360 photography can be stitched using various techniques and number of images. It can be done with only 4 images using full circular fisheye lens with full frame body. Or even 5 using semi-circular images with Tokina 107 NH at 10mm with a similar sensor.
But for commercial application such as real estate or architecture. We need to shoot the scene at full fisheye coverage, utilizing every pixel of the camera. This method will require 8 final shots in total, 6 for vertical (portrait), 1 for up shot or zenith and 1 for down shot or nadir.
This is how our image will look like in equirectangular projection.
Again, our panorama is composed of 6 vertical shots, 1 zenith and 1 nadir.
Although this approach need more frames. It will yield a higher resolution image compared to fewer shots taken. Whether you are on 20-megapixel fullframe or crop sensor, your panorama can reach up to 16,000 by 8,000 pixel. It will have a printable size of 213 by 106 inches at its native resolution. It can go further if you are using a high-resolution camera like Canon 5DR/s or Nikon D810.
Shooting the Scene
On this scenario our client wants us to capture this location as natural as possible. Post-processing should be minimal and retain all details as is. Meaning, they want the final result realistic as possible.
- Tokina 107 ATX, sharpest aperture is between F8.0 to F11. On this case F8.0 is fine, if you will be shooting a landscape you can use F11 for sharper details.
- We need to keep the noise (image) as low as possible since we are capturing a scene with no moving element.
Image Format: RAW
- We are shooting RAW, not JPEG or Fine because we want to capture all the details and take care of the image processing later. There are cases we will have uneven exposures and by using RAW we can adjust it without losing details.
Shutter Speed: Aperture Priority
- Since we have no moving subject, we can select this mode to let the camera decide the shutter speed it needs based on our Aperture and ISO. It will save us some time.
White Balance: Auto White Balance (AWB)
- I choose AWB due to the scene's uneven lighting condition. Like the doors and alley are completely white bright. Then the wall has warmer tones and tables have black walls.
- Since we are shooting RAW we can correct the white balance later in post.
There are situations client wants to freeze the movement of the people on their location. Like for example they want to show how busy their restaurant or event activities.
For these cases we need to shoot in Manual Mode. Typically shutter speed will be at 1/80 to 1/100 to freeze the action with some motion blur. Then for indoor depending on the lighting situation we will set our aperture F5.6 and increase the ISO up to 1600. There is no exact formula on this it depends on how bright or dark your scene is.
Just use your exposure meter and histogram, it's a matter of trial and error to find the correct exposure value of the scene.
Focal Length: 10mm (APSC) or 15mm (FX)
Focus: Manual Focus
- Use your viewfinder or live view and use digital zoom, if available. Set your focus on the farthest object like painting on the wall and not on things closest to you.
- Your focus setting should be the same across all images. Mostly, on this kind of scene I achieve the sharpest focus close to infinity ( ∞ ).
B. Vertical Shooting:
The reason why we need to shoot vertically or in portrait mode due to the fact vertical images can capture most of the ground and ceiling (or sky). Resulting to a higher resolution compared to landscape shooting.
We need to set our rotator at 60° and make 6 shots to complete the rotation. Setting at this degree means at every 60° turn we will capture an image. There is an indentation ring inside the rotator that gives a subtle click indicating your next turn.
My rotation sequence is usually at clockwise but you can do the opposite. However, don't mix it up to avoid confusion and always remember what image you took first, to avoid redundancy.
If you may ask, why we need 60° at 6 frames, if we can do 90° at 4 frame for a total of 360 degrees.
The answer is Overlap. At this kind of setting we need 30° of overlap for each vertical image.
Having a good amount of overlap affects our stitching result. Our program needs to determine the connection of each side of the frame and their geometric relationship. (I'll get more of this later.)
C. Nadir Shooting:
Shooting nadir can be achieved by moving the upper horizontal arm upward at 90°. Making both vertical rail and upper arm straight pointing the camera downwards.
Taking this image can be either easy or challenging. If you are shooting on a homogeneous ground like concrete, grass, asphalt or anything that has no pattern. A simple Photoshop tool called 'content-aware fill' and clone stamp tool will do the trick.
You can use Polygonal Lasso Tool to make a path around the tripod area. Then right click select Fill and choose Content-Aware.
Tripod was completely removed. Time to do some fine-tuning of the carpet floor with clone stamp to remove its shadow.
There are cases we need to take 3 images of the ground at different angle. In order to remove the tripod/panohead. Mostly, this is applied on real estate, hotels, restaurant location where the client wants to show its design.
Our shots below was made using our nadir shooting mode (camera pointing downwards). One on the right and other on the opposite side.
Just remember it should be on the same phase where you took your first vertical image.
Then on the third one you can either shoot it handheld. Or you can reverse the vertical arm and shoot it on the other side. There's no right technique on this one, what is important is to capture the area where our tripod/panohead occupied. So we can patch it with this one, later on post.
Images below are just a preview on the areas (red) we will remove later in Photoshop using Mask, Clone Stamp, Free Transform (distort and warp).
Then we will make a composite or blend all frames together to make a clean and tripod-free image.
D. Zenith Shooting:
Shooting the sky or ceiling on this case, is the easiest. All we need to is point the camera upwards like the one below and we only need one image.
But keep in mind, same as nadir, we need to shoot where on the phase where we took our first vertical shot.
E. Image Compilation
We should be having a total 10 images for this scene, 6 verticals, 1 zenith, 3 nadir (for blending).
Before we proceed on our image post-processing and stitching. I want to give you some shooting tips.
Check your focal length and focus points every time you will change shooting mode like, from vertical to nadir.
As you move your panohead arms, you won't notice you already changed your lens settings. But good thing with Tokina 107 AT-X, zoom and focus ring have good resistance. It stays still most of the time however it doesn't hurt to check it from time to time. This is a great time saver and will prevent you to retake all of your shot.
Remove your camera strap, it will get in the way when you shoot nadir.
If possible, avoid highly reflective walls that will make a shadow and reflection of the gears or yourself. It will add up time on your post-processing.