Special three dimensional photographs created with laser beams, which make objects appear almost real and solid, are called by which name?

Introduction / Context:
Modern imaging technologies allow us to record and reproduce three dimensional information so that objects appear to float in space or look solid and real. One of the most fascinating techniques uses laser beams to create special photographs that preserve both the intensity and phase information of light. These images are common in security stickers, credit cards, and scientific demonstrations, and they are known by a specific term that exam questions often test.

Given Data / Assumptions:
The question describes special three dimensional photographs created with laser beams.
These photographs make objects appear real and solid when viewed properly.
Options include holograms, 3D special effects, portraits, and DVD images.
We assume basic knowledge of modern optical imaging methods.

Concept / Approach:
The technology described is holography, and the resulting images are called holograms. In holography, a laser beam is split into two parts: one illuminates the object, and the other serves as a reference beam. The interference pattern between the light reflected from the object and the reference beam is recorded on a photographic plate or digital medium. When this recorded pattern is illuminated appropriately, it reconstructs the original light field, giving the viewer a three dimensional appearance of the object. This is different from simple 3D special effects or ordinary photographs.

Step-by-Step Solution:
Step 1: Identify key phrases in the question such as three dimensional photographs and use of laser beams. Step 2: Recall that holography is an optical technique that uses coherent laser light to record and reconstruct three dimensional images. Step 3: Recognize that the images produced by this process are called holograms. Step 4: Match this term with the options and choose holograms.

Verification / Alternative check:
You can verify by thinking of holographic stickers on currency or credit cards that change appearance when tilted. These are described in textbooks and articles as holograms created by laser based processes. Ordinary portraits or DVD images do not require laser recording and do not produce true three dimensional reconstruction of the light field. This confirms that the correct term is holograms.

Why Other Options Are Wrong:
3D special effects refer to computer graphics or film techniques that create an illusion of depth but are not the specific laser based photographic process described.
Portraits are simple pictures of a person face or figure taken with normal cameras and do not provide true three dimensional reconstruction.
DVD images are digital video or data stored on optical discs and are unrelated to holographic three dimensional recording.

Common Pitfalls:
Students may confuse any three dimensional looking image with holograms and might think that 3D movie effects or virtual reality are the same as holography. It is important to note the key role of laser beams and the special recording of interference patterns in holography. Recognizing this distinction helps select the correct term when similar options appear in exams.

Final Answer:
These special three dimensional laser based photographs are called Holograms.