6) Stereoscopic Panorama Capture
Side By Side.
Using twin cameras.
Twin Optics: 7,5 / 8 mm.
Twin Optics: 10 / 12 mm.
Twin Optics: 16 / 18 mm.
Twin Optics: 24 mm.
Using just one camera.
Optics: 7,5 / 8 / 10 / 12 mm.
Optics: 16 / 18 mm.
Lateral rotational capture.
6) Stereoscopic panorama capture.
If it’s stereoscopic, it’s not nodal.
A stereoscopic panorama consists of two panoramas captured with a slightly different parallax. This parallax can be obtained in two ways, obtained by misaligning the point of no movement of the nodal head (NPP) with respect to the entrance pupil of the camera in the longitudinal axis “Rotational Capture”, or in the lateral axis “Side by Side Capture”, The distance that separates the longitudinal axes of each nodal point is the interaxial distance (ID), this distance can be equal to the separation of our pupillary ocular reflexes of 6/7cm, being called inter pupillary distance (IDP), in this case we are talking about Orthostereography, if that distance is less; Hypostereography and if it is greater; Hyperstereography.
6.1 Side by side capture.
Contar algo del lado a lado
6.1.1 Using Twin Cameras.
Contar otro poquito.
Nodal Ninja Stereo Kit
Using a horizontal arm; “LP140 / F8174”, a 90º angle connector for the right side; “F6042”, and two brackets; “DS38S / F2013” we get the perfect configuration to make stereopanoramas.
Its optical principle consists of pseudo nodal alignment, in which each of the two entrance pupils is nodally aligned in height and depth, and its lateral misalignment being equal to half the interaxial distance used.
From a practical point of view, we will make the NPP of the RIG coincide with the intermediate point of the hypothetical segment that joins both entrance pupils.
Interaxial and safety distance
In order to obtain the minimum possible interaxial distance, we recommend the use of DSLR´s as small as possible, in the case of the Sony Alpha 5 series, the camera body is even smaller than the diameter of E-mount optics, so its interaxial distance will be equal to the diameter of the optics used, in this case as specified by the manufacturer; 6.2cm.
To calculate our safety distance we will use the constant (30), so multiplying 6.2cm x 30 we get 186cm.
With respect to the ground, this is the height that we will have to place the optics and at the same time it will be our safety distance, for what we will avoid that any element in the composition is placed within this value.
Imagine that your safety distance is a soap bubble that inflates with epicenter in your entrance pupil, that should explode when it touches the ground, if it is punctured before touching the ground is because it has touched some element within this space.
First of all, we must bear in mind that in any panography there is going to be a timelessness between shots, so that even in the case of the “genlock” of the cameras, there will always be an error of time in the seams. You can use an intervalometer and two wires, but in practice an infrared remote never fails.
As for the rest of the parameters to be taken into account, they are the same as in traditional panography, although we must pay attention to the fact that both cameras have been triggered, and making a special mention that we must use the same white balance for both optics.
184.108.40.206 Twin Optics 7,5mm / 8mm
Using two cameras equipped with fish eyes we will get the maximum speed capture, since only three double shots, six photos in total, are enough to obtain the material that will compose the stereo panorama:
6.1.2 Side by side using just one camera.
This capture tutorial has been standardized to work with APS-C or FullFrame sensors and 7.5/8/10 and 12mm optics.
We have to take a total of 24 photographs, twelve for each view, using a 60º base and two columns using plus/minus 45º. This capture system will give us the extra overlap we need and we will obtain a perfect Zenit and Nadir.
BEFORE TO START.
Align your Nodal Ninja to create a 2D panorama. Calculate the interaxial distance you want to work with and desalinate the camera in the right lateral axis, half of the calculated ID.
To calculate the interaxial distance to use, first place the optics a minimum of 1.60 cm from the ground, and now measure the distance to the first object in the composition, divide this distance by the constant (35) and you will get the maximum interaxial distance you can use for that shot. If the first element that appears in the scene is the floor, your interaxial distance to use will be 4,5cm, the result of dividing 160cm by (35).
The safety distance is an important premise, which if not observed will produce tensions within the two spheres, which translates into the appearance of artifacts caused by interpolation.
The safety distance is an important premise, which if not observed will produce tensions within the two spheres, resulting in the emergence of artifacts caused by interpolation.
If we are going to work with an interaxial distance of 4.5cm our safety distance will be equal to the height of the tripod 1.60cm, and we will not be able to allow any element on the screen to be at a lower distance.
And if for some reason we want to increase our interaxial distance, we must also raise the height of the tripod, without forgetting that we are creating a virtual stage and that if we raise the height too high the viewer will feel uncomfortable.
The capture secuence.
There are different methods to make the exposed capture, but the one that offers the best performance is to take four photos in each step of 60º.
We will begin the capture to 0º of panning and with an inclination of -45º to realize the first photo, next we will rotate the horizontal arm 90º in clockwise sense and we will realize the second photo, “these two photographies correspond to the image of the right side”, we will advance again 90º and we will take the third photo, that is the first one of the left side and finally we will advance other 90º and we will capture the second photo of the left side.
We will advance 60º in the horizontal plane and we will repeat the sequence in each one of the six stops that we will have to make to complete the rotation of 360º.
Because we are working with our nodal point shifted, looking at the camera screen, the photographs captured with the Ninja Nodal side arm on the right side correspond to those of the right and biceverse view.
It is important to always capture in the same direction, because we are going to use an automatic stitching system that will only work if we rotate counterclockwise.
In this graph we can see the order of capture:
If you have a VR Gear, click on the photo to activate the WEB VR mode.
Or download this photo in anaglyph format (Red/Cyan) to see it in the “Go Pro VR Player”.
5.2 Side by side capture, 16 / 18 / 20mm.