A different take on a laser projection microscope

[Dusjagr] has another take on building a laser projection microscope. Last year we saw a laser-based microscope that shined the beam of light through a water droplet which contained the subject to be magnified. The droplet bent the focused beam of light and projected the magnified contents onto a screen. Now that’s pretty neat and [Dusjagr] has used that method himself. But most traditional microscopes use glass slides to contain the subject and this new version now makes that possible.

A bit of experimentation led [Dusjagr] to the discovery that a lens re-purposed from a webcam can achieve similar focus results as a water droplet. The video after the break shows the apparatus seen above in action. The laser shines through the lens, then through a slide that contains a water sample from a nearby pond. The image is clear, albeit completely bathed in green.

For us the most interesting part of [Dusjagr’s] writeup is his discussion of the limits of laser amplification based on the wavelength of light the diode puts out.

Continue reading “A different take on a laser projection microscope”

Disco Death Ray

Wielding the power to melt glass or instantly ignite most day to day materials can be intoxicating pretty fun. With a little math, a lot of patience, and 5,800  1cm pieces of mirror, this build requires welding glasses just to look at the 1-2cm focal point. With an idea rumored to date back to Archimedes, this more portable parabolic project is perfect for your home burning needs. Unfortunately, this setup seems to have burnt itself to death at some point, though that makes room for version two, which will reportedly bump the mirror count to 32,000 or so.

There are plenty of other ways to make a death ray out there as well, including using lasers or lenses. Think you have a better tool of destruction? Be sure to tell us about it.

You know that they say about guys with big lenses?

[Tony Lovell] and [dkpeterborough] built a sizable camera lens using optics from a flight simulator projector. What they ended up with is a 900mm lens that can make a beautiful photo of the moon, or capture distant landscapes in great detail. The body of the lens was designed in CAD and sent off for fabrication out of aluminum, as seen above. The concentric baffles help to prevent lens flare but it can’t be used in its bare-aluminum condition. The internals were coated using a stippling finish that leaves a sandy texture. That was covered with matte black barbecue paint, doing a great job of preventing optical interference, and the outside received a glossy white coat. Finished weight: 59 pounds, but once you see the pictures you’ll agree it’s worth lugging the bulky instrument around to grab that killer shot.

[via Make]

Build a cutting laser from an old PC

[Drake Anthony] makes building a cutting laser from a PC look easy, and it seems like it actually is. Almost everything you need can be found in a dead desktop unit. The diode is pulled from a DVD writer (16x or faster), with the power supply unit, and heat sinks from the processor and GPU being used as well. You’ll also need a focusing lens (just a few dollars), some thermal glue, an LM317, a resistor, and a pair of protective goggles matching the laser diode’s wavelength.

He fits the diode into the lens, then glues the assembly into a hole drilled through the processor heat sink. A driver is built using the LM317 variable regulator, resistor, power supply, and the GPU heat sink to keep things cool. Check out the video after the break to see the laser cutting tape, burning plastic, and lighting matches. Continue reading “Build a cutting laser from an old PC”

Wii sensor bar projector

Having experienced quite a bit of trouble getting the Nintendo Wii remotes to work reliably with his home theater projector, [Sprite_TM] designed his own sensor bar replacement. If you’re not familiar, the Wii remotes have an infrared camera in the tip that sense two IR LEDs in the sensor bar that resides above or below your television. The problem is that if you’re too far away, the points of light are not where the remote expects them to be and the cursor will not perform as expected. Since this is a huge projected display it’s no surprise that the player is further away from the screen than the system was designed for.

[Sprite_TM’s] solution was to build a projection system for the two IR points. The unit in the picture above is a driver circuit with two IR emitters mounted on a heat sink, each with its own reflector. The reflected beams are shined through a Fresnel lens and projected on the same wall as the TV image. The viewer will not be able to see this light as it’s in a longer wavelength than the visible spectrum. But the Wii remote performs beautifully now and the replacement sensor bar is happily mounted out of sight above the projector.

Macro lens for a Nexus One

[Thomas] tipped us off about a macro lens attachment for his Nexus One. As you’d expect, adding the lens helps the phone’s camera bring tiny details into focus. He re-purposed a lens from a pair of mini binoculars, using epoxy putty to make a mounting bracket. Now the last time we saw this putty used with a phone it was for a snap-in bracket that cradled the phone and included a lens adapter. Rather than go that route [Thomas] made use of the headphone jack just above the camera lens. An old headphone plug has been epoxied to the macro lens ring, holding it in place securely while remaining easily removable.

Using quality optics with a webcam

[Devon Croy] built a case to join a webcam sensor with a camera lens. The box is a PVC conduit box you’d find at a home center. He used JB Weld to attach four bolts to the back of the box. These are used to fine-tune the mounting plate for the webcam sensor to ensure it’s at the focal point of the lens. The lens connects through a couple of extension tubes to an adapter mounted in the center of the box’s cover plate. The setup above shows a macro lens that takes pretty good pictures.

If you need images of really tiny things you should look into a microscope adapter for your camera.