COMPRESSION
The quality of this image is too low due to the use of too much JPEG compression.

If your photo is wider or higher than 1600 pixels it will be downsized automatically during upload, which may lower the picture quality. It's best to keep the width between approximately 1000 and 1200 pixels and to save your photos with the lowest possible JPEG compression (highest quality, or 12 in Photoshop).

As a general reference, the size of a JPEG file without any compression, of 1024 by 700 pixels, will be somewhere in the range of 400-700 KB, depending on the composition and colour range.

Same picture saved with 3 different compression ratios (left third shows no compression) - Photo copyright © Thierry Deutsch

Always double-check your saving settings to make sure you save your picture with the best possible quality.