Post-processing a backlit image
Once the RAWs are in the camera, the cards (SD) are discarded and it’s time for the post-processing to take action !
If the sun is too “burned”, if you have not under-exposed enough, it is “right click + delete”.
On the other hand, if this is not the case, then the photographer that you are is going to be able to express himself and make the most of the possibilities of his RAW.
Let me show you :
how to process a backlit photo with Lightroom
how to restore the radiance to the sun while paying attention to its surroundings.
And all this without using Photoshop and layers
It will be necessary to play with parsimony on the sliders to obtain a natural rendering without unsightly halo, and without frank “rupture” between the light and dark zones.
For this example of treatment, I chose this picture of a Ptérois in backlight. The picture was taken in December 2016 in Moheli, a small island in the Comoros archipelago.
The material used is a Canon 5ds with 15mm Canon fisheyes optics. The picture is taken at a depth of about 15m.
Let’s go on ! We are gonna load the file to Lightroom CC :
It is immediately noticeable that the white balance is completely off, the dominant one strongly draws towards the green
We’ll correct that right now with the magic pipette!!
Of course, I’m talking about the localized white-balance compensation tool.
As this tool is very handy, you will find it in the Basic Setup tab as shown below :
The principle of this tool is to correct the white balance.
To do this, use the pipette to click on an area of the picture that is supposed to be white (be careful: this tool does not work in burned areas such as the sun).
For this photo, I know that the contour of the eye of the Ptero is white. So I’m going to select the target’ neutral’ color :
Here is the result :
The dominant green is less present.
It can be noted that the color temperature and hue have been automatically modified :
I leave these settings like this because we readjust the WB (White Balance) at the end of processing.
The goal of this action is to have a more precise vision of the final rendering of the photo.
I will now lighten up the shadows and whites and add a bit of clarity before going further :
Now, the next step will be to work on the sun and its contour.
The contour of the sun is too bright for my taste, so I will try to retrieve information on the outline.
Problem: if you vary the High Lights or White slider will appear an unsightly halo as on the example (a bit exaggerated) below.
And that’s just impossible !!!
The problem comes from the transition between the cyan hues, which surround the sun, and the blue of the photo. This problem is recurrent on all underwater photos in backlight.
In addition, the dimming of the high lights also affects the whole image, including the Pteroes and small fish in the foreground.
To avoid this, I reset the high light slider to zero and use the localized processing tool that will allow me to work only the sun and its contour without influencing the rest of the photo.
By clicking on this tool, this should appear :
The circles indicate the area where the treatment will be effective. The first circle represents the area where 100% of the actions will be applied. Between the two circles, this is the transition zone. Beyond the second circle there will be no changes.
Place the center of the circle on the sun and increase its diameter (with the mouse wheel) until it is completely covered as I show you on the screenshot below:
Once the treatment zone has been defined, I will look for information in the area closest to the sun.
To do this I turn down the high lights with the associated slider.
At this stage, the rendering of the sun is not yet correct. The halo is present today.
But don’t panic, it is now that we will get to the point.
Once the sun’s high lights have been recovered, the goal is to suppress the halo that we made appear with our treatment.
To do this, go to the TSL / Color / BW menu. In the hue section select the green blue (cyan) cursor to shift it to the right :
Here is the comparative result on the sun
Changing the cyan shades to blue erases the halo that appears when you pick up the high lights.
This is one of the most important actions when processing a backlight, but also for other types of photos where cyan color is present.
Indeed, the transition between cyan and blue requires a great precision and delicacy. At times, the easiest way is to replace these shades.
Here is the whole picture after the localized changes of the cyans :
Then, still in the TSL / Color / NB tab, click on the Saturation icon and increase the Green Blue saturation. Here a value of +65 is enough.
The purpose of this action is to bring blue back to the place where the cyans disappeared.
We notice that the rendering is no longer the same. We recovered as much information as possible around the halo-free sun.
However, it is still possible to give the sun a little pep’s to reinforce its presence.
To do this, we will return to the localized action tool by clicking again on the tab below the histogram.
The small dot in the center of the sun appears. Just click on this small point to find the local settings you have previously made.
Small precision, the red halo that appears is an indicator of the area where the tool will be active.
I will now boost the clarity to increase the impact of the rays on the sun’s perimeter.
Which gives this :
Sun treatment is now complete
All that remains is to work the foreground with a radial filter (viewed in the last tuto) like this :
Here, in just a few clicks, is the possible result of a backlit photo :
Conclusion on the treatment of an underwater photo in backlight
This treatment remains nothing more or less than a basic work of “derawtization”. There are other ways to refine the rendering of the sun, especially with Photoshop.
I repeat myself, I want to say it again: to make a successful underwater shot in backlight, it is imperative to bear in mind that everything is a matter of shooting.
Normal, as always you’re about to tell me… yes, but in this case it’s crucial.
In other contexts, some errors are allowed.
This is not the case with the sun in the frame.
This tutorial, like most tutorials, is an example of processing.There are other techniques, other ways of doing it.
In the next tutorials, I’ll start talking about Photoshop and setting layers.
Merci pour tes conseils.
Je vais essayer de transcrire ce travail dans photoshop ;) (Lightroom reste une énigme pour moi ;) )