51–60 of 64 posts
Don't forget to make it radioactive!
This is a thing in vintage lenses: https://camerapedia.fandom.com/wiki/Radioactive_lenses I own a Super-Multi-Coated Takumar 50mm f/1.4 and can confirm that the glass browns with age. UV exposure (sunlight) does clear it some.
I was challenged to make a lens for a friend without buying any new optical elements. I have a pile of glass that I've salvaged from old camera lenses that I've modified. I wanted to make a cooke triplet but didn't have any negative elements on hand where I precisely knew their characteristics. I then realized that my eye glasses are relatively well characterized negative lenses, so I had an optometrist cut them into…
i remember making my own camera in the mid 1970s. the lens was one of those crappy macro things you could screw onto a proper slr lens, and the film was actually photographic printing paper. the body was cardboard and tape, and the shutter a bit of cloth. after you had taken a pic, you had to rush into the darkroom, develop the paper and then reverse print it (cannot remember how, or even if i did). all a bit weird,…
It’s a great way both to explain the whole premise behind photography (your fancy camera and lens is just an elaborate way to project an image onto a bit of light-sensitive stuff that you otherwise keep in the dark) and to give students some early hands-on experience developing prints without all the intervening steps involved in making a print from film.
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Why would you use ML to develop well understood formulas from first principle, if you can also have a properly developed program for the same purpose?
I think the ML that the desktop is for, and the optical calculations, are 2 unrelated projects.
The answer was the worlds fastest super computer at the time. I was a bit shocked that he claimed that was the state of the art for lens manufacture in industry too - no idea how true that was. But figured that if you needed that much computation it made sense.
Well I have 2x that under my desk now and I use it to do local development before I push to cloud machines with 100x the power where the actual work happens.
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If you'd like to e.g. crop a vertical frame out of a horizontally framed picture, the sharpness limitations of old lenses also become immediately obvious. Even many newer lenses immediately fail.
Really? Never had the problem, and I print up to A3, even have a A1 sized print from a D70 and a old 18-85 (?) kit Nikkor, which is sharp enough, with enough resolution, at the edges and corners. If you take a 100% crop from a corner so, well, that is different. I'd argue so, that in this case, you should have composed your shot differently in the field. And again, you have to print huge to actually see the differenc…
I'm primarily doing videography, but most of the vintage lenses I've tested are too soft to crop a 1080p vertical "short"-style video out of a 4K landscape video (even though the landscape video may look fine).
It's not just my old konica minolta lenses, though, the more affordable Sony lenses from 2015 are just as bad.
I'm now using contemporary fujinon cine lenses and they're tack sharp all the way to the edge, even fully open at T/2.8
That said: If you've got hidden gems, or like the less clinical look of vintage lenses, go ahead, have fun!
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I think the ML that the desktop is for, and the optical calculations, are 2 unrelated projects.
Yes, OP was doing linear ray tracing to see how the lens would perform on the video. I remember doing the same in a computational physics class way back in the day and talking to the lecturer about what you'd need to simulate real optics without approximations in the equations. The answer was the worlds fastest super computer at the time. I was a bit shocked that he claimed that was the state of the art for lens manu…
Not entirely surprising. You want to be able to run stuff a bunch of times to optimize it.
https://www.synopsys.com/content/dam/synopsys/optical-soluti...
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You weren't wearing your glasses in real life. That might explain the (apparent) bad performance of the lens compared to simulations? /jk
My dad is giving photography lessons, and one of the constants are people realizing during session one that they, in fact, do need glasses when the autofocus does not agree with their eyes. When I borrow my dads camera for the odd shot at times, I totally relly on AF, if I went by the view finder I am almost blind... Same thing the other way round!
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Sort of. My universe broke when Sigma introduced an 18-35mm f/1.8 zoom. An f/1.8 zoom. Wow. And it was optically brilliant. Seventies lenses are super-sharp, but that's because they're mostly slow primes. Any modern prime stepped down to f/5.6 -- even cheap consumerific ones -- will be super-sharp. There's nothing in seventies technology which allows lenses to have the aperture, zoom range, and aberrations of modern…
Appertures, well, those f2.8 Nikkor telephotos from that period still demand high prices for a reason. And f4.5 isn't that slow, even compared to modern zooms. Or those old 50/1.4 (agreed, the 1.8 versions seem to be tad better) and other 1.8 primes. Still great glass. Or those unaffordable NOCT lenses... Not sure what I would need one for so. What those old lenses have so, is build quality. They are machnical master…
f/2.7, sharp at fully open, parfocal, zero focus breathing, fully manual zoom lenses...
and what used to be...
f/5.6, sharp only when stopped down even further, massive focus breathing, prime lenses...
well, vintage lenses start to look like toys.
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Really? Never had the problem, and I print up to A3, even have a A1 sized print from a D70 and a old 18-85 (?) kit Nikkor, which is sharp enough, with enough resolution, at the edges and corners. If you take a 100% crop from a corner so, well, that is different. I'd argue so, that in this case, you should have composed your shot differently in the field. And again, you have to print huge to actually see the differenc…
Vintage lenses describes an entire category. Not all of them are hidden gems. In fact, the vast majority of them aren't. I'm primarily doing videography, but most of the vintage lenses I've tested are too soft to crop a 1080p vertical "short"-style video out of a 4K landscape video (even though the landscape video may look fine). It's not just my old konica minolta lenses, though, the more affordable Sony lenses from…
And yes, not all vintage lenses are good. One has to go look for the good ones, usually the top line pro lenses of the day, those are still very good.
The one, cardinal thing about gear is so, once it hits a certain threshold of performance, e.g. "good" 4k video, whatever makes you feel good is great gear. Doesn't have to be the newest and shiniest, nor a specific brand or something.
My vintage glass so is neither soft nor sub-par, for my purposes, optically. Well, they do have a certain clarity to them, especially for blavk and white, that I like. I also know it is in my head, as I actually cannot tell those lenses apart from new glass by just looking at the pictures. I do like the incredible mechanical build quality so, they are master pieces of precision mechanics in all metal, and I like that feeling using them.
While not always true, there is a connection between price and quality: cheap / affordable products are generally less good than expensive ones, at the same time there can be incredibly good cheap products and crappy expensive ones, also the expensive ones can be bad value by virtue of being overpriced.
I heard good things about Fujinon, never tried them so.
I was challenged to make a lens for a friend without buying any new optical elements. I have a pile of glass that I've salvaged from old camera lenses that I've modified. I wanted to make a cooke triplet but didn't have any negative elements on hand where I precisely knew their characteristics. I then realized that my eye glasses are relatively well characterized negative lenses, so I had an optometrist cut them into…
I swear the only thing that the Bolte Bridge attracts more of than seagulls is photographers. Also the desktop I have now for ML work is powerful enough to do a full 3d simulation of a lens using the full Maxwell equations from first principles. I remember doing the back of the envelope calculations that I'd need the Bluegene/L back in my undergrad days to do it for real, well: https://bnnbreaking.com/arts/video-gami…