| T O P I C R E V I E W |
| Kievuser |
Posted - Oct 05 2008 : 01:58:36 AM
Hi guys,
I have a Tair-3S that is multi-coated with a s/n 9107979. The coating reflecton is green, and I have seen Tair-3S made before and after 1991 that were only coated with a purple colour coating.So is this a rare Tiar-3S?
Thanks,
Zhang |
| 6 L A T E S T R E P L I E S (Newest First) |
| Kievuser |
Posted - Oct 10 2008 : 03:54:51 AM
Hello Luiz and Allain
I agree. I have some old MF Carl Zeiss Jena lenses that look almost like no glasses.:-) The reflaction of light is very, very faint.
Best Regards
Zhang |
| Luiz Paracampo |
Posted - Oct 09 2008 : 10:16:31 AM
Zhang and Allain
I will tell you the truth about coatings.
Single coating is a REFLECTIVE layer of intermediate REFRACTING index air-glass intended to make a 1/4 light wave length interference.
The light reflects in two surfaces with its train of wave lenghts. One of them is totally nullified the others almost nullified but one of them will be reinforced or "ressonant" this will be the most noted colour of the coating, although coatings itself have no colour at all.
The thickness of the coatings will give the apparent colour in the lens. That way, the blue represents the thinnest coatings while the red will be the thickest of them.
Multicoatings do the same with progressive Refracting indexes Thicknesses are controlled to obtain the maximum combination of internal reflections of layers and obtaining the better combination of the red, the green and the blue 1/4 waves. that way, you will note no reflections. So, a good multicoated lens is totally BLACK
You even do not see the glasses of the lenses!
Regards
LP
The great varieties of sold MC lenses does not fulfill what they claim.
LP |
| mermoz37 |
Posted - Oct 07 2008 : 05:08:24 AM
you know ...It is said, good unicoated treatment is better than bad MC technic... |
| Kievuser |
Posted - Oct 07 2008 : 02:41:57 AM
Hi Luiz, alain,
I suspect a different type of glass was used for the MC version. Probably a lower cost one. Or why later lenses returned to single coating when they already made MC version lenses?
Kind Regards
zhang |
| mermoz37 |
Posted - Oct 06 2008 : 11:27:38 AM
I have these two lenses; one on snaiper zenit SDS is green too, and the last one on zenit 412 LS is purple (little yellowish)
I think it was normal product . No ?
alain |
| Luiz Paracampo |
Posted - Oct 06 2008 : 10:19:56 AM
Probably rare!
MC does nor affect performance of telephotos like triplet formulated Tair 3 design.
Regards
LP |
