In this Hindi video tutorial,we have demonstrated you what is the meaning of #HDR photo and tone mapping #persona ,when to use develop persona,how to do HDR merging,how to apply tone mapping persona on normal photos.
The new features in Affinity Photo include an HDR Merge tool for combining a series of different exposures of the same scene into a single, high dynamic range image, and Tone Mapping Persona (or ‘workspace’) which can bring out all this extended shadow and highlight detail to create a richly detailed, finished image.
After tone mapping
High-dynamic-range imaging (HDRI) is a high dynamic range (HDR) technique used in imaging and photography to reproduce a greater dynamic range of luminosity than is possible with standard digital imagingor photographic techniques. The aim is to present a similar range of luminance to that experienced through the human visual system. The human eye, through adaptation of the iris and other methods, adjusts constantly to adapt to a broad range of luminance present in the environment. The brain continuously interprets this information so that a viewer can see in a wide range of light conditions.
Tone mapping reduces the dynamic range, or contrast ratio, of an entire image while retaining localized contrast. Although it is a distinct operation, tone mapping is often applied to HDRI files by the same software package.
What is Tone Mapping?
Tone Mapping is the process of converting the tonal values of an image from a high range to a lower one. For instance, an HDR image with a dynamic range of 100,000:1 will be converted into an image with tonal values ranging from just 1 to 255.
You may wonder why someone would want to reduce the tonal range when an HDR image provides so many benefits compared to a Low Dynamic Range image. After all, HDR images contain a much higher level of detail and are closer to the range of human vision. The reason is simple: standard display devices can only reproduce a low range (around 100 or 200:1), and for paper, the range is even lower.
So, the goal of Tone Mapping is to reproduce the appearance of images having a higher dynamic range than the reproducing media such as prints or standard monitors.
After tone mapping
Many scenes we are photographing have a high contrast, or properly speaking a high dynamic range: part of the scene is in the shadows, part in the highlights. Photographers have to deal with two types of issues with such High Dynamic Range scenes.
· Issue 1: Camera limitation
The first issue is to capture the dynamic range of the scene. This is commonly addressed by taking several photos of the scene under different exposure settings, and then merging those photos into an HDR image.
· Issue 2: Display limitation
The second issue is to reproduce the dynamic range captured on low dynamic range displays. That is, to ensure that the details in highlights and shadows in the HDR image can be correctly viewed on prints and standard monitors in spite of their limited dynamic range capability. Tone mapping deals specifically with this issue of reproducing the dynamic range captured.
In a way, tone mapping has the same purpose as blending exposures which is traditionally used in digital imaging for processing HDR scenes. The differences and similarities between both are detailed here.
After Tone mapping
START THE HDR MERGE PROCESS
In Affinity Photo, select File > New HDR Merge…Now you’re prompted to choose the photos you want to merge on your computer, and when you’ve done that they’re displayed in the ‘New HDR Merge’ dialog. There are settings underneath which are ticked by default – ‘Automatically align images’, ‘Noise reduction’ and ‘Tone map HDR image’ – and you don’t usually need to change these. The noise reduction is designed for raw files, however, and if you’re using JPEGs or you find the effect too strong, you should disable it. Keep the ‘Automatically remove ghosts’ option for shots where objects have moved between frames.
There are some complex processes at work here, so you need to wait a few moments while they finish. Affinity Photo will run through a sequence of steps here, including the alignment of the source images, the HDR merge process, a Denoise process (if you left this option selected in the previous step) and the final tone map phase. The image may change in appearance, but don’t worry about that – it’s the final tone mapped version that counts.
The merged image is displayed in Affinity Photo’s dedicated Tone Mapping Persona, with manual image adjustment controls on the right and a small selection of preset effects on the left.You can add details,increase exposure etc.
Once you’re happy with your tone mapped image, click the Apply button in the top left corner of the Tone Mapping Persona window. This generates a finished image which is then displayed in the regular Photo Persona. You can save this in the Affinity Photo image format and export it as a JPEG or TIFF image.
Photo credits Mr.Saurabh Mehta
HDR Image courtesy https://gratisography.com/
Read more about HDR images-