Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-29-2011, 10:29 PM   #1
New Member




Join Date: May 2010
Location: Hong Kong
Posts: 19
smc takumar 35mm f/2

I have my smc takumar 35mm f/2 arrived last week and when I saw through it...I found a noticeable yellow tint. Are all smc takumar 35mm f/2 having this?

05-29-2011, 10:44 PM   #2
Loyal Site Supporter
SteveM's Avatar

Join Date: Jan 2009
Location: Vancouver Island, BC, Canada
Photos: Gallery
Posts: 3,295
Mine does. It is from the semi radioactive substance they used to be allowed to use in the glass. (not kidding.....but harmless). There are a number of articles here on how to get rid of the yellowing, most of which involve wrapping it in tinfoil (obviously leaving the element clear of the tinfoil), then place it in the sun for a few weeks. The UVs will bleach the elements back to being clear once more.

Cheers,
Steve
05-29-2011, 11:04 PM   #3
New Member




Join Date: May 2010
Location: Hong Kong
Posts: 19
Original Poster
I see thanks a lot smc! The shallow DOF of 35mm is so tempting but I really dislike the yellowing... Not sure whether the K version of 35mm F/2 has this also?
05-30-2011, 05:57 AM   #4
Senior Member
Kim C's Avatar

Join Date: Dec 2006
Location: Lincoln, UK
Photos: Gallery
Posts: 229
No it doesn't

The problem is/was caused by the type of Balsam cement used and it is this which goes yelow. UV light will bleach it clear again so search the yellow issue for the 50/1.4 and you will find lots of advice of how to clear it.

Kim

QuoteOriginally posted by leoyblam Quote
Not sure whether the K version of 35mm F/2 has this also?


05-30-2011, 05:05 PM   #5
New Member




Join Date: May 2010
Location: Hong Kong
Posts: 19
Original Poster
Thanks Kim!
05-31-2011, 02:01 PM   #6
Veteran Member
titrisol's Avatar

Join Date: Dec 2007
Location: In the most populated state... state of denial
Photos: Gallery | Albums
Posts: 1,098
Lucky you!!!
those lenses have such a great reputation.

Leave it in a windowsill for a few days and it will gradually clear
05-31-2011, 03:32 PM   #7
Pentaxian
ChrisPlatt's Avatar

Join Date: Nov 2007
Location: Queens NYC
Posts: 4,859
Radioactive Consumer Products: Thoriated camera lenses

I'm not sure how comprehensive the list on the above webpage is.
The Super-Takumar 35/2.0 lens is included (i.e. it is radioactive),
but the Super-Multi-Coated/SMC Takumar 35/2.0 lens is not.

Chris

Last edited by ChrisPlatt; 05-31-2011 at 06:32 PM.
06-01-2011, 03:17 PM   #8
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,212
Some lenses have a coating with an amber hue on them and they are supposed to be that way. The sun won't change them to clear if that is the case. Just be sure you don't melt some ancient grease and have it running and dripping of the aperture blades.

06-02-2011, 01:28 AM   #9
Senior Member
Kim C's Avatar

Join Date: Dec 2006
Location: Lincoln, UK
Photos: Gallery
Posts: 229
I have both the "large" Super Tak 35/2 which hasn't shown any sign of yellowing and the Super-Multi-Coated/SMC Takumar 35/2.0 lens which is very difinately yellow.

I "suspect" that they used the Thorium element in the small version. the lens diagram for both the small Super tak and the SMC one are the same. I "believe" in most cases, Pentax just applied the SMC coating the the existing range to make them Super Taks.

There were some exceptions to this such as the early Super Tak 50/1.4 which had the extra element but even so the SMC ones are basically the same as the later Super Taks.

Kim

QuoteOriginally posted by ChrisPlatt Quote
Radioactive Consumer Products: Thoriated camera lenses

I'm not sure how comprehensive the list on the above webpage is.
The Super-Takumar 35/2.0 lens is included (i.e. it is radioactive),
but the Super-Multi-Coated/SMC Takumar 35/2.0 lens is not.

Chris
06-02-2011, 05:06 AM   #10
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,212
There were also exceptions with the 28s, 85s, 105s and 135s as well as the slower 35s. Remember that some of the lens coatings were also amber and perhaps even some were purple.

QuoteOriginally posted by Kim C Quote
I have both the "large" Super Tak 35/2 which hasn't shown any sign of yellowing and the Super-Multi-Coated/SMC Takumar 35/2.0 lens which is very difinately yellow.

I "suspect" that they used the Thorium element in the small version. the lens diagram for both the small Super tak and the SMC one are the same. I "believe" in most cases, Pentax just applied the SMC coating the the existing range to make them Super Taks.

There were some exceptions to this such as the early Super Tak 50/1.4 which had the extra element but even so the SMC ones are basically the same as the later Super Taks.

Kim
06-02-2011, 05:21 AM   #11
Senior Member
Kim C's Avatar

Join Date: Dec 2006
Location: Lincoln, UK
Photos: Gallery
Posts: 229
Agreed, but the point I was trying to make was that most of these changes happened within the life of the lens and not on the changeover between Super Tak and S-M-C Pentax were very good at using up "old" parts LOL

Therefore, if the small 35/2 Super Tak had a thorinated element, it is likely that the S-M-C one had.

Kim

QuoteOriginally posted by Blue Quote
There were also exceptions with the 28s, 85s, 105s and 135s as well as the slower 35s. Remember that some of the lens coatings were also amber and perhaps even some were purple.
06-02-2011, 07:21 AM   #12
Site Supporter
boriscleto's Avatar

Join Date: Dec 2009
Location: Liverpool, NY
Photos: Gallery
Posts: 12,869
The only Takumars that were Thoriated were the Super-Takumar 35/2 (49mm filter), the S-M-C Takumar 35/2, the 7-element Super-Takumar 50/1.4, S-M-C Takumar 50/1.4, and the SMC Takumar 50/1.4.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
f/2, smc, smc takumar 35mm, takumar
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: SMC Takumar 35mm f2 With Case (US) germar Sold Items 3 11-07-2010 07:37 AM
For Sale - Sold: s-m-c takumar 85mm/f1.9, s-m-c 35mm/f2, smc-k 50 1.2 and more zhha Sold Items 14 10-03-2010 05:24 PM
Wanted - Acquired: SMC Takumar 35mm f3.5 causey Sold Items 3 09-02-2010 02:49 AM
For Sale - Sold: M42 SMC Takumar 35mm/3.5 (US/CAN) captainslack Sold Items 3 05-04-2010 12:50 PM
For Sale - Sold: SOLD - SMC Takumar 35mm F3.5 for M42 davealta Sold Items 4 09-14-2009 07:16 PM



All times are GMT -7. The time now is 10:57 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top