The focal length of the lens and the distance between the lens and the object.
Never. Since the rays coming from a real object will always be diverging. The action of a concave lens is diverging action. Hence the already diverged rays will be dirverged further. Hence no chance of convergence. Only converging rays would form a real image. Hence the answer, NEVER.
convex lens
You are thinking of a lens. If it is to form an image you need a convex lens, also called a converging lens.
When light rays come together, they converge.
Concave lens (diverging) produces an upright image that is virtual. Although to create a real upright image would require 2 convex (converging) lens with a distance of their respective focal lengths between them.
The image formed by a convex lens depends on the object distance from the lens, the focal length of the lens, and the object size. These factors determine whether the image formed is real or virtual, magnified or diminished, and upright or inverted.
The type of image formed by a lens is determined by the focal length of the lens, the distance between the object and the lens, and the placement of the object relative to the focal point of the lens. Depending on these factors, the image can be real or virtual, upright or inverted, and magnified or diminished.
To calculate the position of the image formed by a lens or mirror, you need to use the thin lens or mirror formula: 1/f = 1/do + 1/di, where f is the focal length of the lens or mirror, do is the object distance, and di is the image distance. Once you have the values for the focal length and object distance, you can solve for the image distance to determine the position of the image formed.
An image is formed by a convex lens when rays of light converge after passing through the lens. This forms a real image on the opposite side of the lens. The position and size of the image depend on the distance of the object from the lens and the focal length of the lens.
If the object is more distant from the lens than the focal length of the lens, a real image is formed.
Image formed by a concave lens or a diverging lens is virtual,upright and smaller than the object.It is used by short sighted people.
A virtual and upright image is formed if the magnification is negative (-4.6) when using a lens.
The image produced is a real image if the object is located at infinity and the lens is a convex lens. The produced image can actually be placed on a screen and photographed.
Virtual image
Lenses form images by bending light rays that pass through them. The curvature and refractive properties of the lens determine how the light rays converge or diverge to create an image. The image formed can be either real or virtual, depending on the configuration of the lens and the position of the object relative to the lens.
To calculate the position of an image formed by a lens or mirror, you can use the thin lens equation (1/f = 1/do + 1/di) where f is the focal length, do is the object distance, and di is the image distance. By solving this equation, you can determine the image position relative to the lens or mirror.
In a concave lens the object always forms a virtual image. The convex lens also forms a virtual image.