Patents related to photo lenses

Started 8 months ago | Discussions
bclaff Forum Pro • Posts: 10,592
Re: Sigma ART 70mm f2.8 Macro
1

Dibyendu Majumdar wrote:

https://patents.google.com/patent/JP2019144441A/en

Of the 7 examples in this patent 2 were broken and needed repair.

But one of those broken ones turned out to be the lens we were after:

This is the level of fit I like to see.

The link is here .

-- hide signature --

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

bclaff Forum Pro • Posts: 10,592
Re: Sigma ART 105mm f1.4
1

Dibyendu Majumdar wrote:

https://patents.google.com/patent/JP2019144477A/en

Another good match:

Link .

-- hide signature --

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

OP Dibyendu Majumdar Contributing Member • Posts: 766
Re: Sigma ART 50mm f1.4

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/JP2015114366A/en

This fit was no so good as most:

Link .

I've decided this is not a fit for my purposes.

In addition to not matching the construction diagram the patent has an aspherical element whereas the lens does not.

Not sure I uderstood above, as the lens does have an aspherical element.

https://www.sigmaphoto.com/lenses/standard-lenses/50mm-f14-dg-hsm-a

bclaff Forum Pro • Posts: 10,592
Re: Sigma ART 50mm f1.4

Dibyendu Majumdar wrote:

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/JP2015114366A/en

This fit was no so good as most:

Link .

I've decided this is not a fit for my purposes.

In addition to not matching the construction diagram the patent has an aspherical element whereas the lens does not.

Not sure I uderstood above, as the lens does have an aspherical element.

https://www.sigmaphoto.com/lenses/standard-lenses/50mm-f14-dg-hsm-a

My bad. I've been staying up too late!

Regards

-- hide signature --

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

AiryDiscus Senior Member • Posts: 2,161
Re: Leitz 800mm f6.3
1

bclaff wrote:

Dibyendu Majumdar wrote:

I think this one is for the Leica 800mm f6.3 which was one of the earliest 35mm lenses to feature ED like glass.

https://patents.google.com/patent/US3536379A/en

FWIW, the patent specifies f/5.9 but they certain could have reduced the element sizes slight for f/6.3

Play with it here . You can change 01 to 01U to see the unscaled version.

5.9 and 6.3 are not very far apart.  They could under specify the F/# in a "T#" like way.  Or they are leaving margins for coating, there are quite a few opportunities.

bclaff Forum Pro • Posts: 10,592
Re: Sigma ART 35mm f1.2 for mirrorless

Dibyendu Majumdar wrote:

https://patents.google.com/patent/JP2019197125A/en

No joy

-- hide signature --

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

bclaff Forum Pro • Posts: 10,592
Re: Canon FD 55mm f1.2 Aspherical
1

Dibyendu Majumdar wrote:

https://www.j-platpat.inpit.go.jp/c1800/PU/JP-S56-075613/49B016ED576D2562FABA38D9D3D6076A2FFDEF6AA598D83197522E151DDD83F7/11/en

Compare with:

https://global.canon/en/c-museum/product/fd158.html

Actually it's the Canon FD 50mm 1.2L not the 55mm.
You can tell by the angle of view and the patent date is too late for the 55mm.

See https://global.canon/en/c-museum/product/nfd208.html

Link

-- hide signature --

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

bclaff Forum Pro • Posts: 10,592
Re: Sonnar® T* FE 55 mm F1.8 ZA Designed by Sony not Zeiss?
1

Dibyendu Majumdar wrote:

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

Another good  match:

Link

-- hide signature --

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

bclaff Forum Pro • Posts: 10,592
Re: Leica Summicron Mandler 1976
1

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

-- hide signature --

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

AiryDiscus Senior Member • Posts: 2,161
Re: Leica Summicron Mandler 1976

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

With how much distortion?  Odds are pretty good that with the barrel distortion it has the field of view of a 50mm lens, or 50mm +/- some closer tolerance than 2mm.

bclaff Forum Pro • Posts: 10,592
Re: Leica Summicron Mandler 1976

AiryDiscus wrote:

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

With how much distortion? Odds are pretty good that with the barrel distortion it has the field of view of a 50mm lens, or 50mm +/- some closer tolerance than 2mm.

Go to the Optical Bench (follow the link) and turn on "SurfaceI" to see the curvature of field.

For more information you'll need to try a more sophisticated program.

-- hide signature --

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

AiryDiscus Senior Member • Posts: 2,161
Re: Leica Summicron Mandler 1976

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

With how much distortion? Odds are pretty good that with the barrel distortion it has the field of view of a 50mm lens, or 50mm +/- some closer tolerance than 2mm.

Go to the Optical Bench (follow the link) and turn on "SurfaceI" to see the curvature of field.

For more information you'll need to try a more sophisticated program.

I said distortion not field curvature.

bclaff Forum Pro • Posts: 10,592
Re: Leica Summicron Mandler 1976

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

With how much distortion? Odds are pretty good that with the barrel distortion it has the field of view of a 50mm lens, or 50mm +/- some closer tolerance than 2mm.

For more information you'll need to try a more sophisticated program.

I said distortion not field curvature.

Sure. With a simple geometric ray tracer I'm not sure I can fully answer that question but the 45 degree angle of view in the patent matches up with a 52mm focal length scaling of the 100mm optical prescription.
Wouldn't distortion affect the angle of view? I'm pretty sure I've seen that with some extreme wide angle lenses.

-- hide signature --

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

bclaff Forum Pro • Posts: 10,592
Re: Canon EF 50mm f1.0L
1

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4717245A/en

Here it is:

Note it is also actually 52mm.

Note also there is insufficient precision in the aspherical coefficients to properly trace rays far off the optical axis so it looks (falsely) as if there is bad abberation in the marginal rays.

-- hide signature --

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

AiryDiscus Senior Member • Posts: 2,161
Re: Leica Summicron Mandler 1976

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

With how much distortion? Odds are pretty good that with the barrel distortion it has the field of view of a 50mm lens, or 50mm +/- some closer tolerance than 2mm.

For more information you'll need to try a more sophisticated program.

I said distortion not field curvature.

Sure. With a simple geometric ray tracer I'm not sure I can fully answer that question but the 45 degree angle of view in the patent matches up with a 52mm focal length scaling of the 100mm optical prescription.
Wouldn't distortion affect the angle of view? I'm pretty sure I've seen that with some extreme wide angle lenses.

Distortion is the difference between the paraxial and real image heights, if you tie FoV to a specific image height, then they are coupled that way.  Otherwise, no.

bclaff Forum Pro • Posts: 10,592
Re: Leica Summicron Mandler 1976

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

With how much distortion? Odds are pretty good that with the barrel distortion it has the field of view of a 50mm lens, or 50mm +/- some closer tolerance than 2mm.

For more information you'll need to try a more sophisticated program.

I said distortion not field curvature.

Sure. With a simple geometric ray tracer I'm not sure I can fully answer that question but the 45 degree angle of view in the patent matches up with a 52mm focal length scaling of the 100mm optical prescription.
Wouldn't distortion affect the angle of view? I'm pretty sure I've seen that with some extreme wide angle lenses.

Distortion is the difference between the paraxial and real image heights, if you tie FoV to a specific image height, then they are coupled that way. Otherwise, no.

OK. So with Image Height of 43.2mm and (measured) focal length of 52.02mm trigonometry predicts a 45.10 degree Angle of View.  So the (measured) 45.59 degree measurement indicates a bit of distortion.

-- hide signature --

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

OP Dibyendu Majumdar Contributing Member • Posts: 766
Re: Leica Summicron Mandler 1976

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

According to https://imaging.nikon.com/history/story/0049/index.htm Leica 50mm lenses were really 51.6 mm. And everyone copied that.

AiryDiscus Senior Member • Posts: 2,161
Re: Leica Summicron Mandler 1976

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

With how much distortion? Odds are pretty good that with the barrel distortion it has the field of view of a 50mm lens, or 50mm +/- some closer tolerance than 2mm.

For more information you'll need to try a more sophisticated program.

I said distortion not field curvature.

Sure. With a simple geometric ray tracer I'm not sure I can fully answer that question but the 45 degree angle of view in the patent matches up with a 52mm focal length scaling of the 100mm optical prescription.
Wouldn't distortion affect the angle of view? I'm pretty sure I've seen that with some extreme wide angle lenses.

Distortion is the difference between the paraxial and real image heights, if you tie FoV to a specific image height, then they are coupled that way. Otherwise, no.

OK. So with Image Height of 43.2mm and (measured) focal length of 52.02mm trigonometry predicts a 45.10 degree Angle of View. So the (measured) 45.59 degree measurement indicates a bit of distortion.

Real or paraxial image height?

All "normal" (in the sense of EFL/FoV) double gauss lenses have on the scale of 1-2% distortion.

bclaff Forum Pro • Posts: 10,592
Re: The famous Noctilux 50mm f1.2
1

Dibyendu Majumdar wrote:

This was world's first 35mm lens with aspherical elements - two of them!

https://patents.google.com/patent/US3459468A/en

Also see:

https://www.pacificrimcamera.com/rl/00307/00307.pdf

Unfortunately the Optical Bench doesn't currently handle that form of aspherical equation so I only got this far:

Link

In reality the 1st and last surfaces are aspherical (showing in light blue in the Optical Bench) and the blue on-axis rays would converge better.

-- hide signature --

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

bclaff Forum Pro • Posts: 10,592
Re: Leica Summicron Mandler 1976

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

AiryDiscus wrote:

bclaff wrote:

Dibyendu Majumdar wrote:

https://patents.google.com/patent/US4123144A/en

Officially the Leica Summicron R 50mm f/2

Like many "50mm" lenses it's actually 52mm

With how much distortion? Odds are pretty good that with the barrel distortion it has the field of view of a 50mm lens, or 50mm +/- some closer tolerance than 2mm.

For more information you'll need to try a more sophisticated program.

I said distortion not field curvature.

Sure. With a simple geometric ray tracer I'm not sure I can fully answer that question but the 45 degree angle of view in the patent matches up with a 52mm focal length scaling of the 100mm optical prescription.
Wouldn't distortion affect the angle of view? I'm pretty sure I've seen that with some extreme wide angle lenses.

Distortion is the difference between the paraxial and real image heights, if you tie FoV to a specific image height, then they are coupled that way. Otherwise, no.

OK. So with Image Height of 43.2mm and (measured) focal length of 52.02mm trigonometry predicts a 45.10 degree Angle of View. So the (measured) 45.59 degree measurement indicates a bit of distortion.

Real or paraxial image height?

Does this answer your question?

All "normal" (in the sense of EFL/FoV) double gauss lenses have on the scale of 1-2% distortion.

-- hide signature --

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

Keyboard shortcuts:
FForum MMy threads