I needed a scope probe with low input capacitance for the following use case:
In one of my projects, I wasn't sure if a crystal oscillator was actually oscillating. Probing with the stock probes that came with my Rigol DS1054Z didn't seem like such a good idea. The probe has about 10 pF of capacitance, and the crystal's nominal load capacitance is about 7 pF - that's a problem. If it's loaded correectly, attaching the probe might stop it. If the load is too little, attaching the probe might allow the oscillator to oscillate at all. So a probe with low input capacitance was needed (this is not a sound assessment of the situation, I just guessed that).
Looking for ready designs online revealed a design from a bachelor's thesis, which I adapted a bit. In fact, it had already been picked up by Wolfgang:
After I (re-)designed the PCB, I sent one to him for some measurements. Here are the results: