This lesson will tell you about the new hot trend in photography. Hdr! You will learn how to take pictures, reduce and produce a tone mapping to expand the dynamic range and create a result that looks drawn.
The lesson for working in Photoshop CS3 and above.
Tonal Compression / Tonmapping
Click on the screenshot to view the image in real size.
Step 0 (Introduction)
In this tutorial we will look at an HDR photo. HDRI (High Dynamic Range Imaging (Wide Dynamic Range Image)) was originally used in 3D, and now fully in photography. Simply speaking, this is a process of shooting with different exposures and flattening images into a single 32-bit image. So, I I will explain: the camera is able to capture a limited number of tones in one photo. Usually we donate any elements of the photo while shooting it. For example, we have a landscape with clouds and rocks. If we expose the clouds, the rocks will become dark. cameras on detail and rocks, the bright sky dimmed, and the details will be lost. This is because the human eye can perceive a wider range of colors than the one that can capture the camera in a single photograph.
The solution to this is to take more than one photo and combine the photo.
Take a photo with a regular exposure, then take a snapshot with a lower exposure so that it is bright, and then with a larger exposure, to capture the details of the shadow.
Ultimately, it is necessary to bring these images together in order to obtain a single image with a wide range of tones, which can now show all the details in highlights and shadows. This lesson will show you how to carry out this process without fuss.
First we need to get the original images (you can use a 32-bit 3D image and immediately go to step 6). Such an image we will shoot on the camera. You need to take at least two pictures with different exposure settings.
Adobe recommends restricting bracketing in steps of one degree of exposure, which will help reduce the range.
Bracketing – Also called “plug”. Camera shooting a series of frames (three or more), which differ in parameters with a given interval of values (exposure, white balance, etc.).
You can also take 5 or more pictures with a smaller bracketing interval. Personally, I get a good result of three shots. I like to increase and decrease shutter speed by two steps. I know that these are larger frames than many people are used to using, but for HDR-type images that I like to create (cityscapes), this is very suitable. If you are an amateur photographer, you can even reduce the bracketing to 3 steps.
(Note: For true HDR, you cannot use a single photo in raw format and change its exposure several times, as some people suggest. This effect is known as pseudo-HDR. Photoshop will not allow you to combine these images because they do not fix the desired tone).
Step 1. Let’s start with three images. One with a normal exposure, the second a smaller exposure and a third with a greater exposure. In this case, I use bracketing with an interval of 2 steps, because basically I shoot flat surfaces. If you are shooting rounded and uneven surfaces, then you’d better lower bracketing for a smoother transition.
I set the bracketing on my camera to 2 steps. Then I set the shooting mode to the timer. After that, I get three photos. I shoot in RAW mode to be able to get a wider dynamic range. You can also create HDR, even if your camera does not support RAW.
Make sure that you shoot in Aperture Priority mode (Aperture Priority) or in manual mode (manual). You need to set the exposure time, but not the aperture. If you change the aperture, the depth of field will not be compatible with the settings, and you will get a blurred image. Also avoid moving objects in the photo, otherwise you will get a “ghost” effect.
Step 2. The time has come to merge the photos together into a single 32-bit image.
Select File–Automate – MergetoHdr (File – Automation – Merge into Hdr). It works in Photoshop CS2 and CS3 (there is no auto-alignment in CS2).
Select all images or folder. I put each set of photos in a separate folder, so I select the option Folder (Folder). Highlight your photos for details. Tick on AutoAlign (Auto Alignment) in Photoshop CS3. Click OK (Photoshop CS3 uses a new auto-alignment technology that even allows you to create HDR without using a tripod!).
Step 3. Your images are now merged into a single photo. You can move individual photos by unchecking checkmarks in the left column. If you get a bit of a blurred effect on any one as a result of camera movement during a long delay, you can turn off this photo.
Step 4. The reduced result is a flexible point image. You can completely change the tones by moving the white slider on the right. Only easier with him – the slightest movement of the slider gives completely excellent results.
Step 5. Click OK to capture the photo into a 32-bit image. Now is a good time to save the image.
Step 6. For normal work with photos, you need to convert them to 16-bit or 8-bit images. When you convert them, we will start creating what I call photo interpretation. The reason that I say this is an unlimited number of ways that we can use to convert photos. As long as we have a huge 32-bit image with a wide dynamic range, we cannot use it for further processing. Always start with a 32-bit image, then convert it and save other options (your own interpretations). Avoid rewriting 32-bit images, they are our magic wand, we can come back to them many times.
Select Image – Mode – 16 bits (Image–Mode-sixteenbit) (or 8 bits (8 bit)). Now let’s play with interesting options. Now you have moved to the process of so-called tonmapping (tonal compression). This is the place for creativity.
(If you want to make a correction without conversion, select View – Preview parameters 32 bits (View – 32 Bit Preview Options). You can also use several Photoshop tools from the menu. Image – Adjustment (Image – Correction). The most important parameter presented is the control parameter. exposure (exposure)).
You will see a dialog box HdrConversion (Conversion / Correction Hdr). The default parameters are Exposure (Exposure) and Gamma (Gamma) (approx. degree of contrast). How to better understand the principle of their work? Set the gamma first and then the exposure, as shown in the example. If you want the image to be more contrast, reduce the gamma value. To decrease contrast, increase gamma value. Finally, adjust the exposure to get the desired brightness. If you want more conversions, read on, if not, click OK.
Step 7. Replace method (method) on local adaptation (localadaptation). (You have 4 available methods, but only two can influence the user).
With this method, you can adjust curves (curves). Work with them, as you used to work, but do not be afraid to cut them off a little. This is permissible because you are working with a large dynamic range than you are used to working. Pull out the details of the image, but do not forget to put shadows where they will be somewhat blurry or ugly. As soon as you figure out the curves, adjust the position of the sliders. radius (radius) and threshold (threshold) to avoid the appearance of ghosting in the photo. (A poorly converted HDR image in places of contrast has a certain glow around). The radius is responsible for masking the blur, while the threshold decides what will be blurred and what will not.
Click OK to convert.
Step 8. Before us is a combined image from HDR. The second image is a variation. In the second variation I applied the exposure. (exposure), curves (curves) and sharpness settings (sharpening) in 32 bit mode (Highlight Compression Method). Photoshop is great for creating very realistic HDR images.
Step 9. If you want to achieve more surreal results, use a variety of plugins. My favorite plugin is Photomatix Pro from HDRsoft. You can use this plug-in for Photoshop, it works fine.
Using the Photomatix Toning mapping plug-in will allow you to detail the texture in your photos. Combine them in Photoshop, as shown in this tutorial. Then select Filter – Photomatix, to apply tonmapping. Convert and save as usual.
Step 10. This image shows how the photo looks after tonmapping in Photomatix pro.
Step 11. Here you can see a comparison between a single image, a transformed image using Photoshop HDR and a radical effect in Photomatix. Regardless of the result you got, I hope this lesson helped dispel the myths about HDR.
Here is another HDR image of mine. This is a night shot transformed into grayscale.
Hope you enjoyed this tutorial!
I thank Eugene Kartashov for advice on terminology.