Go Light Your World

Let us capture your your memory with our cameras. This is our blog…

Details Of The Photo Booth

As promised in a posting about the pseudo-neon sign, here are some details about the physical construction of the photo booth…

Here is the booth in action at a recent luncheon with the neon sign at the top:

photobooth at luncheon

The booth frame is constructed from 1″ electrical conduit. 3/4″ conduit would probably have worked just as well and would have been cheaper, but after buying the 1″ fittings, I was rather committed…

Here are two early photos taken during construction when I was still hanging the monitor on the back wall. (I’ve since moved it because it causes people to be looking up and off into space.) I’m also not using battery powered strobes any more.

1599780_10203192723116286_617373438_o (1)

1026174_10203192723076285_848002558_o

The conduit is joined with car port/canopy fittings I bought from Yuma’s Bargain Warehouse. (I recently discovered there is a relatively local supplier of the same fittings, Shade King, located just north of Austin, TX, so I could have bought these locally and saved the shipping cost.) Below is a diagram of the rough dimensions of the booth. I won’t bother with the specifics of the fittings and lengths because I would construct it slightly differently had I to do it all over again…

photobooth drawing

The shelf was constructed from 1×8 poplar painted black (it was on clearance at Home depot, so I bought it instead of white pine). It’s held to the frame by 1″ single-sided conduit clamps. The camera mounts to the center of the board with a Manfrotto 234RC tilting quick release mount, allowing the camera to tilt up and down for adjustment. It can’t be seen well in the image below because it’s behind the frame that holds the TV with HDMI input.

IMG_3915

The photo booth is skinned with tablecloths I bought from Amazon. These were the cheapest source of good weight material with which to skin the booth AND the edges were already hemmed. All the “real” fabric stores wanted more money for lighter weight material. Along with the tablecloths, I bought a 20 yard roll of hook and loop tape from Amazon for attaching the tablecloth curtains to the booth. More tablecloth was used to fashion a cap to cover the top of the booth. Again, I won’t bore with the details, since I don’t expect anyone to copy me exactly… The tablecloth skin can be seen in the photo at the top of this post.

Inside the booth, white tablecloth hangs as a background (unless the event organizer orders a custom printed background). Behind the camera and monitor, white tablecloth hangs as a bounce diffusion surface. Two 45 Watt-second AC slave strobes are optically triggered by the camera’s flash. The strobes and confined space of the booth allows using an aperture of F11 and pre-focusing the lens so that everything from about 2 feet out to 5 feet are in focus. (The camera I’m using is a Nikon D90 with a 24mm/2.8 prime lens, which has the focus distance markings on it.)

Constant illumination in the booth is provided by a home-made LED stick consisting of 3 meters of 3528 warm white strip LEDs stuck on an aluminum meter stick in a T8 protective tube.

The photo booth software itself is still a work in progress. It’s basically a Python script I wrote. Linux runs on a fanless quad core ARM computer (see below) with a Freescale i.MX6Q, 2GB of RAM, and a 32GB SSD inside. Everything I used is open source, mainly libgphoto2 and piggyphoto, python-pygame, and graphicsmagick. I’m reluctant to release the source code because it is not turn-key software.

IMG_3918

There are two USB flash disks plugged in. For redundancy, I copy each set of image files to multiple drives in case anything goes wrong. The additional advantage of extra flash drives is that at the end of an event, it is fully stocked with all the photos so I can deliver a purchased drive immediately. The USB hub has the wireless keyboard, the camera, and a custom “keyboard” plugged into it.

The custom “keyboard” is a microcontroller board programmed as a USB keyboard. The 50mm lighted arcade buttons (see below) provide the user input.

IMG_3916

The bottom board is a Freescale FRDM-KL25Z with a custom shield board I made on top. There is currently no differentiation in the script between the buttons, but they each generate a different letter. The buttons came from Amazon.

In operation, the Python script waits for a button push to start the sequence. Four photos are taken and displayed in succession, then two versions of composites are generated: one is intended for displaying on screens at the event and the other is a vertical strip much like what the old fashioned photo booths used to spit out. Two of these latter images side by side can be printed on 4×6 paper. All the raw source images are saved along with the composites.

All of the images are shared on the local network via SAMBA. This allows setting up several Android devices around a venue to display the photo booth images in a slide show. Although it’s hard to make out in the photo at the top of this post, there is a TV hanging from the top of the photo booth just to the right of the opening. Having this SAMBA share also allows me to look at the photos with my Android phone to check on things.

The booth is very functional at the moment but not quite ready to hire out. I plan to add near real-time uploading of the images to our SmugMug.com account (where examples of the booth photos can be seen in addition to on Facebook). I am also thinking of adding an option to print the double print strip images.

There are improvements I need to make to the booth physically as well – I need to be able to set it up and break it down in 30-45 minutes. One of the things that can help with this is to build a box to house the camera, computer, monitor and button(s) allowing all the connections to be left intact. All that would need to be done is fasten the box down and plug in the power.

One interesting side note is that the Nikon D90 will drain a battery dead if left plugged into an active USB host. To avoid the hassle of having to use, charge, and switch out batteries, I purchased an AC power supply for the D90.

 

 

Posted by by david

Add a comment

Mic Mono/Stereo Adapter, PCB version…

A previous post detailed an adapter that could combine two mono mics with 1/8″ jacks for use with a camcorder, as well as a headphone splitter so that two headphones can be used with a single jack on a camcorder.

This adapter was used to record a video.  A Rode VideoMic on a boom pole and an Audio Technica ATR-3350 clipped on the talent were used together with the mic combiner part of this design. The boom pole operator and the camera operator both had headphones on using the splitter part.

A board has now been designed that can function as either a mono/stereo combiner or headphone splitter depending on how the jumpers are configured. The board is set up so that 0.1″ headers can be used with computer type jumper blocks but the configuration can be soldered in place as well.

Here is the schematic:

monostereo-sch

The Mic Adapter configuration has three modes of operation:

  1. Two mono mics are combined from jacks J1 and J2 to J5.
  2. A stereo mic can be plugged into J1 with stereo output at J5.
  3. A single mono mic can be plugged into J2 and appears as a stereo mic at J5.

In the headphone configuration, a stereo source may plugged into any jack and two headphones into the remaining two jacks. It should be noted that in this configuration, J1 always needs to have something plugged in to keep the left and right channels from being shorted together. (This could have been avoided but it would have required extra jumper points. Boards made with the existing design can have the trace cut at J1 if this is a concern.)

The layout is here:

monostereo-brd

Boards may be ordered at OSH Park. It uses these jacks (from Digikey).

The board offers no strain relief, so care must be taken to keep the jacks from being pulled off the board.

Posted by by david

Add a comment

Yet another little board…

I successfully made and tested another board based on the QFN32 version of the KL25Z device, the smallest package it comes in. It’s a pain to solder down because the PCB pads need to be pre-wet with solder, a generous helping of flux applied, aligned via eye-ball, and then hot air gently blown so as to melt and reflow the solder. A soldering iron top is too fat to get down into the crevasse to solder.

microKL25Z

The schematic of the board is here:

MicroKL25Z-DIP-v1-board

The Eagle files and fabrication output are zipped up here: MicroKL25Z-DIP

Three boards may be ordered for $4.25 here: http://oshpark.com/shared_projects/MsCRJIem

Posted by by david

9 comments

New board for prototyping the functions of the Swiss Photoknife…

The boards from the previous post finally arrived.

Here’s a photo of the board with the KL25Z mounted along with a few passive components to make it work. The five wires on the left go over to a FRDM-KL25Z board, which supplies power and permits programming the device.

IMG_20131016_110802

All the pins wiggle as they should, so now the various functions of the Swiss Photoknife can be tested before rolling them all up into a single kitchen sink board…

 

[UPDATE 10/22/2013] This board has been shared and can be ordered via OSH Park at a slightly higher cost than Seeed Studio.

Posted by by david

Add a comment

More Printed Circuit boards…

I became very excited after having received a Freescale smart car kit. Although I have yet to get the camera mounted and make it follow a line, I have been playing with the microcontroller board that came with it, and the online IDE/compiler tool chain for it.

So excited that I just had to build my own boards for it…

There are various boards out there for doing various photographic control functions but there are no one-does-nearly-all, kitchen-sin, Swiss army knife, hackable photo controllers to be had. The boards I made will be the test beds for prototyping the various functions I intend to include on a multipurpose photo control board. More on that later as things progress.

The device at the heart of these proto boards is the Freescale Kinetis KL25Z in the 64-pin QFP package. There is a header for a Nordic Semiconductor nRF224L01+ 2.4GHz data transceiver module that’s are commonly available on eBay. There’s also a header for a Nokia 5110 type LCD display and for programming. All the pins are brought out to a hole and a little general purpose prototype area. Total cost for ten boards measuring 50mm x 50mm was $15, where $5 of it was for shipping (the vendor was Seeed Studio, for those interested; they have extremely good prices…).

I received an email this morning that the boards have been shipped back to me. Now the excruciating wait for them to arrive…

Below are the schematic and layout.

 

KL25Z-64QFP-sch

KL25Z-64QFP-brd

Here are the Eagle and Gerber files: MiniKL25Z-64QFP

Posted by by david

1 comment

Bad Behavior has blocked 76 access attempts in the last 7 days.