Mostly 200x to 1000x enough for w/o and o/w emulsion. And for stability you need to chack all range of concentration with upto 15000 rpm because stability depends on emulsifier concentration and energy.

This depends on the size of your droplets：

If u are making the droplets around 100um，100 magnification is the most suitable for u.

If the droplets are around 10 um，40 or 60 magnification is the most suitable.

While if the droplets are around 1um，u need a magnification over 1000 for sure，probably 1500 is the good. Because one of my colleague is making the droplets around 1 um，and 1000 magnification is close to the limit for a clear observation.

Best regards

Can be analysed using the Canty Vector and Microscope System