Removing Ghosting in Photoshop
When you enlarge the stitched images, the quality will be visibly low especially when the image contains a moving object such as people, cars or trees. Exposure bracketing is taken at a slightly different position during the shooting process, so ghosting occurs. Ghosting is a moving object in photos which looks faded and transparent like a ghost. In case of HDR, it is difficult to avoid ghosting on people or trees since it takes the same scene several times. In this case, you should edit them on Photoshop.
In the picture below, you can see that there is some difference in brightness or chroma between the right side and the left side of the background. When this happens, find the original image of the right side, copy this part and create a new layer. Adjust the colors of this layer and place mask on it.
First, find the layer that contains the photo you want to change (the best quality photo), then copy and paste only the part you need.
Select this layer and use Image > Adjustment > Brightness/Contrast or Image > Adjustment > Hue/Saturation to adjust the colors of the background.
Add mask to the layer you created and fill it with black.
By selecting the mask and coloring it using a white brush, you can clear the ghost image problem. Repeat this process until you remove all ghost images.
You can adjust the tone and color of photos after the stitching process. Open Photoshop and go to Image -> Adjustment. Go to Preset and use Linear Contrast or Medium Contrast to increase contrast. You can add blue or orange by using Image -> Adjustments -> Photo Filter if needed.
Summary (Bracketing Shooting and Image Process)
- Equipments Needed to Take a 360º Photo
Nikon D810 for a body, Samyang 8mm fisheye for a lens, Manfrotto for a tripod, Horusbennu for rotator and wireless shutter release are used. Refer to this post for more details.
- Camera Setting When Shooting a 360º Photo
- Storage mode: In RAW mode, it’s easy to control the quality of the photo but it can take up too much capacity, so if you are going to shoot many photos, this method is not recommended. If you save the photos in JPEG, they are compressed to a much smaller size so it can be used in various software.
- Shooting Mode: Set in M. Set the median exposure and take photos using AE bracketing mode. Take 5 photos at each exposure value from -2 to +2 (-2, -1, 0, +1, +2). You can take fewer photos (3 photos) or more (7 photos) depending on the quality of photos you want to achieve.
- White Balance Setting: Depending on the weather, select one among the presets. Never use auto mode. If you set in auto, the white balance and color will change in every photo. These differences may cause stitching errors or interrupt seamless stitching showing a line on the photo when you stitch them to a 360º photo.
- Distance Setting: Set in Manual. When you set in F8, you can shoot infinitely but the best is setting the distance, taking into account the objects within the frame.
- AEB: Shoot in AEB (Auto Exposure Bracketing) in every spot and go to HDR (High Dynamic Range), more specifically shoot in exposure fusion method. all must be set in manual. You can get the best result when you take all images under the same condition/settings.
- The Number of Photos: The most important thing when taking a 360º photo is taking images from all directions. Shooting as much as possible is what’s ideal but it takes up a lot of storage capacity so you should shoot efficiently. If you use 8mm lens and Nikon D810, shoot 4 images tilting the camera 5º upward. Keep in mind that this method aforementioned doesn’t cover the ground area. You can hide the empty area on the ground by inserting a nadir photo or blending the area in Photoshop.
- Stitching: Import all the photos in PTGui. Apply the HDR process with exposure fusion method and set the pixel at 10,000 x 5,000. For more details, click here.