Single-Lens Reflex

In the single-lens reflex camera the photographer sees the scene through the camera lens. This avoids the problem of parallax which occurs when the viewfinder or viewing lens is separated from the taking lens. Single-lens reflex cameras have been made in several formats including 220/120 taking 8, 12 or 16 photographs on a 120 roll and twice that number of a 220 film. These correspond to 6x9, 6x6 and 6x4.5 respectively (all dimensions in cm). Notable manufacturers of large format SLR include Hasselblad, Mamiya, Bronica and Pentax. However the most common format of SLRs has been 35 mm and subsequently the migration to digital SLRs, using almost identical sized bodies and sometimes using the same lens systems.

Folding Camera 

The introduction of films enabled the existing designs for plate cameras to be made much smaller and for the base-plate to be hinged so that it could be folded up compressing the bellows. These designs were very compact and small models were dubbed vest pocket cameras. Folding rollfilm cameras were preceded by folding plate cameras, more compact than other designs. 

Box Camera 

Box cameras were introduced as a budget level camera and had few if any controls. The original box Brownie models had a small reflex viewfinder mounted on the top of the camera and had no aperture or focusing controls and just a simple shutter. Later models such as the Brownie 127 had larger direct view optical viewfinders together with a curved film path to reduce the impact of deficiencies in the lens.

Subminiature Camera 

Cameras taking film significantly smaller than 35 mm were made. Subminiature cameras were first produced in the nineteenth century. The expensive 8×11 mm Minox, the only type of camera produced by the company from 1937 to 1976, became very widely known and was often used for espionage (the Minox company later also produced larger cameras). Later inexpensive subminiatures were made for general use, some using rewound 16 mm cine film. Image quality with these small film sizes was limited.

Aperture: An opening, hole, or gap 
Shutter:  A Mechanical Divice on a camera that opens and closes to control the time of photographic exposure. 

Exposure: a picture of a person or scene in the form of a print or transparent slide; recorded by a camera on light-sensitive material. 
Depth of Field: The distance between the nearest and the furthest objects that give an image judged to be in focus in a camera.
 F Stop: This is the number assigned to determine the aperture, or size of the lens opening. A high f-stop number means a small amount of light is allowed in, which would be used to avoid an overexposed image. A low f-stop number means a large amount of light is let in, as you might use to shoot at a high shutter speed without getting a dark image. 
Focal Length: The distance between the center of a lens or curved mirror and its focus.



Rebel T3

1	Mode dial	13	EF lens mount index
2	Power switch	14	EF-S lens mount index
3	Flash button	15	Flash-sync contacts
4	Main dial	16	Hot shoe
5	Shutter button	17	Focal plane mark
6	Red-eye reduction lamp	18	Strap mount
	Self-timer lamp	19	Microphone
7	Grip	20	Terminal cover
8	Mirror	21	Lens release button
9	Contacts	22	Remote control terminal
10	Lens mount	23	Digital terminal
11	Lens lock pin	24	HDMI mini out terminal
12	Built-in flash	25	Body cap
	AF-assist beam