Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!

SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Fast UV -treatment on yellowed lenses?
View previous topic :: View next topic  


PostPosted: Tue Feb 17, 2009 5:21 pm    Post subject: Reply with quote

It seems, that different 50/1.8 Pancolars use different optical scheme:







so they can be build in different way...


PostPosted: Tue Feb 17, 2009 5:28 pm    Post subject: Reply with quote

Yes, No-X, you're right.

And the front elements (can be yellow too) are glue in all the shames.

Thank you, very much.

Rino.


PostPosted: Sun Mar 01, 2009 10:43 am    Post subject: Reply with quote

Could I ask Pancolar zebra owners for the serial numbers? I saw only 3 samples, but it seems, that the thoriated version is older:

85 - thoriated (yellow)
87 - clear
92 - clear

all of them are "aus Jena"


PostPosted: Sun Mar 01, 2009 1:05 pm    Post subject: Reply with quote

As I post before in this topic, I have a black "Aus Jena" panc 1,8/50 N 10.0xx.xxx that was yellow/green, dark one and the pics with it were all yellow, brown and green colors. Desaster!!

UV and OK. But it seems that the thoriated element not only in zebra ones.

As you said, between the glued elements (front group, 2/3 element's glue), the lens was so so dark yellow/green.

There are certain similarities between Pentax and CZJ (not only between them), and the use of thoriated element/s is one of them.

I suppose that the use of them extended in the time, on the part of CZJ, to compete in the outer market with Pentax. Perhaps this explained why the yellows copies are, mainly, in the "Aus Jena" ones (to be exported).

Rino.


PostPosted: Sun May 03, 2009 10:59 pm    Post subject: What Kind of UV Lamp ? Reply with quote

Hi ppl,
sorry my english, I'm brazillian


I went to buy an UV lamp and the guy asked me what did I want to do with UV.
I suppose there's many things you do with UV lamps... not only cleanning glasses.


So, what kind of UV lamp works at cleaning lenses? Any UV-lamp can "de-yellow" lens ?

There was germicid lamps also..



thank you!


PostPosted: Sun May 03, 2009 11:40 pm    Post subject: Reply with quote

no-X wrote:
Could I ask Pancolar zebra owners for the serial numbers? I saw only 3 samples, but it seems, that the thoriated version is older:

85 - thoriated (yellow)
87 - clear
92 - clear

all of them are "aus Jena"


Mine is zebra Carl Zeiss Jena (not aus Jena) #853xxxxx and it's thoriated.



PostPosted: Mon May 04, 2009 5:38 am    Post subject: Reply with quote

Welcome Pedro
I would imagine in Brazil you could just leave it in the sun for a couple of weeks.


patrickh


PostPosted: Tue May 05, 2009 9:42 am    Post subject: Reply with quote

patrickh wrote:
Welcome Pedro
I would imagine in Brazil you could just leave it in the sun for a couple of weeks.


patrickh


Thanks patrickh,
but I don't have much time to "baby sitting" my lens.

Last time I did that, the sun went down and I didn't moved the lens to pass the UV through the glasses. The result was that the focus moved to inside the lens... and kind of melt down the lens internal surface .. you understand?

Let me be clerar.
The sun rays was crossing all glasses. Then the sun moved down and the focus went to inside the lens, to that part of the lens that is dark to avoid light reflex inside the lens. So that part melted down. you know?


I have to be right here all day rotating the lens so the UV can cross all glass.
And I spend all day at university.


Then the UV lamps would be welcome because I wouldn't worry about this issue. you understand?


Sorry for my english and Thank You !!


PostPosted: Tue May 05, 2009 9:56 am    Post subject: Reply with quote

Pedro Vilas Boas wrote:
Last time I did that, the sun went down and I didn't moved the lens to pass the UV through the glasses. The result was that the focus moved to inside the lens... and kind of melt down the lens internal surface .. you understand?

You could disassemble the lens, remove the thoriated glass and leave it sunbathing a few days outside.

That's what I did with my Pentax 50mm.


PostPosted: Tue May 05, 2009 3:39 pm    Post subject: Reply with quote

Pedro
Embarassed Embarassed Embarassed I am retired and did exactly that.


patrickh


PostPosted: Fri May 15, 2009 9:34 am    Post subject: Reply with quote

Just to ask.... I'm thinking of UV-bleaching my S-M-C 135/3.5 since it's the one that is mostly affected by a loss of around 1.5 stops from the yellowing....

Im on the impression that originally Asahi lenses should had a cold colour cast , the opposite of the aged lens today..

My question is that after the UV treatment did the Taks lost the any of the characteristic of what all this years Asahi lenses were known for and makes them unique do their colours look less saturated or do the contrast have increased.... or their sharpness by any chance?!?!