There's also the issue of image quality. If the original photo was poorly lit or blurred, its purely a waste of everyone's time and bandwidth. To be useful for most purposes, board or component photos need to be high enough resolution to read the component markings. Crop anything that isn't needed, and use a plain background. A sheet of white paper is a good default choice for parts and smaller boards.
Never use JPEG format for schematics or other line art. It inherently blurs fine detail e.g. small text or where lines cross, so to maintain quality you need a vast file size. GIF or PNG is a far better choice. Reduce the colour depth as far as you can without loosing detail. e.g for most computer generated schematics, 256 colours (8 bit) or even 16 colours (4 bit) palletized is fine. Scanned schematics are a lot more problematic, due to stains and dirt particles on the paper and uneven printing. If you want to get the filesize down while maintaining readability, you'll probably need to do a considerable amount of preprocessing at high resolution, full colour depth to tweak the gamma, clip highlights and lowlights and sharpen edges before you can safely reduce the colour depth and resolution. If the original was black & white, convert the scan to monochrome as soon as you've cleaned up any staining.
Photos of schematics rarely work well unless you can keep the original flat, hold the camera rigidly directly over the center of the schematic and provide multiple off-axis light sources. Camera built-in flashes are generally more trouble than they are worth and should be disabled as they tend to cause a large illumination gradient across closeups. If you have nothing better, put the schematic on a flat surface in direct outdoor sunlight with the sun fairly high in the sky, and photo it standing over it.