Lens test surprisegreenspun.com : LUSENET : Large format photography : One Thread
Hi all, Did some lens tests the other day ...man was I in for a surprise.I have never bought a brand new large format(only bought used) lens but am considering just that for future purchases based on the results of these tests.I shot a Goerz f9 RD 240mm, Schneider 135mm 3.5 Xenar, Schneider 180/315 conv, and a 127mm Graflex Optar 4.5.All lenses in great shape and late coated. All shot under the same conditions and enlarging only the middle of the neg...shot using middle apertures or f22.The worst was the 180 conv.which was ok in the middle and soft in the corners.Next worst was 240mm Goerz.This lens is very good but not superb..will probably use on 8x10 for contacts mostly.The next best was the 3.5 xenar which had a very nice rendition...as well as a bright screen, a keeper. But the big surprise was the 4.5 Optar that creamed the competition not only in resolution but contrast and rendition as well.This lens was a LOT better than the others and with a few polish marks to boot...go figure.Anyway...I have always liked this lens and admired it's quality but heard that the other brands would be better a better idea.Not so I think...at least in this case. Anyway, I give the 180mm a 7 score, the 240mm a 8, the 135mm xenar a 9, and the 127mm Optar a 9.8....Got to leave a little bit for a 10 score!I'm probably going to get a 110 xl next or a 180 sironar s and they better be a 10!
-- Emile de Leon (firstname.lastname@example.org), March 30, 2002
surprise, surprise. "Graflex Optars" have a mysterious history. Earlier ones are supposed to be 4-element Tessar types, later ones 3-element triplets of mediocre quality. I don't know if this is true, or how to tell them apart, assuming there are two different types. Graflex of course did not make lenses. This lens may have been made by Bausch&Lomb, Kodak (think Ektar) or by Wollensak, all in Rochester. Your lens was almost certainly original equipment on a Speed Graphic. Enjoy!
-- Mark Sampson (MSampson45@aol.com), March 30, 2002.
Emil: Glad you stroke gold! Not to dispute your results, testing lenses for LF cameras is a tricky thing because of the difficulty of keeping all variables under control. Holders can be a big variable. The only holder I know to come under truly strict tolerances, i.e. 0.001" is Linhof, which I tested along many others with a depth micrometer; Sinar holders also are guaranteed to similar tolerances. As for other brands of holders, it is a game of chance. Logically, positive results are true but negative results may or may not be true for the above reasons. Lens tests using calibrated holders on a camera with a calibrated groundglass is IMO the absolute minimum for lens testing. If you did not do that, do not throw the Goertz out, it may be worth re-testing. The Xenar should give a crisp image at the center of the field which degrades rapidly away from center especially considering its minimum focal length and small IC for even 4X5. For the price paid it may be cost-effective but today there are far better lenses as for example the Apo Symmar or Apo Sironar. Yet, to keep all in balance I must own to the fact that good lenses do not necessarily take good pictures, photographers do. Enjoy!
-- Julio Fernandez (email@example.com), March 30, 2002.
It has been mentioned here before, but try here for lens test results on many modern, and classics.
-- Jonathan Bundick (firstname.lastname@example.org), March 30, 2002.
It just goes to show that sometimes a lens can be under-rated. I have some Raptars (same as Optars?) that are very very sharp and contrasty.
-- Steve Gangi (email@example.com), March 31, 2002.
While you did not specify how you were doing the resolution tests, I must agree with Julio, and urge you to be very careful about the results of your testing. I have tested the same lens, a 210 G-Claron, five or six times, each time getting remarkably different results, ranging anywhere from less than 20 lines/mm to 80 lines/mm in center, that is, from a soft lens barely usable to an excellent sharp lens. Hmmmmmm. Alternatively, to throw a wrench into the works, each of the three times I have tested my 4 3/8" WA Dagor, I find it CONSTANTLY testing at 75 lines/mm in center. No explainations... What is clear however, as you have found, is that lens performance is often very surprising!
-- jason (firstname.lastname@example.org), March 31, 2002.
Yes I realise that I might have a different result on a different test. So I did it again ....with the same results.The holders are brand new and I was pretty picky(technique) but not obsessive.The only thing I think I need to do is run through the whole f stop scale on each lens.To my eye the Goerz looks sharper closer to wide open than closed down to f 22.I did not use a test chart...but used three dimentional objects with great detail so I could see how the lens put together tonalities as well.I made multiple prints in the darkroom so I could be sure the enlarger didnt shake too.Still, the 4.5 Optar kicked butt!
-- Emile de Leon (email@example.com), March 31, 2002.
Emile: The age of the holders is irrelevant to the issue of the holder's accuracy of registration. Brand new holders of a very popular and cheap brand are notoriously inaccurate. Out of curiosity, which brand did you use?
-- Julio Fernandez (firstname.lastname@example.org), April 01, 2002.
Given the following: 1. only a few years LF experience 2. I am not a math / optics genius 3. I don't have a million dollar optics lab ----
How can I reasonably and tolerably accurately calibrate my LF cameras, lenses, holders. That is check them out, calibrate them, test them so that I know I am getting the best out of my equipment. How can I tell if my holders are in / out of spec. Is there a reasonably easier to understand / follow checklist or how-to to go through the process. What tools do I need and can they be afforded on modest budget? There is a lot about how to do Zone in excruciating precision, but about the rest of the calibration necessary to get good, consistent results without black magic?
-- Paul van der Hoof (email@example.com), April 01, 2002.
Paul, may I suggest taking pictures and dont worry so much about all those test? If your pictures come out blurry and you are absolutely sure you focused them correctly then worry! if not, why fix something that is not broken? I been using my 4x5 for 10 years and dont have any idea what a resolution chart looks like...:-))
-- Jorge Gasteazoro (firstname.lastname@example.org), April 01, 2002.
I agree with Jorge. So long as your equipment is not badly smashed, it will work fine. You introduce more "slop" just in focusing/moving/tilting etc than any 1/1000 or even 1/10 of an inch tolerances in your film holders, camera back etc. Plus, using large format you probably stop down to f16/f22/f32 also. I'm still tickled that the Wollensak lens compares so well to other more expensive lenses. Don't fall into the trap that seems so common, some people will have you testing and measuring everything. Measure your films on a kilodollar densitometer, measure all your films with every lens/shutter combination, measure all your filmholders with micrometers, measure all your light meters against some calibrated standard (?), measure your developer with a pH meter, etc etc etc. You'd never have time to take any pictures. If you can focus on the groundglass and your pictures come out sharp, that's all it takes. If you take a meter reading and come out with a decent negative and print, that's all it takes. If you want to apply some tilt, the groundglass will tell you when it's right, you don't need cheat sheets and computers and Scheimpflug books - your eyeball is accurate if you trust it. Keep it simple and enjoyable.
-- Steve Gangi (email@example.com), April 01, 2002.
You may have to adjust your scale a bit after you get the likes of a Sironar or XL lens. (either include values over 10, or shift them all down just a bit) ....That has been my experience anyway.
-- Gary Frost (firstname.lastname@example.org), April 02, 2002.
After shooting large format professionally for 25 years, I considered I have mastered the technique of large format camera, recently starting to shoot with a 4x5 scanning back, what an eye opener, focusing error is more common than you think, images that look perfectly sharp on film can be soft in digital, every time you open an image in photoshop you are basically looking at the file with a microscope, no lupe can even compare, that why the manufacturer supply a focusing aid with the back. No more doubts with film flatness, focus shift when stopping down etc, the other things is I have to throw away my fresnel lens behind my ground glass, its just too vague.
-- ka yeung (Ka@kayeung.com), April 04, 2002.
Hey Ka better yet, get a medium format and get rid of the LF, even better yet give it to me and I will make sure is vanished! As a matter of fact lets all call Kodak and Ilford and Bergger and tell them not to make film anymore, the LF digital back is here and we dont need that pesky terrible film.....and to please forward me ASAP a 12x20 back....
-- Jorge Gasteazoro (email@example.com), April 04, 2002.
If the image looks sharp on the film and print or at a *reasonable* magnification, isn't that good enough? I've read plenty about digital backs, and seen some results, and I still don't believe all the hype. What is the point of zooming in 100,000,000:1 (or whatever) in Photoshop or some other program? It serves no purpose. All you see is pixels.
-- Steve Gangi (firstname.lastname@example.org), April 06, 2002.
Hi Julio. I agree that the best designed holders around (short of the Sinar preci$ion ..... kerching!) are the Linhof ones. Why no-one else has produced a holder with a sprung pressure plate, I don't know. Beware those old Linhof holders though. The one I have has warped a little and is way beyond that 1 thou tolerance now. I came across another recently, old but unused, still in its cardboard package, and the plastic had shifted so much that even a quick glance showed it was way out of spec. Shame :-(
-- Pete Andrews (email@example.com), April 09, 2002.
Those are NOT a pressure plate. Linhof Double Cut Sheet Holders were very precise but had no moving plate in them.
Linhof Double Cutfilm/Plate holders are the ones with the spring loaded plate and the ejector mechanism. The plate was not designed to be and did not act as a pressure plate. The plate adjusted the holder for the difference in thickness between a thick glass plat and a piece of sheet film (what would a pressure plate exert pressure upon in the middle of a sheet of film anyway)? These holders also had an ejector lever to ease the glass plate out of the holder so it would not scratch from a finger nail trying to pry it out. Fortunately it also ejected sheet film but was not made for sheet material.
While Linhof always enjoyed a very good reputation for film flatness and consistency with their Super Cutfilm Holders there is no gain in flatness or consistenancy by using the thicker, heavier and more expensive Linhof Double Cutfilm/Plate holders. All are now discontinued and out of production and out of stock.
-- Bob Salomon (firstname.lastname@example.org), April 09, 2002.