Telephoto lens with a special bubble bokeh effect. Image sensor standard: full frame. Lens mount: Leica M. Focus: manual. Filter thread diameter: 49 mm. Bubble bokeh. Clicked aperture. The TTArtisan 100mm F/2.8 is a lens that highlights bokeh. It features bright edges around the bokeh sphere, and the bokeh is beautiful and textured. Unlike modern lenses that produce creamy smooth bokeh, the TTArtisan 100mm F/2.8 creates a bubble bokeh effect. The bubble bokeh is characterized by a bokeh sphere with a bright edge around its circumference, delivering stunning results. Full frame with a large image circle. The 100 mm F/2.8 is a full-frame lens, and the actual image circle can nearly cover medium format. When used on APS-C or full-frame cameras, it retains the higher quality portion of the large image circle. When used on medium format cameras, the slight vignetting adds an artistic touch. Mechanical feel. The lens body is made of aerospace aluminum with an anodized finish and exhibits good build quality.