Carl Zeiss Jena Flektogon 25mm f/4
The Carl Zeiss Jena Flektogon 25mm f/4 is a camera glass that is suitable for full frame cameras. It is a manual focus photographic lens that has six aperture blades which can produce a rounded out of focus circle shape. The lens has a 77mm filter diameter which is a common size, and it weighs 362 grams and is 52mm long. The lens is well-built and has good resolution. The lens elements are coated to reduce flare and ghosting. The manufacturing time of the lens is not specified. The aperture of the lens is f/4 which is average for this type of lens. Overall, the Carl Zeiss Jena Flektogon 25mm f/4 is a good quality wide angle lens that is suitable for full frame cameras.
Average brightness in this league Has 6 aperture blades, this number of blades are commonly used. Having rounded blades provides out of focus circle shape closer to a circle.
77 mm lens filter diameter, commonly filter size, you have plenty of possibilities this lens deserves a good quality filter. Weights 362 grams so plan ahead, carry only if really necessary. 52 mm long, requires consideration if you want to carry in the camera bag.