You can take it to court and then what? The judge just slams you with the photo (for which you need to pay if you want it as part of your defense).
Speeding tickets in Belgium are part of the government budget. That on its own should make you think about why they make it so hard to defend yourself.
And a picture of a license plate proves just that. The plate was there. I shouldn't have to keep record who drove my car. Especially not 4 weeks ago when the letter gets to my mailbox. Nor should I be required to rat out others.