SV135 fully multi-coated zoom plossl eyepiece zooms to any focal length between 7 mm and 21 mm - pick the better magnification for your subject. As a beginner; SV135 zoom eyepiece is good for starter astronomer!Observation and photography of the moon and planets, astronomical observation, astrophotography. The imaging principle of the MAK astronomical telescope: since it is a reflection of light and there is no dispersion of light, chromatic aberration in imaging is a concern for the entire optical system.SVBONY SV225T tripod is crafted from aluminum alloy, ensuring stability and durability; compatible with various equipment, making it a reliable choice for professionals.SV225 Adjustable all-round viewing angle, observe as one pleases. Helical turbine drive supports 360° all-round adjustment: -60° to +60° altitude adjustment, all-round visual adjustment angle to meet your visual observation needs.