Zeiss T Coating vs Non Coating

[tromboads]

Being new to the whole zeiss concept of "coatings" Im sure this has been asked here, (my search skills turned up trump)

Has anyone had them side by side and taken a comparison? Id love to see if there is any difference

I have a 60's ALU 50mm 2.8 and it flares like a mofo. Having said that, a carefully placed hand solves that Still... id be interested if the "T" coating does anything... ..

[iangreenhalgh1]

Zeiss lenses have been coated since the late 30s, so I suspect your 60s one has damaged coatings. These 50s and 60s coatings were soft and easily wiped away with improper cleaning, you can find many Biotars with destroyed coatings. If the coating isn't damaged, they don't flare much.

[tromboads]

so I'm referring to the lenses marked with usually a red T or a red C It seems these were promoted as $$$$ end glass with anti-reflective coatings different from a lower range non marked lenses they sold side by side....

[iangreenhalgh1]

No, whether marked with a T or not, they are coated, just a cheaper coating on the non-T ones.

[tromboads]

So back to my initial question.. What difference is there to justify the inclusion of the said red "T" over those without?

[iangreenhalgh1]

I answered it, the T coating was more expensive and better.

[themoleman342]

[jjphoto]

A light source within the image won't benefit from a hood. You need excellent coatings to reduce flare, with or without a hood.

[tromboads]

cheers guys.

[danfromm]

From the VM: "Anti-reflection coating of surfaces began early in the WW2 years, or even in 1938 according to M.J.Small,
and initially was with very thin coats giving a clear blue colour. Some of these were engraved with a statement
to this effect but this was not always done. Thus an 18cm f2.8 Sonnar seems to have this coat at Nr
2,275,07x but no other identification. Here the coat is only on some internal surfaces, possibly as it was very
soft. Another early one was No 2,578,72x, a "T" coated f1.4 Sonnar with Luftwaffe engraving as is
No2,687,21x, a T-coated Sonnar f2/50 (part alloy) for Contax.. This last is blue coated on all surfaces. When
the process became general after the war, the lenses were engraved T with a red fill to show it was original
factory work, and the above Luftwaffe lens may be an early case of this. This was later omitted, when coating
had become universally used, and later still T* engraved as multicoating came in."

[aleksanderpolo]

The C-Sonnar is more flare resistant than the ZM Planar, even though they both have the same coating presumably, so I think lens design is more important. Some non-Zeiss lens, such as the Nikkor 28/2, is also very resistant to flare. So I guess again that while coating helps, the lens design is more important.