Meyer-Optik Görlitz Trioplan 2.8/100mm
The Meyer-Optik Görlitz Trioplan 2.8/100mm was fashioned in the 1950's after the famous Cooke Triplet invented just prior to the turn of the 20th Century.
Per SPIE's Optipedia (http://spie.org/publications/pm92_101_triplets?SSO=1)
"The Triplet design is the simplest design that is capable of correcting all of the seven Seidel aberrations over a wide field of view is the Cooke triplet. H. Dennis Taylor invented this in 1893, using the advances of Seidel's theory. It is named after the optical company in York, England, for which Taylor worked at the time, Cooke and Sons (later to become Cooke, Troughton and Sims). The lens is described in two very interesting United States patents, Nos. 540,132 (1895) and 568,053 (1896). Taylor's designs, despite their antiquity, are close to optimum for the aperture and field he intended, given the glass types available in his day. The triplet uses two of the principles of a good design. First, the Petzval sum is corrected by the use of spaced positive and negative lenses, as described in Chapter 9 on telephoto lenses. Secondly, it has approximate front-back symmetry about a central stop, to control the odd-order aberrations, coma, distortion, and transverse color."
The Trioplan 100 f2.8 is today a modestly sharp short telephoto lens of comparatively little distinction, save for one very interesting quality this lens takes on wide open at f2.8. Down to f4 and even f3.5, the lens acts fairly normally. However continue on for that last half to full stop and the lens takes on a highly entertainingly wild bokeh.
Extravagant Bubbles can be obtained under the right circumstance of specular highlights. Move a few degrees one way or the other, or rotate focus just a few more or less degrees, and the lens performs fairly normally for a lens of the 1950's .. soft, with low contrast and flare .. depending upon lighting conditions. However, hit the angle of view just right, with the focus set to just the right point, and watch the Bubbles pop out. And these aren't just the run of the mill bubbles you see from time to time from other lenses. These are bubbles with very highly enhanced and sharp outer circles. Quite unique looking when shot just right.
I've posted a couple of shots from this morning. Not the best examples out there but I think you can get an idea from them. And you can always just Google Trioplan 100 images and see tons of better examples. And there's some really interesting pics out there from this lens. So take a look!
Sun streaming though the Butterflly Bush this morning around 9am
f2.8, 1/2000th sec, ISO 50
Contrasted with the other recent Fuschia pic's I've posted recently, you can see some subdued hinting of the bubble background this lens is famous for
f2.8, 1/800th sec, ISO 125
The infamous Bubbles that make this old lens so sought after .. and a might expensive!
f2.8, 1/1000th sec, ISO 125