Schneider Close Up Diopter - Split +3 - 4.5 tum Round. Half close-up lens, split diopters, are used to obtain two "focus planes" in the same image. One half of the filter socket is without glass and the other half has optical glass with a magnification of +3. Split diopters are made for film scenes where one half of the image should focus on a nearby area while the other half of the image is focused on objects further away. The filter is available with different magnifications, +1/2, +1, +2, and +3. Both lens surfaces on the filter have Schneider's hard anti-glare coating, which minimizes light loss and unwanted optical effects. The filter is completely color-neutral and maintains the lens' image quality and contrast. Schneider's Diopter lenses are mounted in a black anodised aluminum ring. The construction is very wear-resistant and durable and keeps the filter lens in the exact position for maximum image quality.