Photography guidelines for Metareal Stage
1. General guidelines
Whatever your camera setup, a tripod is highly recommended, as it allows most orientation and lens-height information to be applied to all the panoramas.
Tripod height: Position your lens at or above the eye-line. This is particularly important if there are surfaces like tables, shelves, etc. where the detail needs to be captured. Positioning the lens too low will result in occlusions and smearing when reconstructed in 3D.
Exposure: Make sure all your panoramas have the exact same exposure and white balance.
For HDR bracket sets, the aperture and ISO value of all the images must be identical - only the exposure can be varied. Also, the shutter speed of each image should follow a repeating sequence. (For example: 1/25, 1/100, 1/400, 1/25, 1/100, 1/400.)
Shoot a reference panorama that is centrally placed in each room. This will help to minimize floor-placement errors, and thus increase the accuracy of the overall reconstruction.
Record the exact height of the nodal point of the lens (for your reference pano). Metareal Stage derives all scaling and measurements from this initial value - so it's critical that you record it accurately.
Shoot panoramas on a grid - roughly 6m x 6m grid at around 30Mpx, using smaller grid for lower resolution cameras (we use 4m x 4m for the Ricoh Theta S). Exact precision isn't important - line-of-sight, perpendicularity, and overall coverage is what matters most.
In the above image (a plan view of a room) we can see the reference panorama in orange, with a line of sight to as many corners as possible. The other panoramas are positioned to provide good coverage of the various surfaces, with as much perpendicularity as possible (to offer the best quality imagery for each part of the room).
2. Shooting with a DSLR
Make sure the lens nodal point is precisely aligned - don't rely on your stitching software to correct errors, because panoramas with corrections will make precise reconstruction impossible. (*We can add a tutorial on precision lens alignment if required - if you want to see this, please just submit a request.)
When you stitch your panorama, start by switching off as many of the image corrections as possible. This way you can see exactly what distortions are being corrected and if your lens is properly configured.
3. Shooting with a 360 Camera (e.g. Ricoh Theta S)
For LDR, shoot low ISO and long exposure. The Ricoh is a great camera, but it's very noisy at high ISO.
For HDR, for now use an app like hdr360 on the iPhone. It's a bit expensive for what it is, and we will introduce our own, fully automated, Metareal Capture app later in the year. Generally there's no real need to shoot more than 5 brackets for Stage. Make sure to use the "Fixed Brackets" setting or the exposures will be all over the place. After you've shot the images, upload all the brackets to Stage, and make sure to check the "Attempt to group images as HDR bracket sets" box
Updated on: 15/02/2021