A Photoduino variation

Well, I'm sure someone has heard of the Photoduino. A DIY controller for cameras and flash units based around the Arduino.

The Photoduino has a bunch of sensors such as audio, light, pressure and can control various devices such a camera, flash units, laser, LED, solenoid and whatever you can plug in to it.
I  built mine based on the photoduino website and made a few changes, mostly software. The biggest difference is the screen, wich originaly is a small LCD with a parallel interface. I had this lovely VFD display lying around and it ended up in the project.

Now the VFD is a serial device so that meant changing the code and making the software play nice with it. While doing so I decide to do some modifications with the buttons, menus, configurations, multiple languadge support, volume control, extra control ports and provably other minor changes.
The software is based on version 9 and hence the ALT meaning alternative version.

A small mishap (or rather, a string of bad luck) meant burning:
2 Atmega328
1 Atmega8u2
1 USB to serial adapter
1 Disconfigured VFD
If you include the eBay shenanigans, other things breaking, burnt fingers, having to travel 200km for parts and forget something then you could say it was a pretty depressing week!

I never really figured out what killed the Arduinos. The VFD used to share the serial TX from the Arduino so when I programmed the sketch I had to remember to turn the display off or garbage would be displayed on the device. But worse than garbage is changing the configuration parameters of the VFD and it's subsequent lack of functionality, hence the 200km trip to pick up the original VFD wires, install a virtual windows XP (the software only works on XP or previous), setting the configuration and getting everything back up and running.
During this proces the USB adapter and Arduinos died. All 5V TTL signals, current limiting resistor on the serial lines, working in a ESD safe area, verifying the dead microcontrollers with AVRDude, all grounds connected... No idea of what happened.

The photoduino now runs on a damaged arduino with a dead Atmega8u2 programmed via ICSP and the VFD runs on a sofware serial pin with an apropiate current limiting resistor (even the atmega8u2 had resistors on the serial lines and died)

I finally got around to labelling the conectors, a great improvement in functionality! Well... more like less wasting time guessing which conector does what.
Another change is an extra IO used exclusively for IR remote control of the camera.

The cheapest enclosure I found is a storage box from a hardware store. Such a waste of space...

Actually it doubles as a container for the sensors, cables and power supply!

Did I mention L.A.S.E.R.? Everything is better with mighty lasers!

Oh, yeah! And a sample shot that left me with a very oily kitchen and popcorn everywhere!

Read More!

Read Less!

Mini flash with optical slave

Normally each year around christmas I will be involved in a couple of Secret Santas and one of them is a "all hand made" type where buying the gift is not allowed. Some very creative gifts have showed up!

Turns out I had to come up with something for a photographer... being one myself I know there are many usefull things to make but many are expensive or take a decent amount of time to build.
In comes a mini slave flash with an optical trigger!

Like many projects things don't tend to run to well on schedules so I deadbuged the circuit of a disposable camera flash so it would fit inside the case and have room for the battery (nope, didn't happen!). Here is the circuit diagram for the flash from Sam's repair faq.

In order to squeeze the battery inside of the case everything needed to be small and well laid out. Unfortunatly the transformer is what ultimately stop my from my goal. I had to come up with a small and simple trigger for the flash unit. Provably too simple if used in broad daylight, but i works reliably in bright artificial lighting.

Three components make up the trigger. This conects directly to the trigger pins of the flash circuit.

Here is a side view of the little flash unit.

And another from the back. The beam pattern is maybe a bit too wide but it'll do!

And a size comparison to a comercial flash unit.

So what could it be used for? Small spaces, highlights, inside objects... lots of uses!

The person I gave it too seemed to enjoy it quite a bit. I hope he can find a use for it.

Read More!

Read Less!

Studio strobe power hack.

Hello again everyone. Today I shall share a usefull hack for cheap photographers like me. Story time; I bought a couple of monoblocks on eBay a couple of years ago, and after lots of thinking I settled with the Godox Mini Pioneer 300DI. Why? Because two of them cost me 270€. With shipping. So, what is the catch? They are pretty close to 300W/s. They do work. But the power control is miserable. 1/3 to full power... not what is advertised!

Last year I added a switch and some diodes but that didn't work too well, especially when I accidentaly flipped the switch with one bank of capacitors fully charged and the other bank pretty empty... result? A very strong weld inside the switch. Lets begin!

Here is the circuit diagram, pretty simple. Two 3A diodes are responsible for the capacitor charging and blocking revers current flow. A larger 60A diode with a surge rating of 950A is used for blocking the charge from one bank to the other and allows the bank to discharge into the flash tube. The strobe has a 10A/300A diode in series with the flash tube but I think that it might be pushing it so I used what I had on hand.

Please be carefull as there are high voltages and juicy capacitors inside. If you don't know the dangers then I suggest you don't do this.br />

Please ignore the yellow wiring and the power resistor. That is my old hack.

This is the flash end of the strobe, to take it apart we need to desolder the four wires and disconect the trigger coil.

The boar can then slide out the back, here are the conectors for tha back panel and their names.

The front end desoldered.

The hollow case.

The top control board. From left to right and top to bottom;
Sync terminal. "Isolated" with an optocoupler but the negative part of the IRLED is conected to mains with a resistor. So much for bein isolated... I do not recomend using these strobes with a PC cable.
Discharge diode. Used to double the tube voltage when firing. Page 5 of this document.
BTA16 Triac. Used for the modeling lamp tracking.
PIC12C508A. Sole purpose is for pre-flash control.
12v Zener diode to power stuff.
Buzzer and buzzer switch terminal, I cut the link to remove the anoying beep.
TL7805 voltage regulator.
BTA20 Triac. Provably to control the charging circuit.

Capacitor bank and provably a voltage doubling circuit. 7 800uF caps rated at 360V.
A total of 5600uF charged to 330V gives 304Joules.

Underside of control board. A small SH69P86 micro controller is provably responsible for all of the functions. Wich aren't many.

Underside of the capacitor bank. Again, please ignore my awefull hack.

As you can see, the track width is very small on this trace. Especially when it's the discharge path for the flash... Scrape away and apply some solder to help things a bit!

Onto the hack! First I removed my hideos hack and bridged it. Then I cut the track as to separet the bank into two banks of 2 and 5 caps (do as you wish here). And finally at the rightmost part I cut the trace from the charge circuit.

Here I placed the charging diode for the small bank.
Important note! You must place a resistor to the same place as the diode because the diode blocks the reverse voltage and the charge control will not know if it is charged or not! Mine simply didn't charge above 150v, some might continue.

I used a 4.7k resistor as it only draws 300uA. Values up to 100k work but the charge voltage goes up to 350V wich for cheap 360V caps is provably not the best idea. But hey if you want more power now you know!

Edit; Here is a picture from my other strobe of the resistor in place.

Here I have placed the switch, the second 3A diode, the powerful 950A surge diode and I have conected the main board again.

Important detail! The ground wire is conected to one of the scews, don't forget it.

Reconecting the flash head.

Back into the housing. This is where I soldered the 4.7k resistor, on top of the diode. I had to be carefull not to melt the wires. Yeah, I'm lazy.

New switch, uppside down but that can be fixed.

It lives!!

Now for some numbers with my trusty L-358!
The difference between low power and high power with the small capacitor bank is 2.2 f stops.
The difference between low power and high power with all the capacitors is 2.4 f stops.
The difference between 7 and 2 capacitors on low power is 1.5 f stops.
The difference between 7 and 2 capacitors on high power is 1.5 f stops.
The difference between low power with 2 caps and hig power with 7 caps is 3.7 f stops.

When I get hold of some more 3A diodes I will modify my other light!

Happy hacking!


Oh, and if you got this far, check out my photos as many studio shots are taken with these.
http://www.flickr.com/photos/oid-w/

Read More!

Read Less!

Asuka Langley

Something arrived in a box! What could it be?

Wow! I didn't expect this! It's the prize from the Otacool project! I thought it would take a while to arrive. Apparently it arrived before but no one was home...
So here is my second copy of the Otacool book and a nice letter from Kotobukiya.



Also included is the marvelous Kotobukiya Asuka Langley from Neon Genesis Evangelion 2.0. I first saw her on Danny Choo and I was amazed at how lovely she looks!



Opening the box was a challenge, due to static electricity, my arch nemesis. Once opened I battled through some more static plastic and got a good look at the base of the figure; a bust of Eva 02. It is very detailed!



Now onto some pictures!



The hair is slightly transparent and it gives a nice glow to the figure. It's a very nice detail.



Asuka has a lovely expression which is another strong point for me.



The paintwork is really nice although there are a few black lines that are very thin, as is the attention to details in the figure.






Thank you to everyone related with the Otacool project!

Read More!

Read Less!