Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-29-2018, 04:25 AM   #1
Site Supporter
Site Supporter




Join Date: Apr 2015
Location: Winterthur
Posts: 443
7 element Super-Takumar in 8-element body 50/1,4 ???

Just found this Super-Takumar 50/1,4 on ebay.


My guess is, this is a rare version of the 7 element glass in an 8-element body?
What do others think?

Reason:


- I never came across the yellow glass on an 8-element Super-Takumar
- it seems to me the rear glass element is not protruding as it should

see:

How to really identify a early Super Takumar 1.4/50 8 Element - Page 5 - PentaxForums.com
What did I buy? super takumar 50mm 1.4 - PentaxForums.com

of course the infared marker i.e. red line is on the correct place inside the number 4 on the DOF scale which would indicate an 8-element Super-Tak.

If I am right this would have been a left over early body with the later radio active 7-element glass built in?

12-29-2018, 04:34 AM   #2
Pentaxian




Join Date: Jun 2013
Location: Newcastle
Photos: Gallery | Albums
Posts: 1,954
No this is the real deal. To add, the serial number is spot on.

The rear element is exactly how it should be. I think you are put off by the rear element being drawn into the body of the lens.

The yellow you refer to is the coating seen from an oblique view. This is the typical look of this coating for this lens.
12-29-2018, 03:39 PM   #3
PJ1
Site Supporter
Site Supporter
PJ1's Avatar

Join Date: Jul 2012
Location: Mosquito Creek, Australia
Photos: Gallery | Albums
Posts: 2,570
It is definitely an 8 element body as indicated by both the serial number and the position of the IR mark. The rear element only protrudes when the lens is focused at infinity. Unless the focus was changed while the pics were being taken, this lens appears to be focused at 0.8m so the rear element is well inside the body. There is nothing to suggest it is not an 8 element lens.
12-30-2018, 03:12 AM   #4
Site Supporter
Site Supporter




Join Date: Apr 2015
Location: Winterthur
Posts: 443
Original Poster
I am still very uncertain:

Of course the serialnumber and the position of the IR mark indicate the 8-element Takumar.

I have 2 of them here with me and I had 2 more in the past because it is a great lens.
But I also had several 7-element Takumars, all of them had this yellow glass.

The protruding is about the glass of the rear element, not the element itself! Both, the 8-element and the 7-element Takumars have the rear element protruding outside of the main body in the same way.

It is the glass itself which protrudes outside, curves in that way, that you would not be able to place the lens (when focused to infinity) on its backside without the glass touching the surface (and getting scratched or marked).

Compare here again: What did I buy? super takumar 50mm 1.4 - PentaxForums.com

The protruding of the glass is not that clear to be seen.

But this extra mentioning of the yellow straw coating is what is by no means typical for the 8-element Takumar, at least for none of the two I have and none of the two I had
previously! Both had absolutly clear glass.

There never was a yellow coating on Takumars but many had radio active glass (thorium-oxide) which tainted yellow over the time and could be "untainted" by placing it into direct sunlight or another constant UV-light. I have many Takumars with this yellow stain, it is the thorium-oxide for sure. There is no yellow coating!

12-30-2018, 04:09 AM   #5
Pentaxian




Join Date: Jun 2013
Location: Newcastle
Photos: Gallery | Albums
Posts: 1,954
QuoteOriginally posted by photogem Quote
I am still very uncertain:

Of course the serialnumber and the position of the IR mark indicate the 8-element Takumar.

I have 2 of them here with me and I had 2 more in the past because it is a great lens.
But I also had several 7-element Takumars, all of them had this yellow glass.

The protruding is about the glass of the rear element, not the element itself! Both, the 8-element and the 7-element Takumars have the rear element protruding outside of the main body in the same way.

It is the glass itself which protrudes outside, curves in that way, that you would not be able to place the lens (when focused to infinity) on its backside without the glass touching the surface (and getting scratched or marked).

Compare here again: What did I buy? super takumar 50mm 1.4 - PentaxForums.com

The protruding of the glass is not that clear to be seen.

But this extra mentioning of the yellow straw coating is what is by no means typical for the 8-element Takumar, at least for none of the two I have and none of the two I had
previously! Both had absolutly clear glass.

There never was a yellow coating on Takumars but many had radio active glass (thorium-oxide) which tainted yellow over the time and could be "untainted" by placing it into direct sunlight or another constant UV-light. I have many Takumars with this yellow stain, it is the thorium-oxide for sure. There is no yellow coating!
You have been given good advice. If that lens was half the price I would pounce on it.
12-30-2018, 12:37 PM   #6
Pentaxian
ZombieArmy's Avatar

Join Date: Jun 2014
Location: Florida
Posts: 1,644
QuoteOriginally posted by photogem Quote
There never was a yellow coating on Takumars but many had radio active glass (thorium-oxide) which tainted yellow over the time and could be "untainted" by placing it into direct sunlight or another constant UV-light. I have many Takumars with this yellow stain, it is the thorium-oxide for sure. There is no yellow coating!
My Tak 8 element has a yellow looking appearance when viewed at an angle by some light. The glass is completely clear however.

I have the same thing with my Fujinon 55mm.
12-30-2018, 04:45 PM   #7
Pentaxian




Join Date: Jun 2013
Location: Newcastle
Photos: Gallery | Albums
Posts: 1,954
This is a good example of how the coatings change the colour of the elements.

Asahi Pentax Super-Takumar f1.4 50mm Prime Lens M42 UV Treated NEX M4/3 (#3624) | eBay

The front element shows super takumar like coatings. The rear element shows super multi coated like coatings. Neither colour shown is indicative of the 'yellowing' phenomena.

The yellowing phenomena is ONLY evident in one of the elements of the lens. This element is located in the doublet located behind the aperture blades. The yellowing is associated with the presence of thorium (radioactive). This 'yellowing' can be cleared up by exposing the lens to UV light for a period.

The 'yellowing' is not present in eight element lenses as the thoriated element is not part of this design. Rather, the design is based on a triplet thus doing away with the need for a different glass type as needed for the doublet. These elements are clear - always - unless hazed.

Yellowing associated with the thoriated doublet can only be found deep inside the lens - not at the surface. I know this as I have disassembled scores of eight and seven element lenses, cleaned them and done all sorts of things to them. I even tried to put the triplet inside a seven element body in an attempt to upgrade the lens (i.e. surround the triplet with SMC coated surfaces on a SMC variant). This is NOT POSSIBLE as the parts between the seven and eight element lenses are not compatible. You can't even replace the rear element of an eight element lens with that of the first seven element variant (otherwise known as the transition variant where the serial is <2000000 and > 1580000).

Lastly, note the metal annular shroud located on the edge of the rear element of lens shown in the linked 7 element variant. This is classic for 7 element versions. The eight element has no metal shroud. The rear element assembly of the eight element is completely different to the seven element. I know this because I have tried to fix scratched rear elements on the eight element type with the seven element type. Even the thread pitch is different and incompatible.

If you remain unconvinced, then sadly, I have no way of helping you. Best of luck finding one.
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!
8-element, 8-element body, body, element, element super-takumar, glass, k-mount, pentax lens, slr lens, super-takumar, takumar
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Super Takumar 1.4/50mm 8-Element "killer" vs 7-Element Sample Comparison Sliver-Surfer Pentax SLR Lens Discussion 10 10-23-2018 03:11 PM
For Sale - Sold: Super Takumar 50mm f/1.4 8-element, Super Tak 85mm f/1.9, Super Tak 135mm f/2.5 hinman Sold Items 14 09-29-2018 06:31 PM
Sourcing a rear element for an 8-element Super Tak 50/1.4 jtkratzer Pentax SLR Lens Discussion 12 05-31-2018 07:08 PM
7 element super takumar vs 8 element 50 1,4 fikkser Pentax SLR Lens Discussion 3 07-13-2013 07:59 AM



All times are GMT -7. The time now is 06:11 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