2 lens questions: Heliar, Eurynar

[goamules]

On bloom, I have a Wollensak Velostigmat that is a beautiful purple. Not knowing much about coatings (I have no modern lenses except a 1948 Ektar 127mm) I assumed it was coated. But I noted it doesn't have the "circle W" symbol, and is pretty light colored. I assume that it's bloom also.....

[Glenn Thoreson]

Studying the picture of the Heliar leads me to be pretty certain that is not a balsam fault. It looks to me like a good sized fungus growing in there. I now have two Eurynars. Both uncoated. I have since run across several other folks who have coated examples.

[Bernard Kaye]

Antonio, Careful exposure to sunlight will kill fungus, if that is what it is. I used a shorter, uncoated Heliar, do not know if it was a Dynar or Heliar but the result with color negative film was beautiful and like a good beer, full bodied.

Regards
Bernie Kaye

[Antonio Corcuera]

Thanks Bernie & Glenn. Not long after the original post, I tried the lens and the fungus didn't affect the image quality at all.

[Gene McCluney]

Guys, separations can be a real problem. I have a 25/1.4 Cine Ektar II. The 25-15 w/a converter that came with it is separated, shows very strong Newton's rings. These are visible through the camera's finder and showed up on the test footage I shot with it.

Your lens is a very short focal length lens (wide angle) and anything on the surfaces is more likely to be imaged on the film. Long focal length lenses such as the Heliar discussed here can not, even with stopping all the way down, image surface flaws, rather the only effect would be loss of contrast, or softness of the image.

[Dan Fromm]

Interesting assertion, Gene. Please explain further.

I ask because my little 25/1.4 + converter's front surface is more focal lengths in front of the film than that of a lens of normal construction, such as a Heliar.