White 420800mm Aperture F 8.316 Full Manual Focusing Telescope Zoom Telephoto Lens for EF‑S Mount Camera Condition: Item Type: Manual Focusing Lens Material: Plastic + Aluminum Alloy + Optical Glass Color: White Focusing Mode: Full Manual Focusing  Aperture: F/8.3-16 Anti-Shake Function: No Fitment: for EF-S Mount Camera Weight: Approx. 913g Focal Distance: Approx. 420-800mm/16.54-31.50inch Front End Filter Caliber: Approx. 67mm/2.64inch How e:1) Turn on "Shutter Release: No Lens" (if available) and set the camera to M mode; 2) Adjust the lens to the required aperture/set distance; 3) Fine-tune the front focus ring to focus the subject and take sample photos. If the picture becomes dark, please set one of the following steps. a. Reduce the shutter speed from 1/500s to 1/100s or reduce 1/50, etc.; b. Increase the ISO number from ISO 100 to ISO 200/400/800, etc. c. Use remote shutter release and tripod to increase image stability; d. Switch positions to allow more ambient light to enter the camera's imaging sensor through the lens; constant practice and exploration of the fun of manual telephoto lenses may take time to get the ideal photo.