IKOFLEX II

[anthonym3]

I have a question. This is a lever focus serial number 16747. The lens serial number 2020836 dates it at 1937, the compur shutter serial number 1252028 dates it 1929. How is this possible? Also both viewing and taking lens `have an irredescence that appears to be some kind of coating but I didn't think ZEISS lenses of this vintage were coated.

 

[Donald Qualls]

For the last bit, the effects of lens coating were discovered via that "sheen" you're seeing appearing on uncoated glass due to oxidation of doping elements in the glass formula. Lots of better lenses from before WWII developed this, though cleaning often removes it (and it takes many years to come back).

It was also not unheard of for folks with significant investment in a camera to send it to be serviced -- at which time, an older Compur might have replaced the original one, or the lens cells might have been replaced with newer ones. After the War, folks even sent their camera to have things like flash sync added to pre-War shutters or have the lens coated (my Weltini has had both of these done sometime since it was made in 1941).

 

[anthonym3]

For the last bit, the effects of lens coating were discovered via that "sheen" you're seeing appearing on uncoated glass due to oxidation of doping elements in the glass formula. Lots of better lenses from before WWII developed this, though cleaning often removes it (and it takes many years to come back).

It was also not unheard of for folks with significant investment in a camera to send it to be serviced -- at which time, an older Compur might have replaced the original one, or the lens cells might have been replaced with newer ones. After the War, folks even sent their camera to have things like flash sync added to pre-War shutters or have the lens coated (my Weltini has had both of these done sometime since it was made in 1941).

 

[anthonym3]

Thank you!

 

[anthonym3]

For the last bit, the effects of lens coating were discovered via that "sheen" you're seeing appearing on uncoated glass due to oxidation of doping elements in the glass formula. Lots of better lenses from before WWII developed this, though cleaning often removes it (and it takes many years to come back).

It was also not unheard of for folks with significant investment in a camera to send it to be serviced -- at which time, an older Compur might have replaced the original one, or the lens cells might have been replaced with newer ones. After the War, folks even sent their camera to have things like flash sync added to pre-War shutters or have the lens coated (my Weltini has had both of these done sometime since it was made in 1941).I forgot to mention the l

I forgot to mention, the taking lens is 7,5 cm TRIOTAR. I have read that TRIOTAR may have not been ZEISS glass rather another manufacturer.

 

[JPD]

I forgot to mention, the taking lens is 7,5 cm TRIOTAR. I have read that TRIOTAR may have not been ZEISS glass rather another manufacturer.

The Triotar is a Carl Zeiss lens. You are thinking of the Novar.

 

[anthonym3]

The Triotar is a Carl Zeiss lens. You are thinking of the Novar.

85 year old brain fog, the TRIOTAR reads CARL ZEISS. What is your opinion of it and what about the iridescence on the lenses, could they be coated?

 

[JPD]

85 year old brain fog, the TRIOTAR reads CARL ZEISS. What is your opinion of it and what about the iridescence on the lenses, could they be coated?

Iridescence is common on old Triotars and is caused by oxidation of the glass surface, and it's like a "natural coating" that is known to increase contrast somewhat compared to the same type of lens that doesn't have it. Many of the uncoated Triotars on my Rolleicords have this nice iridescent sheen.

I have seen some pre-war Triotars that have been coated after the war and they all had blue reflections.

 

[JPD]

You asked about this in 2019 and must have forgotten about it.

IKOFLEX

I have an IKOFLEX that serial numbers indicate a 1929 manufacture date. Lens serial number 2020836 TRIOTAR 75mm f 1:3.5 ,shutter 1252028.It has a lever focus. In googling information it is described as an IKOFLEX ll however the date given is 1936 onward.What do I have?

www.photrio.com

 

[anthonym3]

Iridescence is common on old Triotars and is caused by oxidation of the glass surface, and it's like a "natural coating" that is known to increase contrast somewhat compared to the same type of lens that doesn't have it. Many of the uncoated Triotars on my Rolleicords have this nice iridescent sheen.

I have seen some pre-war Triotars that have been coated after the war and they all had blue reflections.

Thank you!

 

[anthonym3]

Thank you!

I have received some information however not from any one who has lenses with the coloration. Is it because of unique properties of ZEISS glass of the era? Also I have not yet had film processed, what is your experience with the results from TRIOTARS?

 

[JPD]

I have received some information however not from any one who has lenses with the coloration. Is it because of unique properties of ZEISS glass of the era? Also I have not yet had film processed, what is your experience with the results from TRIOTARS?

No, it can be seen on uncoated lenses from any manufacturer. The Triotar is a very good and versatile lens. Lovely for portraits and group photos at large apertures, and stopped down to f:11 it's very sharp in the center, with some mild aberrations in the corners that gives the lens a very nice character.