MMSC16answered grow question 6 months ago Hi! Personally I use a cheap Amazon Jewellers Loop. Anything above 25x should be fine. The key is to wrap the magnifying glass / jewellers loop directly onto your smartphone. Zoom all the way in with your camera on the phone, which will in turn increase magnification of the jewelers loop.
https://www.amazon.ca/VIVOSUN-Loupe-White/dp/B07VK287M6/ref=asc_df_B07VK287M6/?tag=googleshopc0c-20&linkCode=df0&hvadid=459345866293&hvpos=&hvnetw=g&hvrand=4146691360215337450&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9000945&hvtargid=pla-834424871429&mcid=669e4f8e4edb3827beac012306a5474d&th=1