Sunday, March 30, 2008
It was getting hot inside the cheesy Alexan plastic case, and I still had some finished 1" x 4" boards gathering dust. My woodworking skills are close to nonexistent, but it can't be that hard to cut two pieces of rectangular board, right?
It uses the two heat sinks as sides of the case. Notice the four ultra-fast soft recovery diodes on a piece of veroboard dangling off in the corner:
The diodes really, really close up. Used a reversed Pentax Super-Takumar 50mm f1.4 at around f4.5, using the onboard camera flash, but I put a quadruple-layer of SM Supermarket receipt over the flash to lower the flash power.
The chip-amp really, really close up:
There's not enough depth of field at f4.5 so I should have used f11 or something, but the viewfinder was way too dark at f11 to judge focus (obviously the reversed Super-Takumar has to be used in stop-down mode).
Thursday, March 27, 2008
Also, some of the Canon "L" primes are quite cheap, even compared to their Pentax counterparts. Of course Pentax also has Limited primes, although Pentax's "L" equivalent (the FA* line) seems to be exceedingly rare.
A major advantage of Pentax though, is image stabilization with every lens. But if we compare the 300/4 SDM with 2-stop in-body stabilization, it's still more expensive than the Canon 300/4 L IS, with 4-stop in-lens stabilization. Both have USM/SDM motors, and both are considered luxury lenses.
|20/2.8 $400||21/3.2 $430|
|28/1.8 $400||31/1.8 Limited $860|
|35/2 $220||35/2 $300|
|43/1.9 Limited $460|
|50/1.4 $300||50/1.4 $195|
|50/1.8 II $85|
|50/2.5 Macro $230||50/2.8 Macro $395|
|85/1.8 $340||77/1.8 Limited $670|
|100/2.8 Macro $450||100/2.8 Macro $450|
|200/2.8L $640||200/2.8 SDM $1000|
|300/4L IS $1100||300/4 SDM $1300|
It seems, unless you like the Pentax weird lenses like the 21mm, 31mm, 43mm, if you're building a system and buying all-new lenses, it's better to go with Canon. However, if you like trolling ebay for old Pentax manual focus lenses (which mostly still work with auto-exposure on modern Pentax digital bodies), then Pentax is the better choice.
Monday, March 24, 2008
A break from the usual electronics, DIY, and gadget-tinkering here.
I read about a new book on modern slavery last night on Digg, which is normally full of geeky fluff. But this time I got a link to an article on NPR, describing a journalist's travails as over four years he set out to document the modern-day slave trade. One of the few times I got something worth reading off Digg.
A quote from the NPR article, which is enough to make anyone cringe:
Though now illegal throughout the world, slavery is more or less the same as it was hundreds of years ago, Skinner explains. Slaves are still "those that are forced to work under threat of violence for no pay beyond sustenance."
Something disturbing has changed however — the price of a human. After adjusting for inflation, Skinner found that, "In 1850, a slave would cost roughly $30,000 to $40,000 — in other words it was like investing in a Mercedes. Today you can go to Haiti and buy a 9-year-old girl to use as a sexual and domestic slave for $50. The devaluation of human life is incredibly pronounced."
Skinner obtained this specific figure through a very hands-on process. In the fall of 2005, he visited Haiti, which has one of the highest concentrations of slaves anywhere in the world.
"I pulled up in a car and rolled down the window," he recalls. "Someone said, 'Do you want to get a person?'"
The book is A Crime So Monstrous, Face-to-Face With Modern-Day Slavery, by E. Benjamin Skinner. The reviews have been glowing, but it is a somewhat turgid read. I know far more than I care to about Washington neo-con sensibilities. The book also praised G. W. Bush as the president who has done the most for slaves in the modern era.
Here's a brief excerpt (laboriously re-typed because Adobe Digital Editions won't allow cut-and-paste, damnable Digital Rights Management):
For our purposes, let's say that the center of the moral universe is in Room S-3800 of the UN Secretariat, Manhattan. From here, you are some five hours from being able to negotiate the sale, in broad daylight, of a healthy boy or girl. Your slave will come in any color you like, as Henry Ford said, as long as it's black. Maximum age: fifteen. He or she can be used for anything. Sex or domestic labor are the most frequent uses, but it's up to you.
You can buy a twelve-year old girl in Haiti, for $50, which is little more than the cost of dinner. Of course $50 is FOB Port-au-Prince -- potential human traffickers beware: passport and visa issues are your problem, not the seller's. And, inevitably, these restaveks ("stay-withs") or child slaves end up not just doing the dishes, but bending over for the overseer.
The Haitians (mostly) who employ such child slaves rationalize it as providing the children with better circumstances than back in their hinterland Haitian homes, where they would literally plant kamote (actually, yams..) and live to the age of forty.
And the time-honored means to avail oneself of a Haitian child? apparently the courtiers or.. dealers, for lack of a better word, pop up in these hinterland towns, and promise needy parents that their child will be given an education in Port-au-Prince, in exchange for light housework. So ironically, the parents pick the smartest, brightest child in their brood for this unprecedented blessing, only to consign their offspring to doom.
This reminds me of the oddly-parallel, but (hopefully) less coerced practice here in our country of plumbing the countryside for suitable barrio lasses. The Haitians do not want their slaves from the slums of Cap Haitien, because apparently, street-smart kids run away really quickly. Same thing for middle-class Filipinos, apparently, who continue to lean on our provincial relatives for trustworthy domestic labor.
The really scary thing about what a failed state Haiti is, is that the lower-middle class families which employ slaves earn around.. $30 a month. The upper-class Haitians don't want to be involved with slavery, and they have the money to hire proper servants. So for these Haitian "slave-owners," a purchase of a child is a major undertaking, much like a car payment.
The book also goes into detail about the trafficking of Eastern European women into prostitution. Moldova seems to be the go-to country when it comes to "value for money." But the book describes the long and odious process which ends up with Russian entertainers in Quezon City's finest clubs.
A Crime.. also describes the plight of indentured quarry workers in Bihar State, in India. Apparently, India has the world's highest number of slaves (anywhere up to ten million). Many of these Indian slaves, who generally are from the outcast castes, ended up in slavery due to tiny debts incurred by their fathers or grandfathers. The book describes the circumstances of Gonoo, a forty-something man whose entire family was enslaved because his grandfather borrowed $0.60 in the 1950's.
But let's not think that slavery is confined to Haiti, Sudan, India, and China. The author made it to Singapore (although he goes into no details in this book) where there's an alarmingly high rate of Indonesian maids falling from their employers' HDB flats. "Trouble with hanging out the laundry," is how Skinner describes the official response.
When I was in Singapore with Lalai last month, the news was all over the Straits Times about a Singaporean woman who had failed to pay her Indonesian maid for four years, fed her only scantily, and did not allow her any phone calls. Skinner adopts Kevin Bales' definition of slavery as a human being who is forced to work through fraud or threat of violence for no pay beyond subsistence. By that standard, the Indonesian maid in the Straits Times was a slave.
A Crime So Monstrous, Face-to-Face With Modern-Day Slavery is available in hard-cover (it was released on March 11) but can also be purchased online as an e-book (with DRM). I bought my copy for $12-odd dollars (a bit high to pay for three hours' information, but not outrageous) from the Books on Board web site. A Crime.. is also available in electronic form from Simon & Schuster, which is the publisher. However Simon & Schuster doesn't take Philippine credit cards, so...
Anyway, I paid for it using PayPal on the Books on Board web site, struggled a bit with Adobe DRM, and just finished the book. Appalling. If we Filipinos think we're in poor shape, we have to read this book.
What's even more appalling is that a lot of the practices done by human traffickers and described in the book, probably get done in our country as well. Those persistent car-tapping street kids, for instance, probably are in a similar hole.
The book ends with this: it's all down to poverty. Slavery won't disappear until meaningful attempts have been made to address poverty.
Oh well, off my soapbox then. Because poverty is so entrenched and persistent, that it's more convenient (and guilt-free) for the middle class to collectively put its nose to the grindstone and concentrate on building our own lives.
Sunday, March 23, 2008
Anyway I still had a bunch of those Teccor Q401E3 triacs from my low-voltage flash trigger mod, and I thought I could re-use them.
So I purchased a couple of solar-powered China-made calculators (69 pesos each; just for the solar cells in them) to use as optical sensor.
After lots of work (and destroying one of the solar cells in the process..) failure! it turns out that my understanding of SCR's and triacs in general is wrong: the gate voltage is not necessarily a very low-level one; one must have a logic triac in order to gate the triac with middling voltages.
So this guy's CoolPix 995 flash mod probably only worked because he was using a logic triac without knowing it. Oh well..
In any case the solar cell only puts out 1.6 to 1.8 volts under ordinary indoor lighting, which may not be enough to trigger a logic triac.
Lalai and I were at Megamall today (after Easter mass) but.. I got to Alexan too late and the store was already closed. So no parts for me.
Thursday, March 20, 2008
5.1V zener diode
4M carbon resistor, 1/4 W (2)
22nF, 1000V capacitor
1N4148 signal diode
400V 1A triac (any will do)
I paid a visit to Alexan and, wonder of wonders, they had a new display: 22 nF, 1000V capacitors. In this photo (taken with a reversed 50mm lens), frolicking with zener diodes, Teccor triacs, and resistors:
I also bought correct-valued resistors and zener diodes (4.3M-ohms, 5.1V zeners), although the circuit worked fine previously with values that were way out of line.
A completed circuit (much neater than my earlier attempt):
Low-voltage trigger circuit installed inside Vivitar 283 (trigger voltage is now 3.5 volts, down from 110 volts, which is extra-extra safe):
The flash in all its glory..
With infinitely-variable power! (see hand-labeled "infinitely variable flash power adjustment"):
Professional external power supply cord! (some discarded extension cord, soldered directly to the flash main board):
And the non-Quantum power supply (saves a ton on AA batteries, and lasts forever):
Wednesday, March 19, 2008
Monday, March 10, 2008
The EOS 5D has the same viewfinder magnification as my time-honored EOS Elan II (EOS 50). Which is not bad at all!
I remember before DSLR's became popular, everyone was complaining about how small the viewfinder of AF SLR's were compared to the manual-focus SLR's of yore. As can be seen from my diagram, the EOS 1Ds Mark III (the ultimate top-of-the-line Canon digital SLR at $8,000 plus) has a much smaller viewfinder than my thirty-year old antique Fuji Photo Film screw-mount SLR. But, the 1Ds Mark III has a marginally larger viewfinder (0.76x version 0.72x) than the flagship Canon film SLR, the EOS 1v.
What's even more unsatisfying is that the EOS 350D / 400D viewfinder is literally half the size and a quarter the area of the thirty-year old SLR's (due to both the low 0.80x magnification and the cropping due to the reduced sensor).
Saturday, March 08, 2008
18,000 pesos at Spectra in Park Square 1. I wonder if it's any better sonically than my home-made GainClone. Of course aesthetically it looks much better, has a remote control and everything.
And cheaper than a Rotel RA-04 (which is 18,800 pesos) or the Pioneer A-9 which is 35,000 plus.
So now I will have to visit Makati City Hall, queue up with the unreconstructed public utility and taxi drivers, and pay the 500-peso fine.
I will admit that there is some justification for the existence of such a statute. What burns me up is the uneven application of traffic regulations (and the law, in general). Oh well, I guess the rule is "too bad if you get caught," and I got caught.
Tuesday, March 04, 2008
That price is completely un-economical because a new EOS Digital Rebel XT body is only $395 at Adorama, and probably cheaper at some other places. Sigh. Not even 6,000 shutter actuations, my first DSLR. It feels like I totaled the Mazda3. Except, if I totaled the Mazda3, insurance would pay for a new one, and with the upgrade from 'S' spec to 'V' spec, we'd actually come out ahead..
I will have to see Canon's breakdown. If replacing the front cover is $100, I can forego that to lower the repair cost. I can probably tolerate a $200 repair bill, anything beyond that and I guess I'll have to try to repair it myself and just buy another body in the meantime.
Edit: a refurbished chrome Digital Rebel XT (US-model EOS 350D) is only $335 from Adorama. Yeah it's chrome and so is tacky, and it's refurbished, but refurbished by Canon. That's even less than my repair bill. Or a bit more, factoring in the shipping cost.
Edit again: I finally got the parts breakdown for Canon's so-called repair:
- dc dc motor drive 922
- main pcb 10209
- front cover 610
- service 2900
- total 14641