CONTRAST
There was a problem with the contrasts in your photos.

The photos seem to have a too low or too high contrast setting. Too low settings result in whites that are not pure white, or blacks that are not pure black. The image looks "flat". Too high contrast settings result in very strong differences between dark and light areas in the image, and usually in very strange-looking colours. The image looks very "hard".

The contrast problem may be due to incorrect post-processing with image editing software. If the image is a scan of a photo, negative or slide, it may be caused by incorrect scanner settings. In this case, please try different settings and rescan the image. Finally, this problem may also be the result of certain difficult lighting conditions, such as heavily clouded days, where the aircraft does not stand out sufficiently from the background.

The best way to deal with this problem is to use image editing software to increase or reduce the contrast. A sophisticated and usually very effective method is to adjust the so-called black-point and white-point of the image, where you manually define which areas of the image should be absolute black and white, and let the software adjust the rest of the image accordingly. Most image editing software has tools for this.

If you think you have been able to improve the photos, please re-upload them. Do not forget to include a note to the screeners, detailing what you have done to improve the image. There is a special field available for such notes. Please note that we are still very interested in having these photos in our database, we only ask that you try to improve the quality of the images as much as possible.

Rejected for contrast / Improved version with more contrast - Photo copyright © Thierry Deutsch

Rejected for contrast / Improved version with more contrast - Photo copyright © Thierry Deutsch

Rejected for contrast / accepted after some contrast addition - Photo copyright © Henk Schmidt-Bergemann

Generally speaking a photograph should have a perfect black and a perfect white and a range of tones in between. When contrast is too low the blacks can become a dark grey, frequently with a smoky appearance and whites can be a soft grey rather than a pure white. This results in images that have a muddy appearance and a similar effect can be the result of overuse of certain editing tools such as the shadow / highlight feature in Photoshop. When contrast is too high shadows tend to merge into black areas with little or no detail and highlights can also lose all detail. The appearance is harsh with exaggerated black and white extremes.

Interesting read concerning the curves tool:

- Curves