uncoated lenses with colour negative film

[Dan Fromm]

Rule of thumb, not always true: tessars have less coverage than plasmats of the same focal length. They are therefore more prone to producing images that aren't as sharp towards the edges and especially in the corners unless the lens is stopped well down.

I'm an ignorant barbarian, find discussions of lenses' rendition and "aesthetic" silly. I have played the name the lens game with shots of the same subject, same lighting, same emulsion, same exposure (aperture and shutter speed) with a variety of lenses of the same focal length but different designs with people who held themselves out as connoisseurs of lenses and their "signatures." The experts failed miserably at matching lens to image.

If you want to know how you'll characterize a lens' signature, get it and use it. No one else sees the way you do, and you're probably inconsistent. Asking others what you'll see makes no sense.

Plasmats' big advantage over tessars is coverage. Focal length for focal length they allow larger movements for the same loss of image quality at the edges.

[Will Frostmill]

I'm an ignorant barbarian, find discussions of lenses' rendition and "aesthetic" silly. I have played the name the lens game with shots of the same subject, same lighting, same emulsion, same exposure (aperture and shutter speed) with a variety of lenses of the same focal length but different designs with people who held themselves out as connoisseurs of lenses and their "signatures." The experts failed miserably at matching lens to image.

I'd love to hear more about this. That sounds like a fun experiment.

Personally, I believe I can tell that there is a difference between Petzvals, Tessars, meniscus lenses, some soft-focus lenses, and occasionally Planars, but only when used in "extreme" ways. E.g., wide open, and on a format that's larger than it is designed for. But only Petzvals, and only in extreme cases, have I seen differences in color rendition at the edges. The differences I'm sensitive to have to do with resolution and contrast falloff, or really weird bokeh. (There's a Leica lens that renders telephone wires as triplicates, for some reason.) I don't think I could ever perceive a difference at normal taking apertures on LF.

I do think the OP would be well served by getting a nice compendium shade, avoiding filters, checking the rear element for damage, and buying a postwar lens, preferably something inexpensive that Calumet re-branded.

[BrianShaw]

'd like to hear more about the "ignorant barbarian". Most of my friends fit that characterization. Maybe you'll be my BFF, Dan?

[IanG]

Dan has summed up the differences betwen Tessar (& type) and Plasmats well. I couldn't tell you just by looking at them which prints/negatives were shot with my CZJ 150mm Tessar, 150mm f5,6 Xenar or 135mm f5.5 MC Symmar. I could tell which were made with a 1930's 135mm f4.5 Tessar, and I'd know some images were made with the Tessar or Xenar because that was all I was using for a while in Turkey.

I no longer shoot colour LF work and when I did used mostly 2 Rodenstock MC lenses, MC Schneiders are equally as good. At some point Schneider improved their coatings significantly and the single coated 75mm f8 SA, 90mm f5.6 SA and 165mm f8 SA's I own are all excellent for colour work, my earlier 65mm f8 SA doesn't match as well.

Whatever lenses you use it's about knowing how to get the best from them, if you need a lot of movements then Tessar & Xenar lenses are not a good choice, particularly the 135mm's, and if you want sharpness that matches a plasmat then shoot at f22.

Ian

[Dan Fromm]

Brian, the classical definition of barbarian is a person who's not a native speaker of Greek. I'm a birthright barbarian and proud of it.

As for ignorance, well, when I was much younger one of my ambitions was to know everything. When I got stack privileges in my hometown's library I looked at the miles of shelves and measured. After making allowance for fiction, duplicates and near duplicates and old books whose wisdom was subsumed into newer ones, I calculated that I couldn't read and absorb fast enough to get through them all before I died of old age. I also measured the periodicals, especially scientific journals, and the rate at which new issues arrived and new journals popped up. Same story. Not only couldn't I learn all that was known, I couldn't keep up with additions to knowledge. And then it hit me that I didn't know enough to decide what was truly important and learn only that.

We're born ignorant, learn a little as we live, and will never know enough.

Thanks for y'r kind offer to be my BFF. I'm sorry, your comments in a discussion of who should have handicapped parking privileges makes me think that if we tried to be friends we'll fall out in a big way almost instantly. Wary and distant respect is the best you and I can aspire to.

[BrianShaw]

... Thanks for y'r kind offer to be my BFF. I'm sorry, your comments in a discussion of who should have handicapped parking privileges makes me think that if we tried to be friends we'll fall out in a big way almost instantly. Wary and distant respect is the best you and I can aspire to.

Gosh... and I thought I was being quite rational. Oh well, wary and distant respect it will be.

You wouldn't happen to be using a 3-letter handle over at the other forum, would you? Or do you think I was being to kind by not telling someone that he is a moron? P.S. Rhetorical questions meant to be read in jest. Don't bother thinking too much about them or answering if you don't want.

[Dan Fromm]

Brian, I post under my own name, don't hide behind a screen name. There seem to be many curmudgeons around who, um, snipe from cover.

About calling people morons. Bad practice and often frowned on by forums' moderators. I try not to do it in spite of repeated provocations from several regulars on that other forum. Besides, I'm not smart enough for thinking "I'm smarter than that there person" to be safe. I worked with a couple of economics PhDs who were dumber than the average fence post -- I've measured, I'm not quite that stupid -- but couldn't see that telling them what they were would accomplish anything useful. One was a Berkeley product. I can't imagine how he got his degree.

Will, I did it seven or eight years ago when Emmanuel Bigler and I were preparing my lens diary for publication of the French LF site. The expert I stumped was the late Charlie Barringer. Lenses involved were tessar, dialyte, heliar, dagor and plasmat types. I used an ISO 100 E6 film and Charlie looked hard at the 2x3 trannies on a light table. No scanning involved. The shots I took for the lens diary weren't published. I found differences in sharpness between lenses; that's what I was looking in the shootouts reported on in the lens diary. Now that I know what they do I can separate shots taken with my 4.75"/7.7 Uno from ones taken with my 127/4.7 Tominon but I couldn't have done that until I knew how both lenses shoot. The Uno is, as reported in the VM, contrasty (uncoated but only 4 air-glass interfaces) but just isn't as sharp as a modern tessar type. On a one lens versus another trial the Uno is always the softer lens. It is very possible that if I'd practiced lens abuse -- shot my trials on a format larger than my lenses cover -- predictable and easily recognized differences might have turned up.