Explain in detail the pre and post process of the four synthesis techniques of landscape photography
This article comes from Hummingbird.com
When it comes to synthesis, many people will misunderstand it as changing the sky and the ground and moving flowers and trees. The concept of synthesis in the field of landscape photography refers to the use of late technology to make up for the lack of equipment and achieve early shooting A picture that cannot be presented due to equipment limitations.
With the continuous recognition of post-production technology by photography enthusiasts, exposure synthesis, panoramic splicing, stack synthesis and depth synthesis have been widely accepted, and have been recognized in some large international photography competitions. This article will introduce in detail the applicable scenes, pre-shooting techniques and post-processing procedures of these four synthesis techniques. Since the focal length synthesis and the time period synthesis are still controversial, this article will not cover it.
These photos above All shots were taken using the synthesis method introduced in this article
No matter which synthesis method, as long as the mention of synthesis means that this is not a primary technology, I believe readers interested in this topic will also have a certain foundation Yes, due to limited space, this article mainly explains the core technical points and ideas.
Exposure Bracketing Synthesis
Landscape photography is usually taken during prime time. There are two ways to balance the light ratio in a backlit environment with high light ratio. : Gradient gray mirror and exposure bracketing. Authors usually prefer gradient filters, but if there is no filter or the filter cannot fully function due to conditions, you can use bracketing to shoot and post-composite.
Shooting mode: Aperture Priority, fixed aperture value to ensure consistent depth of field.
Bracketing 3 exposures: -2, 0, +2
Bracketing 5 exposures: -2, -1,0,+ 1,+2
Is it three or five shots? Under normal circumstances, it is recommended to take three shots with two exposure intervals for each shot, so that it will be more efficient both in the early and late stages. Moreover, the current high-end cameras have a large dynamic range, no matter under-exposure or over-exposure, it is easy to adjust back after one-stop exposure.
Note: When shooting, check the histogram to check whether the details are complete. If the highlights in the photo with two stops are still overexposed, or the shadow area in the photo with two stops is not detailed enough, then Need to make up shots +3/-3 gears, or even -+4/4 gears, until the details of the highlights and shadows are fully recorded.
I personally like to use a gradient lens to balance the light ratio, which can be omitted Later troubles. However, due to the limitations of the real scene in the above picture, huge rocks stand on the sea level. The use of a reverse gradient lens will make the rocks in the backlit environment darker. The soft gradient is not enough to balance the sun and the sea surface on the sea level. Light ratio. In this case, only three exposures can be taken with bracketing, and the shooting parameters are shown in the figure below.
A. Automatic synthesis -Two kinds of HDR automatic synthesis software:
The above two kinds of software can be used for automatic Composite, but not suitable for photos with dynamic elements, such as brushed seascape photos.
used in the picture above ACR is automatically synthesized, and the smooth drawing of the foreground becomes very chaotic.
B. Manual synthesis:
One of the three photos without exposure compensation is a normal picture with sea water drawing, but the highlights are overexposed and the shadows have no details, so exposure compensation is used separately -2 The highlight part of the photo and the shadow part of the +2 photo are compensated. The process is as follows:
Use the normal exposure photo as the background layer
Exposure compensation -2 Place the photo on the background layer, add a mask to the selection, and only show the highlight area
Place the photo with exposure compensation +2 on the top of the layer, add a mask to the selection, and only show the shadow area
After compositing into a photo with detailed highlights and shadows, do regular color correction and rendering.
1. Applicable scenes
The vast scenes that are not enough to express in a single frame can be shot in panoramic splicing mode. The camera’s built-in panoramic shooting mode is not recommended. The shooting effect is not good and the details are not enough. Clear, and can only shoot JPG, no RAW format.
2. About the level adjustment table
There is a green bubble circle on the level adjustment table. Just adjust the angle of the tripod to make the bubbles in Just in the center of the circle.
Horizontal adjustment table
Why use a horizontal adjustment table for panoramic splices:
Ensure that the camera rotates horizontally on a horizontal plane to avoid vertical movement.
The scale on the panoramic pan-tilt allows precise control of the rotation angle between each photo. If you use an ultra-wide-angle lens, it is recommended to rotate about 30-40 degrees each time.
3. Shooting method
focal length: In order to avoid the influence of ultra-wide-angle end distortion on the later filming, the best focal length is usually 20-28mm
shooting mode : M file, fix the parameters after metering to ensure the same exposure value for each photo
Number of shots: the viewing range is determined, 4-8 shots are more common. A single shot is taken from left to right or right to left, and the effect of each heavy contract is more than 30%-40%. The degree of coincidence is related to the focal length. The longer the focal length, the smaller the degree of coincidence. Conversely, the shorter the focal length, the larger the degree of coincidence.
4. The particularity of the panoramic galaxy
A. Ultra-wide-angle lens is used to shoot the Milky Way, usually 16mm is universal, so it is recommended to overlap each frame by about 50% when shooting, and the success rate of splicing is high.
B. Because of the rotation of the earth, the starry sky we see is relatively moving. Each set of splices should be completed as soon as possible, and the interval between each sheet should not be too long. Otherwise, it will be more difficult to splice later.
C. Starry sky photos are more blurred than ordinary scenes. Check whether each one is clear, as long as there is a problem with one of them, it will directly affect the subsequent filming. It is best to shoot two groups from left to right and then from right to left.
5, post synthesis software
A. Panorama connection software-PTGui can be downloaded from the official website www.ptgui.com
B. The RAW format can be retained when connecting the film in ACR. After connecting the film, continue to make preliminary adjustments in ACR, and then import it into Photoshop
depth of field composition
Depth-of-field synthesis is often regarded as a very high-depth technique, but in fact, as long as you master the key technical points, the operation is not complicated. Its core technology in the early stage is only manual focus, as long as it can achieve accurate manual focus, it is easy to complete the synthesis in the later stage.
1, applicable scenarios
foreground is off The lens is very close, even if the depth of field is shot at a small aperture, there is no guarantee that the foreground to the distant view are clear enough. Landscape photography usually uses ultra-wide-angle focal length of 12mm-16mm and small aperture F8-F16 to shoot. In this case, the general foreground is within about 2 meters before using the depth of field synthesis. If the foreground is 2 meters away, the depth of field of the hyperfocal distance is already Enough to ensure that the picture is all clear.
The texture of the ice surface in the foreground can be seen from the above live photos The distance to the lens is very close. In this case, even hyperfocal distance cannot guarantee that the entire image is within the depth of field. This is a problem that cannot be solved by current photographic equipment. The solution is to focus on the ice in the foreground and the snow-capped mountains in the distant view separately, and then adopt the method of depth-of-field synthesis in the later stage to achieve a clear and high-quality image from the foreground to the distant view.
2, shooting method
shooting mode: aperture priority or M gear, the light changes during prime time, it is recommended to shoot at a small aperture F8-F16, the smaller the aperture, the greater the depth of field, so you can Reduce the number of shots to save time.
Focus mode: manual focus, focus on the foreground, middle and long distance respectively
Example picture: This photo is characterized by a flat mid-range, and the focus of the picture is only the straw hat mountain in the distance and the ice in the foreground. Because the small aperture has a relatively large depth of field, in order to save time, only the foreground Focusing with the distant view, one is that the foreground to the middle shot are within the depth of field, and the other is that both the far view and the middle shot are within the depth of field, so you can take two shots.
The following picture is a detailed comparison picture of focusing on foreground and distant scene, ice surface and snow mountain:
The left image focuses on the foreground details; the right image focuses on the distant snowy mountains, the foreground is not clear enough
The image on the left focuses on the details of the snow mountain Picture; the right picture focuses on the foreground, the snowy mountains in the distant view are not clear enough
3. Post-synthesis process
The post-processing of the depth-of-field synthesis is more clear and intuitive with screenshots. The following is the specific operation process: p>
align two in ACR After making basic regular adjustments to the photos, open them in Photoshop, and put the two photos as two layers in one file
Select two layers, and select “Edit-Auto Align Layers” in the menu
check automatic alignment
After aligning, execute “Edit- Automatically mix layers” command
select “stack image”, check “seamless tone and color”. After calculation, Photoshop selects the clearest part of each layer for synthesis. The synthesized image is from the foreground The vision is all clear.
stack synthesis has two main functions, one is noise reduction, and the other is to simulate long exposure effects. The two functions are explained separately below.
stack noise reduction
1, applicable scene
stack noise reduction is often used in starry sky photography to shoot the Milky Way, high ISO or long exposure (usually more than 2 minutes) In the photos taken, high ISO will produce a lot of brightness noise and color noise, and long exposure will produce a lot of thermal noise. Although stack noise reduction is more cumbersome before and after, it is the best noise reduction method to improve image quality.
2, shooting method
fixed camera position, M file fixed parameter continuous shooting 4-10 pictures, stacking effect is decreasing effect, front The effect of 4 shots is the most obvious, and the noise reduction effect becomes weaker after more than 8 shots, so the number of shots depends on the photographer’s requirements for image quality.
six stacks before and after noise reduction, zoomed in 400% detail comparison chart
3. Noise reduction process
First, make basic regular adjustments to the two photos in ACR
Open in Photoshop, several photos are placed as two layers in one file
Select two layers and use the menu “Edit-Auto Align Layer” to perform image alignment
Select “Layer-Smart Object-Convert to Smart Object” in the menu
again select “Layer-Smart Object-Stack Mode-Intermediate Value or Average Value”
simulate long exposure
1, applicable scene
Using a light-reducing mirror can shoot a long time exposure to achieve the photographer’s creative intentions, such as fogging the water surface or capturing the dynamics of clouds, etc. If there is no light-reducing mirror or the number of gears of the light-reducing mirror is not enough, it is not enough to achieve The planned shooting time can be used to simulate long exposure by stacking.
2, shooting method
Shooting mode can be selected according to personal habits A or M file, the key is to fix the camera position and fixed parameters (Aperture/Shutter Speed) Continuous shooting, the number of shots depends on the shooting intention.
For example, the motion trajectory of the cloud in the picture above is usually taken It takes at least 3 minutes of exposure time. At that time, only a six-speed filter was brought, a single exposure was 30 seconds, 7 shots were taken, and the stack synthesis was equivalent to a long exposure of 3 and a half minutes.
The picture below shows seven single photos taken
3. Post-composition process
First, make basic regular adjustments to the two photos in ACR
open in Photoshop, and place several photos as two layers In a file
select two layers, use the menu “Edit-Auto align layer” to perform image alignment
in the menu, select “Layer-Smart Object-Conversion For a smart object”
again select “Layer-Smart Object-Stack Mode-Average”
Stacked composite star trails also belong to the simulation long exposure, a single 30-second exposure shot 120 Zhang can synthesize one-hour star trails, but change the average value of the last step of the synthesis process to the maximum value.
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