Why are images of the correct size still cached additionally? Mar 20, 2012 / Updated: Apr 13, 2012
Once-upon-a-time the image was not cached for display on the single image display (image.php) if the size is already the needed size.
Remember Zenphoto's albums are file system based so there was a serious problem with that strategy. Caching an image happens only once per "size" and takes some disk space. Testing to see if the image should be cached happens every time the image is referenced for display in any way.
So the trade-off is storage space vs. processing overhead. With the cost of disk so low these days the choice is a no-brainer.
If you want no processiong/caching you need to modify your theme's image.php to use the full image directly.
This work by www.zenphoto.org is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.