Exposure Fix

ColorWasher offers a special method for adjusting photos that were exposed with a wrong exposure time. Many image applications offer a brightness slider which usually produces shifted colors, a faded look, a lowered contrast and cutoff details in shadows and highlights. Another method that is offers by many image applications is called gamma correction. This method is used for adjusting the brightness of monitors and was also used by ColorWasher 1.0. It works relatively well, but for stronger adjustments it cuts off details in the shadows and lowers contrast.
ColorWasher 2.0 now uses a superior method that avoids these side effects.



The Exposure Fix Options

The Autodetect option of the Exposure Fix feature will automatically choose between Remove Shadows, Balance Midtones and Fix Highlights options. However, it tries to preserve the character of the photo. So in the case of a photo with a lot of shadows it won't try to completely lighten the shadows to remove them completely. It assumes that the photo is partly attractive because of these shadows. If you prefer well lit photos, you should better set Exposure Fix to "Balance Midtones" which will lighten shadows relatively strongly.

If a photo is very bright, Autodetect will reduce brightness to compensate for that. If a photo has a lot of overexposed areas, Autodetect won't change the brightness, because reducing it won't help in that case. Photos that largely consist of a bright area, e.g. sky or a wall, may be wrongly interpreted by Autodetect and darkened, although it would be necessary to brighten a small object in the foreground. In that case please choose one of the three other options.

Using one of the Remove Shadows, Balance Midtones and Fix Highlights options is sometimes more or less a matter of taste. For example if you prefer photos that have deep shadows, you can set Exposure Fix to "Remove Shadows". If you prefer photos that are evenly lit, you should choose "Balance Midtones" setting. The "Fix Highlights" setting is meant for fixing overexposed photos. Don't use it with underexposed photos as it may brighten them too much.

The Normal to Extreme settings of Exposure Fix sometimes produce a better result than the four other option, but if you apply ColorWasher to the same image again, they will increase or reduce the brightness a second time instead of applying no adjustment like the other options.


The Exposure Slider

The Exposure slider can be used to adjust the Exposure Fix option. Its unit is Exposure Value (EV) from -3.00 to +3.00. This slider works just like the exposure compensation feature of cameras, which usually range from -2 to +2 EV in 1/2 or 1/2 steps. Usually a higher exposure values means less light, but so it would be more correct to use negative values for increasing exposure. But to avoid confusing users and to make it work more logically, we use positive values for increased exposure. The exposure compensation feature of cameras do that, too.

An increase of one EV corresponds to setting the next lower f-number or next higher exposure tome on your camera. For example if the photo was takes with an aperture of f/5.6 and a exposure time of 1/60 second, a setting of -3.00 simulates how the photo would look if it was taken with an aperture of f/16 or with an exposure time of 1/500 second. A setting of +3.00 simulates an aperture of f/2 or an exposure time of 1/8 second. Of course ColorWasher is bound by the data that the camera has recorded, but it tries to lure hidden information that is compressed in the shadows or stretched in the highlights.

Please notice that the Exposure slider works non-linear. The strongest effect is visible between +0.00 to +1.00, the exposure is less strongly increased between +1.00 and +2.00 and even less between +2.00 and +3.00. Using an exposure value that is smaller than -2.00 or larger than +2.00 is usually not recommended. Only if your photo is extremely over or underexposed it may help to make the photo more presentable.


The Sensitivity Slider

The Sensitivity slider defines how strong the exposure correction affects the shadows and midtones. A larger value produces a stronger contrast and more saturated colors and preserves the shadows better. So it basically lets you adjust the shadow and midtone contrast of the exposure adjustment. The sensitivity adjustment is especially effective and may be necessary for exposure corrections of more than -/+ 1.00 EV. Below that value its effect is not that clearly visible.


Sat Fix

If the 'Sat Fix' check box is activated, ColorWasher will process the image while keeping saturation constant when adjusting contrast, exposure, highlights, midtones and shadows. This can improve some photos and avoid oversaturation, but sometimes if the adjustment is too strong, it decreases or increases saturation too much. In such a case it is better to deactivate the Sat Fix check box. An alternative to Sat Fix is the Saturation slider.


Histo Fix

The 'Histo Fix' check box removes gaps that can be seen in the histogram view of a corrected image. This means that the number of colors in the image will increase. These gaps are only a sign that a photo was corrected, but otherwise you can forget about them. Please only use 'Histo Fix' if you don't plan to sharpen the photo, because sharpening automatically removes the histogram gaps. However, this feature produces a larger JPG file size.