Single Lens Reflex camera or popularly know by their acronym as SLR is a type of camera that uses mirror system called pentprism. This system allows the user or the photographer in this case, to capture image as how he exactly sees in the viewfinder. This is achieved through the help of automatic moving mirror system in the camera.

The basic optical components of an SLR come in eight parts. This is the section of the camera where the images pass through from the front the camera to your eye. The eight basic components are the front-mount lens, reflex mirror, focal plane shutter, image sensor, focusing screen, condenser lens, the prism (also known as pentamirror) and the eyepiece.

1.Front-mount Lens this is where the image, in form of light, first comes in. It then reflects it to the mirror behind called reflex mirror. This lens can still be enhanced by attaching another lens to it. Those lenses come in different names. Others call it photographic lens, some call it objective lens or for those who want to shout out loud that they are indeed photographers call it photographic objective lens (a mouthful worth of name truly makes it sound more professional).

2.Reflex Mirror once the reflex mirror receives the image, it is then projected on a matte called focusing mirror.

3.Focusing Screen it is a flat material usually made of glass that allows the photographer to preview the image to the viewfinder. Focusing screen comes with distinct markings depending on the purpose and use of the camera and camera models. The most common used for digital cameras is the split screen that helps in focusing images for non-autofocus 35 mm SLRs. There are also focusing screens that have no markings like the overall-matte that commonly found in astrophotography or low-lighting shoots.

4.Condesing Lens after the image passed through the focusing mirror, it is then transferred to condensing lens. It helps concentrate light of the transferred image.

5.Optical Glass Prism some slr's use roof pentaprism or penta-mirror to reflect the light to the eyepiece. In this process, the light that travels through the condensing lens passes to the bottom straight to the roof of the prism. Then the light is reflected to the front side then bounced horizontally to its back. Another prism design is called porro prism. A photographer can also use a right-angle finder which can be attached to the eyepiece that allows viewing like a waist-level finder

6.Eyepiece the backside of the pentaprism is connected to the eyepiece and there is where you see the image focused in front of the lens.

7.Focal Plane Shutter at the same time with focusing mirror, the same image travel beyond the reflex mirror as it moves upwards and to the focal plane shutter.

8.Image Sensor as soon as the focal plane shutter opens, the image will be directed to image sensors that translate the lights to electrical signal. Most image sensor in digital slr cameras are made of charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) active-pixel sensor.