Patents related to photo lenses

Started 9 months ago | Discussions
bclaff Forum Pro • Posts: 10,903
Re: Leitz 50mm f1.4 Summilux-R

Dibyendu Majumdar wrote:

I think this is the original version:

https://patents.google.com/patent/US3552829A/en

JP,47-024417,Y(1972)

Not sure what you mean by "original version" but it doesn't match this:

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Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

OP Dibyendu Majumdar Contributing Member • Posts: 784
Re: Leitz 50mm f1.4 Summilux-R

bclaff wrote:

Dibyendu Majumdar wrote:

I think this is the original version:

https://patents.google.com/patent/US3552829A/en

JP,47-024417,Y(1972)

Not sure what you mean by "original version" but it doesn't match this:

Yes this is the version introduced in the 1990s. It's called the E60 version due to the diameter of its filter. The original is the previous version which was made until mid 1990s.

OP Dibyendu Majumdar Contributing Member • Posts: 784
Re: Leitz 50mm f1.4 Summilux-R

Some more info.

bclaff Forum Pro • Posts: 10,903
Re: Leitz 50mm f1.4 Summilux-R

OK. But I didn't consider it a match to my standards:

US 3,552,829 Example 1

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Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

OP Dibyendu Majumdar Contributing Member • Posts: 784
Re: Leitz 50mm f1.4 Summilux-R

bclaff wrote:

OK. But I didn't consider it a match to my standards:

US 3,552,829 Example 1

Fair enough. This is the best we have unfortunately.

There are other folks who think this patent and its inventor are related to the summilux. For example:

http://www.marcocavina.com/articoli_fotografici/Leitz_Summilux-R_50mm_1,4/00_pag.htm

http://www.l-camera-forum.com/leica-wiki.en/index.php/50mm_f/1.4_Summilux-R_I

https://www.l-camera-forum.com/leica-wiki.en/index.php/Heinz_Marquardt

https://vintage-camera-lenses.com/summilux-r-50mm-1-4-leica-r/

As you know, in my opinion this is the correct patent - despite not matching the production lens exactly.

OP Dibyendu Majumdar Contributing Member • Posts: 784
Leica SL Summicron patent

This looks like related to the Leica SL Summicron lenses:

https://worldwide.espacenet.com/patent/search?q=pn%3DUS2019212531A1

Main innovation appears to be "double focusing" - or use of two different focusing groups internally. This is similar to "multi-focusing" used by Nikon Z lenses.

bclaff Forum Pro • Posts: 10,903
Re: Leica SL Summicron patent

Dibyendu Majumdar wrote:

This looks like related to the Leica SL Summicron lenses:

https://worldwide.espacenet.com/patent/search?q=pn%3DUS2019212531A1

Main innovation appears to be "double focusing" - or use of two different focusing groups internally. This is similar to "multi-focusing" used by Nikon Z lenses.

Yes, looks related; initial indications are not a match for my purposes.

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Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

Erik Kaffehr
Erik Kaffehr Veteran Member • Posts: 4,996
Re: Sonnar® T* FE 55 mm F1.8 ZA Designed by Sony not Zeiss?

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US20150092100A1/en

i don't think the patent covers the main selling point:

Best regards

Erik

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Erik Kaffehr
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OP Dibyendu Majumdar Contributing Member • Posts: 784
Sony FE 20mm f1.8

https://patents.google.com/patent/WO2020213337A1/en

https://www.sony.co.uk/electronics/camera-lenses/sel20f18g

Also describes a 35mm f1.4 that is not exact match for the newly announced lens but looks like it might be related.

bclaff Forum Pro • Posts: 10,903
Re: Sigma ART 28mm f1.4

Dibyendu Majumdar wrote:

https://patents.google.com/patent/JP2019219472A/en

https://www.sigma-global.com/en/lenses/cas/product/art/a_28_14/specifications/

FWIW, I already have that one in the PhotonsToPhotos Optical Hub as Sigma 28mm F1.4 DG HSM A

Although the fit isn't perfect.

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Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

bclaff Forum Pro • Posts: 10,903
Re: Cosina Voigtlander VM 75mm f1.5

Dibyendu Majumdar wrote:

https://patents.google.com/patent/JP2020122918A/en

http://www.cosina.co.jp/seihin/voigtlander/english/e-vm-mount/vm75mm1_5.html

Sadly, not a close as I would like:

Regards

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Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

OP Dibyendu Majumdar Contributing Member • Posts: 784
Cosina Voigtlander SL Macro Apo Lanthar 125 mm f/2.5

Kind of legendary lens renowned for correction of chromatic aberration. I could not find the optical formula online, and neither can I read the patent which is Japanese to verify that it is this one but thought worth posting.

https://worldwide.espacenet.com/patent/search?q=pn%3DJP2002090622A

p.s. Luckily found this:

OP Dibyendu Majumdar Contributing Member • Posts: 784
Cosina Voigtlander Apo-Lanthar 180mm f4
bclaff Forum Pro • Posts: 10,903
Re: Cosina Voigtlander SL Macro Apo Lanthar 125 mm f/2.5

Dibyendu Majumdar wrote:

Kind of legendary lens renowned for correction of chromatic aberration. I could not find the optical formula online, and neither can I read the patent which is Japanese to verify that it is this one but thought worth posting.

https://worldwide.espacenet.com/patent/search?q=pn%3DJP2002090622A

p.s. Luckily found this:

I haven't entered it (yet?) but the diagrams don't look that close.

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Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

bclaff Forum Pro • Posts: 10,903
Re: Cosina Voigtlander Apo-Lanthar 180mm f4

Dibyendu Majumdar wrote:

This one is closer match I think:

https://worldwide.espacenet.com/patent/search?q=pn%3DJP2003270529A

Close but there are some significant spacing issues.

Regards

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Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

OP Dibyendu Majumdar Contributing Member • Posts: 784
Re: Cosina Voigtlander SL Macro Apo Lanthar 125 mm f/2.5

bclaff wrote:

Dibyendu Majumdar wrote:

Kind of legendary lens renowned for correction of chromatic aberration. I could not find the optical formula online, and neither can I read the patent which is Japanese to verify that it is this one but thought worth posting.

https://worldwide.espacenet.com/patent/search?q=pn%3DJP2002090622A

p.s. Luckily found this:

I haven't entered it (yet?) but the diagrams don't look that close.

Yes particularly spacing and the last two elements look different. But believe this is the correct patent, even though the actual production lens appears to be a slightly different arrangement than the one in the patent.

[quote]

The half field angle is 9.8° and the F value is 2.53 when the object is focused at infinity without extending the lens.

OP Dibyendu Majumdar Contributing Member • Posts: 784
Cosina Voigtlander Heliar 12mm f5.6 Aspherical
OP Dibyendu Majumdar Contributing Member • Posts: 784
Cosina Voigtlander Nokton 50mm f1.5 Asph v1

https://worldwide.espacenet.com/patent/search?q=pn%3DJP2000330014A

Again not an exact match of the production lens (aspherical element looks different) but nevertheless seems like the patent is for this lens.

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