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Tag : curves


The “Solar Curve” (Solarization curve)

What is the “Solar Curve”?

The “Solar Curve” looks like a wave created from the normal linear curve inside of Photoshop. Normally 4 or 6 points are inserted. Mathematically one divides the entire range (0-255) into 5 or 7 parts and sets accordingly the points:

4-point Solar Curve

If you want to set 4 new points, simply divide the 255 (maximum) by five and get 51. These points result accordingly:

Input / Output


It will look like that:

6-point Solar Curve

If you want to set 6 new points, you simply divide the 255 (maximum) by seven and get 36. Accordingly, these points result in:

Input / Output
109/255 * actually 108, has been rounded up
218/0 * actually 217, has been rounded up

It will look like that:

What does the solar curve do with the image?


As you can see in the picture, the Solar Curve is used to map the small contrasts to extreme changes. This creates a very alienated but also enlightening view. This view is ideal for revealing sensor spots/freckles or a single hair, but also to be able better to judge the gentle transitions between light and shadow.

Here it reveals everything that could be somehow “dirty”. So here’s a round of criticism of your own work (from a time when the solar curve was not yet part of my standard workflow):

On the left, you can see a bit of banding; at the top, a sensor spot/freckle was overlooked, and there are still a lot of spots on the forehead. Yeah. Did you see that in the picture above?

Why do you need such precise editing?

This question often pops up (“No one sees that anyway”), and usually, that’s true.
One thing you must not forget: not every screen is the same. Those aspects that your screen may not display could be displayed on another display (possibly a disastrous low-budget discount screen that had been in the public office of the pro-chain smoker association for years and had its best times – if you can speak of it) can look completely different – and indeed by unnatural extreme shifts, such editing errors are no longer almost invisible.

Another example is backlit displays – everything that is printed and then backlit should be very smooth and clean. Mirror foil is also really mean and does not always reveal the best in retouching.

When one works for a client, you never know what he will do with the files – maybe just a brochure is planned, but a bit later could be an exhibition/fair asking for a large format display. You never know.

Working with a visible Solar Curve?

That does not sound tempting?
Immediately seeing where these minimal changes have yet to be made, seeing the little luminance issues burning in the night at Dodge & Burn, that sounds great, doesn’t it?
I use the Solar Curve for sensor spots/freckles, clone stamp, double-check, and hair. To sum up, everything you want to remove 100% clean and has very low contrasts.
Miraculously, you can use this view as a negative or with additional contrast enhancement to unmask even more of the problem areas.

For everything else: Leave it. You run the risk to retouch any naturalness away.

Do you have any suggestions, additions, is this post out of date, or have you found any mistakes? Then we look forward to your comment.
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2-Point Curve as best option to do Dodge&Burn

Dodge & Burn – Different methods compared

Dodge & Burn is a subject where opinions differ. There are many ways to make areas in the picture lighter or darker. We quickly discuss the different methods and test them for suitability – there are sky-wide differences.

Dodge & Burn Tools (DE: Abwedler & Nachbelichter)

Photoshop has always offered two tools for Dodge & Burn. Surely everyone has experienced this situation: take the Dodge tool and painted around in the picture, oops done too much, used the Burn tool to compensate, and the final result: light and dark patches in the image in which nothing would fit anymore. Many put these two tools in the “not to use” drawer.

It gets much better if you create an additional layer, fill it with neutral gray (50% gray) and switch it to the “Linear Light” blending mode:

50% gray layer

A 50% gray layer in blending mode “Linear Light” initially does not change the image. But if you make the layer lighter or darker — of course also partially — the picture also becomes lighter or darker. The advantage of the 50% gray layer is that we can also work with regular brushes, and if something went wrong, you could always paint over with 50% gray to get back to the original state.

Some people use the blending mode “Soft Light”, which has a more subtle effect (hard to push it really dark or light). Other than the layer has an impact on saturation, which should be taken into consideration.

Pro Tip: You can also leave the layer empty and paint with black or white – the effect is 100% the same and saves storage space.

Multiple RAW conversions

What is sometimes helpful is to use different RAW conversions.
One for the skin tones, one for the background, one for the hair — depending on what the picture requires. These individual RAW developments are loaded as layers in Photoshop and can then be masked accordingly. Of course, there are a lot of options here, because RAW development offers countless parameters — but this technique inflates the Photoshop file properly and can only be used at the very beginning. So you have to be sure of your decisions here.

Dodge & Burn Curves

Two curves – one for Dodge and one for Burn – are the optimal solution. Masking the effect in and out with white and black is very simple. Switching between layers is pretty easy with the following shortcut
Windows: Alt +, (down), or Alt +. (up)
Mac: Option +, (down), or Option +. (up)

However, the correct usage of curves for Dodge & Burn needs to be learned. There are many people out there, pushing and pulling their curves by their current mood. In addition to luminance, curves can also influence saturation and contrast. Tiny differences can make big differences.

Conny Wallström (a photographer, retouching-teacher, and software developer based in Sweden) tested various curves over a more extended time and compared them with the results of exposure levels of the raw converter Capture One.

The idea for that process was that a raw converter such as Capture One reproduces the most natural and realistic way of dealing with color with different exposures without simultaneously causing color problems and color shifts.

The result of the research was a 2-point gradation curve that he integrated into this retouching toolkit. So if we use the following Dodge & Burn curves, we can assume a natural, realistic result. At the same time, we work consistently and time-efficiently, since it is an action in Photoshop that always works in the same way.

But that’s not all. Many who already use this retouching toolkit know that this action creates two folders and that in addition to the special curves for Dodge and Burn, hue/saturation corrections are included.
Here is the reason for the hue/saturation corrections:
When we take an analytic look at a portrait picture, we find out that by increasing luminance, the saturation tends to decrease; with decreasing luminance, the saturation tends to increase. If we only lighten an image based on luminance, the proportion of saturation in the now lighter areas is suddenly too high (vise versa). The use of such hue/saturation corrections is, therefore, a measure against saturation problems caused by Dodge and Burn to save editing time in retouching.

Such hue/saturation corrections make the most sense when processing skin (skin build-up, blood flow in the skin).

Of course, this cannot be generalized 100%. Every image requires slight adjustments to the hue/saturation correction layers due to other camera manufacturers and raw formats. Therefore, a recommendation is to adjust those layers slightly for each image. However, one cannot avoid looking at the saturation in the image afterward (at least briefly).

Hidden Gems / Tips and Tricks

Pro tip 1: Separately adjusted curves for very granular, high-contrast structures such as make-up (see example below) are useful to avoid flattening the contrast.

(Photo by 𝐕𝐞𝐧𝐮𝐬 𝐇𝐃 𝐌𝐚𝐤𝐞- 𝐮𝐩 & 𝐏𝐞𝐫𝐟𝐮𝐦𝐞 from Pexels)

Pro tip 2: Dodge & Burn tools — these work perfectly for eyebrows. If you paint them on an empty layer, you can make individual hair lighter and darker for a realistic result. You will only affect the painted hair, which is very useful.

Don’t forget Dodge & Burn is much easier by using Wacom tablets.


Do you have any suggestions, additions, is this post out of date, or have you found any mistakes? Then we look forward to your comment.
You are welcome to share this post. We are very grateful for every recommendation.