The Hugo Meyer Plasmat 90mm f1.5. This lens was likely mounted on medium format cameras such as the Record-Primar from the German Bentzin company and the Nachtreflex by Ihagee. The distance scale is in meters, and the aperture ranges from f1.5 to f8 with an international aperture scale. It was manufactured in 1931 with a serial number of 46xxxx, covering medium format sizes.
The Plasmat was designed by Dr. Rudolf, who also invented other renowned lenses such as the Anastigmat, Planar, and Tessar. This particular lens shares the same optical design as the Kino-Plasmat.
The Plasmat 90mm f1.5 is a rare lens that we have only handled a few times in the past. At f1.5, it produces a very soft image, and even when stopped down to f4, this softness remains noticeable. At f5.6, the image sharpens dramatically, and by f8, the image quality starts to degrade slightly.
Unlike the Kino-Plasmat for 35mm cameras, which exhibits noticeable swirl distortion, this lens shows minimal such effects, likely because the image circle is larger due to its medium format design, and only the center is used when mounted on 35mm cameras. When used with a medium format camera, the lens will likely exhibit a very different character.
Weighing 1330g, including the adapter, this lens is quite heavy, requiring effort to handle while shooting. Beyond its weight, it has a unique rendering that demands practice to master. However, when conditions are right, the image quality it produces is truly one-of-a-kind.
The brass underneath is slightly visible due to handling, but there are no dents or impacts, and the black paint and nickel-plated finish contribute to the lens's solid, beautiful appearance. It seems that careful modifications were made, and the modified parts are finished to look like genuine components.
The lens shows slight aging, such as minor haze on the glass and a little dust inside, but there are no noticeable cleaning marks, and the glass is in very good condition for an old large-aperture lens. The aperture and focusing helicoid both operate smoothly.
When using this lens with mirrorless or live view shooting, if you rely too much on peaking, you might find that the focus doesn't align with the point of maximum resolution. It seems best to avoid using peaking during shooting and instead zoom in on the live view image to fine-tune focus for better results.
Through repeated testing, we found that near the wide-open aperture, the contrast (light-dark shades) peaks just slightly before the resolution peak. Therefore, if you judge focus based only on contrast in the viewfinder, you might end up with a slightly soft image. It is recommended to slightly adjust the focus by turning the helicoid.
Additionally, at wide open to about f2.8, flare can occur at the resolution peak, making focus a little more difficult to judge.
As mentioned, to achieve optimal focus, it's best to avoid relying on peaking and instead use the digital mirrorless camera's focus magnification to fine-tune focus and ensure sharpness. It will require some trial and error to get used to, but with patience, you will enjoy the unique rendering of the Plasmat, which has been cherished by collectors and lens enthusiasts for many years.
Sample images have been posted in our test gallery, and we hope you'll take a look. For reference, the examples include photos taken at the contrast and resolution peaks, showing the differences.
Included are a versatile M42 mount adapter, a M65 mount adapter for large format and other mounts, a mount adapter with an inner thread of approximately 57-58mm, and the genuine lens hood.
