I own a few telescopes from Astro-Physics, each lovingly hand-crafted and hand-figured. One is an oil-space triplet refractor, f/7 and wonderful color correction. For photography, you need a corrector optic to get a larger flat field at the focal plane. That each of the 3 objective lenses (of two different types of glass) are hand figured at the end is just remarkable.. There's theory in the modeling software, and then there's the "practice" of actually being able to fabricate these things to work in the field. I have another telescope from them, really an astrograph -- it's only for photography, never had an eyepiece on it. It's "Honders" design; looks like a reflector-style telescope, but the rear "mirror" is actually a large spherical lens, back silvered. Very nicely color corrected and a very large, flat, focal plane. I talked with Roland Christen at Astro-Physics after he gave a talk at an astrophotography conference. I asked him why the telescope had an aluminum optical tube assembly, rather than some fancy carbon-fiber material that was dimensionally stable with temperature change. He told me that was on purpose; the change in length of the tube as the temperature dropped offsets the corresponding change in the optics! All the fancy optical design tools might give you a great theoretical result, but.. that was something I'm sure was learned the hard way. I love that telescope! f/3.8, 305mm aperture -- very fast and wonderful for astrophotography. Of course, it cost more than my first car; even so, my expectations were exceeded.

Another optics video! Awesome! :))) Please continue this series. I would greatly appreciate seeing how these defects could be improved or eliminated by adding additional elements. Your demonstrations with the simulation software are very clear.

Interesting. I find that I learn more, quicker about the way things work, from discussions of why they don't work so well than from discussions the theoretical optimum.

This is a great video! There are plenty of basic physics presentations on lenses, and some high end presentations, but practically nothing in the middle. While a bit away from electronics, and I'm sure after working forever one of the last things you want to do is more optics work, but I for one would love a series on lenses and optics---optics are often an integral part of electronics, so relevant I think. Maybe something to consider. Thanks for what you have presented, however.

Nice Video about optics . Learned something again

Back in the late 70's early 80's I worked for a company that made optical inspection equipment Though I worked in the mechanical end of things, I had some exposure to the lens design aspect of that business. These lens assemblies had multiple individual lenses and the design process was considerably more complicated because back then the software was arcane and difficult to use, as were the computers it ran on. I think a lot of the lens design was done by experimentation tweaked with analysis. To have had software like you display here would have been a great boon to the design process.

With display technology where it is today. Producing image quality so good that a lot of people in the TV and Film industry should consider moving to radio, is there a way reengineer or tweak a display’s output to compensate for a person decline in vision? Say a person is near sighted and has to wear glasses to watch the giant flat screen. There’s gotta be some way to program the person’s Lens Rx into the displays brain(mcu/mpu/gpu…etc.) to end up with a crisp , clear image on the person’s retina. If that gets gets developed from here, all I ask is to beta test.

nice change of technology keep it up

Interesting video. I’ve simulated a few older lens designs in software a couple of years ago. Learned a lot from it. The software was a java applet, can’t remember who wrote it. What software are you using?

Interesting video , now I think I understand a bit better on how the bokeh works with my large aperture on the SLR. I am still curious for the star light rays with a small exposure, I know it comes from the shutter blades but don’t understand how Does it also mean that most of the point and shoot will have a Plano convex or modified outside surfaces and not a simple lens or due to the small aperture hole and may be fixed distance they work ok Thanks for sharing and have a good one

I love this subject. There seems to come a time in every math/engineer/physicist/polymath, etc.'s life where you can't resist optics. I've been fascinated for a long time, like probably everyone else watching; first with the theory, then my first Newtonian reflector telescope (Dob mounted, ofc, modest means), then having instruments that were precise enough where propagation coefficients mattered, and then finally applying everything learned in projects. From my laser-obsessed friends to my astronomically and photographically inclined self (all EE's and CS's professionally), you can make as many videos on this subject as you like!

For image formation, do we really want distinct parallel rays to be focused on the same spot? I'm confused,

I know in your previous video you said that you kind of got out of this field and don't like to talk about it much, but we're gonna need more optics videos from you.

Aspheric lenses of molded plastics were used in inexpensive cameras by Kodak, Fuji and Polaroid to improve focus

Hi, What were you trying to achieve by using the lenses? And also tell us about the simulation software that you were using.

Optics was so easy in college.. whoops lol