author

ralph.peteranderl

Inbox View Profile
11Comments

Tell us about yourself!

  • DIY Low Cost Spectrometer

    The width of the aperture of at the front of the spectrometer is a trade-off between spectral resolution (wide opening "smears" out the lines, narrow opening makes nice sharp lines) and sensitivity (The wider the aperture, the more light). Adjusting the width of the slit to the thickness of a sheet of paper will let in very little light, and you might even end up with diffraction from the aperture. I have been using credit cards or similar as a spacer when I made a spectrometer.Also, if you work with kids, two pieces of note cards with a single layer of aluminum foil wrapped over the edges also makes for a good enough aperture

    The spectrum on the box must be a print-out; mostly decorative (The angle over which the spectrum is spread out is just too large)

    Carefull, a CD-R disk will have less resolving power than a DVD-R (The tracks on a DVD-R are closer, so the diffraction effect is larger)

    View Instructable »
  • Photographing Comets From Your Backyard

    Manual focus is really important. At first I used AF with manual over-ride, Looks good when you check out the image at the start of the exposure. But then my camera will try to re-focus and it all turns to blur

    View Instructable »
  • Build UV LED Box for Cyanotypes

    I have tried to do digital negatives on a semi-fancy b&w laser printer before, and it looked horrible. If I were to try it again, I'd start with something smaller than a A3, just to save money. Or get a grey-scale print of one of your pictures on a piece of regular paper before you commit to expensive transparency film. Again, I am really not an expert in this, but the one time I tried it, I had to use the inkjet negative

    View Instructable »
  • Build UV LED Box for Cyanotypes

    Laser prints make horrible digital negatives for this - at least in my experience. Inkjet prints have worked so much better for me

    View Instructable »
  • Hi - This will be too late for your project, but if somebody else sees this:You want to use magnet wire - that is, very thin single strand copper wire with just a thin layer of lacquer as an insulation. Look at the picture for step 3 - the proper wire about the thickness of hair.And no, you cannot use the ready-made inductors. Most of these are build to be used as electronic components, and they are small to fit on circuit boards. A metal detector works by bringing some conductive material into the inside of a coil - the coil of a metal detector is large so that you can test a larger area

    View Instructable »
  • I ended up buying a bundle of laser pointers (Red, green, blue) from a Chinese site on Amazon, and the price was not all that bad.

    Quinine fluorescence is a different mechanism - the electrons in the molecule get bumped up into a higher energy level by the UV or blue light, they loose some energy as heat, and then release the remainder as a fluorescence photon. It seems that people are not quite sure yet how the emission works in carbon quantum dots, but for regular quantum dots the dimensions of the particle determine the wavelength/energy of the photon that can be emitted.

    View Instructable »