.05x to over 3.0X! Found via google.
Macro Varon CAS setup for machine vision use.