VanDuuren Media announced the forthcoming title Handbook of photography, 11th edition by Pieter Dhaeze. Read the preview of chapter 15 here now, Image montage, which discusses panorama, HDR and focus stacking.
High-end compact cameras and cameras with interchangeable lenses (DSLR and MILC) are excellent for taking beautiful photos in various situations. However, some photos require combining multiple images, such as panoramas, and also at HDR and focus stacking two or more images are combined. This chapter covers these three image-montage techniques and explains how to make the required series of photographs.
Panorama
A panoramic photo is a widescreen shot with an aspect ratio between 2:1 and 360°, with 17:6 (approximately 3:1) being a classic standard. Panoramas can be either horizontal or vertical. In the digital age, overlapping images can be merged into matrix panoramas with gigapixels.
Even simple wide shots of two overlapping photos can be impressive and reduce the need for a super wide-angle lens.
Some points to consider for a seamless result when editing a panoramic photo are: use a tripod, ensure sufficient overlap, maintain the same focal point, pay attention to exposure, choose a suitable aperture, consider a vertical frame, disable autofocus, adjust white balance, use RAW files for high quality and correct lens aberrations in the RAW converter.
Not all subjects are suitable for panoramic photos. Vast landscapes work well, but with a lot of movement, such as at events, it becomes more difficult. Overlapping areas can be disturbed by movement, passing clouds or large differences in perspective. However, with the right tools and software, special results can be achieved even in challenging situations.
A panorama can be edited manually or with software intelligence in an image editing program. Manually merging a few overlapping shots can be done with a photo editing program that supports layers. For more complex subjects or more photos, special software such as Photoshop Elements with the Photomerge Panorama option, can be used to create high-quality wide-format composites.
Panoramas can expand the photographer's field of view and emphasize the vastness of a subject. Cameras with a full-frame sensor are ideal thanks to their large field of view, high detail registration and dynamic range, but it is important to work in RAW. Although panorama software is becoming increasingly smarter, good preparation is crucial.
High Dynamic Range (HDR)
Photo cameras have a more limited ability than the human eye to bridge large contrast differences. In backlight or in landscape, architecture and interiors, photographers often have to choose between detail in highlights or shadows. HDR makes it possible to combine multiple shots with different exposures into one image with a wide contrast range and high image quality.
For an HDR composite, start with a well-exposed RAW bracket spanning at least -3 Ev to +3 Ev and containing three to seven images. Work from a tripod whenever possible to avoid motion blur and shifts in framing. Try to avoid moving elements such as people, vegetation, and clouds. An automatic exposure bracket shot in quick succession can help freeze slower movement.
Import RAW photographs with different exposure settings into the Lightroom catalog. Correct lens aberrations and white balance, but leave exposure unchanged. In the Develop module, select the photographs, enable Auto Sync, and apply lens corrections and white balance simultaneously to the selected images.
After capturing the exposure bracket and completing the preliminary adjustments in Lightroom, creating an HDR composite as a 32-bit DNG file is straightforward. Select the series, right-click a photograph, and choose “Photo Merge > HDR” (Ctrl-H). Let Lightroom create a preview and adjust the dialog options: enable “Auto Align,” disable “Auto Settings,” and choose the appropriate deghosting option. Click “Merge” to complete the HDR composite.
The final DNG file will end up in the same folder as the original RAW files of the exposure sequence and will also be automatically imported into Lightroom.
When editing the DNG in the Develop module, all parameters are active, but the exposure range is now -10 to +10 Ev instead of -5 to +5 Ev on a normal RAW file. Highlights and shadows now work on areas not available in a single RAW file with 14-bit color depth. This ensures natural results in high-contrast subjects, with maximum detail and minimum noise.
Although a graduated neutral-density filter can reduce contrast in a single RAW exposure, a bracketed RAW series followed by an HDR merge in Lightroom generally offers the strongest results. Consider using exposure bracketing and HDR techniques more often.
Focus Stacking
A crucial aspect of a photo is the depth of field, especially in close-ups or macro photography. To capture a subject sharply from start to finish, you can 'stack' photos with a limited depth of field and different focus points, retaining only the sharp parts. This principle is called focus stacking.
Depth of field is the visually sharp area in a photo, influenced by aperture, distance to the subject, and focal point of the lens. A larger aperture, smaller distance to the subject and larger focal point result in a smaller depth of field. System cameras have a smaller depth of field than compact cameras. An example: with a full-frame sensor, 180mm macro lens and 50cm distance at aperture f/3.5, the depth of field is only 1mm.
Due to the manual focus with focus stacking, an interchangeable lens on a system camera is required. Photos can be merged with a photo editing program or special software. The frames of the individual photos must overlap (almost) exactly. So the subject must be stationary and the camera is on a tripod.
Use a fast shutter speed and a self-timer or remote control for sharpness. Focus manually (MF), use aperture priority (A) and f/4-f/8 aperture. Ensure a shutter speed is faster than 1/60s and adjust ISO if necessary. For maximum image quality and control, switch to RAW.
The manual focus steps are good universal options, but many modern mirrorless system cameras now have an automatic function to take series shots with a changing focus point.
Merging the sharp parts of several photos taken for focus stacking can be done in two ways: manually using a photo editing program that supports layer editing or automatically using specialized software. The manual method is intended for experienced users of programs such as Photoshop Elements or CC. Specialized software is accessible to everyone, as long as the photos are captured properly.
For a manual workflow, stack the images as layers and use the Eraser tool to remove the blurred areas in each layer. The sharp areas can then be merged with the background into one photograph and saved as a JPEG.
For a faster, easier, and sometimes better focus stack, Photoshop CC also offers an automated workflow. After installation, open the photographs, click Run and wait a few minutes for a seamless, highly detailed result with continuous depth of field between the nearest and farthest focus points.
If you are a macro or product photographer and you struggle with the depth of field of subjects, focus stacking is the solution to this problem.
Text: © Fotografie.nl based on Photography Handbook, 11th edition - Pieter Dhaeze
Handbook of photography, 11th edition - Pieter Dhaeze
Pages: 416
Price: €49.99
Publisher: VanDuuren Media. Language: Dutch. This article refers to the Dutch-language edition.
