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Min Heo

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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.

Remove any moving objects away from the scene if you can to obtain better quality 360º photos for a 3D virtual tour.
When you enlarge the stitched images, the quality will be visibly low especially when the image contains a moving object. Ghosting is a moving object in photos which looks faded and transparent like a ghost. In this case, you should edit them in Photoshop.

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.

When you enlarge the stitched images, the quality will be visibly low especially when the image contains a moving object. Ghosting is a moving object in photos which looks faded and transparent like a ghost. In this case, you should edit them in Photoshop.

Select this layer and use Image > Adjustment > Brightness/Contrast or Image > Adjustment > Hue/Saturation to adjust the colors of the background.

When you enlarge the stitched images, the quality will be visibly low especially when the image contains a moving object. Ghosting is a moving object in photos which looks faded and transparent like a ghost. In this case, you should edit them in Photoshop.

Add mask to the layer you created and fill it with black.

When the ghosting which is a moving object that looks faded and transparent like a ghost occurs, you can manually remove it using layers in photoshop.

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.

Remove any moving objects away from the scene if you can to obtain better quality 360º photos for a 3D virtual tour.

Color Adjustment

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.

You can adjust the tone and color of photos after the stitching process to get a better quality.

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.

Using AE Bracketing Method

Bracketing is the method of taking generally three photos, one using the camera’s standard settings, one underexposed and one overexposed. This technique is used to get a properly exposed image with a single shot without having to post-process the image separately. You can choose to use auto bracketing using a built-in camera preset to take several bracketed photos.

Bracketed photos can be processed in HDR (High-Dynamic-Range Imaging) that reproduces a greater dynamic range of luminosity than what is normally possible so that the overall quality of the photo is improved.

To take 360º photos using bracketing method, set your camera to M (manual) mode. Set the aperture to 8 then choose AE bracketing mode. Depending on your camera, you can have exposure options. The more photos you take, the better quality you get. However, normally 3, 5 or 7 sets are recommended considering the file size and efficiency when post-processing. Check the level of exposure by pressing the shutter halfway to find the median exposure. Set the median exposure then take photos overexposed/normally exposed/underexposed. For instance, Take 7 photos at each exposure value from -3 to +3(-3, -2, -1, 0, +1, +2, +3).

Additional Tips

  • If the camera is shaking while shooting, it may cause many problems including blurred images. Use a release to help you shoot, especially when doing a long exposure shot.
  • Set the value of F to the highest possible number (at least 8 or above) and the distance at infinite manually.

HDR Photos

Put all images taken using AE bracketing into PTGui Pro and process them. You can have the results processed by each exposure and stitched through HDR. The image below shows 7 sets processed at each exposure.

The image shot underexposed shows better texture of the sky, while the image shot overexposed have clear separation in shadows. When the dark and bright areas are put together, use AE Bracketing to get a partially detailed image.

Bracketing is the method of taking multiple photos with different exposure values, under/overexposed, and standard, then combine them to get a properly exposed image with a single shot without having to post process the image separately. This method is useful when you want to obtain the best quality 360º photos to create a 3D virtual tour for real estate.

The photo shoot underexposed shows the better texture of the sky, while the overexposed photo has clear separation in shadows. Therefore, you can obtain an image with much more detail and color in both dark and bright areas by mixing them together after taking photos in AE bracketing method.

You can read more details on how to stitch HDR 360º photos in this blog post.

The images below show the stitched photos at each exposure value (-2, -1, 0, +1, +2) and the last image is the HDR photo with all images combined.

You can adjust the brightness of the photo in other post photo editing program.

When taking 360º photos for a 3D virtual tour, try to keep the same exposure for all photos. You can adjust the brightness of the photo in other post photo editing program. Set your camera to manual mode and adjust the exposure in the middle.

When comparing them, you can see that the result of Exposure Fusion is better, especially when looking at the shadow details. Also, as evident in the images below, the HDR photo has better color and contrast.

The HDR photos are combined several images with different exposure values and they ensure the better quality of 360º photos for a 3D virtual tour.

Ordinary photo – No HDR

The HDR photos are combined several images with different exposure values and they ensure the better quality of 360º photos for a 3D virtual tour.

Ordinary photo – No HDR

The HDR photos are combined several images with different exposure values and they ensure the better quality of 360º photos for a 3D virtual tour.

HDR photo

The HDR photos are combined several images with different exposure values and they ensure the better quality of 360º photos for a 3D virtual tour.

HDR photo

Even though the file size is over 7 times bigger and the processing time is considerably longer compared to non-HDR photos, taking auto exposure bracketing and process it to HDR is highly recommended because of its overall better results.

Shooting Tips

1. Remove any moving objects away from the scene if you can.

A moving object may hamper the photo quality even though the software adjusts them to some degree during the process. This is common if you capture movements using bracketing method. The objects appear like a ghost or transparent double images in areas of the panoramic photos where two adjacent photos are overlapped.

Some photo stitching programs have a blend path that automatically blends frames together and removes ghosts. Also, you can manually erase it in Photoshop. However, the best way is to still be aware of the movement when you capture the scene.

Remove any moving objects away from the scene if you can to obtain better quality 360º photos for a 3D virtual tour.

2. Don’t get too close to objects.

If you have an object located too close to the camera, distortion may occur in the panoramic photo. Also, if objects such as walls are too close to the camera, the photos can’t obtain sufficient overlaps which can trigger an error during stitching.

A common mistake, especially in real estate when trying to take photos to make the room appear bigger, is to take photos from a corner.

A common mistake especially in real estate when trying to take photos to make the room appear bigger is to take photos from a corner. If you take photos too close to walls it has a high chance to have an error stitching error.

3. Avoid grounds with cross or striped pattern.

When selecting a shooting site, avoid grounds with cross or striped pattern. It can lower photo quality since it is difficult to have these lines meet when the photos are later stitched. The best areas are lawn or grounds with no visual and physical obstruction.

4. Avoid the sun when taking photos.

If you take photos outdoor, consider the shadow and shoot it within the shadow so that traces of the shooter doesn’t appear in the photo. Normally, a wide-angle lens which can capture a wider range of a scene is used for panoramic photos, so there’s a higher chance of containing a shooter’s shadow.

5. If it’s sunny, shoot at AEB (Auto Exposure Bracketing) mode.

Especially on a sunny day, even if you’ve adjusted the correct median exposure following the instructions above, the photo may still appear too dark or too bright. When you adjust the exposure of dark areas, details on dark areas disappear and vice versa. In this case, the best possible way is to shoot at AEB: Auto Exposure Bracketing mode and stitch the photos with HDR. Note that HDR process is only available on PTGui Pro version.

6. Save your photos in RAW format.

Even though the size of the RAW file is bigger than JPEG, you can achieve better quality because it doesn’t compress the image which inevitably lowers the quality. The RAW format is less universally readable compared to JPEG format but it’s more useful when you import photos to other photo editing programs such as Photoshop and Lightroom. In these programs, you can export from RAW to DNG to keep the image quality high.

7. Keep the same exposure for all photos.

If you set the exposure to automatic, each photo may have different levels of exposure which can lower the quality of the panoramic photo.

The best way is manually setting the camera. DSLR cameras usually have ‘M’ mode which allows users to set the aperture or shutter speed. In this mode, adjust the exposure in the middle and set the aperture and shutter speed so not to overexpose or underexpose. If your camera doesn’t have the manual mode, use the AE-lock function which fixes the shutter and aperture. A narrow aperture(F8~11) is recommended to achieve a deeper DoF which consequently brings clear photos with wide focus.

When taking 360º photos for a 3D virtual tour, try to keep the same exposure for all photos. You can adjust the brightness of the photo in other post photo editing program. Set your camera to manual mode and adjust the exposure in the middle.

8. Save the photo in PSD format in PTGui to erase or edit it in Photoshop.

There are various stitching programs available for use. I’ll show you how to process 360º panoramas with PTGui program. This program is very convenient since it can process most photos automatically.

Sometimes, you have a moving object like a car or a person while shooting. So you may have half of the photos with this object while the rest don’t. In this case, you can remove the unwanted object from Photoshop. In order to do this, you should save the final version as a Photoshop file. On the Create Panorama tab, activate Photoshop (.psd) and Blended and Layers options then save it.

There are devices that take 360º photos with a click of a shutter, but in most cases, we take several photos, partially overlapped, with an ordinary camera and use a stitching software to produce a panoramic photo.

A simple explanation for taking a 360º photo is to take several photos of about 30% or more overlapped horizontally (360º) or vertically (90º+90º), at a fixed position.

Shown below is an example of photos taken horizontally, vertically or at 45º. The number of photos you take depends on which kind of lens you use. If the angle of view is narrow, take many photos and if you use a wide-angle lens or fisheye lens, you can take fewer photos.

You can use various stitching programs to combine these photos and create a big photo with a length to width ratio of 2:1. Using a panoramic photo viewer, you can rotate the photo in all directions.

Principles of a 360º Photo

This photo is composed of several photos (about 10 photos).

You need to cover the entire surrounding of the spot ensuring each photo has a sufficient overlap to get a 360º photo. Depending on your camera and lens, you may need more than 4 photos to cover 360º.

After taking several photos overlapped, combine them into one image with a computer program.

To take a panoramic photo, you need a camera that supports panorama function. As shown below, such camera is made with different methods from an ordinary camera. It has a slit type lens system, so as a slit revolve, a line of light is recorded. Ordinary camera records a full shot at once.

This is the reason why a panoramic photo and an ordinary photo are taken using different methods.

A panoramic photo projects the images onto the surface of a cylinder, then unrolls the cylinder to make a flat plane, while a standard non-panoramic photo displays the images on a flat plane directly. If there is a rectangular object (ex. building), an ordinary photo shows it as a flat rectangle while a panoramic photo shows a straight vertical line and a curved horizontal line.

You can’t create a 360º photo by simply stitching ordinary photos together. It is possible but there is a huge chance the quality will not be as seamless as the original panoramic photo.

To transform an ordinary photo into a panoramic one, you should change the projection method. Change to panoramic mode first, and stitch the photos together.

Rules of Taking a Panoramic Photo

To take a panoramic photo, you should keep a few things in mind. The most important step is to keep a steady surface of rotation. You should fix the camera on a single axis and move it towards one direction, from one side to the other. The surface of rotation can be a horizontal line, vertical line or diagonal line. No matter which line you choose, you should fix the camera on one axis to prevent it from shaking.

Second, the photos you take should be partially overlapped. Overlapped photos will help the program identify the same spots to process. The best overlap ratio is about 20~50%. More than 50% overlap is not necessary and will only make the process complicated. Less than 20% overlap may cause errors. At least 10% overlap is essential to create a seamless panoramic photo.

To take a panoramic photo accurately, you should use a tripod to keep a steady surface of rotation.

Install the tripod and camera first. Do not fully tighten them. Spin the camera on the supporting surface to check whether the camera can smoothly move from side to side.

Take a photo at the first position, slightly rotate the camera to the right and take another photo.

Repeat this process until the end. If you rotate the camera to the left, you should change the order when you edit. The photos should be partially overlapped.

Make sure not to change the position of the camera on the tripod while capturing the scene. If you set the camera vertically you must maintain the position while capturing. Also, if the tripod is not set properly, take photos again to ensure you get clear images.