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

Ever wondered how lens radioactive glow looks like?
Post new topic   Reply to topic
Home   Manual Focus Lenses
View previous topic :: View next topic  


PostPosted: Tue Dec 10, 2013 4:13 pm    Post subject: Ever wondered how lens radioactive glow looks like? Reply with quote
Wink See this beautiful aus Jena PANCOLAR 1.4/55mm Click here to see on Ebay.de
While posting still a bargain at 330 EUR.


PostPosted: Tue Dec 10, 2013 6:59 pm    Post subject: Re: Ever wondered how lens radioactive glow looks like? Reply with quote
Pancolart wrote:
Wink See this beautiful aus Jena PANCOLAR 1.4/55mm Click here to see on Ebay.de
While posting still a bargain at 330 EUR.


That's not glow. That's glass discolored by radiation damage.


PostPosted: Wed Dec 11, 2013 3:54 am    Post subject: Re: Ever wondered how lens radioactive glow looks like? Reply with quote
danfromm wrote:
Pancolart wrote:
Wink See this beautiful aus Jena PANCOLAR 1.4/55mm Click here to see on Ebay.de
While posting still a bargain at 330 EUR.


That's not glow. That's glass discolored by radiation damage.

Correction, it's the bonding agent between the cemented elements that's been discoloured from radiation, UV can clean that in many cases.


PostPosted: Wed Dec 11, 2013 1:36 pm    Post subject: Re: Ever wondered how lens radioactive glow looks like? Reply with quote
Lightshow wrote:
danfromm wrote:
Pancolart wrote:
Wink See this beautiful aus Jena PANCOLAR 1.4/55mm Click here to see on Ebay.de
While posting still a bargain at 330 EUR.


That's not glow. That's glass discolored by radiation damage.

Correction, it's the bonding agent between the cemented elements that's been discoloured from radiation, UV can clean that in many cases.


Why do you believe that? See http://home.earthlink.net/~michaelbriggs/aeroektar/aeroektar.html

If you're right, how can you explain radiation damage in Schneider Repro-Claron lenses, which are 4/4 dialyte types? They have no cemented elements.


PostPosted: Wed Dec 11, 2013 1:50 pm    Post subject: Reply with quote
I just see yellow glas?


PostPosted: Wed Dec 11, 2013 1:55 pm    Post subject: Reply with quote
I've owned the Pancolar 1.4/55 and had tried clearing it with a UVA bulb. I've done about 20 1.4/50 Takumars and those clear about 95% in 3 days. The Pancolar sat for more than a month and only cleared about 75%. The same is true for the older 1.8/50 pancolar built around the same time. Later 1.8 Pancolars do not yellow so they changed the thorium content, methinks.

There is something clearly different about the yellowing of the Pancolar vs. Takumar.


PostPosted: Wed Dec 11, 2013 2:07 pm    Post subject: Reply with quote
€513 now, which is a big premium for a built in warm up filter…

I did once have the highly regarded Canon 35/2 concave with the same appearance and, honestly, it wasn't that any better than the nFD 35/2.8 to my eyes.


PostPosted: Wed Dec 11, 2013 2:38 pm    Post subject: Reply with quote
themoleman342 wrote:
Later 1.8 Pancolars do not yellow so they changed the thorium content, methinks.


Yes, I have an MC Pancolar 1.8, and it is not radioactive (I have a dosimeter to measure it with, so not based on speculation about yellowing).


PostPosted: Wed Dec 11, 2013 2:42 pm    Post subject: Reply with quote
themoleman342 wrote:
I've owned the Pancolar 1.4/55 and had tried clearing it with a UVA bulb. I've done about 20 1.4/50 Takumars and those clear about 95% in 3 days. The Pancolar sat for more than a month and only cleared about 75%. The same is true for the older 1.8/50 pancolar built around the same time.


Patience. I've used a 20w BVB bulb to clear three TTH "Apo-tessars" and a 55/8 Repro-Claron. Complete clearing took months.


PostPosted: Wed Dec 11, 2013 2:52 pm    Post subject: Reply with quote
Quote:
Patience. I've used a 20w BVB bulb to clear three TTH "Apo-tessars" and a 55/8 Repro-Claron. Complete clearing took months.


Huh. I saw zero change for the last couple weeks it was under the light so I just stopped. Doesn't matter now. Sold it for something like $900 more than a year ago.


PostPosted: Wed Dec 11, 2013 10:44 pm    Post subject: Re: Ever wondered how lens radioactive glow looks like? Reply with quote
danfromm wrote:
Lightshow wrote:
danfromm wrote:
Pancolart wrote:
Wink See this beautiful aus Jena PANCOLAR 1.4/55mm Click here to see on Ebay.de
While posting still a bargain at 330 EUR.


That's not glow. That's glass discolored by radiation damage.

Correction, it's the bonding agent between the cemented elements that's been discoloured from radiation, UV can clean that in many cases.


Why do you believe that? See http://home.earthlink.net/~michaelbriggs/aeroektar/aeroektar.html

If you're right, how can you explain radiation damage in Schneider Repro-Claron lenses, which are 4/4 dialyte types? They have no cemented elements.

Everything I've read suggested the glue(other than random comments), this is the first I've seen anything that has any merit, so thanks for posting the link, looks like I'll have to do more research on the glass it's self.


PostPosted: Wed Dec 11, 2013 11:31 pm    Post subject: Re: Ever wondered how lens radioactive glow looks like? Reply with quote
Lightshow wrote:

Everything I've read suggested the glue(other than random comments), this is the first I've seen anything that has any merit, so thanks for posting the link, looks like I'll have to do more research on the glass it's self.


There's a lot of nonsense on the Internet. Did you take my point about Repro-Clarons with radiation-darkened elements? That design has no cemented elements, is enough to refute the glue story.
Post new topic   Reply to topic
Home   Manual Focus Lenses
Page 1 of 1