Tuesday, April 30, 2019

DIY Red-light Head Light



You might ask, "Who would want a red-light head light?" Well, amateur astronomers, for hands-free seeing at night, especially if they're carrying or handling equipment, such as telescopes. Other night-sky observers might want to wear them for being able to walk around without bumping into people or items, and they can retain night vision while viewing objects, whether through telescopes or binoculars at night-sky watching events.

You might wonder why it's important to use red light at night to see with instead of using other-color light. Red light helps illuminate dark areas without adversely affecting night vision. Eyes need time to adjust to dark surroundings. At night, when someone turns on a non-red light, such as car headlights or white-light flashlight, sky objects become less visible and vibrant until the eyesight becomes re-accustomed to darkness.

A red light head light is a modification of an off-the-shelf elastic headband lamp. (More on acquiring the lamp and similar later.) The bulb itself is white—suitable for normal uses. For astronomy purposes, the light needs to be red.

Step-by-step Modifying Regular Headlight to Red Headlight

The video shows items needed, procedure, and white lightcircle next to red light circle. Items required:
  • Head lamp (Western Safety brand) or similar elastic-band lamp with center bulb
  • Red automotive tail light tape, available at auto parts stores
  • Scissors
Note: The tape should be wider than the diameter of the lamp's screw-on transparent cap. For example, the tape I used was 1 7/8" wide, and the cap was 1 5/8" across. (Ruler in video is for tape width reference.)

Procedure
  1. Unscrew the retainer ring with clear cap from the rest of the lamp.
  2. Separate the clear cap from the ring.
  3. Cut a squarish piece of red tape that overlaps the cap with a reasonable margin all around. In my case, the tape was wider than the cap diameter by only 1/4".
  4. Firmly place the center of the flat part of the cap onto the sticky part of the tape.
  5. With scissors, snip the red tape's corners and sides up to the cap's edge.
  6. Fold and evenly press each of the snipped tape corners to the cap's edge, pressing at opposite corners for evenness in stickiness and surfaces.
  7. Press the retainer ring back onto the cap.
  8. Screw the retainer ring and cap onto the lamp.
For contrast, the video shows red and white flashlight circles side by side.

Getting an Elastic-band Headlight

Western Safety manufactures a headlamp commonly available at Amazon and Harbor Freight. Amazon's price is $1.79, and Harbor Freight's list price is $2.99. For additional types of headlamps, visit Google image offerings.

Some Caveats of the Western Safety Headlamp

You might run into at least one of the following situations if you get headlamps that this company manufactures. The first two items have workarounds.
  • Slots for straps might be wide; straps might loosen from the unit. (Tape the strap pegs together.)

    Related: Contrast two styles of strap retainers and slots.

  • Straps might be short (tight fit) for the wearer. (Stitch an extender, such as a piece of a lanyard or wide ribbon.)

  • Switch sometimes doesn't turn on reliably.
  • Battery cavity can be slightly undersized and batteries not fitting well.

Monday, April 29, 2019

Nandina Domestica—Good, Bad, not Ugly

Out on a walk early February 4, I spotted a plant with striking red berries and vibrant leaves, making me think of Christmas and holly. It was growing wild in a shallow ravine just behind a guard rail.

The weather around that time was surprisingly moderate—mid-60s to 70ish, no precipitation. For that matter, January and February this year seemed mostly pretty springy, with February staying moderate except for about February 8 and 9, when wintery weather came for a short visit.

Took a few pix, then created a composite. Being pretty ignorant about plants, I posted the image to LinkedIn and requested ID help. Happily for me, a connection shortly replied and IDed it as "nandina", enthusiastically embracing its ever greenness and presence in her yard.

That enthusiasm and ID at that time sent me off web-hunting A Google search for "nandina" returned numerous hits that allude to poisonous and invasive properties. Hmmm, maybe nandina has both fans and haters. More on that later.

About a week or so ago, I ran across a copy of native plant species that a blogger friend of mine provided for one of the annual nearby nature walks. One item was "Nandina, heavenly bamboo — Nandina domestica", in the category of "Some Alien Invasive Plant Species ...". ("Alien" and "Invasive" in the same breath don't sound complimentary to me.)

"What Are the Different Types of Nandina Shrubs?" provides a good overview of the plant.
The shrubs are also called heavenly bamboo due to their upright shoots, which resemble those of bamboo, but in fact they're no relation. In U.S. Department of Agriculture plant hardiness zones 6 through 9, where nandina shrubs grow year-round, they can become invasive. ... To help prevent nandinas from taking over your yard, grow nonfruiting varieties. … Nandina leaves and berries are toxic and may be harmful to birds, humans, grazing animals and cats.

"Nandina domestica Heavenly Bamboo" provides both positive and negative points. (BTW, the site's pic at the left side shows just the berries and leaves that are very similar to my pic.)

Good and not Ugly (Upside)
Nandina spreads slowly by underground stems, providing attractive clumps for entryways, containers, or as specimen plantings in a ground cover. They also add an accent to the front of a shrub border when planted in groups or clumps.

Nandina is a low maintenance shrub, requiring only one pruning each year to control plant height, if needed.

Bad (Downside)
Plants have been reported as invasive into selected natural areas in Florida and other southern states.

"Nandina domestica (Heavenly Bamboo)" echoes a similar downside sentiment: "Native to Japan, China and India. Plants tend to be invasive in some southern states".

"Nandina (Nandina domestica)" is a two-minute video that provides good basic description and images of the plant. It, like several resources I've run across, mention the invasiveness.

"Heavenly Bamboo" provides description, pictures, and care information. No downside info. Wonder why? It's a plant vendor. Gave me pause to see the price—$69, considering the one I spotted was growing wild and free.

Additional Resources
  • "Nandina domestica Heavenly bamboo" heavily describes the plant's physical characteristics, propagation means, toxicity to some animals, and difficulty in controlling it. Note the website's name includes "invasives".
  • "Why nandina berries and certain birds don't mix" provides good basic info about nandina with a bit more specifics about the cedar waxwing bird's eating habits that make the berries more dangerous for them than most other animals. The embedded video describes the berries and leaf shape and configuration for those of us curious non-botanists.
  • "Just Try To Kill Nandina!" is an entertaining article that the author seems to both grudgingly admire the nandina for its beauty, yet also disdain the plant's tenacity for survival and propagation.
More Recent Composite, with Flowers

Three months after having taken the February pix, saw flowers and no berries. From "Nandina domestica" WRT order of flowers/berries, "8-15 in. erect panicle of white flowers in early summer; panicle of 0.3 in. bright red berries fall into winter". Panicle's a new term for me! Wisegeek's "What is a Panicle?" explains, "A panicle is a cluster of flowers which grows on the end of a branch or shoot."