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on Jan 11, 2019 13:19:17 GMT
Last Edit: Jan 11, 2019 13:33:26 GMT by pascalgol
Hello, I just found an old yashica mat em with a yashikor lens at home. In the Internet I have just found out that the yashica mat em was only produced with yashinon lenses, do you have more informations and can help me why my yashica mat em have yashikor lenses? ![]() With kind regards, Pascal Golebiewski |
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on Jan 11, 2019 14:27:05 GMT
Posted: Jan 11, 2019 14:27:05 GMT
A few possibilities:
1. The dress ring with the name on it has been replaced
2. The lenses have been replaced
3. Don't believe everything you read on the internet
You would have to take the rear elements out to tell for sure which lens it is - Yashikors have a single rear element, Yashinons have two elements glued together.
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on Jan 12, 2019 3:27:52 GMT
Posted: Jan 12, 2019 3:27:52 GMT
A few possibilities: 1. The dress ring with the name on it has been replaced 2. The lenses have been replaced 3. Don't believe everything you read on the internet You would have to take the rear elements out to tell for sure which lens it is - Yashikors have a single rear element, Yashinons have two elements glued together.(My enhancement of the last line from peterr)
Another way to tell is without resorting to deconstructing the camera is to look at the reflections in the lens. I think these are all single coated elements, so you should see one reflection in the rear of a Yashikor, and two in the rear of a Yashinon.
PF
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on Jan 12, 2019 9:23:39 GMT
Posted: Jan 12, 2019 9:23:39 GMT
Hadn't thought of that. But I just tried it with my Yashica Mat which has Yashinons and I can only see one reflection from the rear elements. If you open the shutter you can see three - one each for the two front elements plus one for the rear pair. Would it be normal to get a reflection from a cemented joint? It's not something I'm familiar with.
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on Jan 12, 2019 23:09:44 GMT
Last Edit: Jan 13, 2019 21:31:10 GMT by pauls
Each air to glass/ glass to air surface should provide a reflection due to the change in refractive index. A cemented pair doesn't have an air surface at the change but there will still be a change in refractive index so that will also provide a reflection but typically smaller/fainter. In other words, one element should have two reflections, two elements separated by an air gap should throw up 4 reflections and two elements cemented together should have two stronger reflections and one fainter one. Sounds easy but in practice is a lot harder to do if you have never succeeded in the past - here I am speaking from personal experience! There are different ways to go about it. On my Yashica TLR site are photos of how I did it and what to look for. As all Yashica TLR viewing lenses are 3 element, if the taking lens result looks exactly like the viewing lens, the taking lens is also a triplet. If the large reflection in the taking lens is bigger than for the viewing lens and there is a smaller 7th reflection, then it is a Tessar design (Yashinon). BTW, yes you shouldn't believe everything you read on the net but you can positively absolutely believe that every Yashica Mat-EM left the factory with Yashinon lenses. Yashica TLRs share as many parts as possible and therefore it is possible to share and mix parts in many creative ways. It would help to see some photos. |
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