Joined: 01 Aug 2006
Location: Richland, Washington State, USA
|Posted: Thu Sep 19, 2019 2:27 pm Post subject: FAQ: Why do my images lose sharpness when posted?
|Why do my images lose sharpness when posted?
There are two common reasons for this effect.
1. If you upload an image to photomacrography.net that is larger than 1024 pixels on either side, then the forum software will silently downsize it to be 1024 pixels max. This resizing process loses information and is guaranteed to lose sharpness.
2. If you're using a high-DPI monitor, such as an Apple Retina display or a small 4K monitor on Windows, then your browser may be automatically up-sizing images by some factor that matches the computer's overall settings. This up-sizing probably will not lose information, but by spreading the same information across more display pixels, it can make images look less sharp.
The solution to problem #1 is to resize images yourself so that the upload fits within the pixel and file length limits, currently 1024 pixels on each size and 300 kilobytes total. Images like this are served back by the forum software exactly the same as they were uploaded, bit-for-bit identical.
For problem #2, there is no perfect solution. The problem may be less severe with integer resizing such as 2X (200%), as opposed to non-integer resizing such as 1.75X (175%).