2010-05-24

diy collapsible softbox

Not wanting to spend the money for a professional softbox I decided to go the diy route. I had a few criteria I wanted to meet. I wanted something large, portable, and the ability to use two flashes. I searched out a few other designs to get some ideas, particularly some designs from DIY Photography.net. For the size and shape I based it off this model. It is a 40"x24" face and about 20" deep. The idea would be to construct the box so it could fold into triangles. Initially I was thinking of using some sort of plastic, but in the end went with foam core and gaffers tape for the joints. Each "wall" was actually two pieces to fold into a smaller size. With some simple geometry I figured out the dimensions I need and started to cut the foam core. Once I had the pieces cut, it was time to tape them all together. The outside edge has a long strip of velcro to hold it together. The inside was painted flat white which helps bounce the light since foam core is quite translucent.

2010-05-13

New target of rights erosions: U.S. citizens

Glenn Greenwald wrote a great piece on the erosion of rights for U.S. citizens under the Obama Administration. This is a must read. Just like the Bush administration, the Obama admin is further eroding civil liberties. Except now the targets are US citizens who can be denied trial, citizenship, and even assassinated for acts of terror. What is an act of terror you ask? Well, it can be simply protesting at the RNC. Truth is terror is at the discretion of those making the charges. This is the beginning of a police state.

From the article:

"It is not hyperbole to observe that all of the above-cited recent examples are designed to formally exempt a certain class of American citizens -- those accused of being Terrorists and arrested on U.S. soil -- from the most basic legal protections. They're all intended, in the name of Scary Terrorists, to rewrite the core rules of our justice system in order to increase the already-vast detention powers of the U.S. Government and further minimize the remaining safeguards against abuse. The most disgraceful episodes in American history have been about exempting classes of Americans from core rights, and that is exactly what these recent, Terrorism-justified proposals do as well. Anyone who believes that these sorts of abusive powers will be exercised only in narrow and magnanimous ways should just read a little bit of history, or just look at what has happened with the always-expanding police powers vested in the name of the never-ending War on Drugs, the precursor to the never-ending War on Terrorism in so many ways."

2010-03-13

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.

2010-03-08

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.

2010-01-16

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.