Resolution Testing Open Wide...
and more tests below
I began this project in September of 2002, looking for very fast lenses which would work as an all-purpose lens for daguerreotyping, which I could use as both a portrait lens and landscape. Daguerreotyping, particularly the non-mercury based Becquerel process I was using at the time, is remarkably low speed so a portrait at f/9 was out of the question. On an overcast day my exposures, using a f/4.5 Tessar wide-open, were hanging around 4 to 6 minutes, far far too long.
Preferably the lens would be between 150 and 240mm and should cover, aperture open wide, a half-plate (4.25 x 5.5 inches, 104 x 135 mm) at infinity, so I figured I needed an image circle of 170mm, extra would be luxury. I had identified a number of lenses which might do the job. The next task was to purchase them for cheap. I set aside the maximum I was willing to spend, and started on eBay, the most likely place to find lenses on the cheap.
All the lenses needed a good cleaning, and in the case of the Aero-Ektar, a liberal dose of Acetone. After figuring out various ways of taping and securing the lenses I ran resolution testing with the aperture wide open. Testing was done using Charles Sleicher's resolution chart, with a Canham 4x5/5x7 wooden field camera, on expired Kodak Ektachrome E100SW or EPP transparency film, with indirect light in my cramped living room, and read using a 1950s American Optics Microscope at 100x. Exposures, metered at ASA 125, were usually: f/2.8@1/8 second, f/4@1/4 second, et cetera.
Maker, Model & Details |
Lines/mm and Notes |
Lens Coverage |
Comments |
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Ross WA Xpres #VV181274 (WWII) |
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Reported Coverage: |
An unmarked WWII British Air Ministry lens. |
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Schneider Xenotar #4505xxx(1955) |
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Reported Coverage: |
Much larger coverage than reported by Schneider. Doesn't appear as sharp as the f/2.8 Xenotar. |
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Schneider Xenar #2089997(1948) |
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Reported Coverage: |
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Schneider Xenotar #12696814 (1975) |
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Reported Coverage: |
High contrast and very sharp compared to the other lenses . My most frequently used lens. |
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Kodak Aero-Ektar #EM5831 (1943) |
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Reported Coverage: |
Brown discoloration due to radiation damage from Thorium glass cuts out at least a stop of light, effectively making the lens f/3.5. Significant field curvature. | |||||||||
Dallmeyer Pentac |
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Found Coverage: |
An unmarked WWII British Air Ministry lens originally mounted aluminum barrel. I had the lens mounted in shutter by S.K. Grimes. | |||||||||
Schneider Xenar #2884379 (1952) |
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Reported Coverage: 250mm@f/16(55°) |
Nice sharp lens when stopped down a bit. |
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Voigtländer Heliar #4619389 (1958) |
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Reported Coverage: |
Slow in comparison to the other lenses. Lens tests shoed color abberation (banding) | |||||||||
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Eastman Anastigmat #EY128 (1940) |
untested |
Reported Coverage: 323mm@f/3.5(50°) |
Too large to mount on my camera, but the aerial image looks very promising |
Other possibilities: Dallmeyer 7.5 inch f/2.5 Series X (Speedic): I experimented with one of these triplets, and was shocked at how poor it was. Very low contrast, poor resolution. Considering the crazy prices these sell for, they are best off being avoided. Another lens which has an underserved price tag is Carl Meyer 5" f/2 Speed Anastigmat. These are apparently surplus elements from Schneider's WWII aerial survey lens, the Xenon, remarketed by Burke and James. These will not cover 4x5. I would love to try an Ernostar 165mm f/2, but these are very rare and very expensive. There I also saw a number of odd aerial lenses, such as a Perkins-Elmer 9 inch f/1.5 which was quite expensive and weighed more than me, and a Russian 200mm f/2.5 Helos which I knew nothing about. In addition a few triplets, such as the Steinheil Cassar, Meyer Trioplan, and a few Heliars were produced at f/3.5. I would have like to have tested a Zeiss 135mm f/3.5 Planar, but I never found one to purchase or borrow. While it is the same design as the Xenotar, I have heard that it is sharper wide open. There are also a few modern wide angle lenses which are relatively fast; Nikon, Rodenstock and Schneider all make wide angles at f /4.5. The Zeiss 75mm f/4.5 Biogon, from what I have heard, is designed to work open wide.
Conclusions: Like everything else, my recommendations for a fast lens depend upon budget and format.
Super Fast f/2.5-f/2.9 Lenses: If you are using 4x5 and can afford dropping a sizable chunk of cash for a Schneider 150mm f/2.8 Xenotar, I would suggest doing so, as it is clearly the best compromise between speed and sharpness. However, the Xenotar, while very contrasty and sharper in center than any of the other lenses, is hardly a stellar performer at the edge. The Dallmeyer 8" f/2.9 Pentac, while flat and showing mediocre center performance at f/2.9, and poor on the edges is an affordable lens, and may work well for 4x5 portrait work, or contact printing. Both the Xenotar and the Pentac sharpened up nicely by f/5.6. The Kodak 7" f/2.5 Aero-Ektar was the most disappointing of the lot, and in my opinion should be avoided. Its poor performance and effective f/3.5 speed, due to staining of rear element, more than made up for the low prices to be found on eBay. I have no experience with the Kodak 12" f/2.5 Aero-Ektar, but have no reason to believe that it would perform any better than the smaller model. Note also that the brown discoloration makes use of color film with this lens impractical.
Fast f/3.5 Lenses: For 4x5 or smaller, the Schneider 135mm f/3.5 Xenotar or Zeiss 135mm f/3.5 Planar are the same 5 element Gauss design. While I have no practical experience with the Zeiss I would guess that it would perform similarly to the 135mm Xenotar, since they are of similar design. Both lenses cover the 4x5. I would love to hear from anyone who has practical experience using the Zeiss.
For 8x10 or 5x7 format, other than the dissapointing Aero-Ektars, f/3.5 is the fastest speed available. Zeiss Tessar, Kodak Anastigmat, Steinheil Cassar, Meyer Trioplan, and Schneider Xenar were all made in f/3.5, this is not to say however that they are easily found, and Tessars designs perform poorly at at f/3.5. Note that any fast lens which covers these larger formats will be really massive, weighing more than many cameras, and will be difficult, if not impossible, to fit into shutters. My 13.5" Kodak Anastigmat although quite sharp, is barely usable due to its size and weight (10 lbs), and is only mountable on an 8x10 studio camera with 9x9 lensboards. The same will go for the 12" f/2.5 Aero-Ektars, whose elements alone weight 15 lbs.
Medium Speed f/4.5 Lenses: There are too many of these lenses to comment on or test in any sort of systematic way. The Zeiss Tessar and Schneider Xenar are readily available in both shutter and barrel mount. These lenses, at least the Schneider 300mm f/4.5 Xenar and Zeiss 165mm f/4.5 Tessar I have owned perform poorly open wide. The Voigtländer 300mm f/4.5 Heliar would not really be considered a sharp lens, but would work great for portraits. There are also a number of wide angle lenses available at f/4.5, I have not used any.
Recommendations: For 4x5, if extreme speed is necessary and pockets are deep, the Schneider 150mm f/2.8 Xenotar performs very well, especially when slightly stopped down. For those with shallow pockets who still need speed, the Dallmeyer 8" f/2.9 Pentac may be an acceptable option, especially for portraits. For my own use, I have settled on a using the Pentac as a portrait lens and the Xenotar for everything else. I would also recommend looking at period portrait lenses; Although I have not done formal resolution tests, I have been surprised at the quality of many of the Petzval-type lenses. This is especially true for users of 5x7 and 8x10, who will find very few lenses which will be faster or perform better.
Prices:
Xenotar Prices: I spent $600 on my Copal 3 mounted Xenotar at Midwest Camera Exchange, on eBay Compur 2 mounted Xenotars fetch upwards of $700, In NYC these lenses seem to sell for about $1400. Barrel mounted Xenotars sell for about $300 on eBay, and $600 in NYC stores. The 135mm f/3.5 Xenotar can often be found on eBay, running from $100 to $200 for a barrel mounted, which should fit directly into a regular no.1 shutter. The Zeiss Planar lenses, like the other modern LF Zeiss lenses, are very expensive, upwards of $1000.
Pentac Prices: I purchased my barrel mounted Pentac on eBay for $100, which seems to be the going rate. They are pretty rare in shutter, although one NYC store was selling a Pentac in a Betax no. 5 for $1450. They can be mounted in your no.5 shutter for $225 by Steve Grimes. Note however that since these lenses are often unmarked, the sellers do not know how to describe them. The best bet is to simply look for lenses marked at 8" f/2.9 and take a guess from there. Often there is an Air Ministry logo, "AM" with a crown between, on the barrel.
Tessar Prices: It is difficult to predict, these lenses seem to fetch on eBay between 20¢ to a dollar per millimeter, depending upon coating and manufacturer. I bought a Zeiss Jena 190mm f/3.5 Tessar T in mediocre condition for $120, which was far more than I should have spent. On the other hand, I purchased a 300mm f/4.5 Xenar in near mint condition for $100 and a 240mm f/3.5 Xenar for $40, both in barrel.
I see little reason to use 19th century landscape lenses, they are painfully dim and really don’t have any attractive features. In general, modern lenses far outshine them. Portrait lenses however are another story. The Petzval portrait lens, designed by Max Petzval in 1840 with the computational help of several Austrian artillery officers, is a wonder of 19th century technology. It is very sharp in the center of its image circle, blurring attractively towards the edge.
Max Petzval, because of Voigtländer's dishonesty, never patented his invention. This meant that his design was copied by hundreds of opticians in Europe and the United States. Consequently, they are relatively easy to find, and are not terribly expensive, although prices have been increasing of late.
Open wide, most Petzval lenses will be as sharp in their center as a Xenotar, however their field of sharpness is much smaller, only about 30 degrees or so at infinity, so they need to be used with care and in relatively long lengths. I find that a 9" Petzval lens works perfectly for 4x5 or smaller, and may cover 5x7 with some funky bokeh. An 11" lens will work very well with 5x7, and may cover up to full plate. A 16" lens works very well with both full plate and 8x10.
Most Petzval lenses are f/3.8, although a few are faster. I use a 11” f/3 Dallmeyer 3B from the 1880s which works wonderfully with 5x7 and will cover whole plate at portrait distances, as well as a monstrous 22" f/4 Dallmeyer 5A from the 1870s which works beautifully for 11x14.
Other
Lenses
see also C.
Perez and K. Thalmann's tests
The following chart are the results of resolution tests which I have been doing for some time now.
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Resolution |
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Rodenstock Sironar-N MC #10110xxx (1980s) |
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A really excellent lens, sharp, contrasty, and tiny. Great for medium format. Replaced the 105mm Xenotar on my Technika 23. |
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Linhof Schneider Xenotar #7037xxx (1961) |
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Goerz WA Dagor |
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"Black Rim Dagor," apparently made under military contract. This is a remarkably sharp and contrasty lens. Stopped down to f/32 it will just cover 5x7. |
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Schneider Angulon |
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Schneider Symmar-S MC |
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Why did I sell this lens? | |||||||||||||||
Linhof Schneider Tele-Arton #6923xxx (1960) |
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Linhof Selected Junk |
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Goerz WA Dagor #778xxx (1950s) |
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Anther "Black Rim" Dagor. I bought this lens for cheap because of the cleaning marks on front and rear elements. |
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Schneider G-Claron |
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Goerz Red Dot Apo-Artar |
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This lens doesn't appear to be quite as sharp or as contrasty as I thought it should be, and as everybody told me it would be, but it is small and performs just fine for my purposes. |
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Rodenstock Apo-Ronar #99589507 (1979) |
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I purchased this big process lens for almost nothing, and had it mounted to a lensboard. Like the Artar, it is no where near as sharp as a modern plasmat. Eventually I replaced it with a 450/9 Nikkor-M, a really fantastic lens. |
