Running with Vinny - 3D camera testing – 8. Sony RX100 twin rig
Sony RX100 – Clear winner?
I have been using a twin Sony RX100 rig for a year and a half now and I am very pleased with it. See the attached summary from the last Stereogram tutorial to see pictures of the setup and Vinny.
The RX100 is Sony’s highly acclaimed compact travel camera. It is currently in its 7th version. Sony introduces a new version every so often. The old versions are not discontinued. At any point you can buy any version you want, brand new. Because a lot of people trade their old camera to get the newer version, there is a good market of used older version cameras.
This link summarizes all RX100 versions: https://www.dpreview.com/articles/7237085229/which-sony-rx100-is-right-for-you
Version 1 does not have a multiport, so stay away from it
Version 2 has a flash shoe but no Viewfinder
Versions 3-5 have a fast 24-70mm f1.8-2.8 lens and electronic viewfinder (EVF)
Versions 6-7 have a 24-200mm f2.8-4.5 lens
Note: All versions are exactly the same dimensions so any bar (z-bar, for example) made for one version, will work for all others.
The fact that Sony stands behind this camera with new versions is good news. It means that you are getting a reliable popular camera, fully supported by Sony and third party manufacturers and you have a large supply of used cameras at your disposal.
I went for a pair of used Version 6 cameras because I wanted the 200mm long focal length (good for portraits and close-ups) and I did not want to get a loan to pay the price for new version 7 pair :) I also like the EFV and I use it a lot to adjust settings, compose, study the pictures. I need reading glasses to see the screen so I will happily use the EFV instead. Looking through the EFV makes me pay more attention to composition and ultimately results in better pictures.
The lens is excellent IMO and the sensor size is of the 1 inch type (13.2x8.8mm) same as the RX0 and RX10, which is pretty good.
Synchronization is very simple, like all Sony cameras with pultiport. Werner has measured synchronization in one pair to be around 1/1000s average and this is in line with what I am seeing.
This camera makes a good study for the different ways to arrange two cameras for 3D. Here is the minimum stereo base for different arrangements:
I started with the side-by-side and z-configurations and I was happy. Then I tried the overlapping configuration and now I am even happier.
The reason I avoided the overlapping configuration is because of the inherent error (to be explained more in the next posting). In this configuration, one camera (front) is 25mm ahead of the other camera (back). The front camera is closer to the near object, which will appear slightly larger, while infinity is the same size.
As it turns out, the error is z/D, where z is the displacement of the cameras (25mm here) and D is the distance to the nearest object. The error is independent of the focal length (expected, considering that the error is due to perspective which only depends on distances and not focal lengths). This error is not eliminated during alignment with software.
But when I tried it, I was happy to find out that the error was not very obvious (more later). I try to keep this ratio at 1/100 or less, which means that I keep the near object at 100z = 2.5m (~8 ft).
This is the situation when infinity is in the picture. For close-ups I can get closer with even less error (more later).
Here is how I use these cameras:
I have the cameras on a bar. I use panoramic mini clamps, which allow me to change the spacing of the cameras without disturbing their alignment. They also allow me to change the convergence very easily. I am able to switch from side-by-side to overlapping quickly and accurately. I am able to converge the cameras for close-ups, easily. I am very happy with these clamps, even though they add a bit of weight.
I normally use the cameras in P mode (with -1/3 exposure compensation) and daylight color balance. I use shutter priority (S) to force a high shutter speed for action. I use Auto in tricky lighting situations. I use auto focus and have no problems with it.
I have the cameras set to step zoom mode. When I turn the front ring, the zoom changes in steps and not continuously (but still changes continuously using the lever). In step mode it goes: 24, 28, 25, 50, etc. So, in step mode it is easier to match the zooms.
To help me stay away from the near object, and also because I don’t like the 24mm focal length setting for general 3D photography, I routinely use either 35mm or 50mm focal length.
You would expect that there is a way to have the zoom go straight to 35mm when you turn the cameras on. But, no! The zoom always goes to 24mm when the cameras are turned on in every mode setting, except for one (MR, Memory Recall). Panasonic cameras have a setting where the camera will remember the zoom and return to it when turned on, while Sony does not. I prefer the Panasonic menus / options over the Sony.
A couple of problems I have had:
From all the cameras I tested, this is definitely the best. Yes, it weighs more and takes more space, but it definitely takes better pictures. This is the camera I will take if I am going to do serious photography. Pictures in low light or actions shots (Vinny leaping over logs) come out great.
In addition to “running with Vinny” this is now my main travel 3D rig. I use it for everything from normal, to hyperstereos, and even close-ups.
So, the way it goes with my runs with Vinny: