In general, Midjourney doesn't handle shutter speeds well. Mention of the word shutter or shutter speed seems to ccause motion blur, no matter the specified shutter speed. Seeing as fractions (ex: 1/1000) are a common mathematical format, it's fair to assume MJ can't distinguish between shutter speeds and regular integer expressions. Using s or second also doesn't produce desired results. This is likely due to the source material not having a clear and consistent set of shutter speed examples across subject matter. Your mileage may vary, and hopefully this will get better in the future.
Ball bouncing
ball bouncing:: [term] --sameseed 1
1/2
1/1000
1/2s
1/1000s
1/2 second
1/1000 second
1/2 shutter
1/1000 shutter
1/2 shutter speed
1/1000 shutter speed
