SNAFU: Digital or Lens Effect?

[FTQL]

Equipment: Canon FL 135mm at F2.5 with Sony a7ii

Just testing out this portrait/commercial vintage lens of about 1964 design, which has a magenta coating. Behind iron "fences" are bright and dark areas, being a white roof versus tree-leafs. So, in brighter backgrounds, fence turns purplish, and in darker backgrounds, fence's normal grayish color.

Bottom photo taken with 5x IRND filter, with both pics at 300%. Lens wide open in both shots, and when stopped down, everything is OK

Extreme dynamic range, lens flare, chromatic aberration, interpolation algorithm, etc. ???
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[Manfred M]

First of all the lens will not have a magenta coating. Rather it is an anti-reflective coating and the reflected colour that you see is likely just those wavelengths of light bouncing back. I would be suspicious of the 5X filter; while it is not particularly dense, but these types of filters often introduce colour casts and that could be what you are seeing here. The casts tend to be at either end of the visible light spectrum, so the red sensitivity and the blue sensitivity can be affected.

[FTQL]

...lens will not have a magenta coating....

Canon stated this in their literature, "THE CANON SYSTEM OF PHOTOGRAPHY," around 1969 copyright. Coating magenta....

5x IRND filter was for a comparison test. Top photo is without a filter. IRND filter is not related to this topic; both photos show same effect.

[shreds]

With the lens wide open, I would be suspicious of chromatic aberation, especially in a backlit subject. Clearly stopping down eradicates the effect. I have seen exactly this demonstrated on another lens when wide open, despite it being a very high quality lens in other respects.

The answer being to avoid heavily backlit subjects and stopping down in such circumstances. Does your lens combo create the same effect under other lighting conditions?

Obviously a portrait lens wide open is designed to give a nice bokeh effect and throw the background out of focus which is usually the purpose of an aperture of f2.5 in such equipment.

[Manfred M]

Canon stated this in their literature, "THE CANON SYSTEM OF PHOTOGRAPHY," around 1969 copyright. Coating magenta....

That comment continues to puzzle me. One thought that does come to mind is that back in the 1960's Canon was much more of a budget camera / lens brand than it is today, so in order to meet retail price points some interesting design considerations could have been made to keep lens costs down.

If the lens designers used a low cost crown glass which tends to have a slight green colour to it, a magenta coating could have been used to counteract / neutralize the natural green cast of the lens (magenta is the complement of green).

Another thought is that some lenses, especially those designed in the 1950s and possibly into the 1960s were designed to work the B&W film. These films tended to be a bit more sensitive to the blue end of the spectrum, so the red component in a lens coating could have been used to accentuate that end of the spectrum.

[FTQL]

...in the 1960's Canon was much more of a budget camera / lens brand than it is today, so in order to meet retail price points some interesting design considerations could have been made to keep lens costs down....

That lens was for portrait/commercial interests. It has about 210° of focus rotation....one has to nail focus...very fine.

Side notes

1. "Leitz began computer-aided lens computations after about 1960 at their factory in Midland, Ontario, Canada, under the guidance of Dr. Walter Mandler (from Erwin Puts). It is an interesting history of international competition that about this time, Japanese optical companies such as Canon, Nikon, and Topcon were also exploring new lens designs with the aide of early computers. They were able to market lenses with almost as refined optical characteristics as Leica but at lower price. The brilliance of the Japanese companies was to bring superb optics to a wide audience at reasonable price."

2. Wiki - "In 1954, the Japan Camera Industry Association (JCIA) began promoting the development of a high quality photographic industry to increase exports as part of Japan's post-World War II economic recovery. To that end, the Japan Machine Design Center (JMDC) and Japan Camera Inspection Institute (JCII) banned the slavish copying of designs and the export of low quality photographic equipment, enforced by a testing program before issuance of shipping permits.[209][210]"

[FTQL]

With the lens wide open, I would be suspicious of chromatic aberation, especially in a backlit subject.

From this article, "Improve the Level of Detail by Fixing Chromatic Aberration," and looking at upper left railing in first photo, I assumed this might be chromatic aberration. Author suggests Capture One fiddles with this via Bayer interpolation algorithm.

I was thinking about sending this photo to them...but I don't know if lens, camera, or their algorithm is the issue.

Yes, closing down aperture eliminates this issue. I'm only curious as to what it is, nothing more. Thx

[Manfred M]

That lens was for portrait/commercial interests. It has about 210° of focus rotation....one has to nail focus...very fine.

Side notes

1. "Leitz began computer-aided lens computations after about 1960 at their factory in Midland, Ontario, Canada, under the guidance of Dr. Walter Mandler (from Erwin Puts). It is an interesting history of international competition that about this time, Japanese optical companies such as Canon, Nikon, and Topcon were also exploring new lens designs with the aide of early computers. They were able to market lenses with almost as refined optical characteristics as Leica but at lower price. The brilliance of the Japanese companies was to bring superb optics to a wide audience at reasonable price."

2. Wiki - "In 1954, the Japan Camera Industry Association (JCIA) began promoting the development of a high quality photographic industry to increase exports as part of Japan's post-World War II economic recovery. To that end, the Japan Machine Design Center (JMDC) and Japan Camera Inspection Institute (JCII) banned the slavish copying of designs and the export of low quality photographic equipment, enforced by a testing program before issuance of shipping permits.[209][210]"

The side notes are of historical interest but have little to do with the question at hand. Much of the Japanese "revolution" can be traced to J. Edwards Demming's work in Japan in the early 1950s. The plans and revolution did not occur overnight and were the result of Japan's Ministry of Commerce and Industry (which was established in 1949) to concentrate on specific industries (automotive, cameras, electronics, etc). In the 1950's much of the work in the Japanese optical industry was still quite immature and it was well into the late 1950s and early 1960s before the cameras were little more than cheap copies of German designs. Nippon Kōgaku Kōgyō (now called Nikon) was probably the leader in the "pro" field. Canon did not even produce lenses and initially used Nikon lenses on Canon bodies.

So far as I know, neither Nikon nor Canon produced any single lens reflex cameras before 1959, so the lens you are using in a rangefinder lens that would have been designed to sit quite close to the camera's shutter. These lenses were definitely not designed to work with the optical stack found in all modern digital cameras. While the issues are well known when it comes to wide angle lenses, I'm not sure what other impact such an old lens might have with a modern sensor:

http://theonlinephotographer.typepad...o-reasons.html

By the way, a 135mm lens is typically viewed as being a portrait lens and with a 210 degree throw, focus can be hit very accurately. Modern lenses have a much shorter focus throw, which means they tend to be harder to focus manually.

[FTQL]

...question at hand.

See post seven above.

Sidebar:

1. "Canon did not even produce lenses and initially used Nikon lenses on Canon bodies."

Via Canon's literature, I can trace their computer designed lenses happening before 1969.

2. "...well known when it comes to wide angle lenses.... I'm not sure what other impact such an old lens might have with a modern sensor:"

Canon R, FL and FD all had a flange focal distance of 42mm. All adapters I'm aware of, except one, are cut short, including Novoflex for Canon to Nex. c7Adapter has a shimmable flange. I'm not aware of normal perceptible issues with 35mm onward when respectable aperture/shutter speeds are used..

3. "135mm...portrait lens and with a 210 degree throw, focus can be hit very accurately."

Amateur reviewers don't always get the focus right, and then, blah, blah, and blah about their mirrorless to vintage lens shoot.

4. Optical Stack - Interesting, but with 35mm Canon FL lens, I'm not aware of this issue. But, I'm not using a "microscope" to examine.

[xpatUSA]

Manfred said: "135mm...portrait lens and with a 210 degree throw, focus can be hit very accurately."

Amateur reviewers don't always get the focus right, and then, blah, blah, and blah about their mirrorless to vintage lens shoot.

What?

From your earlier comment in post #5 "That lens was for portrait/commercial interests. It has about 210° of focus rotation....one has to nail focus...very fine" - and from your later response above - it is not clear whether you consider a larger rotation easier to focus or not.

Please clarify ...

[William W]

Equipment: Canon FL 135mm at F2.5 with Sony a7ii

Just testing out this portrait/commercial vintage lens of about 1964 design, . . . in brighter backgrounds, fence turns purplish, and in darker backgrounds, fence's normal grayish color.
Bottom photo taken with 5x IRND filter, with both pics at 300%. Lens wide open in both shots, and when stopped down, everything is OK . . .

. . . Yes , closing down aperture eliminates this issue. I'm only curious as to what it is, nothing more. Thx

curious as to what it is, nothing more.

Veiling Flare.

I think that your confusion lead to over-thinking it.

Examine the facts you have gathered:

1. Bright Back-lit areas cause it.
2. Lens is wide open
3. INDR Filter does change it – conclusion: probably not IR Pollution
4. Stopping down fixes it – conclusion, obvious first choice: Veiling Flare

I think that your confusion is being swayed by three facts which are irrelevant:
a) it being an old lens
b) it being a new digital camera
c) the lens having a ‘magenta coating’

I suggest that you keep your analysis simple:

I think that there would be a similar result 50 years ago, using Kodachrome 25.

WW

post scriptum: It is a really it is a nice lens, by the way.
I suggest that you use only Front and Side Lighting for your Portraits.

[rpcrowe]

Manfred is quite correct regarding the advent of SLR cameras from Nikon and Canon...

The early 35mm Canon rangefinder cameras were designed along the lines of the Leica while the early Nikon cameras were designed along the lines of the Contax cameras.

About 1966 or 1967 I went into, Mitsubashi, my local camera store in Yokuska, Japan to purchase a Nikon SLR camera. They were running about $125 USD (after currency conversion at 360 Japanese Yen to the U.S. Dollar).

Unfortunately Mitsubashi had sold out of Nikons so I purchased a Canon FX (I think that the converted price was about $90 USD). I wanted a personal SLR camera because I was leaving for Vietnam the following day. Anyway, I purchase that body and a 50mm lens.


https://en.wikipedia.org/wiki/Canon_FX

It was a fairly nice camera but the mount for the lens was a PITA and would allow all sorts of dirt into the body. One day I was shooting 16mm motion pictures in Dong Ha (up near the DMZ) and I had the Canon FX with me. Dong Ha is the only place that I have ever been in which rain stirs up dust

My Canon FX crapped out on me shortly after I began using it in that harsh environment. The other photographer shooting the job along with me was using a Nikon F. That camera kept on going and going, Just like the Energizer Bunny

BTW: as an aside: The advent of "black" 35mm cameras began (as far as I can tell) during the Vietnam conflict when photojournalists painted the silver colored metal bodies of their cameras black so that the bright camera would not attract the attention of snipers.

Always looking at a way to sell cameras, Japanese camera manufacturers (mainly Nikon and Canon) began producing black camera bodies. They sold well because, every photographer wanted to "look like" a photojournalist!

[shreds]

Some great history in this thread from extremely knowledgeable camera historians….a fascinating read.

Returning to the original questions at the start of the thread, it is possible to create such purple fringing and CA using Nikon's very fine f2 135mm DC lens if shooting backlit subjects into the sun. It has nevertheless been the portrait lens of choice for many Pro's for years and even now continues in such a role. Most Nikon portrait shooters will have one in their armoury even though it is not a budget lens. Quite stunningly sharp lens, (reputed to be one of Nikon's sharpest lenses ever) but knowing how to use it and its distortion control (DC) is an art in itself.

[Manfred M]

Always looking at a way to sell cameras, Japanese camera manufacturers (mainly Nikon and Canon) began producing black camera bodies.

The problem with paint versus chrome was that paint was not nearly as tough as a chrome plating and would chip and wear off. Leica, for instance, used black chrome plating on their camera bodies, rather than paint for that reason.

[Manfred M]

Some great history in this thread from extremely knowledgeable camera historians….a fascinating read.

Returning to the original questions at the start of the thread, it is possible to create such purple fringing and CA using Nikon's very fine f2 135mm DC lens if shooting backlit subjects into the sun. It has nevertheless been the portrait lens of choice for many Pro's for years and even now continues in such a role. Most Nikon portrait shooters will have one in their armoury even though it is not a budget lens. Quite stunningly sharp lens, (reputed to be one of Nikon's sharpest lenses ever) but knowing how to use it and its distortion control (DC) is an art in itself.

As an owner of the Nikkor f/2.8 105mm DC lens, I would have to agree with what you have written (it applies to both the 105 DC and the 135 DC). I believe both lenses were introduced in 1998. The 135 is still in production and the 105 was discontinued a couple of years ago. Having a lens around for 30 years suggests Nikon nailed it with that design.