Sunday, October 30, 2016

Connecting A Pair of Twin Camera Bars

These are the instructions for connecting a pair of twin camera bars. Each bar is described in this blog: http://drt3d.blogspot.com/2016/10/twin-camera-bar-by-drt.html

I sell these bars and also supply a pair of bars, a connecting plate, and 4 screws, as you see here:


Start by putting the two bars side by side. Remove the plastic stoppers. You can remove the friction pads if you like or you can leave them on. The connection will feel more secure without the friction pads.

Connect the two bars with one sliding platform. From the pair of bars you have 4 platforms. You only need two for the cameras so you can use one of the other two to connect the bars.




The platform can be enough to hold the two bars together, but for extra support, I recommend that you use the aluminum plate to connect the bars. To do this, align the plate. The two outer openings align with the bar holes (these are standard ¼”x20 tripod sockets). Secure the plate with a pair of screws. You can use the larger screws that are easy to tighten by hand, or use the smaller screws. You can tighten the smaller screws by hand or use the the Allen (hex) key (same key as the one supplied with the bars).





Using the smaller screws will allow you to attach a thicker handle between the screws, as seen here:



If you are using longer lenses, you might want to use one of the other tripod sockets that are forward in the plate, to get a better balance.

What I like about the twin bars is that they attach to the side of my compact photo bag so I can carry everything neatly as seen here (everything that you see on the left picture fits in the camera bag as you see in the right picture - I have a separate blog about this):


Here is a picture of me with the pair of the bars, Samsung NX1000 cameras connected with a wired twin remote and 50-200mm lenses, for long distance action shooting:


If you want, you can use two grips to hold the double bar. You can attach each grip at the center of each bar.

Twin camera bar by DrT

I have been using twin cameras for stereo photography for a long time. Back in the "good old film days" I used twin Minolta (X700) and later Pentax cameras. I now use: 1) Panasonic LX5 wired internally by Ekeren. 2) Panasonic GX1 (or GX7) with a wired remote or wireless. 3) Samsung NX1000 cameras (see my blogs on this system). Others use Canon camera and SMD or a variety of cameras with spliced remote cables.

I have looked for a good twin camera bar. I was using bars by Jasper Engineering but these were not made any more. Also, they were a bit heavy and rather expensive. There are plenty of inexpensive twin camera bars but they leave something to be desired, in my opinion. So, I ended up making my own twin camera bar, shown here:



To make this, I buy the parts and put the bars together myself. So they might have some small imperfections due to the fact that they are custom-made by hand and not factory-made. But they work very well. Also, they might be slightly different than the ones pictured here but quite similar and identical in specifications and function.

What I personally like about this twin camera bar is that it is lightweight (due to the large openings that you see in the pictures - note that the weight of the bar itself is about the same as the weight of the platforms) and also sturdy. It will support most cameras without problems. Also, the sliding platforms allow you to change the spacing of the cameras without disturbing their alignment. (Note: The platforms move by friction only.)  Finally, it is possible to connect two bars to make one of twice as long but still easy to transport.

Parts:




(1) Bar (rail) 300mm (~12in) in length
(2) Pair of sliding platforms (see below).
(3) Allen (hex) key, 5/32" size (about 4mm) needed to attach the cameras to the platforms.
(4) Nylon stoppers: Standard 1/4"x20, attach to the bar and prevent the platforms (or cameras!) from falling off. They can be removed if desired. Other screws or accessories can be attached there too.
(5) Tripod support via 1/4" adapter. It can be removed to reveal a 3/8" socket, if needed.
(6) Friction pads, prevent the bar from sliding on a smooth surface or scratching furniture. They can be removed if desired.

Specifications:


  • Length: 300mm (12").
  • Weight: 125g (6.5 oz) without the platforms (bar only) or 330g (12 oz) with the supplied platforms.

Instructions for Use:


  • Attach the cameras to the sliding platforms using the supplied hex key. The large platform screw goes normally to the back of the camera.
  • Make sure that the platform is parallel to the camera (look at the back) and tighten the screws using only hand pressure.
  • Place the platforms (with the cameras attached) over the the bar and tighten the platform screws so the cameras do not move around.
  • Loosen the platforms to slide the cameras to change the spacing of the cameras as required, and tighten again. 
  • You can converge the cameras for close ups. You can also change their vertical alignment by changing the loosening one platform just a bit (not a lot).
  • You can use the stoppers or not, it is up to you. If you are not using the stoppers, be careful that the camera(s) do not slide and fall off the rail (it has happened to me!)
  • Put the Allen key somewhere that you can find it when you need it.

Sliding Platforms

 

The beauty of this system is that the cameras are attached to sliding platforms (rails) which slide (with friction) when attached to the bar. So you can very easily change the space of the cameras without loosening anything and risking rotating the cameras. But you need a small Allen key (supplied) to attach the cameras on the platform.

The platforms are spring loaded and can be tightened or loosened to your satisfaction. I often use 100-300mm lenses with my GX1 cameras. At 300mm these lenses are equivalent to 600mm and any (vertical) misalignment is obvious. I am able to slightly converge the cameras on the platforms (for close-ups) and also achieve perfect vertical alignment by tightening or loosening one of the platforms a bit.

The same platforms can be used with other bars too. For example I use them with a long & heavy bar from Really Right Stuff.

You can also use different platforms if you like, to replace the standard platforms supplied with the bar. You can find these from many vendors. They come in a variety of sizes and shapes.

The screws in the rails are standard 1/4"x20, 5/8" length. The Allen key is 5/32". The screws are being held in place by the rubber pads who also serve the purpose of holding the cameras in place better. You can remove the pads if you need to (be careful not to lose the screws if you remove the pads).



Camera Spacing:

With the stoppers used, the cameras can be separated up to 205mm (approximately 8 inches). Without the stoppers, you could extend them all the way to 12 inches, but with the rails hanging out of the bar (do this with care!)

It is possible to connect two (or more) bars to make a longer bar -  see a separate blog on this: http://drt3d.blogspot.com/2016/10/connecting-pair-of-twin-camera-bars.html

 

Extra comments:
  • I find a grip handle useful for holding the bar. I like this particular handle shown here because it both soft (lightweight) but also substantial.
  • I used to make a longer twin bar (16") but I could not find the parts and stopped making it. From experience, there is not much difference in the pictures taken with these two stereo bases. Plus, the 12" bars are easier to carry and also attract less attention through security screenings, etc. 

Here is a picture of me (from 2015) and this slide bar with twin Panasonic GX1 cameras, with a wired remote:


Thursday, October 27, 2016

Twin Samsung NX1000 For Stereo – III - Firing

This is part III of a series of blogs regarding using twin Samsung NX1000 cameras for stereo and deals with ways to fire the pair of cameras.

Most Samsung NX cameras can be fired via the camera's micro USB port. This is on the longer side of the camera, which is fortunate because it makes the z-configuration possible.


The schematic above (from:  https://antibore.wordpress.com/2013/04/30/diy-remote-shutter-release-for-samsung-nx20-nx210-and-nx1000-cameras/) shows how the remote uses the micro USB port for shutter remote control. There is a resistor between pins 4 and 5. Focus is achieved by shorting pins 2 and 5, and the shutter is fired by shorting pins 3 and 5, but only if the resistor is present. The resistor is built into the specialty cable used for remote control of the NX cameras.

This is a picture of a typical Samsung NX remote cable:


There is a male micro USB plug on one side and a 2.5mm plug on the other. What is not seen is the built-in resistor that makes it work as a shutter release cable for the Samsung NX cameras.

To fire two cameras at the same time, you need to connect two remote cables into one switch.

Here are some useful products for firing a pair of Samsung NX cameras:



  1. Wired twin remote by Werner.
  2. Standard Samsung NX remote by JJC (the switch is seen in the front, the cable is in the back, not seen in the picture).
  3. Samsung NX remote cable by JJC.
  4. Right Angle micro USB cable
  5. 2.5mm twin cable connector (combines two 2.5mm plugs into one 2.5mm plug).
  6. 2.5mm male to male coupler (connects two 2.5mm plugs).
  7. Wireless remote for Samsung NX by JJC.

Here are some connecting options:


A. Werner-twin remote (1): This is a complete solution. Connect each plug to each camera and fire the cameras by pressing the switch. This remote is a bit bulky (long and heavy) but the cables are of good quality. The switch has a plug on the side (see picture below) where you can attach a wireless remote to fire the cameras from a distance. This is the remote that I use most often. I import this from Germany and offer it for sale in the USA.



B. Pair of standard remotes (pair of 2, or 2 and 3) connected with a connector (5): Get a pair of the JJC remotes (2) or one remote (2) and one cable (3). Plug each cable to each camera. Connect the ends to the connector (5). Connect the end of the connector to the switch that comes with the JJC remote and use this switch to fire the cameras.




C. Wireless Remote (7) cable (3) and connector (5):  This is a variation of B. Instead of the standard JJC remote, get the wireless remote. Then you can fire the cameras either by pressing a button on the receiver or the button of the emitter. The cameras can be fired from a distance by using the emitter. An interesting feature of the emitter is that it has a timer so it can be used as a timer too.



If you have pair of wireless remotes, you can fire the cameras without connecting the cables. Attach each receiver to each camera and fire both cameras with one emitter.  I am not sure how this affects synchronization (my feeling is that it does not). The advantage is that you can separate the cameras at any distance, since they are not connected with wires.



A comment regarding wireless remotes: While these need power (batteries) to work, you can still fire the cameras by pressing their switch even without power.

D. Pair of Remote Cables (3) and a coupler (6): An interesting fact is that if the cameras have their remote cables connected (as in any of the above methods) they can be fired by pressing the shutter button of only one camera. So, one could use the simplest of configurations, two remote cables (3) connected with one simple connector (6) and use one of the camera shutter buttons to fire the cameras.


One peculiarity of the twin remotes is that when one camera is turned off, the other camera will fire. Or when one camera is turned on while the other is off, the camera will fire. This is happening because the camera that is turned off acts as a closed switch. To avoid this, I turn on and off both cameras as the same time. If only one camera fires, I delete the picture. Before processing the pairs, I always check and delete any extra pictures.

In my opinion, the remote control is the weak point of these cameras. The micro USB plugs and cords are not as reliable as the standard 2.5mm or 3.5mm plugs found in other cameras (the Panasonic micro 4/3 cameras, for example). Some inexpensive cables fail after a while. The cables stick out on the side and can be bumped and end up damaging the camera’s plug. To avoid connecting troubles, I recommend two things:
- Use good quality remote cables
- Use 90 degree extension cables (4)

The 90 degree extension cables for me are a necessity. They protect the camera plug and reduce the spacing of the cameras when placed side-by-side and touching. I leave the extensions permanently in the cameras and attach/detach cables to the extensions, not the camera plug itself. This picture compares a standard cable (left, see how it is ticking out) vs. a 90 degree extension cable (right):


A Word of Caution: Most 90 degree extension cables or attachments for sale will not work with the remotes because they do not have all the pins connected. (I believe no. 5 is not connected). They still work for other things, like charging the battery, but not for remote. I had to special-order 90 degree extension cables with all the pins connected.

You can get a pair of 90 degree extension cables with Right and Left orientation. If you connect the R cable to the R camera and the L cable to the L camera, in the z-configuration both cables point down as shown in this picture:


Potential Connection Problems:

If you have a problem with one camera not responding to the remote (this is happening with one of my cameras, not sure why), try these solutions:
  • Unplug and plug again the remote cable
  • Turn on/off this camera (or both cameras)
  • If the problem persists, switch cables. If the same camera does not respond, then the problem is with the camera. If now the other camera does not respond, then the problem is with the cable. In this case, try a different cable.

One last but important note: If you are using auto focusing, you must half press the button (of the camera or the switch) for the cameras to lock focus before pressing the shutter button fully for the cameras to fire. If you hurry, the cameras can focus at different times and synchronization will be off.

Wednesday, October 26, 2016

Twin Samsung NX1000 For Stereo – II - Mounting

There are a number of questions/issues that I would like to discuss:

1- What are the advantages of the NX1000 for twin camera stereo?
2- Mounting a pair of Samsung NX1000 cameras
3- Firing a pair of Samsung NX1000 cameras
4- How good is the synchronization?
5- What are the best camera settings for twin camera stereo?
6- What are some good lenses for these cameras for stereo use?
7- Are other Samsung NX cameras suitable for a twin camera rig?
8- How do you process stereo pairs taken from these cameras?
9- Samsung twin rig vs. other cameras

Note: I decided to break the topics above to more than one blogs, as they were getting quite long. I will revise these blogs as I gain more experience and get feedback and information from other users of this system.

1. Advantages of the NX1000 for stereo


The two big advantages are:
  1.  Lenses come very close together in the z-configuration
  2. Good synchronization, including flash (I discuss this later under #4)

To understand the first one, look at this picture of the NX1000 from the top:



The lens is offset (off-center), more than other cameras of similar sensor size. When one camera is turned upside down, the lenses came quite close. How close? Depends if you remove the lugs on the short end of the camera:
- With the lugs in place: 72mm
- With the lugs removed: 68mm

I personally try to get the lens spacing as narrow as possible. I started in stereo photography with a Realist (70mm). Later, I got an RBT S1 (59mm) and I enjoyed using the RBT a lot more because of better image quality, wider images, and also because I was able to get closer to my subject, thanks to its smaller lens spacing. With digital, I find Fuji’s 75mm to be too much in many situations. Panasonic’s 30mm is good for close-ups but falls short for normal stereo. For me, the ideal stereo camera has a lens spacing around 50-60mm. The 68mm possible with the NX1000 is still a bit larger than the ideal for me, but better than many alternatives. So, the narrow lens spacing is the biggest attraction for me in this twin camera rig.

Given my desire to reduce the lens spacing, I removed the lugs from my cameras. There are two ways to do this: You can open the camera to remove them, or you can cut them/grind them off. I tried to open a camera until I reached the point where I was uncomfortable digging in further. It is not easy. So, I ended up cutting the lugs and filing smooth what’s left. This of course reduces the value of the camera if you ever need to sell it as a 2D camera but I think it increases the value is sold as part of a 3D camera. Here is how my cameras look with the lugs removed. Not particularly pretty, but functional:


2. Mounting a pair of NX1000 cameras


The cameras can be mounted in 4 different configurations:
- Z-configuration
- Side-by-side
- Bottom-to-bottom
- Top-to-top

Z-Configuration


The Z-configuration is the most useful, in my opinion. In this configuration one camera is used upside-down to reduce the spacing of the lenses (hence the "Z" name). With the NX1000 cameras the closest spacing in the Z-configuration is 68mm (with the lugs removed), or 72mm (with the lugs in place).

There are two mount options:
- Traditional Z-mount
- Werner-mount

A traditional Z-mount holds the cameras from their tripod sockets. As far as I know, there is no commercial traditional z-mount for sale, but some people (myself included) have made their own. Following instructions from Bob Karambelas, I used a twin aluminum channel and cut it, to produce the z-mount shown here:




Here are a few notes for anyone thinking of doing the same:

- From ThyssenKrupp Online Metals, I purchased a piece of “Aluminum 6063-T52 BareExtruded Channel 3" x 1" x 0.125" Cut to: 24", Item #: 9712”

- I measured the cameras and made a quick diagram:


This is a poor sketch with overlapping revisions, but the main points are: Center "Column" is 20mm. The legs extend 65mm from the center to one side (the other side can be omitted, this makes cutting easy). The step that holds the cameras aligned should be 12mm in height (I made it 10mm but forgot to account for the fact that the cameras will be raised a bit - see below).

 - For the aluminum machining work I bought a jig saw (Rockwell RK7323 Blade Runner X2 Portable Tabletop Saw) per Bob's recommendation.

- After I cut the main  piece, I drilled the mounting holes by measuring the cameras. I made these a bit larger to have some freedom to move the cameras. Ideally, these holes can be elongated channels to make it possible to change the camera spacing. Finally, you can tap a mounting tripod hole (I had to learn how to do that). For finishing touches, round all edges.

- The distance between the top and bottom edges of the channel is 69.4mm while the cameras are 63mm tall. To take care of the extra space, I used a pair of rubber pieces (seen in the picture). This brought the cameras to good alignment. Bob used card stock to achieve the same goal. The only thing needed is a pair of tripod screws to hold the cameras.

Another option is a universal z-mount”. This can work for any pair of cameras, including the NX1000, if the top and bottom bars of the mount are spaced appropriately. With the cameras mounted in moving platforms (see picture below) it is easy to adjust their spacing. I discuss this in a separate blog.




The Werner-mount is unique in this camera system. It attaches to the cameras from the lens mount (see picture). This leaves the bottoms and tops free.


The cameras are aligned well and cannot be bumped out of alignment. But they also cannot be converged and their spacing is fixed. The rig looks and functions pretty much like an RBT film camera. The only accessory possibly needed is a camera grip to attach to the bottom of the mount, to hold the rig better. Because of the importance of this mount, I discuss it further in a separate blog here: http://drt3d.blogspot.com/2016/10/z-mount-for-samsung-nx-cameras.html

Side-by-Side


The NX1000 cameras are not particularly wide (again, compared to other cameras of similar sensor size – compact cameras with small sensors are generally smaller) so even when placed side-by-side, they come quite close (as close as 114mm, the length of the camera, when touching each other, or 125mm, about 5 inches, with space for remote cables that attach to the side).


You can use any twin camera bar for this, there are many choices. My personal choice is a twin camera bar with sliding platforms that I make (and sell) myself. It is lightweight and offers easy adjustment of camera spacing. I discuss this bar in a separate blog.

Bottom-To-Bottom


The Samsung NX cameras have the tripod sockets centered with the lens so it is easy to mount them bottom-to-bottom using only one piece of screw. I sell a kit that is useful for mounting these cameras bottom to bottom. I discuss this configuration is a separate blog.

When mounting the NX1000 cameras bottom-to-bottom, they come as close as in the z-configuration (66mm if the bottoms touch). So, why would anyone select this vs. the Z? I can think of one reason: The mount (a simple piece of screw and some felt material) is simple and inexpensive.


Top-To-Top


With the tops touching, the lenses come even closer (62mm) but the mount can be awkward plus you also lose the wider aspect ratio. I am not sure why would anyone select this, but you never know.

One disadvantage of the bottom-to-bottom and top-to-top configurations is that you lose the wider landscape aspect ratio. It works fine for square or portrait aspect ratio. Also, you get a lot of pixels with these cameras so you can always crop a square image to a landscape ratio.


Compared to the other system I have worked with, the Panasonic micro 4/3 cameras (GX1 and GX7), the Samsung NX1000 cameras come closer to each other in all configurations, but the biggest draw for me is that the lens spacing is about normal in the z-configuration.

Z-Mount for Samsung NX cameras

Werner Z-Mount for Samsung NX cameras


This is an ingenious mount that “grabs” the cameras from the lens mounts, with one camera oriented upside down to bring the lenses closer together. This configuration is known as z-mount. Traditional z-mounts hold the cameras from the tripod sockets. This mount is unique and it is designed for the Samsung cameras where the lens mount sticks out from body of the camera, as seen in this picture:


Metrics, useful to understand how the mounts works, are shown in the Figure below. In the original image from cameradescision.com, I have added extra dimensions, marked in red. The distance from the center of the lens to the “short” end is 34mm with the side lug removed or 36mm with the lug in place. So the closest the cameras can come to each other is 68mm with the lugs removed and one camera upside down, or 72mm without the lugs removed.


Also, note that the lens is not centered vertically but it is offset towards the top of the camera by 3mm. This is important when it comes to aligning the cameras (see below). The lens mount is 58mm in diameter and comes out from the body of the camera by about 12mm. The Werner mount attaches to this lens mount. There is about 1 mm from the top of the mount to the top of the camera and 4 mm from the bottom of the mount to the bottom of the camera.

Features of the Werner-mount and comparison with traditional z-mounts:

  • The mount is lightweight and the resulting rig looks like a stereo camera.
  • The cameras are held perfectly aligned and cannot be misaligned by accident (something that can happen in traditional z-mounts).
  • The spacing of the cameras is fixed and the lenses cannot be converged (maybe only by a small mount).
  • Some thick lenses will not work (the diameter of lens, at the thickest point, must be smaller than the spacing of the cameras). In practice this is not an issue except for some specialty lenses (60mm macro for example, or long lenses that are normally better used with side-by-side cameras).
  • The mount has a tripod socket located a bit forward, balancing the cameras with lenses nicely.
  • The tripod sockets of the camera and flash contacts are free. Also, nothing stops the screens from moving (but the NX1000 does not have tilting screens).
  • To attach the cameras, you must first remove the camera lenses (in traditional z-mounts you do not need the remove the lenses).
  • You should be careful not to lose the Hex key for the mount screws. Without the key, you cannot remove or attach the cameras. No key is needed for traditional z-mounts.
Currently the Werner-mount is made for two NX1000 camera spacings:
  • 68 mm, this requires that the lugs on the “short side” of the cameras (the side closer to the lens) are removed.
  • 72mm, the lugs can be left in place.
Other camera spacings can be made available for other Samsung NX cameras, provided that the lens mount is the same. I stock these mounts for sale in the USA.

How to attach the cameras to the mount:

The procedure below shows a pair of cameras with the lugs on the "short side" removed and the 68mm mount. Same ideas apply for cameras with the lugs in place and the 72mm mount.

1. Remove the lenses from the cameras.

2. Line up the cameras and mount as shown below. Note that the mount has two openings to provide access to the lens-removing buttons. Also, the mount has a tripod socket at the bottom. This helps orient the mount correctly.


3. Insert each camera to the mount and flush the mount to the camera bodies.

4. Align the cameras

With the cameras attached and the mount loose, there is quite a bit of freedom to move (pivot) the cameras up and down with respect to each other, sliding over the edge. This is shown in the upper row of the picture below where the cameras are moved to the two extremes. The bottom row shows the cameras aligned.


One intuitively might think that the camera bodies should be aligned. But this is not the case, because the lenses are offset by 3mm with respect to the camera body.

The cameras are approximately aligned when the bottom of each camera is flushed with the edge of the mount. This results in a slight offset of the cameras, where the right camera sits 3mm lower than the left camera. This is shown in the picture below.

So, to align the cameras, rotate them so that the bottoms are aligned with the mount.  It helps if you lay them on a hard surface (like a table).

You can also put a line (with white marker for the black body or black marker for the white body) to mark 3mm below the bottom of the left camera and align the top of the right camera to this mark.


5. After the cameras are aligned, tighten the two screws using the provided 2.5mm Allen (Hex) key.

WARNING: Do not over-tighten the screws! Use only slight hand pressure. This is enough to hold the cameras. I once tightened the screws so tight that the mount was deformed and the lenses would not “click” into position. So, be careful.

If you attach the lenses and turn on both cameras you will notice that the images in the screen are aligned, even though the cameras (and the screens) are not aligned (as we discussed, the cameras are off by 3mm and the screens are off by 8mm because the screen is off set in the opposite diction with the respect to the lens). That’s because the image is offset with respect to the screen (the space is taken up by the line with shutter speed/shutter and exposure compensation information). This is shown here:


This alignment is good enough for me. Any slight errors will be corrected by StereoPhoto Maker (note: slight vertical alignment errors can be corrected, gross errors should be avoided). If you want near perfect alignment, you can use the standard 20-50mm, zoom the lenses at 50mm and observe that the same object is “cut” in the upper and lower edge of the screen in both cameras (check both top and bottom because the lenses might not be matched perfectly at this end). If they are not aligned, loosen the screws slightly and move the cameras to improve the alignment. Excellent alignment is shown here:



It is interesting that the image in the left camera is shown upside down, so it has the correct orientation for viewing. This way you can easily compare the images. Notice that the same objects are being "cut" in the upper and lower edges (red arrows). As a rule, to check alignment, always zoom in (if you have the option) to obtain the highest image magnification. Do not use heavy lenses for camera alignment as they might be rotating the cameras because of their weight, unless if these are the lenses you plan to use.

One last observation: Since the mount extends by 3mm above the camera's top, some flash units will not fit, if there is not enough clearance from the flash shoe to the flash body. From my two favorite compact flash units, the Nikon SB-30 fits without a problem, while the Fujifilm EF-X20 does not fit. For the units that do not fit, you can use a flash adapter, like the Hama tilt adapter shown below, to raise the flash higher.


To remove the cameras from the mount:

- Remove the lenses
- Loosen the two screws
- Pull the cameras out

The procedure for attaching the 72mm mount (see below) is exactly the same.




In summary, the Werner mount is very simple and guarantees good and stable alignment.  I am personally attracted to the functionality and simplicity of this mount. With the Samsung NX1000 cameras I am mainly interested in their minimum spacing. Variable spacing close to the normal spacing is not an attractive option for me. If I want a wider spacing, I will switch to the side-by-side configuration. The Werner mount takes very little space and weighs next to nothing. It has smooth edges so it will not damage other objects next to it. Even though I have made my own (traditional) z-mount, I now use the Werner mount exclusively.

In terms of cost, z-mounts can be expensive since if they are custom-made. The Werner-mount is manufactured in Germany using computer controlled milling. The material is some kind of plastic/composite (not metal). It seems to have sufficient mechanical strength to hold the cameras without a problem.

I would be interested to hear feedback from users of this mount.

Tuesday, October 25, 2016

Twin Samsung NX1000 For Stereo – Part I

From the beginning of my stereo photography I always used twin cameras for stereo to supplement my stereo camera. In film photography I used Minolta MD cameras and later Pentax cameras. In digital photography, I used compact Panasonic cameras, wired by Ekeren, and, later, larger Panasonic micro 4/3 cameras. One issue with larger cameras is that they cannot get close together for normal stereo (stereo base of 75mm or shorter). So I used twin cameras mostly side-by-side for hyperstereos.

In June 2015, Bob Karambelas told me about a project he was working on, using a pair of Samsung NX1000 cameras for stereo. He got the idea from this image in phereo:
http://phereo.com/image/5544ae9de7e56460490000b9
(See also the discussion below the image)

Bob is a professional photographer, best known for his model photoshoots (http://stereostyles.com/) where he makes heavy use of off-camera flash. He was attracted to the Samsung NX1000 cameras mainly for two reasons:
  1. When used in the z-configuration (one camera upside down) they come quite close (68mm, with the lugs removed).
  2. Synchronization is quite good, and they work with flash.
The larger APS-C sensor and ability to shoot RAW is an extra bonus. As Bob said, with a 68mm lens spacing and a 30mm lens (wide end of the standard zoom) this is like a digital Realist. The Fuji W3 and Panasonic 3D1 just don’t cut it in terms of quality and use of flash, and the twin Rebels cannot come close enough for normal stereo base.

Here are two pictures from Bob’s first twin camera tests. The cameras are side-by-side in the left picture, showing the wired remote, and on a custom-made z-mount in the right picture.


 I bought my first Samsung NX1000 in June 2015 and very soon accumulated several cameras and all the parts to make a z-mount and a remote. Used cameras at the time were selling for around $200 (NX1000 body and standard 20-50mm zoom lens). In addition to the NX1000 I was also intrigued by the NX-Mini which makes an even more compact rig with closer lens spacing. So I bought a couple of these cameras too.


But I was busy so I put everything away. A year later I pulled the cameras out. I was still busy with work and other projects so I was thinking of selling everything. But I decided to take a look at the cameras first, and was intrigued. With Bob’s guidance I made a z-mount and a twin remote. I tested the cameras in late August 2016. The results from the NX1000 were very encouraging but the turning point was shooting at a Cleveland Indians game in early September.

I used the cameras side-by-side on a bar and the 50-200mm zoom lenses (mostly zoomed at the 200mm end which is a full frame equivalent of 300mm) to take pictures of the action from deep into the stands. These pictures turned out quite well. Synchronization is not perfect but very good. In most pictures the players and bats are “frozen”. Only when the ball, if it happened to be in the field of view, it often appeared out of the plane it should have been. After the game I took some night pictures with the cameras on a tripod, and these also turned surprisingly well. Here is one example from the baseball game:



You can see this and other 3d pictures from the Samsung rig in my phereo account, here:
http://phereo.com/DrT3d
(go under the Samsung NX1000 album)

I then experimented with flash and got excellent results.  The flash is recorded in both pictures without an issue. Here are two early examples:




In both pictures I have balanced available light and flash. The picture of Milo (our cat) was taken with minimum lens spacing (68mm on a z-bar) and standard zoom lenses zoomed at 50mm (75mm equivalent) while the picture of the Blue jay was taken with the cameras next to each other, using the 50-200mm lenses.  You can tell that flash is used by the reflections in the eyes. In these cases I used two flash units off camera. One flash was triggered wirelessly and the other was slaved. But I have also used on-camera flash with good results in all camera modes (not only Manual but also Program, etc.).

After my initial tests, I corresponded with Werner Bloos in Germany, who informed me that he makes a mount and a twin remote for these cameras, not listed (at the time) at his web site. I tried these products and was extremely pleased, to the point that I am stocking them and selling them for buyers in the USA.

The Werner-mount (this is how I will call it, to distinguish it from other mounts) is one of the most clever designs I have ever seen. It takes advantage of the fact that the lens mount for the Samsung NX cameras sticks out quite a bit out of the camera body, so the Werner-mount “grabs” the cameras from the lens mount instead of using the tripod sockets, like other traditional mounts do. The result is a very compact configuration that looks like a stereo camera instead of a rig put together (see pictures below), with good and stable (cannot get knocked off) alignment. There are a couple of disadvantages though (expense, inability to converge or change the spacing of the cameras) that I discuss in a separate blog.

The Werner-Twin-Remote is made by joining two remotes. It works quite well and the cables are of good quality. I have had some problems with other cables but not these ones. I discuss the hardware required to fire these cameras in another blog.

The bottom line is that with these two products, one must only supply a pair of cameras (easy to find used on ebay for around $200 or less) and then he/she is up and running with a good quality twin camera rig, without having to worry about making mounts or joining remotes.

Here is a picture of the twin NX1000 rig with the Werner-mount, twin remote with 90 degree extensions, fixed 16mm lenses (24mm equivalent) and my favorite camera grip:





Here is a picture of me in action (NX1000 cameras with standard 20-50mm zoom lenses):


More details about the Samsung NX1000 rig in part II of the blog.