Monthly Archives: October 2011

AF Assist tool v3.0 – more testing

I tried out the 540ez lens with both the LED that came with the assembly as well as the LED I bought from digikey. The digikey LED was brighter then the led that came with the 540ez lens. Brightness was judged with the LED installed in the housing, and the projected pattern was the object of judgment.

However, when it came to what the camera saw, it was a different story. At 40ft (the length of my basement; can’t go any longer indoors) the camera was pointed at a blank wall, and all the lights were turned off. The LED that came with the 540ez lens assembly was able to get a focus confirmation out of my 40D whereas installing the Digikey LED in the same lens assembly, did not provide AF confirmation. This was very interesting because the same contrast producing pattern was projected, and even though to the human eye (my eye) the digikey LED seemed brighter, the camera saw something else. At 40ft, I was could not visually  see the pattern projected by the 540ez led (yet focus was confirmed by the camera). With the Digikey LED, I could see the projected pattern (just barely) but the camera was not able to use that information to focus.

The Digikey LED is of 66onm wavelength. I can only guess that the led that came with the 540ez flash is higher then that (nearer to infrared).

I also tested a few other flashes to see if I could achieve AF confirmation on the same blank wall in total darkness, 40ft away.

Canon 420ex – AF confirmation achieved (pattern just visible 40ft away)
Nissin Di622 mark II – AF confirmation achieved (pattern not visible 40ft away)
Younguo ST-E2 – AF confirmation achieved (pattern clearly visible 40ft away)

Looking at the flash quoted AF assist distance I compiled for a few flashes seems to be understated?

The Plan:

Near-infrared is starts at 780nm and goes up from there. So I’ll have to find some LEDs that are between high 600nm and 800nm
OR
Find some brighter deep red LEDs.

UPDATE:

For the next version of the autofocus tool I’m currently working on I need to test several wavelengths of IR light .
3 x IR LED 770nm (p/n: 15P2280)
3 x IR LED 830nm (p/n: 93K0966)
3 x IR LED 850nm (p/n: 97M1058)

Sizing LED resistors

For LED 2X2.5MM SUPER RED CLEAR 1.7V forward voltage, 25mA max current draw

@ 9v, need 330 Ohm resistor
@ 6v, need 180 Ohm resistor
@ 3v, need 56 Ohms resistor,

For LED 2X2.5MM SUPER YELLOW CLEAR, 2V forward voltage, 30mA max current draw

@ 9v, need 270 Ohm resistor
@ 6v, need 150 Ohm resistor
@ 3v, need 39 Ohms resistor,

For IR EMITTER 1.9MM 950NM DOME SMD,

@ 9v, need xx Ohm resistor
@ 6v, need xx Ohm resistor
@ 3v, need xx Ohms resistor,

AF assist tool v3.0 – testing

So I got some parts from DigiKey today; enough to  do some more testing. Took out the ebay purchase I’ve had for a few weeks, and got to work.
I picked up this AF assist lens from a Canon 540EZ flash, complete with LEDs.

CANON AF LED UNIT SPEEDLITE 540EZ FLASH NEW

I hooked up an LED to the 540EZ AF lens along with a resistor (200 ohm) and a 9v battery.

This is what I got in terms of a pattern. Shot on the left was from 7.5ft, then 15ft, then 30ft. At 30ft, I could barely, just barely make out the pattern on the flat white door onto which I was projecting the pattern.

The camera exposure was:  ISO:3200, aparture: f1.4, exposure: 1/40

Again I must stress, there was VERY little light on that door from 30ft away, however the AF sensor on the camera locked in an instant. Maybe took a fraction of a second longer then from the 15ft distance, but it was hard to say.

I can hardly believe that such little amount of light can produce such a focus lock on a flat color (white) door in total darkness.

I took out my 420EX flash and fired the AF assist light (was not able to capture it since the flash was on the camera, and the light goes off once AF is achieved) and the light is much brighter. Maybe 1-2 stops brighter from 30ft. Maybe I need to use a lower value resistor to get more power out of the LED that came with the 540ez lens, or just replace it with a brighter LED.

Either way, it looks like adding contrast is MUCH more effective then just adding light to help the AF sensor focus and the idea of using a flash AF assist lens is looking much more promising then the laser pointer idea.

The 540ez lens module is kind of bulky. I would prefer it to be a little slimmer. The AF assist lights in my 420ex is made of 2 side by side lenses which are a better size. Will need to scope out some of those lenses.

Pocket Wizard Flex system : now works with more flashes

I had purchased a PW Flex TT1, 2 flex TT5s and an AC3 a while back and could not get my Sigma EF-500 DG Super or the Nissin Di622 MkII to adjust their power. The Canon 430EX I owned would work beautifully (Of course, it was on Pocket Wizard’s compatibility list).
The Sigma and Nissin flashes fire, but they always fire at full power, no matter what setting I chose on the AC3 or the camera FEC.

I had installed version 6 .00 of the Flex firmware a while back when it came out (a month ago or so) but never re-tested the Sigma and Nissis flashes. The compatibility list on the Pocket Wizard website had not changed.

I was preparing for a photo shoot and was testing all my gear, and I accidentally put the Nissis flash on a Flex TT5 unit. To my amazement, the flash power was adjusted! I was amazed!
I then quickly tested the Sigma flash, and it too worked. The power was adjusted as per the setting on the AC3 contreller. All of a sudden I have 2 more flashes that I can use on the TT5 units!

Horray!

If you have a Flex TT5 unit, and own either the Nissin or Sigma flashes I mentioned above, please test them and let me know if they work for you.
Just to mention it again this change has been in effect only since the firware 6.00 has been released for the Flex TT5/TT1 units.

UPDATE:
The Nissin works great; rock solid especially in manual mode. No HSS though, but they have their time and place.

As for the Sigma, I have some reservations. The shots fired are hit and miss. Some are proper exposure, some are not. There’s the occasional firing of the flash by itself. And the biggest gripe is that the pocket wizards fail to communicate with each other way too often. The dreaded red blinking light. I have not found a pattern as to why/how this happens. Maybe to much interference from the flash?
It’s too bad though, since these flashes are quite powerful and inexpensive.

CNC conversion

I’m now in a position to actually start the CNC conversion of my milling machine.

CNC4PC site has a  LOT of great stuff to get. Between it and the Keling site, I should be able to get all that I need for the conversion.

What I should need:

3 x KL-5042 or KL-6050 : $41 ea
3 x KL23H2100-50-4B : $55 ea
1 x KL-350-48 : $50

Total = $338

And From CNC4PC

C35 Breakout board : $39
Limit Switches : Mechanical or Optical : $78
E-Stop button : $10
3 x Ethernet to Keling driver adapter : $4 ea

Still need: cable for power from controller to motors.
Also posted a question on CNCZone.com to see if I’m missing anything critical to my parts list.

So far by my calculations, the total is US$569

Bacula and webmin setup

Tried to install Bacula on webmin. After a bit of fussing, got everything squared and working. Shame there’s no list of dependencies; anyway, here it is for OpenSuse 11.4.

Assuming Webmin is working.
To install bacula, need to add a new repository

zypper ar http://download.opensuse.org/repositories/openSUSE:/11.4:/Contrib/standard/openSUSE:11.4:Contrib.repo

Install the packages bacula, bacula-director-common, bacula-storage-mysql, bacula-console

The bacula package is faulty (source). in #/usr/sbin need to replace the zero size files bacula-dir, bcopy, bscan and dbcheck with their .mysql counterpart by doing something like this for all the files:

#ln -s bacula.mysql bacula

Add mysql by installing these packages mysql-community-server,  mysql-community-server-client

Also need DBD::mysql perl package. for which we’lll need another repository installed:

zypper ar http://download.opensuse.org/repositories/devel:/languages:/perl/openSUSE_11.4/devel:languages:perl.repo

Install the package perl-DBD-mysql

Now need to configure mysql. Set my mysql root password with this:

/usr/bin/mysqladmin -u root password <choose your password to put here>

Then while logged in as root, run

#mysql –password=<password set above>

and create database in mysql by typing “create database bacula;” while in mysql.

In Webmin, add the root sql password to the bacula config screen. Change the user from bacula to root.

 

 

Still not working.

Interesting Hackaday projects

Which resistor values should you order for all circumstances?

ATmega328p Videos

The cheapest and easiest 3D printer we’ve seen so far

Building a 1300 lumen bike light

An introduction to stepper motors

Aluminum bending tutorial and a DIY brake

Etching your own PCBs

DIY: How to bend aluminium the easy way with a home

Video: Learning Eagle CAD part 2

8 Breadboard Hacks

Video: Eagle CAD Layout

Quadcopter build ready for first flight/Build log