Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Sunday, August 31, 2025

Laptop Screen Too Bright During Night Sky Session?


If you do night sky observing or astrophotography, you learn that your eyes adapt to the night sky, but bright lights quickly thwart the vision. Using red lighting is suitable for seeing objects and retaining the night vision. Use a clear plexiglass sheet over a laptop screen to achieve a night-sky user friendly interface.

If using a laptop during a session at night, some software tools have night settings—changing white background to dark, and text to red. The user can vision-adapt to the night sky or continue to not have night vision disturbed. Other nearby astronomers can also be retain their night vision.

Our rather old and lower-end laptop has limited capabilities for night sky adaptations. The keys don't have red displays. The astronomy software tools are not commercially developed specialized packages, but open-source tweak-it-yourself tools.

Our Laptop Screen Fix—Red Overlaying

We picked the clear red plexiglass (details farther down, more elaboration in the YouTube video). The minimal fix would have been to order the best-dimensions pre-cut sheet and simply lay it over the screen.

With an eye for frugality, we trimmed excess height, saving a piece for possible future project(s). With consideration for secure fastening, then drilled small holes for shoelacing the larger piece to the laptop screen. View the video for guidelines on our overlay fix for the laptop screen.

Laptop Screen Overlay Candidates

Online, we researched getting a clear red overlay for placing in front of the laptop screen during astrophotography. Ideas for See-through red screening included the following:

  • Red cellophane that florists use
  • Acrylic sheets from Michael's and Hobby Lobby
  • Acetate (polypropylene) sheets at Michael's
  • Rubylith (photographic plastic)
  • Red tail-light tape
  • Clear red plexiglass

After consideration, most of the items have downsides, which I cover farther down the article. First, the winner!

Clear Red Plexiglass

The fix we chose was a clear red plexiglass from Canal Plastics Center in NY—"Red Transparent Acrylic Sheet" ($3.68 for 6" x 12" x 1/8" initial offering)

Also known as plexiglass, lucite, or perspex, acrylic is a popular and versatile plastic for many applications. It is a common substitute for glass as it is crystal clear, lighter, more shatter resistant and easy to work with. Acrylic sheets can be laser cut or saw cut, as well as machined with routers, drills and sanders.

The webpage provides good pricing info for the multiple precut dimensions and thicknesses. (We picked 12 x 18 for laptop fit.) Other interactive webpage options included custom dimensions, holes, edge finishings, and shipping priorities.

A Close Candidate Red Plastic, But No Cigar

"Lesnlok Red Acrylic Sheets - 1/8" Thick, ..."

Translucent red plexiglass red acrylic,with 2 pieces of red acrylic sheet,This acrylic resin has excellent optical stability and uniform thickness.

The term translucent nudged us away, along with two negative reviews that indicated shortcomings of using the product.

The No-go Reds

The other red transparent items under consideration were food for thought, but didn't seem suitable enough.

Red Cellophane Wrap, Used By Florists

It took some doing to find out what the item was called. Wound up with reasonable finds when googling "Cellophane wrapping paper for floral arrangements" and "floral arrangement red transparent wrapping mylar sheets". AI showed reasonable info for the product—"red transparent wrapping mylar sheets, often called red cellophane wrap"

An Amazon find further helped with info—"Vanhench Red Cellophane Wrapping Paper, ...". Color and transparency were winning points, however, the product looked too flimsy and scrunchy.

Acrylic Sheets from Michael's and Hobby Lobby, Acetate (polypropylene) Sheets at Michael's

These products are bundled with additional color sheets and tend to be smaller than laptop screen sizes. It didn't look feasible to buy package deals to obtain a onesie-twosie (red) item.

Rubylith, Used in Photography Masking

In the distant past, I used rubylith for printed circuit board artwork layout, particularly analog circuitry. Technology has long made manual layout obsolete; however, photographers and artists still buy the product.

Snippet description from "Rubylith"
Rubylith consists of two films sandwiched together. The bottom layer is a clear polyester backing sheet; the top layer is a translucent, red (ruby) coloured sheet. The top layer can be cut and peeled away from the bottom layer.

Idea discarded—

  • Color translucency reduces clarity and readability of screen info.
  • Colored sheet could be easily damaged, letting light bleed through and reducing effectiveness for user.

Red taillight Lens Repair Tape

The tape comes in about 2" width rolls. We considered taping a small piece onto a scrap piece of 7 mil clear mylar to test transparency. Even if the small sample looked OK, idea of pulling and taping SEVERAL aligned rows was not appealing. Also, transparency might less than optimal because of tape's intended use on taillights.

Advisory Webpages for Buying, Cutting, and Drilling Plexiglass

  1. Canal Plastic Center "Red Transparent Acrylic Sheet" (pre-cut 12" x 18" x 1/8" sheet)
  2. "Cut Plexiglass, Acrylic, Plastics with Draw Knife Scoring - Cheap, Fast", 1:49
    My gist: Draw knife, thin plexiglass, main points-draw knife several times on firmly held-down plexiglass (using metal straight edge), then snap.
  3. "How to easily drill plexiglass, lexan and acrylic sheets", 3:10
    My gist: Clamp plexiglass to scrap board, then use step drill or twist drill with tape protection and lubricant. Additional drilling considerations--slowness, light pressure.
  4. "Simple Solutions: Tips for Drilling Through Plexiglass", 0:44
    My gist: Sandwich plexiglass between two layers of quarter-inch plywood ... mark the holes ... line plexiglass with plywood ... drill right through all three layers.

Related: Keyed-in text and image of PLASKOLITE Plastic Cutter for cutting plexiglass.


Want additional astronomy-themed articles? Click for "astro topic" search results in my blog.

Thursday, August 7, 2025

Planisphere, Star Atlas, Stellarium, Oh, My Stars!

Starting out viewing the night sky? This article briefly describes three items recommended for beginner astronomers (recent astronomy club presentation Navigating the Night Sky). Resources for more info follow.

  • Planisphere—a handheld flat, circular item for identifying stars and constellations that are visible in the night sky for specific time and date
  • Star atlas (aka sky atlas)—a map of the night sky, to locate and identify celestial objects. Can be in book or chart form that maps the positions of stars, constellations, and other celestial objects in the night sky.
  • Stellarium—free open-source planetarium software that provides 3D simulation of the night sky

Planisphere, Star/Sky Atlas

This section covers both planispheres and star/sky atlas' because of interrelatedness in Google results.

YouTube video— "How to use a Planisphere" (9:09), latitude version shown—40° to 50°

From video description:

Step by step instructions on using a planisphere for locating objects in the night sky. This is a useful tool in astronomy for locating constellations and other notable features.

Where to buy? Amazon browsing for "planisphere" shows various planispheres and some sky atlas'.

Noteworthy—above webpage includes a link to "Starfinder: The Complete Beginner's Guide to Exploring the Night Sky Hardcover – October 21, 2013" ($25),

Now with removable planisphere!

Where to buy star atlas or sky atlas?
Amazon results for "star atlas"
Amazon results for "sky atlas" (more varieties of offerings)

Prices: From under $10 to astronomical

Stellarium

Stellarium is free software for Windows, Mac, or Linux. Download from main page https://stellarium.org

Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.

Note the system requirements to ensure if you can install on your device.

Read features section to discover sky items to see, when you can see them, and various other info. (Before you look for sky objects, you must set the tool for where you are and the date/time.)

Additional Resources

Visit Cloudy Nights Forum, "Beginner Star Gazing: Planisphere, Star Atlas, or Sky Maps?" for comment and recommendations.

"Want to learn how to stargaze? Here's how to get started in 12 easy steps" provides helpful titled subtopic sections, such as
  • Read beginners' books and online resources
  • Choose your stargazing site
  • Let your eyes adapt to darkness
  • Take time to observe individual stars
  • Spot the planets with your naked eye
  • See how the stars move across the sky
  • Get kids and family involved
  • Learn the constellations and asterisms (informal but recognizable star patterns, which can be part of one or more constellations)

Related: "Constellations and asterisms: what's the difference?"

"How to Stargaze" includes handy titled sections as follows:

Stargazing for Beginners
 Start by Looking Up
 Locate the Big Dipper
  Locate Other Bright Star Patterns
Helpful Stargazing Tools
 Star Charts or Stargazing Apps
 Grab Binoculars
 Borrow a Telescope

Note: If you join Austin Astronomical Society (AAS), you can borrow a telescope. (Membership levels are at "To Join AAS".)

From "Become A Member"

Loaner Scope Program

8″ Dobsonian telescopes with very good eyepieces and all the needed accessories to have a good visual observing experience or to test your next scope upgrade!

Want additional astronomy-themed articles? Click for "astro topic" search results in my blog. Related: Sky/Astronomy Items YouTube playlist

Thursday, May 29, 2025

Sky Objects, Mostly Moon Shots


The pix in my YouTube collection are from having used mostly two point-and-shoot cameras. Incidentally, smart-phone cameras also have capabilities for taking similar sky pix.

For people who haven't considered photographing sky objects, look, up in the sky. It could be Supermoon! Build your own pic collection for day or night moons! Also, pick other sky objects that catch your fancy.

I recently perused my cloud account for pix I've uploaded there within maybe 10 years. One folder that caught my eye—"NearSkyObjects-Canon PowerShot ELPH 190 IS". It consisted of eight images from 2020 and six in 2021. I poked through my computer listings, seeing additional sky images I could include in my slide show.

Most images are of the moon—day, night, various phases. Several are in plant views. The final item is my time-lapse slide show of May 16 2022 lunar eclipse. Final tally of my sky objects for this blog topic is 23. (The count does not include YT videos from 2023 and 2024.)

Want additional astronomy-themed articles? Click for "astro topic" search results in my blog. Related: Sky/Astronomy Items YouTube playlist

Related: 4-sky-objects video—
Sky Objects, Mostly Moon Shots (Minute Teaser)"

Friday, February 28, 2025

Astro Imaging Session Piques Three-item Topic

What arose when the sun set down at the dark site we went to? Dark skies and objects (constellations, star clusters, nebulae, ...) that don't show up well in light-pollution, densely populated areas. What three items am I talking about? A TV tray table, a transparent cookbook stand, and a thin, portable gaming monitor.

In the Beginning (of the Astrophotography Session)

We met with another astronomy photographer (AKA astrophotographer) at a dark site, both parties for a nebula 1000 light years away. Our friend stayed long enough to also photograph a set of galaxies 60 million light years away. BTW, astrophotography is not merely taking one pic and seeing loads of details. Each session for each target tends to take hours, sometimes multiple sessions, specialized equipment for taking out-of-the-world pix, and cooperative climate conditions.

Portable Gaming Monitor

Our friend showed a new acquisition for showing audience members at outreach events—a portable gaming monitor that he read about in a NYT Wirecutter article, maybe "The Best Monitors". Arzopa seems eye-poppingly low cost, compared to other reviewed monitors. "Arzopa Z1FC 144Hz Portable Gaming Monitor Review" lists the measurements as 8.2 by 14.9 by 0.5 inches, weighing 1.7 pounds. (The traditional dimension reference is 16.1 (corner to corner).

Table Slots Between Slats a Hindrance to Stable Monitor Support

Anyway, he is understandably concerned about the monitor's thin foldable corner support falling through slots on his display table (square with narrow gaps between slats). Noting the monitor's thinness, I mentioned having a plastic, transparent cookbook stand that would probably work with such a monitor.

Another idea was trying a different table. I thought of our foldable TV tray table that measures 14.5 x 19 and has no gap hazards. BTW, Google images search shows good results for "acrylic cookbook stands" and "foldable TV trays". BTW, a quick, low-effort, low-cost solution to preventing monitor support fall-through, using a square piece of cardboard the same size as the square table would help.

Music Stand as Monitor Support? Nah!

An idea for stable displaying of the monitor briefly arose—using a music stand. It has variable height and tilt adjustments and horizontal lip. Downsides, however, are heaviness from metal weight and feet that take up space during transport. Furthermore, securing a monitor to avoid tipping or toppling it is concerning.

Musing Monitor Support Using No-slat TV Tray Table and Cookbook Stand

The next day, I thought about taking pix showing my cookbook stand and TV tray table. I took a set of pix—one of the stand (with open book) atop the table, one with additional items, and several showing different-angle views.

It occurred to me that I had the makings of a blog topic that included some idea exchanges about items not specific to astronomy. Also, I got to thinking of how to organize and create a helpful slide-show video.

Besides Monitor Musings

Some additional items in the video are are a yardstick and a set of trekking poles. The yardstick provides dimensional references. The sticks were mentioned during the imaging session. FWIW, a dark site can be challenging for those unfamiliar with the terrain. Even more challenging is navigating after the sun goes down. Better to have sticks and not need them than need them and not have them.

Update: Additional Info After Video's Upload on Feb 28 2025

After publishing the blog article and uploading the movie, our friend sent an image of his table and portable gaming monitor with the monitor's support leg. His fix for possible leg fall-through was a bottle cap.

A bottle cap does the job for the leg and the display is too thick to slide through. The [table's] gap actually cradles the bottom of the display! ... I added a couple of bits of foam insulation to the bottle cap to keep the leg centered in it.

The video's thumbmail shows the initial suggestion, the friend's pic, and additional ideas. The newer items include bungee cords for better securing a monitor for display and avoiding pit falls.




View use of slotted aluminum folding table and bottle cap.

Want additional astronomy-themed articles? Click for "astro topic" search results in my blog. Related: Sky/Astronomy Items YouTube playlist

Tuesday, December 25, 2018

April Fooling Easter Halloween and More

This year's hoppening day was the convergence of April Fool's Day and Easter Sunday, very rare. How rare? From "Easter falls on April Fools Day in 2018: How often does that happen? …":
For the first time since 1956, Easter Sunday falls on April 1 - or April Fool's Day. Since 1900, Easter has fallen on April Fool's Day only four times - 1923, 1934, 1945 and 1956. It won't happen again until 2029. … Easter generally falls between March 22 and April 25 each year. … egg hunts, family gatherings and visits from the Easter Bunny, who leaves treats in children's Easter baskets.
Were-Rabbit for April Fool's Day/Easter Sunday and Halloween

A weirdly appropriate item to use this year was the Burger King Curse of the Were-Rabbit basket, which came out around Halloween 2005. This basket promoted "Wallace & Gromit: The Curse of the Were-Rabbit (2005)".

From "Clay Time: Wallace & Gromit's U.S. Romp" (publish date October 2, 2005):
Wallace and Gromit are asked to protect a small town from night-raiding rabbits who chomp people's prized vegetables…. Prepare for Halloween buckets, ….
Thoughts back in 2005 about the were-rabbit might not have extended to 2018 and Easter. Think rabbits and Easter baskets. And having Easter and April Fool's Day made that Sunday even more cutesy, imho. The basket did double duty this year. (I gave a friend my basket so her grandchild could tote it for this year's Easter/April Fool's Day and Halloween. If I'd only had the foresight to stash away some 2017 Halloween candy, …)

What Else Hoppened?

During a walk in the neighborhood last week, I spotted symbols of differing occasions at one house. Christmas-themed, to be sure, but a rabbit (Easter symbol) and winged dragon (Halloween symbol) are unusual. If the homeowner also laid out some hearts, shamrocks, and American flags, the display could cover six holiday seasons.


Speaking of shamrocks, during yesterday evening's walk, I spotted a snowman balloon that made me think of St. Patrick's Day. The hatband has a sprig of hollies and berries, but could probably look appropriate with a shamrock or leprechaun around March 17 in cold areas.


Circling back to an offbeat symbol, how about a fangy snowman, or two? Spotted them during yesterday's walk. Imho, their faces look more Halloweeny scary than Frosty friendly.


Heck, why not just have Halloween inflatables and lights up starting in September? F'rinstance, "Christmas Disney Inflatable 5.5 Santa Jack Skellington The Nightmare Before Christmas Airblown Decoration" is available at Amazon. Another inflatable, fangy like my finds, is "Gemmy Bumble Christmas Inflatable Fabric 1 Multicolored".

April Fool's Day and Sunday, no Hoppening Easter Bunny)

My tshirt's design shows a footrace for April 1, 1990. That day was a Sunday ("Sunday 1 April 1990"). It was not, however, Easter Sunday. "When Was Easter Sunday in 1990?" shows that date was April 15. This site provides dates for Easter Sundays that you can click for links up through 2047 and also use the calculator for an unlisted year.

Want another calendar source? Astronomical Society of South Australia's "Calculate the Date of Easter Sunday" includes links to Easter Sunday dates that span six centuries (18th through 23rd). Speaking of astronomy, the following is my 2018 April Fool's story, which I sent out to a select audience March 31.


March Madness Under a Full Moon (Awoooo!)
 

The March astronomy meeting triggered a melee during a speaker's Raspberry Pi Astrophotography: LinGuider presentation. A precocious youth blew a raspberry during the discussion about the Raspberry Pi, then exclaimed, "Where's the pie!" The youth's father, embarrassed and angry at his son's outburst, went full Homer and started to throttle the boy's throat, growling, "Why you little …!"
 

Another audience member, shocked at the physical interaction, threw his pocket pen protector (PPP) at the dueling pair. The plastic envelope started to float harmlessly towards earth, but somehow picked up an air pocket, then veered and jabbed someone nearer the PPP thrower. The unintended target, enraged at the jab, shaped a hardcopy celestial-events handout into a paper plane, then hurled it toward the PPP thrower. It missed, and instead pricked yet another audience member.
 

Within minutes, handouts, spectacles, smartphones, laptops, and soda cans ranging in fluid capacity from empty to full flew everywhere. Police were summoned. Dozens were arrested and escorted into a paddy wagon under the full-moon evening, presumably arraigned and released in time to attend the next month's meeting.


APRIL FOOL'S DAY! Actually, the speaker's March 1 presentation was very well-received. Lots of questions, answers, comments, suggestions.


This article brings me to the end of 2018, having hopped from and to a few special occasions this year. Happy Holidays!

For more articles about Halloween, enter "Halloween" in the search box at the upper left of this window. Or find and click "Halloween" link at Partial Index of Keywords section (just below Popular Posts section).

Wednesday, February 28, 2018

Close Word Groupings for Pause

Did you think I mean "close" as proximity or imperative? As the text is visual rather than aural, the pronunciation can be either, and the title's meaning ambiguous.

Various words seem to have at least visually related words that cause pause before I pick one for uttering or inserting in text. Some word "sets" apply maybe more for people that English is not their first language. This article lists mostly pairs of words that can cause misunderstanding because of picking the incorrect word. Context helps with the correct word selection. The trade-off is a time slowdown to assess the situation.

I've run across most of my hesitancy-inducing terms that I list while writing technical documentation or composing or answering email. Occasionally, I've run across some terms in a conversation, a TV show, or visual text that I read. For an example of pause-causing terms, think of this sample sentence and my use of "read" in the previous sentence. I used "example", "sample", and "read". "Read" is past tense in the context of my having used "I've run", although "read" can be present or past tense.

example, sample
In differentiating example from sample, an example serves as a pattern to imitate or not, per m-w.com, and a sample is a representative part of something larger. If you take a morsel from a tray of same-items to taste, that's a sample. If I see a crowd of people and notice someone dressed especially neatly, the person is an example of someone well-dressed.

resent, re-sent
If I send email and state that I sent something again, I will always write "re-sent" and not "resent", differentiating the action from a word that has negative meanings. (From M-w.com: "to feel or express annoyance or ill will at".)

pane, panel
"Pane" and "panel" differ by only one letter, but I often got confused when I confronted style guides that referred to both terms. Even googling "pane vs. panel" leaves uncertainty. In thinking out loud, I arrived at "instrument panel" for menu option panels, and at "window panes" for separate sections that display on a graphic interface.

A style guide at a current workplace would be the best source. If not thinking technical writing use, think of context—visualize window pane and wood panel.

astronomy, astrophysics, astrology
Of the three star-pertinent words, the two most recognizable ones are astronomer and astrologer. Their occupations are, uh, worlds apart despite their (uh again) focus on celestial bodies. From "The difference between astronomy and astrology":
Astronomy is ‘the branch of science which deals with celestial objects, space, and the physical universe as a whole’. If you’re thinking about the academic study, stargazers, telescopes, and the like, then the word you need is astronomy.

Astrology, on the other hand, is ‘the study of the movements and relative positions of celestial bodies interpreted as having an influence on human affairs and the natural world’. If you are writing about people using stars or planets to predict favourable or unfavourable events happening to humans, then astrology is the correct word.

Astrology originally included the calculation of natural phenomena and meteorological events (such as the measurement of time and the times of tides and eclipses) that are now considered the domain of astronomy.
"What is Astrophysics?" explains the professional's field. (The most well-known astrophysicist in our time might be Neil deGrasse Tyson.)
Astrophysics is a branch of space science that applies the laws of physics and chemistry to explain the birth, life and death of stars, planets, galaxies, nebulae and other objects in the universe. It has two sibling sciences, astronomy and cosmology, and the lines between them blur.
cosmology (science), cosmetology (certain appearance enhancement)
"Cosmology is not Astronomy/Astrophysics" is a YouTube explanation of cosmology (study of the universe as a whole), with nod to astronomy (study of individual celestial bodies, such as stars and galaxies).

Cosmetology is a field of hair, skin, and nail care, with subfields with varying occupation titles. "Cosmetology" shows cosmetology example focuses—hair, skin, and nail care.
Cosmetologists work on hair, skin, and nails. Estheticians work on skin care only. From "What’s the Difference Between a Cosmetologist and an Esthetician?"
Cosmetology is an area of study and a career that focuses on hair, skin, and nails. Cosmetologists can do both hair and nails, or focus their careers in one area. In comparison, esthetics focuses on skin care only. An esthetician is not qualified to perform pedicures, cut hair, or work with hair chemicals. With additional training and education a cosmetologist can also be an esthetician. … However, estheticians are generally not cosmetologists. Most states require separate licensing for each career.
The make-up artist in "What Is the Difference Between Cosmetologists & Makeup Artists? : Makeup Tips & Application" explains the differences between the occupations and also touches on esthetician roles. She also states that make-up artists only apply items to skin, a more narrow scope than esthetician.

Close Enough
close
If adjective, "s" pronunciation.
If verb, "z" pronunciation.

"English Pronunciation, common mistakes, close" is a good video for presenting both pronunciations and contexts.

closer
If adjective, "s" pronunciation.
If noun, "z" pronunciation.

Numerous YouTube videos pronounce with "s" without explanation. I found some videos that provide context for "closer" pronunciation. Examples:
Additional Items (Short Looks)
read
If present tense, long "e" pronunciation.
If past tense, short "e" pronunciation.

lead
If present-tense, long "e" pronunciation. Coincidentally, past tense has short "e" sound, but is spelled "led" rather than "lead".
If noun (the metal or periodic table element), short "e" pronunciation.

bass
If adjective (denoting very low-note type or types of musical instrument), long "a" pronunciation.
If noun (fish), short "a" pronunciation.

herb
If noun for seasoning or spice plant, silent "h".
If noun for male's name, spoken "h".

silicon
If noun for element or material for making particular type of semiconductor, short "o" pronunciation.

silicone
If noun for certain rubbery and flexible material, long "o" pronunciation.

union
If noun for items joined together, long "u" pronunciation in the first syllable, short "u" in the second syllable. Examples: Union vs. Confederacy, Western Union.

onion
If noun for the plant, short "u" pronunciation in the first syllable, short "u" in the second syllable. Examples: Green onion, Eastern Onion Singing Telegram.

hummus
If noun for the pureed chickpeas food, short "u" pronunciation in the first syllable, short "u" in the second syllable.

humus
If noun for decayed material for plant food, long "u" pronunciation in the first syllable, short "u" in the second syllable.

Wednesday, March 16, 2016

Pizza Boxes Part 1

I’m guessing that way more than 99% of pizza boxes function as containers for pizza. Afterward, the boxes get tossed in the trash. (A recycle advisory says to not recycle them because grease and food contaminate the boxes. A few might serve as overnight leftover pizza containers, then tossed out.

Pizza Box Uses Besides for Pizzas
I can think of three additional purposes for pizza boxes (brand spankin’ new, however), of which I’ve used for two purposes in the past.
  • Container for a pizza jigsaw puzzle (similar to some Zazzle images)
  • Storage for a Bahtinov mask, my more recent pizza box use. Some masks are professionally manufactured, some are DIY and might or might not include an embroidery hoop, as the image at the top of the article.
  • If unfolded, a surface for a partially assembled jigsaw puzzle. To make it a corral for transporting a puzzle to another tabletop, fold and tape some edges to form walls.
Note: Typical pizza places probably sell three to five different pizza sizes, so you can pick your suitable box size.

Products that are Called Pizza Boxes
Some products are referred to as pizza boxes because of shape similarities, often box-like with matching length by width and short height.
Wending from Bhatinov Focusing Mask to Pizza Box
We recently made a Bhatinov focusing mask, which included lots of tedium in gingerly and accurately cutting slots. To protect the finished mask and its embroidery hoop, I thought a pizza box, with its stiff corrugated cardboard structure, would be perfect for storage.

After measuring the mask with hoop (about 10.5" diameter), I poked around the web for pizza box info. (Read nitty gritty details about boxes in Pizza Boxes Part 2.) Anyway, we bought a new 12" pizza box for 25¢ while buying an extra large pizza to go.

Those who are interested in astronomy and astrophotography and want to know more about Bhatinov focusing masks can start with some resources as follows: