【420-800mm f/8.3-16 Manual Telephoto Zoom Lens】: Compatible/Replacement for Canon EOS Rebel SL3 SL2 T8i T7i T7 T6 T6s T6i 1D 5D 6D 90D 80D 77D 4000D etc | 【User Instruction】: This is a MANUAL lens, NO electronic contacts, that's why your camera will not recognize the lens, it requires full manual settings on camera & lens body, please switch to M MODE in order to use this lens correctly. Tips to use our Manual Lens: 1)Attaching the lens with T ring adapter(including) to your camera; 2)Set the mode dial to Manual (M). | 【Manual Focus】: Please rotate the focus ring of the lens to achieve focus. Shutter speed and ISO need to be adjusted in general, so it is recommended to use it at "M". At the same time, due to the large magnification of the telephoto lens, the slightest shaking of the hand greatly affects the quality of the picture, so pls use it with a tripod. | 【Telephoto Lens】: Equipped with ultra-high-definition multi-layer optical components and aluminum alloy housing. For those who photograph wildlife or the moon as a hobby, this lens would be a great choice. | 【Note】: EF mount lens is not suitable for Canon M and R series cameras. Please check the camera mount carefully. Please feel free to contact us for more information on the settings and using. Meanwhile, manual lenses all need to be used by buyers with shooting experience. It is not recommended for beginners.