I recently wrote a blog entry where I talked about lenses that seem to fill the gap between Full Blown Soft Focus for 35mm format and "normal" sharp/clinical lenses. What I shared were mainly Lens Porn, er, sorry, Portraits illustrations because I find these cheap lenses beautiful to take photos of. I did not share my homework, even though I wrote at length about differences between the optics. This blog entry corrects this omission.
Keep in mind that the trick to these first element focusing lenses is that the greatest optical imperfection effect is generally found in subjects closer/closest to the camera. Of course it depends on lens design, but this is the tendency I've seen thus far.
Often these first element focusing lenses for 35mm format that are easily adaptable to digital derive from or are implementations of the early Cooke Triplet. The design is two positive elements on each end with one negative element in the middle. This is pretty simple, easy to manufacture, and can be very low cost. Lenses on the used market can be nearly Give Away cheap. I recently picked up a digital adaptable first element focusing Cooke triplet design lens for less than 9Euro.
Homework ~
Steinheil Auto-Cassaron
50mm f/2.8 at f/4
processed using a film sim
that I like just to see how
the low contrast of the lens
might play out against a
contrast-inducing LUT
Comments ~ (borrowed in large part from an earlier blog post)
In reverse order, from bottom to top...
Ricoh 55mm f/2.2 Riconar - Optical imperfections galore - the kinds of imperfections vary depending on subject distance. While I don't show this here, it's easily seems comparing close to distance focused subject at f/2.2 and f/4. It delivers rather decent contrast, actually.
Interesting highlight "glow" effects. Controllable by aperture and subject distance, which is potentially useful. One would have to map out distance/aperture to know which settings to use.
f/11 can make a pretty sharp image of distant subjects. Regarding the effects I'm going after, between f/2.2 and f/5.6 the optical imperfections at all distances can play well toward generating a decent "Pictorialist" style enlarged to "normal" viewing size/distance.
ISOC Iscotar 50mm f/2.8 - Optical imperfects somewhere between the Ricoh and Steinheil. Good contrast.
Interesting highlight "glow" effects. Controllable, as with the Ricoh, by aperture and subject distance. f/8 and f/11 can make a decently sharp image at greater subject distances if desired.
Between f/2.8 and f/5.6 the optical imperfections can play well toward generating a decent "Pictorialist" style enlarged to "normal" viewing size/distance. I think of the ISCO as a slightly more rational German Riconar.
Steinheil Auto-Cassaron 50mm f/2.8 - Subtle optical imperfections, spherical aberration at all apertures and all subject distances. Low contrast. Using the "haze" removal control during processing cleans up a scene, but why use it if I'm looking for "soft focus?" Have I mentioned this is a low contrast lens? There must be an echo in here. Either that or it's strongly evident from looking at the results.
To me this lens is like using a Heliar large format lens from Voigtlander. Back in the day I owned two of these, a 15cm and 21cm f/4.5, both in Compound shutter. These lenses had similar underlying detail to what I see with the 50mm. Missing the rendering of those old lenses I'm happy to discover the Steinheil. The more I stare at Steinheil images the more I wonder if this isn't a basic trait to how Steinheil designed their optics? As with the Heliars I find this a really interesting way to make an image. There seems to me to be a lot of potential for processing unique small format digital images. I have at least one more Steinheil optic coming to try to confirm/deny this line of thinking.
As the lens is stopped down the underlying detail begins to extend from the center toward the edges of the field. The effect is common to how triplets behave and I saw this most particularly in a Meyer Domiplan 50mm I once had. It was sharper from wide open than any Zeiss Tessar I ever saw (and I had more than a few of these over the years). The ISCO behaves this way too. That is, wide open the center of the field can be surprisingly sharp and the mid to edge of the field showing subtle/not-so-subtle optical defects of various kinds. These clean up as the aperture is stopped down and the sharpness spreads out.
With my Auto-Cassaron it's as if the lens designers kept/allowed the spherical aberration to gain consistency in other areas of optical design. Resolution, field distortion, chromatic aberration and coma are better controlled than in the Ricoh and ISCO. While more subtle than many large format soft focus lenses from Back in the Day, the Steinheil for small format might make for a decent "Pictorialist" style lens where image viewing sizes can vary depending on the electronic display system.
Images made with a Steinheil
Auto-Cassaron 50mm f/2.8 at f/2.8 or f/4
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