Yeah, whether a loupe or a digital microscope or just shooting some good digital close ups in macro mode, being able to really see the trichomes (resin glands) is really helpful--essential, really.
Be sure to look at the trichomes in bright light and have a way to hold the plant and the magnifier steady. (I just brace against a chair up close to the plant.) Trying to hand-hold a high-magnification lens and keep it in focus can make you crazy. You need a steady view under bright light. I think sunlight is best.