My instructor lectured us about macro photography and she showed how to take macro photographs by using normal lens by reversing with out fixing it to the camera, but when I unfix the lens it shows nothing. I have a Nikon D5200 and I used nikkor 18-55mm lens. Luckily I used Canon 5D and I could take some amazing photos using the same lens?! What's wrong with Nikon D5200 and how can I overcome it?!
The problem is, once the normal lens is detached, the lens no longer able to exchanges electronic and mechanical instructions with the camera body. You can work this way, but now the burden to make lens adjustments, such as aperture settings, falls on your shoulders. The good news is, you can purchase advanced tubes and spacer rings that will maintain camera body to lens communications. With these advanced rings, “macro” work becomes a breeze. These spacers called rings and tubes have been used successfully for many years. However, the demonstration of hand-holding a detached lens and making pictures should be viewed as a curiosity. This is not a viable way to operate. The detached lens allows light to leak into the camera. This light will intermingle with the imaging rays from the lens and degrade the results. Additionally, hand-holding makes it difficult to compose and focus, plus it is unlikely that the lens will be square with the body.
As to lens reversal: It is unnecessary to reverse the lens to do “macro” photography. We sometimes reverse the lens as this act may slightly improve acuity. This is because the “normal” camera lens is optimized to image objects at different distances from the camera and project their image on flat film or digital chip. The rear of the lens is optimized to work on a flat surface. Most “macro” work is done on flat objects like stamps or coins. A reversed lens often preforms better for these tasks. The rings and tubes mentioned earlier accept a reversing ring mount. We use these accessories to make “macro” images. However, best you keep in mind that spacers, tubes and reversing rings are poor substitutes for a “macro” lens, as this lens is optimized to do close up work