Smart web sites display images using HTML codes that automatically limit the basic display to a certain size. The 'size limiting' helps the pictures appear at some reasonable size within a web page but it doesn't limit your ability to see it 'full size' if you click on it to isolate it from the web page sizing codes. If the picture is actually larger than the size it appears on the smart web page then you can click on it to see it larger (which disconnects the picture from the size-limiting codes). The size-limiting codes turn the picture into a kind of 'thumbnail' you can see but which you also can click on to see fully enlarged.
For those who upload large images, even JPEG'd, the coded
'size limiting' doesn't reduce the image loading time when the browser gets to it. The whole image (whatever its file size actually is) still
loads in and, in general, it takes longer for bigger pictures. IOW if a picture is actually 1000x1000 pixels it may take a while to load even if the web page is 'coded
' to show it as 200x200 pixels. But when you click on the 200x200 version the big version will appear immediately because it's actually already loaded into your browser.
A workable rule of thumb for uploading coin pictures is about 250 pixels per
centimeter of the coin's size. IOW, if you have a 4 centimeter (diameter
) coin then a picture of 1000 (x 1000) pixels may be needed to see it clearly. It's just a rule of thumb. If your smaller coin has fine
details only visible in a greatly enlarged view then a high pixel count may also be justified. For the average
coin ID, 250 pixels per
centimeter should be plenty if the photo is sharp
and decently lit. If you have a 1000 x 1000 picture of a small coin you can use your graphics program (IrFan, etc.) to cut it down to 250x250 and upload the smaller pic. That reduction alone will cut the image-load time by a factor of 16. And JPEG (even at 90% 'Q' level) will reduce the file size a lot more while leaving most of the detail intact
- small files help
phone-modem visitors (and everyone else, too
. Picking a good pixel size and JPEG quality
is just good netiquette. You can easily reduce image-load time for those who view the picture by a factor of 50-100 overall, compared to uploading a PNG or BMP image that is unnecessarily bloated.PtolemAE