Here the most important thing: it is commanded with the diameter of Raynox lenses caution. These have a diameter of only 43 mm, an adapter is supplied to the thread fits of 52-67 mm. Fast lenses often have a larger diameter. My Sigma 17-70 for example, has 72 mm diameter, the Raynox fits only with another adapter ring and produces strong vignetting. Even with a full filter size of 67 mm, the focal length of the lens should be avoided at least 90 mm to strong vignetting. With a smaller size of 58 or 52 mm focal length range and then 50-70 mm from already.
The greatest effect is of course on a lens with high focal length, the focus range of the Raynox 250 is here, however, is extremely small. On a macro lens with its own 1: 1 mapping of the Focus range with additional Raynox is 250 less than a millimeter (for use on a pure prime macro lens [Fixed Focal Length, 1: 1 mapping or better] therefore recommended rather the Raynox 150 with less strong inherent magnification). In addition, the familiar of a DSLR photosensitivity declines significantly - tripod and flash or good lighting are good for macro shots here mandatory.
Good for the Raynox 250 lenses with at least 50-70 mm focal length and a filter diameter 52-58 mm, with a larger diameter, the focal length should be 90-100 mm already. Interestingly, the Raynox is especially for telephoto lenses with macro function, but it is of course no. With short focal length pictures in natural lighting from the open hand are still possible at telephoto focal lengths is an external flash or strong lighting duty recommended a tripod. In example, a Tamron 70-300mm with macro function with macro focus can be reached by Raynox 250 at 300 mm an extension of good 2-3x. However, the focus area lies less than one millimeter and makes the images so again almost unusable (of course you do not take pictures at full 300 mm!). Good preparation, patience and equipment (lighting, tripod) are needed to achieve here still useful results.
The picture quality itself is a conversion lens (actually here a lens system) exceptionally well. The focusing range is an area, not a point (like simple magnifying lenses) and thus has the full image section useful. Contrast and color are good. The intent may be thanks to the practical clip function attach quickly and remove and makes spontaneous photography possible without any problems. Be careful here again for lenses with a narrow filter thread - terminals of Raynox are relatively large and it is possible that when placing a small gap between Raynox and the lens remains that should be sealed in order to avoid stray light. Processing is otherwise exemplary, to be delivered 2 covers and a transport box including padding.
In summary: On a standard zoom lens with focal length of 50 mm (with filter diameter 52-58 mm) or 90 mm (67 mm or more filter diameter) to about 200 mm brings the Raynox 250 the greatest effect. It does not replace a high quality macro lens, but it allows the rapid transformation of a zoom lens in a useful macro lens that in the great outdoors in the sunshine can deliver stunning images at relatively short focal length also of the free hand. This enables spontaneous and flexible shooting. For larger focal lengths also telephoto lenses with appropriate lighting and preparation can still provide useful and impressive macro shots. Also as a supplement to pure macro lenses the Raynox is available. You should not expect miracles though. At high magnification and long focal length of the minimum focus distance and the light sensitivity is low. However, in view of the comparatively low price of the Raynox is a real alternative for a standard macro lens and a small budget. The image quality is excellent for the price and finally, and finally brings the gain in flexibility and spontaneity that is always easy to mount on a daily lens also simply love to take pictures.