Vivitar thyristor flash manual power control mod

A little over a week ago I learned that I can very easily modify my Vivitar 3500/35-D flashes to have manual power output control. Previously I tested the different settings on the flash. To give me full manual control I have replaced the photo resistor with a potentiometer. This should work with all Vivitar flashes that use a photo resistor to adjust light output. This mod is quite easy and only took about 15 minutes the second time I did it. The 3500 has a separate module where this circuitry is housed. I know some Vivitar models are one unit, so be aware that flashes have a high voltage capacitor in them and you can shock yourself.

Vivitar 3500 Thyristor Flash

I have two Vivitar 3500 flashes (one is a 35-D, but they are identical as far as I can tell). For the longest time I could not figure out how these things actually worked. There are four settings on back; red, blue, orange, and manual. From the 'calculator' up top you can tell the three color settings are two stops apart, and manual is full power. But until recently I did not know that there is a photo resistor up front which actually adjusts the power of the flash based on the amount of light the sensor sees. The more less light, the more resistance, and the stronger the flash. Thanks to this discussion on the Strobist Flickr discussion group I was able to get a better understanding on how this flash works. I decided to set up an experiment to see how this sensor works in practice. This will apply to all Vivitar thyristor flashes.

photography

It's been a while since I've updated here. I've been mostly focused on my project over at Flux 53. If you're in the bay area come stop by and check us out. I have been taking a great deal of photographs over the past few months. Here's a select few. To see more, check out my Flickr.

news roundup

Got no time to really write a post, so here are some worthwhile links:

US funds dry up for Iran rights watchdog - Federal funding denied for watchdog group that investigated abuses of protesters after this summer's disputed presidential election in Iran.

Price of gold soars on report of Arab states ditching dollar - The dollar will no longer be the currency tied to the price of gold.

Voices against the G20 - Report of protests and activities during the G20 Summit in Pittsburgh.

House cuts workweek to 2 1/2 days - Congress gets lazier.

Progressivism? Not so fast, folks - Dummest thing I've read all week. But it's like a train wreck, you just can't look away.

From Frontline, Obama's War - If it's like Bush's War, it's definetely worth a watch. Still haven't watched this preview.

Mom's designated driver: her 13-year-old son - And for the story that makes you go 'what the fuck?'

more suck from the Obama Administration, net nuetrality, g20, and a robbery

Obama drops demand that Israel freeze settlements

Prodding Israel and the Palestinian Authority to restart talks aimed at a permanent resolution of their decades-old conflict, President Obama dropped a demand for an Israeli settlement freeze, U.S., Israeli and Palestinian officials said.

"Simply put, it is past time to talk about starting negotiations. It is time to move forward," Obama told reporters before a meeting with Palestinian President Mahmoud Abbas and Israeli Prime Minister Benjamin Netanyahu.

"It is time to show the flexibility and common sense and sense of compromise that is necessary to achieve our goals," Obama said.

So ask Israel to block building settlements, do absolutely nothing when they ignore you, then say its not a big deal and things should just move along anyway.


Federal Communications Commission Chairman proposes to possibly extend the agency's network neutrality principles to the mobile Internet

As expected wireless carriers are opposing the statement arguing against government interference to the Internet. The truth is that net neutrality would protect the Internet to be free and open and keep it from a corporate takeover where the highest bidder would control bandwidth. Most people are unaware of the importance of net neutrality legislation and how without it the Internet will be controlled by just a few rich companies like radio and tv are, taking the voice away from the people.


The G20 summit is in Pittsburgh this weekend and the police is prepared. It has been extremely difficult for activists to get permits for marches and rallies and they will most likely be overwhelmed by the police presence. Upward of $20 million will be spent on security while at the same time neglecting the first amendment rights of activists.


On a lighter note, thieves stole a helicopter and robbed a security firm in Stockholm and got away. This sounds good enough for a movie.

Stormtroopers reflect on destruction of the Death Star

Reminds me of something I found a couple years ago:

Uncomfortable Questions about the Death Star Attack

1) Why were a handful of rebel fighters able to penetrate the defenses of a battle station that had the capability of destroying an entire planet and the defenses to ward off several fleets of battle ships?

2) Why did Grand Moff Tarkin refuse to deploy the station's large fleet of TIE Fighters until it was too late? Was he acting on orders from somebody to not shoot down the rebel attack force? If so, who, and why?

3) Why was the rebel pilot who supposedly destroyed the Death Star reported to be on the Death Star days, maybe hours, prior to its destruction? Why was he allowed to escape, and why were several individuals dressed in Stormtrooper uniforms seen helping him?

4) Why has there not been an investigation into allegations that Darth Vader, the second-ranking member of the Imperial Government, is in fact the father of the pilot who allegedly destroyed the Death Star?

5) Why did Lord Vader decide to break all protocols and personally pilot a lightly armored TIE Fighter? Conveniently, this placed Lord Vader outside of the Death Star when it was destroyed, where he was also conveniently able to escape from a large-sized rebel fleet that had just routed the Imperial forces. Why would Lord Vader, one of the highest ranking members of the Imperial Government, suddenly decide to fly away from the Death Star in the middle of a battle? Did he know something that the rest of the Imperial Navy didn't?

6) How could any pilot shoot a missile into a 2 meter-wide exhaust port, let alone a pilot with no formal training, whose only claim to fame was his ability to "bullseye womprats" on Tatooine? This shot, according to one pilot, would be "impossible, even for a computer." Yet, according to additional evidence, the pilot who allegedly fired the missile turned off his targeting computer when he was supposedly firing the shot that destroyed the Death Star. Why have these discrepancies never been investigated, let alone explained?

7) Why has their been no investigation into evidence that the droids who provided the rebels with the Death Star plans were once owned by none other than Lord Vader himself, and were found, conveniently, by the pilot who destroyed the Death Star, and who is also believed to be Lord Vader's son? Evidence also shows that the droids were brought to one Ben Kenobi, who, records indicate, was Darth Vader's teacher many years earlier! Are all these personal connections between the conspirators and a key figure in the Imperial government supposed to be coincidences?

8) How could a single missile destroy a battle station the size of a moon? No records, anywhere, show that any battle station or capital ship has ever been destroyed by a single missile. Furthermore, analysis of the tape of the last moments of the Death Star show numerous small explosions along its surface, prior to it exploding completely! Why does all evidence indicate that strategically placed explosives, not a single missile, is what destroyed the Death Star?

United for Iran Global Day of Action photos

Here are my photos from the United for Iran Global Day of Action in San Francisco on July 25th. See more of my photos on Flickr.

news roundup: California budget and Obama's secret guests

An agreement was made between California Governor Arnold Schwarzenegger and state legislators that would dramatically cut social spending and start offshore oil drilling. Part of the budget cuts include:

$6 billion from K-12 schools and community colleges over two years
$3 billion from the University of California and California State University systems
$1.3 billion from Medi-Cal, the state's healthcare program for the poor
$1.2 billion from the state prison system

Republicans warned the deal could fall through over the proposed release of prisoners of non-violent crimes (other key points of the deal can be seen in that SFGate article).

On the topic of California's budget crisis, here is a talk by Mike Davis and David Bacon at Socialism 2009.


President Obama continues President Bush's policy of keeping certain White House visitors a secret. Obama administration officials of denied requests of top health care industry executives visiting the president. Obama criticized the same types of practices by former President Bush during his presidental campaign.


Today on Democracy Now! there was a good interview with Princeton University professor Cornel West and Carl Dix of the Revolutionary Communist Party on race in the age of Obama and the social struggles that need to rise to push Obama. From Cornel West:

Lincoln supported the slave trade when he was in the House. He supported the Fugitive Slave Act. In the first inaugural lecture he gave, he supported the first proposed Thirteenth Amendment, which said there would be slavery forever in America, the unamendable amendment. That was Lincoln. If it were not for the abolitionist movement, the courageous black and white freedom fighters, from John Brown to Douglass, who put pressure on Lincoln, we would have been dealing with a white supremacist Lincoln.
Lincoln became great, because a social movement pushed him against slavery in that regard. And Obama is looking to the wrong Lincoln. And if he doesn’t understand the greatness of Lincoln was responding to the social movements of working people and poor people, he’s going to end up with a failed presidency, with a lot of symbolic gestures, but, on the ground, everyday people, those Sly Stone called “everyday people,” suffering still.

Rafsanjani speaks at Friday Prayers

Yesterday was another defining moment in the movement in Iran. Former president Akbar Hashemi Rafsanjani gave the Friday Prayer. He is on the Assembly of Experts which is the group responsible for appointing, monitoring, and dismissing the Supreme Leader. As an Ayatollah he is in rotation of giving the Friday Prayers and this is the first time a pro-reform leader has been in such a position. There was lots of speculation how far Rafsanjani would go in his speech. At the same time numbers of people in the street rivaled early days after the elections as hundreds of thousands, possibly a million, gathered in the streets, many shouting "death to the dictator" and "I am ready to die to get my vote back," strong signs that this movement is still in its early stages. Meanwhile, Mousavi may be calling for the military for support.

He made a number of points during his speech. Calling for the freeing of prisoners, stating peoples voices need to be heard and censorship in the media needs to stop. He called for talks to dispute the crisis, and said the Government and security forces should act within the limits of the law. He criticized the Guardian Council for not acting faster and called for unity. In a rare move, state TV did not run the speech, but instead had said Rafsanjani had simply called for unity trying to quiet the protests. Rafsanjani noted China should listen to all its people and was critical of their response to the protest there. He also mentioned violence in Palestine and Pakistan.

Many pro-reform politicians were at the prayer including Mir Hossein Mousavi. Rafsanjani tried to quiet down slogans and chants, but they sporadically appeared.

Protesters inside the mosque chanted “Allah o Akbar”, “Azadi… Azadi” (Freedom… Freedom) and slogans against Russia and China.

[...]

It is worth mentioning that there was a loudspeaker inside the mosque which chanted, “Death to America!”, but every time that slogan was heard, people loudly replied with, “Death to Russia, Death to China!”

Numbers of people in the streets was anywhere between hundreds of thousands to over a million. A group gathered around Evin Prison, where many protesters are being held. Basijis forces clashed with protesters using teargas, batons, knives, and tasers. There were reports of them targeting women, pulling them away from the crowds.

Basijis and other security forces today brutalized protesters once again. At least two people were shot and one girl was reportedly killed during the protests. Basijis used batons to beat people – even small children and women were not spared. Many women were reportedly stabbed with knives by Basijis dressed as women. Several mosques around the city were packed with Basijis waiting to come out and clash with protesters.

I also got unconfirmed reports from Twitter that Mousavi was with a group of protesters converging at the Interior Ministry in an attempt to get the military to his side. There were also talks of him being arrested if he were to speak. A general strike is to be called if Mousavi is arrested. I'll report more on this if I hear anything else. It has been confirmed that 36 high ranking military personnel were arrested along with a number of lower ranking officials. We may see more concrete developments involving the military in the coming days. It should be noted that neither the Iran Revolutionary Guard nor the Army has really involved itself in the unrest.

I also found news of oil workers being arrested due to fear of strike. Weeks ago when talk of a general strike first started it was stated that the oil workers would be the first to strike.

Pictures in Seattle Liberal Examiner

Erik Strand used a couple of my pictures in his article Socialism Conference 2009: is this their time? for the Seattle Liberal Examiner.