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MarkB
12-19-2006, 11:53 AM
A How-To Project: Make your own stereo photo slide bar

I’ve always enjoyed the 3D effect of stereo photos. Adams on the Pinhole Forum motivated me to make a slide bar for my camera so I could experiment on my own. Here are links to 2 of Adams’ posts (camera, images):
http://f295.f295.org/uploads/Blah.pl?m-1162171634/s-7/highlight-/#num7
http://f295.f295.org/uploads/Blah.pl?m-1162513852/s-0/highlight-/#num0

The slide bar allows you to take 2 sequential, side-by-side photos of the same scene, rather than simultaneously exposing 2 images.

This took 2 or 3 hours to put together. Mainly I’ll just show photos below with a few tips, rather than step-by-step instructions. It’s pretty easy and self-explanatory.

Total cost to me was about $2 for a package of threaded inserts. I had all the other materials on hand (scraps from earlier projects). If you had to buy all the materials you could still do it for under $10.

The overall dimensions are:
16cm long (when top plate is centered on base)
7.5cm wide
3.5cm high (total height of top + bottom plates, assembled)

First 3 pictures are:
SB 01 – overview, showing the sliding plate moved to one side.
SB 02 – overview, showing the SB on a tripod with a pinhole camera mounted.
SB 03 – stereo pair taken with the SB (using a lens/digital camera, not pinhole).
Use the “crossed-eyes” method to merge the 2 images and get the 3D effect.
Attached files http://f295.f295.org/uploads/sb_01_8058.jpg (http://f295.f295.org/uploads/sb_01_8058.jpg)

MarkB
12-19-2006, 11:54 AM
next...

Attached files http://f295.f295.org/uploads/sb_02_9607.jpg (http://f295.f295.org/uploads/sb_02_9607.jpg)

MarkB
12-19-2006, 11:54 AM
next...

Attached files http://f295.f295.org/uploads/sb_03_3735.jpg (http://f295.f295.org/uploads/sb_03_3735.jpg)

MarkB
12-19-2006, 11:55 AM
SB 04 – shows an end view.

I cut the wood (3/4” thick oak) to size on a table saw, cut the slots also on the table saw, then sanded the pieces.
Attached files http://f295.f295.org/uploads/sb_04_2389.jpg (http://f295.f295.org/uploads/sb_04_2389.jpg)

MarkB
12-19-2006, 11:55 AM
SB 05 – shows detail of the side.

The “guides” are made of aluminum extrusion that you can find in a hardware store. I had this on hand – each leg is 1” long, and they are about 1/16” in thickness. I cut them to length with a hacksaw and rounded the corners with a file.

I drilled holes in the aluminum and the wood base for the screws. I filed a small notch in the middle of the rail and painted it black with some acrylic paint (that makes the reference mark visible above the screw). I created the scale on the computer, and glued it to the sliding bar when everything else was done.

After assembly the sliding action was very stiff, so I sanded the edges and bottom of the sliding bar until I got the amount of resistance I wanted.
Attached files http://f295.f295.org/uploads/sb_05_5281.jpg (http://f295.f295.org/uploads/sb_05_5281.jpg)

MarkB
12-19-2006, 11:56 AM
SB 06 – shows the bottom of the 2 pieces.

For the tripod mount I used a threaded insert bought in the hardware store. Drill a hole so you can recess the flange part of the insert, then drill a smaller hole for the body. Tap it in place with a hammer.

You can also see here the second bolt -- a 1/4-20 bolt – that goes through a hole drilled in the sliding block to attach the camera.
Attached files http://f295.f295.org/uploads/sb_06_7257.jpg (http://f295.f295.org/uploads/sb_06_7257.jpg)

MarkB
12-19-2006, 11:56 AM
SB 07 – this is what the threaded inserts look like (you only need one of them for this project).

Attached files http://f295.f295.org/uploads/sb_07_9049.jpg (http://f295.f295.org/uploads/sb_07_9049.jpg)

MarkB
12-19-2006, 11:57 AM
SB 08 – how to make it smaller.

I used some aluminum angle extrusions that I already had on hand, but the legs that stick into the slots on the sliding block are longer than necessary. This makes the whole device wider than it really needs to be. You could use smaller aluminum, or cut down one leg, to make a narrower slide bar (see drawing of smaller sliding bar).

Note: There is no means to keep the sliding bar “captive” on the base. If you don’t pay attention you could possibly slide it off the base and your camera would fall down. Not good. Attached files http://f295.f295.org/uploads/sb_08_5897.jpg (http://f295.f295.org/uploads/sb_08_5897.jpg)

JoeVanCleave
12-19-2006, 03:18 PM
This is a real nifty idea, well executed.

I like your example set of photos; I have a Barista machine identical to yours; in fact, I'm drinking a latte just now, watching the snow come down.

MarkB
12-19-2006, 08:49 PM
Stewart emailed me with this very elegant solution to "capturing" the sliding part of the device. (Stewart I hope you don't mind me re-posting your comments). Thanks for a great idea. Mark

- - - - - - - (from Stewart) - - - -
First, I wanted to say what a great job you did with the how-to. In reference to the potential problem of the block sliding out:

http://www.f295.org/DIYforum/cgi-bin/forum/Blah.pl?b-misEquip/m-1166543630/

A channel could be routed on the bottom of the top block of wood and a matching channel routed on the top of the bottom block. Drill a hole at one end of the routed channel on the top block, drop a small marble or ball bearing in and plug the hole. The block will still move, but it will no longer slide far enough to fall out of the enclosure, as the ball bearing will catch when the opposite ends of the channels meet! To remove the block, remove the plug and turn the slide bar upside down and shake the ball bearing out.

Maybe it isn't practical and maybe it wouldn't even work at all, but I wanted to get my thoughts in just in case it would help save a camera or two!

Thanks,

Stewart

paulbeard
12-19-2006, 11:45 PM
This is great, I saw it in the MAKE blog feed.

Ignoring your disturbingly tidy kitchen (gah, how does he do that?), do you have instructions to build a viewing stand?

MarkB
12-20-2006, 09:13 AM
...tidy kitchen

(I thank my wife for the state of the kitchen)


...to build a viewing stand?

I assume you mean a stand to view the images(?)... Here's what I've been doing so far. When I get an image-pair that looks good on the display, I print it -- I've got a couple of packets of 4"x6" paper for printing snapshots on an inkjet printer (got them cheap, on sale). This seems to be a useful size, and gives a sharp image. Then I just hold it up in front of my face, cross my eyes, and enjoy the stereo effect.

timeruinsbelief
12-20-2006, 09:58 AM
are thoes inserts as sturdy as the ones with screw threads on the outside? i love them but the HUGE threads make them such a pain in the you-know-what to get in.

MarkB
12-20-2006, 11:23 AM
are thoes inserts as sturdy as the ones with screw threads

TRB: I have used these same inserts (bought at Home Depot) on all the wooden cameras I've built in the last 18 months or so. I have not had any problem with them loosening or pulling out. Just make sure you use the right sized drill bits (read the package). When I insert them I first run a bolt with a nut on it into the insert and then hammer on the bolt rather than the insert itself. I'm very pleased with them so far.

timeruinsbelief
12-20-2006, 04:55 PM
thanks, without fail- trying to screw in the threaded inserts is always the most stressful part of the build for me, i'll give these a try! thanks much!!

EMolczan
12-21-2006, 01:27 AM
Great project. Well done.

The cross-eyed method of viewing gives me a headache. For viewing options try here:

http://www.berezin.com/3d/viewers1.htm

A lorgnette is an cheap tool to have around. They also have lenses to build a viewer.

MarkB
01-28-2007, 12:07 AM
I used Stewart's design (see earlier post in this thread) to "capture" the sliding bar using a ball bearing in a channel. I routed matching channels in the top and bottom parts of the slide bar. I put in a ball bearing and reassembled. Works like a charm... the top piece can't slide off the base now. Here's a picture showing the channels before re-assembly.

Thanks Stewart. Attached files http://f295.f295.org/uploads/img_3304_1690.jpg (http://f295.f295.org/uploads/img_3304_1690.jpg)

retroshooter
02-23-2007, 05:29 PM
I have used the drive in tripod screw things on several wooden rail type cameras.. I second the use the right size drill bit if not you will definitely split the wood.