Question about the coating mark of Schneider-Kreuznach Lens.

[kevin h. y. lui.]

What is the actual meaning of the red triangle mark on the lens made by

Schneider-Kreuznach? I see some of the Retina IIc/IIIc have while some haven't.

My Retina IIIc does not have too. However, nearly all of the Rolleiflex with

Schneider lens do have the small red triangle. What is that triangle mean?

[colin carron]

Kevin, others may be able to give you a more precise answer but as I understand it the red triangle means that the lens has the Schneider 'Duroplan' coating - a trade name for their single coating at the time. It seems to have begun late 1940's or early 1950's when Schneider wanted to indicate that their lenses were coated. Once coating became commonplace the red triangle disappeared.

 

My 1946 Retina with Xenon 50/2 lens is coated but no red triangle. I wonder if there are any other examples out there to narrow the red triangle time period down. Any idea of the dates of your lenses?

[ben_hutcherson]

According to the Rolleiflex history book I have, which Mr. Kerry Kennedy of this forum so kindly sent me, the red triangle does indeed mean that the lens is coated.

 

With that said, my Rolleiflex Automat 3 and Rolleicord III both have the red triangle, while my Rolleicord Va does not have it.

[dan_fromm2]

Ben, I'm with Colin on this one. After coating was applied by all manufacturers, indicating that a lens was coated got it no advantage in the marketplace.

[kevin h. y. lui.]

I have found 2 Retina IIc in a second hand shop. One has the triangle mark on the lens while the other does not. I am not sure whether the triangle mark's meaning but I am sure their prices have a great difference. Nearly HKD 500 differences.

[thomas_vaehrmann]

Hi Kevin,

 

an old photo-book translated this greek letter as "Duroptan". The dropped it as coating became common.

 

kind regard

 

Thomas