Chromatic-aberration-corrected diffractive lenses for ultra-broadband focusing : Scientific Reports. Recent work has suggested the use of metalenses for broadband achromatic focusing1. Here, we show that it is not necessary to invoke concepts of metasurfaces or metalenses to enable such focusing. Scalar diffractive optics, when designed appropriately, can readily enable ultra-broadband achromatic focusing. Such diffractive optics can be far simpler to manufacture and can allow for polarization-independent focusing.
An ideal lens focuses one point in the object space to one point in the image space2. Almost all imaging systems suffer from chromatic aberrations, which means that light of different wavelengths generate focal spots at different spatial locations2. Chromatic aberration is due to either the dispersion properties of the material or the structure of the optic. Normally incident uniform illumination is assumed. Chromatic aberration can be corrected approximately by using materials that exhibit complementary dispersion, as in an achromatic doublet and triplet9,10,11. . This ultra-thin lens could slim your smartphone and camera. New flat lens could change the way cameras are designed A team of engineers at the University of Utah have developed a new method of creating optics which are flat, but are still able to bend light to a single point like traditional lenses.
This breakthrough could allow some cameras to use paper-thin lenses in the near future. The super-achromatic lens is 10 times thinner than the width of a human hair. Photo source: University of Utah. Led by professor Rajesh Menon of the Department of Electrical and Computer Engineering, the research challenges the view that flat, diffractive lenses cannot be corrected for all colors simultaneously. Usually diffractive lenses bend various wavelengths differently, which leads to large chromatic aberrations. What the engineers have created is a super-achromatic lens that’s 10 times thinner than the width of a human hair, and it uses a microstructure-geometry to bring multiple wavelengths to the same focus.
A Coffee with…No. 7 – Becky Ramotowski. After a long, long (too long) break, we continue with our Series “A Coffee with…” where we present analog enthusiasts and their work. Today I am happy to talk with Becky Ramotowski, who has a real passion about pinhole cameras and ‘marinating’ prints in caffenol. Becky also wrote an awesome book about the “Secrets of Stargazing”. If you are interested in Astronomy, I can highly recommend this book! Surprisingly, Becky doesn’t drink coffee but enjoys a good glass of red wine, tea or mountain water… (Which all of makes nice caffeic acid based developer) Becky is also a group admin in our beautiful Caffenol Facebook Group, so if you are a Facebook member, go ahead and join our group. Caffenol: Hi Becky, nice to have you here!
Can you please introduce yourself to our readers: Becky: Hi, my name is Becky Ramotowski, you all might know me as Astro Beck. Caffenol: Anything else you want to add about you as a person? Becky: I grew up in Texas, love football and old cars and pickup trucks. Programming tips, code and tutorials. Article Source(223KB) Nikon Infrared Remote Control I've been wanting to do this project for quite some time but have been waiting for the cooler weather, that's when I do most of my projects. This was one of the first projects on my list because I want to use what I learned here in another more ambitious project that I'll be starting shortly.
The picture below shows the finished product and as you can see there are very few parts and a very simple layout. I'm a software guy if I can do it anyone can. I googled for some C code to use so I wouldn't have to reinvent the wheel but couldn't find any code where timers and interrupts were used. When I first saw the timing image I took off right away and started to code withoug reading the part of the article that mentioned you have to use a 38.4kHz-40kHz modulated frequency in order for it to work which means that whenever the level is high the level will oscillate at a frequency of 38.4KHz which calculates to a width of 25us.
Conclusion. Infrared remote control for Nikon. The story Searching for an alternative to buying an expensive remote control for my Nikon D70, I found a small program for the Palm. It works well, but the Palm isn’t really comfortable for that kind of use. At this point I decided to build a pocket circuit, using a micro-controller, to release the camera’s shutter. The choice of which processor to use was simple: I’ve been working for many years with the ST6 family, but recently, I discovered the AVR micro-controllers. Why not use one of these? It would be a great way to learn how to create a real application with these amazing chips. 01/2012 : I started to work to this project in the far 2005, when the original ML-L3 was very expensive. Some theory Using an infrared demodulator and a digital oscilloscope I captured the wave generated by the Palm.
Figure 1 Note: High levels show when the transmitter’s led is on, low levels when the led is off. Before concluding this paragraph, I must say a few words regarding the transmitter. Hardware.