Film-Tech Forum ARCHIVE: Kollmorgen lenses

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Posted by Bill Enos (Member # 440) on 02-21-2001, 11:45 PM:

I found these lenses in a box I had ignored for years in the theatre attic
1 Kollmorgen BX241 3 3/4" gold color
1 Kollmorgen Snaplight SeriesII Model BX163
5 1/2" this lens is black and extremely
light weight, feels almost like plastic.
1 Kollmorgen Cinematic 35/70 5" gold color

Anybody know about these lenses? How old are they? Are they considered to be any good? Whatever you know will be appreciated.

Posted by John Pytlak (Member # 331) on 02-22-2001, 06:04 AM:

These old lenses all predate the significant improvements in lens design by Isco and Schneider during the last 20 years. They are likely to have much higher levels of contrast-reducing flare than modern lenses. Focus uniformity may also be poor.

If you compare the lenses to modern lenses using a roll of the SMPTE Projector Alignment Film 35-PA (RP-40), you will see the resolution and focus uniformity are not as good. If you compare the quality using images having a wide range of contrast, the old lenses will look much softer (more flare) and lack the crispness of modern lenses.

Using a roll of SMPTE 35-PA, you should ideally be able to resolve 80 line pairs/mm in the center, and at least 56 line pairs/mm at the corners of the image. Some of these older lenses will be lucky to achieve half of that resolution.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Larry Myers (Member # 738) on 02-22-2001, 07:14 AM:

I just wonder with the mix and match of old lenses vs new lenses, old print stock vs new print stock and old original negative stock vs new original stock if indeed 35mm scope images of today are really as good as 70mm presentations of the 50's and 60's.

If what you say is true. These older lenses are half the resolution of todays lenses, then it would stand to reason with todays improved print and negative stocks, 35mm presentations are at least twice as good as 35mm presentations 20 to 40 years ago.

Although, I haven't seen this improvement in the last several features I have attended. Any idea of how many of these older lenses are still in use?

Larry

Posted by John Walsh (Member # 168) on 02-22-2001, 07:44 AM:

Kollmorgen stopped making lenses for motion picture use in about 1973. I think they still make lenses for instrumentation / scientific applications.

With the invention of the personal computer in about 1978, it became cheap and easy for engineers to play with complex mathematical models. Lens and speaker design were two of the many industries that benefited.

Posted by John Pytlak (Member # 331) on 02-22-2001, 07:52 AM:

The quality that can be achieved on the screen is very dependent on the quality of the original cinematography, and the image area of the film.

Today, many features with digital effects are not done at the highest resolution available because of the expense, and it sometimes shows on the screen. Super-35 cinematography, "done right", can produce excellent scope release prints. Done wrong, the images are grainy and unsharp.

I was especially impressed with the on-screen image quality of "The Thin Red Line" which was shot and presented in 35mm "scope". Images were very sharp and grain-free. I have also looked at 35mm prints from decades ago that my memory said were wonderful, only to see how grainy and unsharp they really were. For example, Hitchcock's "Rear Window" is a wonderful film, but the recent prints (as good as they are) show the limitations of the color negative film and camera lenses of 45 years ago.

Posted by Larry Myers (Member # 738) on 02-22-2001, 08:12 AM:

Well the $64000 question is, what would happen if the "Thin Red Line" was shown with an older lens which measures half the resolution as a newer lenses? Could you see the difference between the older lens and the newer lens in the presentation? Are these older lenses still in use today?

Larry

Posted by Scott Balko (Member # 438) on 02-22-2001, 08:19 AM:

I just recently bought some Isco lenses from Brad and replaced my old Kollmorgen lenses. The difference is day and night. The Kollmorgen lenses were the Super Snaplight 3.75". A direct comparison shows the Kollmorgen lenses to be incredibly inferior to the Isco. Like everybody else says, running both back to back with RP-40, the resolution is much better with the Isco (especially in anamorphic).

Posted by John Pytlak (Member # 331) on 02-22-2001, 08:27 AM:

The answer is that you WILL see the difference. And unfortunately, too many of these old lenses are still in use, even in new theatres.

It's not that the lenses deteriorate with age or use (although some do), but that the technology has gotten so much better:
http://www.kodak.com/country/US/en/motion/newsletters/reel/december99/pytlak.shtml

Posted by Scott Norwood (Member # 30) on 02-22-2001, 08:59 AM:

I agree that lenses have improved substantially over time, but I am still amazed at how good they were even in the early days of still and motion-picture photography.

If you ever get the chance to see an original nitrate print from the silent era, I highly recommend taking advantage of the opportunity. The oldest print that I have personally seen is a 1916 silent short printed on tinted nitrate stock (not Kodak, if I remember correctly) and it was razor sharp when projected with modern lenses. I was blown away by it.

Old lenses seem to vary so much in condition...I have a near-mint B&L scope adapter from the '60s that gives stunning images even on a short throw, while lots of other lenses made in that era are still in use yet are really total junk.

Posted by John Pytlak (Member # 331) on 02-22-2001, 09:42 AM:

The most significant improvements in modern projection lenses have been in the area of anti-reflection coatings to reduce flare, and in much better focus uniformity from center to edge. Modern spherical projection lenses typically have at least 7 to 8 elements to improve focus uniformity and reduce chromatic aberration, whereas old lens designs may have had as few as four. Modern lenses also avoid using cemented elements, which deteriorated with age and heat.

Posted by Larry Myers (Member # 738) on 02-22-2001, 09:44 AM:

My point to all this is, could you not have a excellent quality 35mm scope film using new modern ISCO lenses play against a older 70mm print with a older type lens and have both look about the same using a screen under 1000 sq ft?

It seems to me that the difference between a 35mm scope image and a 70mm flat image is about 2.77 sq inches or about 1.4 average magnification.

An older lens with half the resolution of a modern lens could actually have more image loss then what a 70mm print could make up by size.

The 35mm print in that case might even look better then the 70mm print.

Am I missing something or is it these older lenses really can't be all that bad.

Larry

Posted by John Pytlak (Member # 331) on 02-22-2001, 10:13 AM:

Larry --- what you are missing is the effect of radiant energy on the film. A 70mm print has significant advantages over the same image on 35mm because it spreads the radiant energy of the lamp over a much larger area of film, greatly reducing "focus flutter" --- the rapid "breathing" of the film in the gate as the emulsion absorbs energy and heats to hundreds of degrees 24 times a second.

Check out the excellent paper by Kodak, published in the September 1983 SMPTE Journal: "Projection Performance of Theatrical Motion-Picture Films Using Xenon Short-Arc Lamps" by Paul Preo. The thing that causes problems is the "watts per square millimetre", not the total watts. Spreading the energy of a 6000 watt lamp over a 70mm frame has five times less energy concentration than the same lamp illuminating a 35mm 1.85:1 frame, and three time less than a 35mm scope frame:
http://www.kodak.com/country/US/en/motion/newsletters/reel/december98/pppp.shtml
http://www.kodak.com/country/US/en/motion/newsletters/reel/march99/pytlak.shtml

On a large 1000 square foot screen, the 70mm blow-up will look better than 35mm, mostly because of the reduced heat concentration. Taking your argument further, I'm sure you will agree you'd never try to fill a 1000 square foot screen with a 16mm or Super-8 print, even though the small format prints can look very good on a small screen. Size DOES matter when it comes to filling really big screens.

Posted by Larry Myers (Member # 738) on 02-22-2001, 10:56 AM:

John--- So what your saying is, regardless of what type of lens is being used, old or new, the light or radiant energy issue is more then enough to cancel out any image loss due to poor resolution of an older lens. Even more so with a 35mm vs 70mm presentation.

I never thought of it this way. I always thought of the photographc system as a set of links. That the weakest link controls the system.

Has anybody ever made a math model of the motion picture system. In other words, calculating the MTF of the camera, the MTF of the printing system, and the radiant energy issue plus the MTF of the projection system along with the MTF of the viewer.

It just seems to me that this all can be mixed and matched to come up with a final product.

I guess I am trying to figure out if the projection lens is really a weak link in the system or that the whole system is more or less controlled by the radiant energy issue.

Larry

Posted by John Pytlak (Member # 331) on 02-22-2001, 11:34 AM:

Larry: Since you are a retired CIA image scientist, you certainly should know the science.

Over the years, Kodak has presented quite a few technical papers on the subject of photographic systems modeling. For example, check out the paper "Today's Photographic Imaging Technology for Tomorrow's HDTV System" by Michael A. Kriss and Jeanine Liang, SMPTE Journal, August 1983. Film was ready for HDTV decades ago! Roger Morton of Kodak just presented papers with systems modeling results at last October's SMPTE Technical Conference in Pasadena, and this February's SMPTE Winter Television Conference. Other Kodak researchers included C.N. Nelson, E.C.Doerner, and John C. Norris.

The physics of projection was studied and recommendations for improvement were made by Kodak reseachers like Frederick Kolb, Paul Preo, A.C. Robertson, R.H.Talbot, Ray Estes, E.K.Carver, J.G. Stott, Eric Yavitz, J.R. Turner, etc. Others outside of Kodak like Glenn Berggren and William Borberg also made significant contributions. At the SMPTE Technical Conference last October, I presented a paper and showed a demo clearly showing the advantages of a 1.5X anamorphic system to replace the inefficient 1.85:1 "flat" format --- an idea ("IscoVision") first proposed by Glenn Berggren almost twenty years ago!

The technology to project superb images on huge screens has existed for almost 50 years, and continues to improve. Why don't we use it? Why do we have to ask if a 40 year old lens is "good enough"? Why are labs forced to use a continuous contact printer to print all the intermediate stages? Why do some theatres try to light a 20x48 foot screen with only a 3000 watt lamp? Why do some theatres crop both "flat" and "scope" images to fit a 2:1 screen with fixed masking? Why do EXIT signs still shine on screens?

Hint: Don't blame a lack of good technology.

Posted by Larry Myers (Member # 738) on 02-22-2001, 03:08 PM:

Hi

I am just trying to understand the presentation issues with regard to motion picture photography. In other words, why are things the way they are? The older to newer lens resolution values for projection lenses are of interest to me. Just wondering if they indeed make a big improvement in the system

I can see were radiant energy might be the a fixed value or at least a control value where everything is balanced to it.

I am sure all this has been worked out at sometime by someone. What I didn't realize is, many theaters tend not to conform to any type of standard even though a standard is available. I noticed that the test film your talking about is about $500 although a shorter version is available for about $175.
Actually a test film should be attached to the start of all presentations. How much would this cost at 15 cents a foot. Maybe 5 bucks?

It looks to me that you can have two very different presentations from the very same print.

I blame no one for this. I am just trying to understand it.

Larry

Posted by John Walsh (Member # 168) on 02-22-2001, 03:32 PM:

Actually, the idea of a test film on the beginning is a good one, but that test film (the 35PA) is painstakingly printed on very accurately punched stock from an original. Prints for theaters are 2 or 3 generations removed, using duplicating machines that run at high speed, using film stock that is not punched as accurately.

Although, to answer your real question, many theaters are cheap, plain and simple. I don't mean to be sarcastic, but that's usually the reason. Many times the public will accept lower quality if they don't know better, or there no other theater close by.

In addition to focus, different lamps, lenses, screen types will change the color temptature, requiring a 3-color temp meter (very expensive, $20,000 last time I looked.)

There are some places that do care, but it takes money, and theaters have always been a 'feast-or-famine biz' kind of biz.

I do feel that printing a simple version of a test/alignment film onto the heads or tails (just like the "color-test-girl") would be very beneficial, but no one liked my idea when I suggested it awhile ago (sniff-sniff!) I did make a proposed pattern, if anyone wants to see it.

Posted by Larry Myers (Member # 738) on 02-22-2001, 04:15 PM:

Hi

I am not suggesting that a full blown projector test image be printed on the head of the film. I was just thinking of a simple focus test and maybe a lens test.

In the machinist world you have "go" and "no go" gauges. I am sure the resolution of the print film would support a diffraction pattern that would spell out "go" in focus and "no go" in a defocus condition.

Just a thought.

I am using a Kollomorgen BX241 3.75 inch lens in my system. The same lens listed in the beginning of the post. I am also using a Kollomorgen-ISCO KA298 Anamorphic. Both together have been opticl bench tested at about 125 l/mm at 15 ft. Not bad for an old system and at 15 ft.

I should retest it. At the time only interested in how close I could get the anamorphic to focus and not it's maximum resolution.

Larry

Posted by Scott Norwood (Member # 30) on 02-22-2001, 04:55 PM:

A resolution chart printed on release prints probably wouldn't provide all that much information that would be actually useful due to the problems inherent in high-speed printing. I would like to see VistaVision-style cue marks at the start of each reel, though, with the 1.85, 1.66, and 2.00 framing marks. Obviously, this would be for flat prints only...

Posted by John Pytlak (Member # 331) on 02-22-2001, 06:46 PM:

Larry:
I'm not surprised that you got 115 lp/mm on an optical bench. But when you put that old lens in a projector, it doesn't handle the heat-deformed film image as well as a modern lens, especially at the edges of the image. It likely has a much higher level of optical flare than a modern multi-coated lens. The best system test available today is the SMPTE 35-PA (RP-40) Projector Alignment Film, which puts the entire projection system through its paces for resolution, chromatic aberration, focus uniformity, steadiness, travel ghost, geometric distortion, and image size.

Posted by Larry Myers (Member # 738) on 02-22-2001, 07:23 PM:

Yes, I am sure resolution readings would change with a test in the other direction. My ony reason for the optical bench test is to see just exactly how close I could focus the anamorphic.

Actually, I did get to 12.5 ft before resolution fell off a cliff. I didn't check it the other way. I am sure these lenses are distance dependent and have a peak resolution distance.

The Kollmorgen ISCO KA 298 German made anamorphic was pulled out of a newer bankrupt theater. It does say ISCO on it. Does anyone know the history on this optic?
It looks to me that Kollmorgen and ISCO at least had one lens in common.

I do think that a simple focus test or maybe a Phase Contrast target using the words "go" and "no go" could be done. It would not take any more technology then the digital sound timing data located on the edge of the film.

It would be more or less using a Moire pattern to check focus and lens quality. I guess I am sort of into Moire patterns. They are kind of fun to play around with.

I notice that several people on the net have the newer ISCO MC lenses for sale for about $200 each. I would like to get down to about 3 inches focal length. I just might buy one of these.

Larry

Posted by Paul G. Thompson (Member # 655) on 02-22-2001, 08:29 PM:

Well, those old Kollmorgan lenses make excellent magnifying glasses...when you use one of those to inspect film path around the scanner drum and slit lense target while the film is running, you can verify errors very easily!

Also, you can use them to read the fine print on perscription bottles! (Us old foggies need that....)

You can easily see that steel sliver you ran into your thumb so you can yank it out with a wire cutter, blah blah blah..., and if you are not well-endowed, they can be very handy in the restroom. (Ahem)

Posted by Mark Gulbrandsen (Member # 72) on 02-23-2001, 05:16 PM:

Better yet,
Get a short loop of the Schneider test and target film and use that for the comparison. Its much better that RP-40! There are few lenses out there, including Schneiders, or Iscos, that have an easy time with that film. Everything in the projection chain must be adjusted perfectly. A true acid test film!
Mark @ GTS

Posted by Steve Guttag (Member # 268) on 02-24-2001, 09:03 AM:

The Schneider test film is too black overall. Part of what you are testing is the heat absorbtion of the film.

Now I too have issues with 35-PA not being nearly consistant enough.

Steve

------------------
"Old projectionists never die, they just changeover!"

Posted by Mark Gulbrandsen (Member # 72) on 02-24-2001, 01:09 PM:

Stewve,
Thats the best feature of the Schneider film. It tells you several things. 1. That the film is or is not getting too hot. 2. How good the depth of focus of your lens is. 3. It gives you an idea of how well the lens can control flare. For instance try it woth a Magnacom and you will see what I mean. These have no light baffles at all and the flare is horrible. Indeed the Schneider film is a great acid test that not many systems can project properly. If you utilize this test film to mnimize film flutter as much as possible you WILL have a better projected image!
Mark @ GTS

Posted by Steve Guttag (Member # 268) on 02-24-2001, 05:27 PM:

Mark,

The problem is that it isn't representative of the typical frame...it is too black. Sure it will put the optical system through it's paces and give you more information than 35-PA in some respects, but isn't as good in others.

One of the nice features with it is the grid lines to see geometric distortions caused by the lens and keystone. (SMPTE used to produce a film called 35-FA that had a better grid and was more of a neutral gray).

On your Magnacom tests...have you tried different vintages? For instance, ISCO has two different versions now (Type S and Type-L) that replaced the older Magna-com 65. Schneider still has theirs. Then there are the old Kollmorgan Magna Coms.

A current magnacom or Ulta-Star Zoom Converter (as they are now called) can be a dynamite lens in the proper application.

Steve

------------------
"Old projectionists never die, they just changeover!"

Posted by Mark Gulbrandsen (Member # 72) on 02-24-2001, 06:11 PM:

The magnacoms and zoom convertors can be handy in an emergency but they produce either too much barrel or pincussion distortion depending on which one you go to. IMHO way too much distortion for everyday use. Have tried em and was always disappointed. I have not tried the new variable primes yet, but doesn't look like much more than a standard backup with a zoom converter built in. If Manufacturers correct for all of the distortion in these adaptors no one could afford them and they would contain 20+ elements as do high quality Cinematogaphy zoom lenses. As far as the Magnacoms go they still do not have any light baffles to stop stray reflection within. Henry Greese told me that they do not sell enough of them to make including the baffles economically feesable.
The Schneider film isn't any blacker than say outer space segments in a Star Trek, or Star Wars film. And definately a good deal of Rear Window in I.B. Tech is easily as black as the test film. Thats what makes Rear Window's cinematography so good! Professional lens test projectors used in testing lenses in the shop or laboratory also utilize a black background with white resolution lines and lettering. Several of these use laser cut metal plates that go beyond the resolution of a photoetched version.
Mark @ GTS

Posted by Steve Guttag (Member # 268) on 02-24-2001, 07:26 PM:

So then you haven't tested the new ISCO "zoom converters" aka Magna-coms? And I mean new...at least the Type "S" looks to be of a new design in that the front of it is significantly larger than the magna coms of yesteryear.

As I said before, in the right application, Magna-Coms can be wonderful. Take, for instance, projecting onto a Cinerama Curve screen...what distortion? The picture will start to square up more so than with a conventional lens...sure the sides will pincushion a bit but this is less noticable than the barrel distortion of a conventional lens on horizon lines. In fact, the Zoom Converters are nice on curved screens in general where the radius is less than throw.

As to Schneider's Variable Primes...The claim is that they offer a varible focal length without any of the downfalls of traditional zoom attachments. In fact, Dwight wanted to have the front of the lens say something to the effect of " not a zoom, not a magnacom!" Hence the "variable prime" designator to make it sound somewhat better. Personally, I think they are just too expensive for what they offer, that is the bare minimum of cropping. Now that Schneider and ISCO offer the shorter focal lengths in 2.5mm increments, what is the point? The fringe area caused by the aperture plate spacing from the film plane has a greater effect than the 1mm of focal length difference!

Well those are my opinions and observations.

Steve

------------------
"Old projectionists never die, they just changeover!"

Posted by John Pytlak (Member # 331) on 02-24-2001, 09:24 PM:

Although Mark is correct that the Schneider test film is good at evaluating the "worst case" situation of a silver-image B&W film and high overall density, I agree with Steve that the SMPTE 35-PA (RP40) does a better job of looking at the effect of radiant energy on the focus uniformity of "average" picture material. And in reality, the color (magenta dye) SMPTE 35-IQ film should also be used as a final check:
http://www.schneideroptics.com/projection/testfilm.htm
http://www.smpte.org/testmat/rp40.pdf

Posted by Mark Gulbrandsen (Member # 72) on 02-24-2001, 09:49 PM:

Steve,
I agree with you on the use of a magnacomon a curved screen. The main problem though is of flare. Sharpness and efficiency are not an issue on these lenses. As far as the variable primes are concerned the idea is sound if the distortion is low. Personally the price is way to high for me. I agree that with 2.5mm increments there is not really a need for them. I suppose that for a rental department situation they would be nice though.
Mark @ GTS

Posted by Stefan Scholz (Member # 147) on 02-25-2001, 04:24 AM:

Mark,

I have recently (yesterday) tested the new ISCO Ultra Star HDZoom converter on a Siemens / Bauer U4 projector. With this type of projector, you need to use the converter, as the base lens remains, and only the attachment is changed with the electric turret. The picture looked extremely good, and with RP40 the distortions were not worse than with the other projector's lenses.
Compared to the original black converter that was delivered with the projector, and something called ISCO MagnaCom, the evolution isclearly visible. The two mentioned typed are good for one purpose only - Glass, valuable recycling material.

Posted by Mark Gulbrandsen (Member # 72) on 02-27-2001, 05:43 PM:

Stefan,
I hope that Isco and Schneider don't use recycled coke bottles to make lenses from. That term is common over here when referring to old Kollmorgen or B&L lenses. We call them "Cokebottles"
At any rate it is good to hear that the zoom converters have gotten better than they were. I have used them a couple of times in the past with much disappointment as they always had too much distortion(pincussion I think). I have shyed away from them since. Next time around if I get stuck needing an odd focal length I give them another drive around the block.
Mark @ GTS
Mark

Posted by Larry Myers (Member # 738) on 04-02-2001, 11:01 AM:

Hi

I just purchased a new 2.75 Schneider Super Cinelux on Ebay for $300. It's the same lens that sells for $1600 at your local Cine supply store.

I bench tested this lens against the Kollmorgen lenses. Over all, the Schneider has about twice the contrast and resolution (200+ l/mm vs 100 l/mm) with the Kollmorgens.

Now my problem. My Kollmorgen/ISCO K298 Anamorphic won't fit the threads of the Schneider. I guess I need an adaptor. I may also need a spacer.

Does anyone know what adaptor I need?

Also, does anyone know the history on the Kollmorgen/Isco K298 anamorphic?

Larry

Posted by John Pytlak (Member # 331) on 04-02-2001, 11:20 AM:

At the Academy Scientific and Technical Awards on March 3, both Schneider and IscoOptic were recognized with Technical Achievement Awards:
http://www3.oscars.org/scitech/73/index.html

The Academy citation for IscoOptic states:

"To Glenn M. Berggren for the concept, Horst Linge for research and
development, and Wolfgang Reinecke for the optical design of the ISCO
Ultra-Star Plus lenses for motion picture projection.

The unique optical design of the Ultra-Star Plus projection lenses achieves
unprecedented edge-to-edge uniformity of illumination, combined with a
significant increase in screen brightness, thus providing a substantial
improvement in the cinema viewing experience."

Schneider's said:

"To Udo Schauss, Hildegard Ebbesmeier and Karl Lenhardt for the optical
design, and Ralf Linn and Norbert Brinker for the mechanical design of the
Schneider Super Cinelux lenses for motion picture projection.

These projection lenses provide a significant improvement in the quality of
the cinema viewing experience."

Today's projection lenses offer superb optical performance, and much better image quality than even a few years ago.

Posted by Mark Gulbrandsen (Member # 72) on 04-02-2001, 11:41 AM:

What you need is the Schneider AX-287 Adapter to go to the Kollmorgen Scope lens. The Schneider is threaded at 36 tpi and the Kolmorgen at 32 tpi. List is 80.00 and my price is way-way-far lower than that. If you need one contact me and I can have a new one drop shipped to you.
Mark @ GTS