Bausch & Lomb 20x Hastings Triplet Magnifier
Truly the finest magnifiers Bausch & Lomb has to offer, Hastings Triplet Magnifiers incorporate three separate lenses, bonded together to form a compound lens to provide sharp, very distinct magnified image without distortion.
A swing-away, nickel-plated case protects the lens and serves as a handle.
- focal distance of .5/1.3 cm
- 80 diopters
- 8.3 mm lens diameter.
The Bausch & Lomb 20x Hastings Triplet Magnifier has extremely strong magnification for a hand held loupe but has limitations too. Make sure you need this much magnification.
The information below is true of all high magnification lenses including cameras, telescopes, and magnifiers. It is NOT a unique characteristic of the Bausch & Lomb 20x Hastings Triplet Magnifier.
The strong magnification comes at the cost of a very small lens. The lens diameter is what collects the light. With a small lens diameter it doesn't collect much light. A larger lens would really have to be larger and much more expensive. A 10x power loupe gives very nice magnification with a lot brighter image.
The lens has a very short focal distance, the point at which the image appears in focus. The distance at which the object appears in focus is one half inch (0.5''). Your hand will be one half inch away from the object and your hand will be blocking much of the light available to this small lens.
The lens offers very little Depth of Field. Depth of Field is the vertical relief that appears in focus. The focus slop if you will. The more magnification, the less Depth of Field. If the object you're viewing is rough, like a rock or a mineral, you'll have to keep moving the object towards and away from the loupe.
A 20x loupe is good for looking under high magnification, at the surface of rocks and minerals, the faces of gemstones, coins, stamps, cloth thread counts and other objects where you must have high magnification.
This much magnification would not be useful for reading.
A 20x loupe should NOT be the only loupe that you have.
|
|
