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Are Graflex Optars Defective

 

From rec.photo.equipment.large-format:

The Wollensak Optar/Raptar is a defective design. Its not a matter of B&W vs: color but of its fundamental correction. Again, others have found the same thing as I have. You can prove it easily enough to yourself. Use a reasonably good loupe or magnifier, even 3 power is enough. Set up a small bright source. Get it focused at the center of the ground glass, it will be sharp wide open. Then try to focus it at a corner. It will be badly smeared. Close down the diaphragm until it becomes sharp. You will find that the Wollensak does not become at all sharp until closed down to f/22 and there is still some residual smearing visible there. A Kodak Ektar or Zeiss Tessar will be free of this smearing at f/8. I am speaking of 127mm or 135mm lenses on 4x5. I found exactly the same problem with the 101mm, f/4.5 Optar/Raptar as used on 2x3 press cameras, sharp in the center but very excessive coma. It is not a QC problem because it does not vary with individual samples. All of this series have the problem. The same for the Wollensak Enlarging Raptar, they are poorly designed and nearly anything else is better. I have no idea of who designed these lenses for Wollensak. Again, others have observed the same problems.

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My reply was:

I will just say, that is not a defect but a feature. They called the effect luminosity.

I am going to use this as a basis for an article in my press camera webpages as it makes and interesting comment on the difference between lens testers and picture makers.

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And here is is the short article:

You are saying that the designers of the Optar (also known as the Velostigmat and Raptar) did not know what they were doing? You are saying that Wollensack never noticed in the not so short time (1930-1965 or so) they manufactured this lens that their designers had screwed up? Or are you saying that they knew they were producing an inferior product, but just didn't care? I submit that it is more likely that you are missing something, than that the above was true.

Luminosity was an effect that was highly prized back in the 1930's and 40's. It was caused by a bit of bleeding over of the highlights into the shadows. It gave a black and white image a kind of 3D effect. Now those who are familiar with purpose built portrait lenses are familiar with this as a soft-focus effect. Both are caused by uncorrected spherical aberrations. The difference is that the portrait lens does it to the extent that the image is actually very soft to slightly soft. Luminosity is subtler; it varies from slightly soft at wide apertures to not soft at all at smaller ones. My understanding is the Wollensack made Velostigmats (later known as Raptars, and Optars) were designed to provide this effect. By f/16 they were razor sharp, but at wider apertures they were very slightly soft but displayed the luminosity effect quite nicely. Optimum aperture for this effect was usually about f/8. At wider apertures it tended to be over done by my taste. However, in my opinion, it does not seem to work quite so well with color film, as the designed in aberrations tend to cause objectionable color fringing.

Anyway rather than take the word of the "Experts" like Richard, or myself for that matter, why try it out yourself if you have one of these old lenses as many readers of this site do; you may find you like the effect.