A word to the wise…
If you are ever naming images in German, do not use Umlauts (ö, ü, ä). I wish I’d realised this 2 hours ago. That’s how long it took me to figure out why some photos on my yoga and qi gong studio website were missing on the published site.
You should never use special characters in file names. I would leave it to a-zA-Z0-9_-.
As a native speaker (I’m not), would you substitute the Umlauted (') vowel for one without, or would you use the vowel + e spelling (uber or ueber zB.)? Would a search engine recognise u+e as ü?