Infrared Filters

July 20, 2006

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The first time I tried setting up an infrared flash to do flash photography without visible light was back in the film days. The experiment didn't last long due to the price of materials. To filter the flash, I saved up and bought a 3x3 Kodak 87C infrared filter. These things aren't cheep. I think they were like $45-50 back then. Now they go for about $57. One thing to keep in mind with a filter that blocks all the visible light and only lets infrared pass is that the visible energy turns into heat.

The first time I popped the strobe after taping the flash to the front I had it at full power and the filter singed, hissed and crumpled up a fair amount. If you have ever seen a piece of surran wrap get to hot and crinkle up it's the same thing. This was when I was in high school or early college. And while $50 is nothing to sneeze at today, it was way more of my income back then.

This time I'm going to try the trick of using an unexposed but developed piece of slide film for the filter. Originally, I was thinking about doing this with my Alien Bees which would have probably required getting 4x5 film, but since I've been reading a lot of strobist, I'm going to be running this with smaller strobes which will allow me to run with 120 film. If this works, it'll be waaaayyy less expensive per filter, and I won't mind as much if they burn themselves up.


Learning by doing

July 19, 2006

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I've always been a fan of learning by doing. Just jumping in. It's the way that I've picked up most of what I know. No surprise to me, but scientists are finding out that we are wired this way. The article is longish for web reading, but worth it.


IR conversion in progress

July 17, 2006

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Just sent my old 10D off to Life Pixel to have it converted. After years of talking about this, I'm finally starting the process.


Keep on learning

July 13, 2006

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I would not have guessed that at age 31 I would learn a new way to tie my shoes. Thank you, internet for reminding me that you can always learn and improve. Even if you have been doing something the same way for most of your life.


CCleaner and HijackThis

July 12, 2006

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Cnet recommends a free tool called CCleaner that is supposed to have a registry cleaner as part of it. They also list HijackThis as a good tool to look for spyware on your windows machine if you are having specific problems. I've heard of that one before, but wasn't sure if it was legit. Seems so. Mainly, I'm posting these here so I can find them again later.


Poor drive support web site

July 11, 2006

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I was screwing around with my computer and deleted a peice of software that I needed to make my wireless internet connection work. Silly mistake, normally I don't uninstall anything because it always seems to lead to problems, but I thought it was messing with something elseā€¦.. Anyway, I needed to reinstall it, but discovered that I can't find the CD. I've been straightening up and after organizing a bunch of stuff I can't find anything. Anyway, I searched for the part number in google and got to the manufacturer's web site where I could download the software. I had two options. The original version and version 4. The card itself didn't have any version listed so I tried version 1. No go. Then version 4. No go. After doing some looking around on other sites I saw people mention version 2 of the software. I went back to the equipment web site and walked thru it a different way and discover that both version 2 and 3 exist. I try v2 first, but no luck. Finally, I get to version 3 and at last the wireless connection comes back to life. Through a combination of bad (meaning no) version labeling on the physical part and a deceptive web page (only listing two of the possible four versions) I spent probably an hour and a half trouble trying to figure out what was going on and swaping software on and off my machine. This is a prime example of one of the things that the overall Computer Industry needs to start getting right. I'm fairly savy when it comes to computer stuff and it still took me what seemed like forever. Most people I know would have given up long before, and the problem wasn't with a bug in the software, it was just labeling.


Variable Vivitar 283/285 - follow up

July 11, 2006

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Yep. It works. I stopped by radio shack on the way home yesterday and picked up a box of assorted resistors (my local shop didn't have a single 100k Ohm potentiometer by itself). My flash is a 285 which has a little different pin out for the sensor. If you are looking directly at the flash, the resistor should be wired into the lowest socket in the center and the lower one on the left. Here is a shot of my first test using gator clips to wire up the flash. Vivitar 285 hack photo 1 After confirming that this worked, I bent the pins on the potentiometer and socketed it directly. (Technically, the potentiometer is really being used as a rheostat since only two of it's three pins are connected.) Vivitar 285 hack photo 2 All that's left now is to epoxy the parts together and you end up with a handy-dandy continuously variable manual strobe. In testing, with the dial in place, the max output of the strobe was about one stop under what it was without modification. Looking up online, one unofficial site has the resistance settings listed as 1/16 power at 24k, 1/4 power at 92k, 1/2 power at 168k, and an open circuit for full power. I'm not sure, but I think this means that using a 200k Ohm potentiometer instead of a 100k Ohm will get you back to full steam. So, last night while I was trying to go to sleep my mind kinda latch onto this and would let go. A potential next step would be to replace the potentiometer with a microcotroller and a set of resistors. The microcotroller could be setup to be run by remote control to choose a specific resistor set thereby providing the ability to adjust flash output without having to mess with the flash setup itself. By assigning each flash/controller setup a unique number, it would then be possible to setup lighting patters and easily switch between them. The specific application I'm thinking of would be shooting a band on stage. You could have a bunch of flashes setup around and above the stage before the show then switch out the lighting patterns during the performance from the floor. I'm envisioning the master controller being driving by a Treo or something with a touch screen so you could just tap "pattern 1" and it would light the lead singer from the side with a little back light. I've shot in a lot of bars with shitty lighting. Getting a setup like this would mean that given a little time, a ladder, and permission of the owner and band, you could get some really well lit shots.


Variable Vivitar 283

July 10, 2006

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David is in the process of setting up a light kit using ever reliable vivitar 283 flashes. I think I've mentioned before that a 285 was my main strobe for several years. I've always used these flashes with their Auto setting where the flash figures out how much light it thinks the scene needs the provides that amount and cuts itself off. Whit David's talk of setting up the kit, I got to wondering if there was a way to control the light output so that you could have a consistent, controllable light burst. The goal being, for example, to setup two 283s pointed at umbrellas and dial one back a stop less than the other. A quick google and I found this page on high speed flash photography. While the topic is a little different, the solution looks like it'll work like a champ. The salient point on that page is #5. On a Vivitar 283, remove the Auto-thyristor module and plug a 100 k ohm varialbe resistor in the right two holes (as you are facing the strobe). You should then be able to dial in the amount of light you want the strobe to release with each flash. (I haven't tried this yet, but will soon. If you beat me to it, let me know if anything explodes.) If this works, as I expect it will, I'm gonna end up buying a bunch of 283s. This will also make it easy for me to set them up someday when I start doing my infrared band photography.


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