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06-21-2011, 02:02 AM   #1
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"6 X 7 A" branding

Since my 6X7 Super Takumar 105/2.4 needed some bleaching in the sun (The UV light can reactivate the radioactive coating and thus remove the yellowing color) I clad it in alu-foil to protect the lens from overheating and to reflect the sun rays back out through the glas. Then as I was looking into how the project was working (..and it really does work) I found these letters on the glas. Never noticed them before.

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06-21-2011, 06:44 AM   #2
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I de-yellowed mine and can not find the same type of identification. What lighting did you use to show it up so well? I have seen eyeglasses than have a similar manufacturer mark that shows up with a oblige reflection off the surface.

BTW, it's not a radioactive coating, it's in the make up of the rear glass element itself.
06-21-2011, 06:57 AM   #3
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Yeah, itīs on the rear element, which is also the yellowing one. I found it in the sun light and spend
about a half our to get the angle right for obtaining the shot with my ist DS2, it was kind of tricky.
Thanks for the info on the glass.
06-21-2011, 07:22 AM   #4
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..This photo is shot into the lens, with the alu-foil in the back and thus reflecting the light and it is the rear end, that is foremost towards the view. So it seems to me, that the identification is on the front glass if itīs centered.

06-21-2011, 10:11 AM   #5
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I can't understand why any kind of marking would be on the glass like that intentionally. it is almost like someone screwed up and allowed the end-piece from glass rod to get cut and turned into an element.
06-21-2011, 11:23 AM   #6
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Please excuse the Silly question, but is the rear lens cap is attached?
06-21-2011, 01:34 PM   #7
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QuoteOriginally posted by j.scooter Quote
Please excuse the Silly question, but is the rear lens cap is attached?
What he said.
06-21-2011, 01:43 PM   #8
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Oh flip! Hysterical


Last edited by Blue; 06-27-2011 at 06:30 AM.
06-21-2011, 02:03 PM   #9
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Let me guess- this lens has front bayonet lens cap on it. The inside of cap has those words (for 67mm size cap).
06-21-2011, 04:00 PM   #10
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There is no cap attached. This is a 105/2.4 lens and you are looking through it from the back end
(..that attaches to the camera). I cannot explain where it sits on the glas, as it is not visible when I look through the lens, except as in this case, with alu-foil at the back and reflected sun light from over my shoulder into the lens and back out
06-21-2011, 04:17 PM   #11
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..and I have to correct myself: in my comment #3 ŧitīs on the rear element, which is also the yellowing oneŦ Im wrong I guess or so it seems. In the photo it looks more like the marks are
at the far (front) end of the lens and not the end (yellowing rear glass) pointing out towards the viewer.
06-21-2011, 04:40 PM   #12
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Here at flickr I have posted an uncroped photo, clearly showing that it is the rear end pointing towards the viewer:

(Removed the photo and deleted the link, see end of the thread)

Last edited by jt_cph_dk; 06-27-2011 at 01:37 AM. Reason: (photo removed from flickr, link deleted)
06-21-2011, 08:15 PM   #13
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Check the inside of your caps--front or rear. You will find the answer there. There is no branding on the glass.
06-21-2011, 11:58 PM   #14
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@Yamanobori: Hi, The lens was not caped, when I took the photo. The back ground is the alu-foil.
If you look at the photo on flickr, then you will see, that it looks like that the brand is placed on
one of the middle elements. If not? Then it must be a reflection of some kind from the interior?
06-25-2011, 11:37 AM   #15
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On the inside of one of my front bayonet Takumar lens caps it says "6x7 B" with plastic scratches around it just like in that picture. I think glass etching would look different too.
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