The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Home Ec

Things around the home & hearth

  • Digital Camera Resolution: It’s Not The Dots

    Overview of the scene - 8 MP image
    Overview of the scene – 8 MP image

    A rule of thumb for cameras is that more glass is better, so I’ve always been skeptical of those little bitty chips o’ glass in front of all those pocket-sized camera CCDs.

    A while ago I took some shots with my Casio EX-Z850 at various resolutions, chopped out a chunk with some good detail from the middle of the images, and resized (cubic interpolation) the smaller ones to match the 8 MP image. The exposure was automagic: 1/200 sec at f/7.4. Zoomed as far as the optical zoom would go, hand-held ’cause at that shutter speed it’s OK, sharpness and contrast one click higher than the default.

    As nearly as I can tell, there’s only a slight difference between 8 & 6 MP, enough to be noticeable at 4 MP, and it’s getting on toward icky at 2 MP. The picture isn’t any bigger because I wanted to preserve the actual dots in the 8 MP image.

    Resolution Test - Shield
    Resolution Test – Shield

    Notice the weird color gradations in the shields with bright primary colors. This was hand-held, so the camera reached the same image conversion conclusions each time, starting with different physical pixels. A bit of rummaging turns up the Island Coffee Co logo at http://www.islandcoffee.net/.

    Just to show that resolution doesn’t matter in real life, check out the snail. Zoomed all the way out, macro focus, 1/125 f/2.8 (wide open), hand held, resized as above.

    Snail
    Resolution Test Images: Snail

    As nearly as I can tell, the 2 MP image is the only one that’s noticeably worse and it’s still just fine. The other three are different, but even the 2 MP one isn’t bad.

    Moral of the story: lots o’ dots is good, but beyond a few MP it just doesn’t matter. I think 4 MP is the sweet spot, based on an entirely insufficient sample, with 8 MP if you’re planning tight cropping. Otherwise, save 2 MB per image: 8 MP -> 4-5 MB, 4 MP -> 2-3 MB.

    The other High Truth: lots of light is a Good Thing. You get really crappy pictures when there’s not enough light, but it seems that’s where all the interesting stuff happens.

    Update: Uploaded the PNG version of the shield resolution test, as the JPG was fairly crappy, plus 8 MP overviews of the scenes. The text is antialiased and looks awful when you zoom in, but the whole point is to show the actual dots produced by the camera: there aren’t that many dots for the letters.

    Snail overview - 8 MP image
    Snail overview – 8 MP image

  • Pocket Camera: Griptivity Thereof

    Casio EX-Z850 and homebrew case
    Casio EX-Z850 and homebrew case

    I carry a small camera with me at all times and find it invaluable for recording details and documenting events; now I never say “I wish I had a camera!”

    This one is a Casio EX-Z850, which trades off nearly everything in favor of compact size. It has great battery life, enough resolution (the optics could be better), and manual controls (so it serves nicely as a microscope camera). It’s obsolete, of course, but you get the idea.

    I have bigger & better cameras, but this one is always with me and that counts for nearly everything. The camera in a cellphone or PDA is not the same as a real camera.

    Unfortunately, the thing has the griptivity of a bar of soap: all stylin’ metal and plastic. The black nubbly surfaces in the photo are my idea of a Good Thing: chunks of stair-tread tape providing enough traction that the camera no longer flies out of my hand with the greatest of ease.

    Despite that, I always slip the lanyard over my wrist when I take it out of my pocket; often I do that before removing it from the case. That nervous tic saves me the cost of a new camera about twice a year.

    If your camera fits into a desktop charging / USB cradle, as this one does, make sure you don’t stick the tape where the cradle fits against the camera. It’s really tough to peel off after the adhesive sets up…

    Mary made that nice packcloth (she says “Cordura“) case, with a fuzzy fleece liner facing the LCD panel. The hook-and-loop closure is a tad noisy in quiet places, but it’s better than buttons or a zipper for this application.

    I’ve learned to not keep tissues in the same pocket as the camera.

  • Cheap cellphone service for non-talkers

    Basically, we don’t need a cellphone except for the occasional biz trip and to tote along while cycling Just In Case. Paying a buck or two a day for something we don’t need doesn’t sit well with us.

    So here’s the cheapest alternative we’ve found…

    Go to virginmobileusa.com and buy a $10 phone. Some are free, but as of right now the Kyocera Marbl has the longest battery life and the fewest features. It’ll be obsolete by the time you see this; struggle through their “compare phones” and specs to find the really valuable number: standby battery life.

    They strongly encourage a monthly plan. If you actually use the phone, a monthly plan might make sense. If you never do any talking and don’t expect any calls, skip all that.

    The key step: sign up for Auto Top-up with either a credit card or PayPal. That reduces the mandatory payment to $15 every three months. Well, it’s really $16.22 after title, taxes, tags, and tip, but you get the idea: five-and-change a month for a phone.

    The cost per minute is staggering: 20 cents/minute or some such. That’s 75-ish minutes of air time per month, far more than we ever talk. We must occasionally talk to somebody and burn down the account just to keep it under control.

    Text messaging is worse: 10 or 15 cents each. A major ripoff. ‘Nuff said.

    Coverage is by Sprint, so you take your chances. It’s marginal in the house, OK outdoors, better elsewhere.

    Their Website is choked with gratuitous Flash, difficult to navigate, has no search function, and suffers from terrible layout. Oh, yeah and their customer service is stunningly bad.

    I did get an actual competent human when I had to swap out the first Marbl: the hinge spring broke, holding it slightly open. As they say on the website: For everything else, give us a call at 1-888-322-1122.

    It’s not obvious that paying more gets you better service, though.

  • Inkjet Refilling: Economics of the Empire

    A year ago I bought an Epson R380 printer along with a $10 piece-of-crap digital camera for 90 bucks, then got a $75 rebate. I figure the printer cost 15 bucks and the camera was free.

    cimg2863-continuous-ink-for-epson-r380
    Continuous inking system for Epson R380 printer

    I also bought a $55 continuous flow ink system from a place that no longer sells them. Turns out that Epson won a patent lawsuit that forced most of those vendors out of the reinking business and made the remaining systems staggeringly expensive.

    Well, maybe not.

    I print a bunch of text (I hate reading long documents on the screen), plenty of schematics & diagrams, low-quality pictures (webbish junk), relatively few photo-quality pictures, and the Annual Christmas Letter. The printer spends an inordinate amount of time blowing its nose and clearing its throat at the start of each session, so I suspect most of the ink goes directly into the diaper inside the printer.

    Genuine Epson 78-series cartridges contain 11 ml of ink and cost $20: $1.80 / ml or, in US terms, $2k per quart. In the last year, I’ve used about 200 ml of black and 110 ml of each of the five colors: $360 + 5 * $200 = $1360, if I were stupid enough to pay full price for 68 cartridges.

    That makes the $150-ish I actually paid for seven 8-ounce (250 ml) bottles of ink a downright bargain: $0.09 / ml.

    No, the color isn’t the same as the Epson inks and I’m certain it won’t last as long on the page, but that’s not what I’m using this printer for. When I need long-lasting, high-quality prints, I send ’em to an online service… which right now is running a sale on 4×6″ prints at $0.09 each. What’s not to like?

    When I hear printer companies boast about how ecological their printers are, I say bad things. If they wanted to be green, they’d make it trivially easy to connect bulk-ink tanks to their printers.

    I’ll put up with a few colorful spots on my fingers and the occasional sploosh on the table to save that much coin o’ the realm…

  • Ed’s High-traction Multi-grain Bread

    I bake a loaf of this every few days…

    Dump in a 4.5-quart mixer bowl:

    • 1/2 Tbsp dry yeast
    • 2 Tbsp brown sugar
    • 1/2 cup dried milk
    • 1-1/2 cup warm water

    I find it’s easiest to mush the three dry ingredients together so the brown sugar coats everything, then stir in the water. Let it sit for ten minutes or so if you have the patience, then, with the yeast up & running, add the goodies:

    • 1/2 cup flax seed meal
    • 1/2 cup bread flour
    • 1/2 cup rye flour
    • 1/2 cup wheat flour
    • 3 cups wheat flour (easier to measure that way)
    • 1 tsp salt
    • 2 Tbsp canola oil

    Put the dough hook on the mixer, screw down the bowl, and let ‘er grind on lowest speed until the dough gets nice & cohesive. Dump out the dough, oil the bowl, throw the lump back in, and roll it around to coat all sides.

    Put a lid on the bowl and let it rise overnight; perhaps in the oven after warming. If your yeast is more enthusiastic than ours it’ll take less time, but this is bread of unparalleled density.

    I’ve been baking this bread in a classic Pyrex Bake-A-Round that we’ve been toting unused from house to house ever since we got it as a wedding present. Turns out it’s really slick for this purpose. You can certainly use an ordinary loaf pan.

    Whatever you use to contain the dough: butter it thoroughly, pop in the dough without mushing it too much, and let it rise for another hour or two. If you’re using a B-A-R tube, push-and-hold the ends to plump up the middle just before you pop it in the oven. Best if you add aluminum foil caps to the end to keep ’em soft.

    Bake at 325 F for maybe 50 minutes. Cool on a rack while you get the peanut butter out of the refrigerator. Slather with PB, give thanks to the yeasty-beasties, eat.

    Speaking of which, it’s worth noting that our tap water now comes with chloramines that seem to kill yeast stone cold dead. We run the water through a Brita filter, but it’s not clear how much that helps; our yeast seems rather dispirited even in filtered water.

    [Update: A new batch of yeast reveals that we were using dead yeast. I’d bought several pounds of the stuff, as we use a lot of it, but evidently it aged out. Now we know.]

    This recipe started life as the Fundamental Tassajara Whole-Wheat Bread recipe, but has mutated over the years. The flax seed meal adds a surprisingly good taste.

    Update: if you’re in a hurry, dump the just-mixed dough out of the bowl, roll it into a log that barely fits into the B-A-R tube, slide it to the middle, cap the ends, and pop the B-A-R into a warm oven (ours hits 170, more or less). Let the yeasty beasties fart for an hour or two, then fire up the oven with the B-A-R inside; you can even use the Automatic Oven setting. Works like a champ!

  • Fluorescent Shop Lights, Early Failures Thereof

    A decade ago I installed a few dozen two-tube fluorescent fixtures (a.k.a. “shop lights”) throughout the basement. Visitors always say something like “Wow, I can actually see what I’m doing!” That was the whole point, of course.

    Being that sort of bear, I write the date on one end of a fluorescent tube when I replace it. Tubes seem to last 3-5 years, which is short compared to the 20k power-on hours touted on the carton: 5 years * 300 days/yr * 6 hr/day = 9 k hours. That’s an overestimate, as I don’t spend all my time crouched in my basement laboratory, honest.

    It turns out that there’s also a spec for the number of lamp turn-ons (“starts”) hidden deep in the lamp datasheets. For example, if you manage to browse the current Lamp and Ballast catalog at http://www.sylvania.com/ProductCatalogs/, you’ll find that a 20k hour rated life comes at “3 hr/start”, which works out to a mere 6.7k starts over the expected life.

    More starts = shorter life.

    I tend to turn the lights off if I think I’ll be upstairs for a few hours, which happens a lot during the winter.  My back of the envelope says that the tubes fail right around the expected value: 5 years * 300 days/yr * 4 starts/day = 6 k starts.

    Lately I’ve had a rash of early lamp failures and it seems the fixtures are failing after a decade; nothing lasts any more. I’m now installing electronic-ballast fixtures that fire right up in the winter and don’t have that annoying subliminal flicker. At a cost of $20 each, I’m not replacing all of them at once, I assure you.

    The only real problem with fluorescent lamps is that they make white people look dead. I managed to buy a contractor pack of warm-white tubes at the local Lowe’s, but they’re hard to find around here. Go for the lowest color temperature bulbs you can find.

  • Unusual Tea Additive

    Green tea is supposed to be good for you and Tazo China Green Tips is supposed to be pretty good tasting, so I’ve been sipping a cuppa or two in the morning. Teabags are a spendy way to buy tea, so I’ve been buying half a kilo at a shot from cooking.com, storing it in glass jars, and teaspooning it into a tea ball infuser over the course of the next year.

    This interesting additive appeared in one of my teaballs; fortunately I was awake enough to notice it before it wound up in hot water.

    Beetle found in Tazo Green Tea
    Beetle found in Tazo Green Tea

    It looked pretty much like the hull of a generic Asian Garden Beetle, although we haven’t seen anything quite like it in our gardens. Not a big deal, as garden beetles are fairly inoffensive critters, but not something that should make its way into a bag of lah-dee-dah tea. On the other paw, it’s hard to filter stuff like that out of the stream.

    Fought my way through the Flash-saturated Tazo site, sent a note to the Customer Service folks, eventually had a pleasant phone chat. After convincing her that I wasn’t rabidly angry and that it really was one of their beetles, she dispatched fifteen bucks worth of Starbucks gift card.

    It seems Starbucks either owns Tazo, both of ’em are controlled by the same outfit, or something like that. She was in the Starbucks Customer Service chain o’ command, anyway.

    Beetle bottom view
    Beetle bottom view

    So I picked up three boxes of Tazo tea bags at the local Starbucks: more China Green Tips and some Green Tea with Lemon Grass (which doesn’t appear on their website). Left me with three cents on the card; I’m not a regular customer, so it’s now in the pile of cards I use as measurement shims in the workshop.

    I’d been adding lemon grass from our garden to the morning cuppa for a pleasant lemon scent. The Tazo version includes Lemon Verbena, some mint, and other flavors that cranked the scent up to 11 and the taste far into my ptui range. Unpleasant, indeed.

    For what it’s worth, if you’ve tried & disliked other green teas, give Tazo China Green Tips a shot. It’s delicate and much better than the other (far cheaper) green teas I’ve tried; Salada Green Tea is particularly noxious.

    One of the China Green Tips reviewers on cooking.com comments “I found a rather long, nasty, kinky hair … I was shocked. I threw out the whole bag  … I was unable to drink tea for a week”.

    Mexican Bean Beetle on Soybeans
    Mexican Bean Beetle on Soybeans

    Now, party people, I’m here to tell you that food just doesn’t pop out of the ground in a pristine state. Maybe it’s because we eat a lot of food from our own gardens, but passengers like that, let alone the odd hair, just aren’t an issue. Consider, for example, this critter that made it all the way into the house on some soybeans: he’s likely related to the Asian Garden Beetle family and not all that far back in their family trees.

    If you want to really worry about something, ask yourself whether your tea grew downwind of, say, Zhejiang Happy Face Metal Refinery Complex Number Six. No way to tell about that, other than through a detailed chemical analysis of every cuppa.

    Bon appétit!