1. Opera glasses put to use Galilean Optics, meaning they have a convex objective lens but a concave eyepiece. This results in an upright image with a short length. There may be some loss of image quality.
2. Magnification power below 5x is recommended; most opera glasses have a power of 3x. This level of magnification minimizes image-shake and maintains a large field of view.
3. Traditional glasses resemble binoculars and generally feature a center focus knob. Many of our traditional opera glasses feature a convenient fixed focus so all you do is lift them up and look through them.
4. Lorgnette opera glasses feature a handle on one end to easily lift the glasses to your face and keep them steady. Many models have handles that extend and center focus that needs no adjustment once set.
5. Fold-up glasses are pocket-sized, making them convenient and easily portable in a formal clutch or tuxedo jacket. Fold-up opera glasses are generally simpler in design than other models.