The Canon EF 28–105 mm 4-5.6 is an inexpensive zoom lens

Zoom lens

A zoom lens is a mechanical assembly of lens elements for which the focal length can be varied, as opposed to a fixed focal length lens...

 often included as a kit lens with Canon

Canon Inc.

is a Japanese multinational corporation that specialises in the manufacture of imaging and optical products, including cameras, camcorders, photocopiers, steppers and computer printers. Its headquarters are located in Ōta, Tokyo, Japan.-Origins:...

 35 mm single-lens reflex camera

Single-lens reflex camera

A single-lens reflex camera is a camera that typically uses a semi-automatic moving mirror system that permits the photographer to see exactly what will be captured by the film or digital imaging system, as opposed to pre-SLR cameras where the view through the viewfinder could be significantly...

s. 28–105 mm is a standard wide to telephoto zoom range. The Canon EF 28–105 mm 3.5-4.5 USM is a higher quality zoom lens with a better build quality. Currently every version of this lens is discontinued.

EF 28-105mm 3.5-4.5 USM

This lens is a well-regarded consumer-grade lens. Its focus motor is ring USM, resulting in quick and quiet autofocus operation; this motor also allows the lens to offer full-time manual focusing. The lens uses internal focusing so the inner lens barrel does not rotate when focusing. This lens uses a "duo cam" type zoom barrel, this allows a more compact design, but still does not rotate while zooming.

This duo cam type zoom barrel is illustrated with the following two pictures:
There are two versions of this lens. The original lens has a five-blade diaphragm. The second version, named 28-105 3.5-4.5 II, has a 7 blade diaphragm.

EF 28-105mm 4-5.6 USM

These are two inexpensive versions of the 28-105mm, cosmetically similar to the EF-S 18-55mm

Canon EF-S 18-55mm lens

The Canon EF-S 18-55mm lens 3.5-5.6 is a wide-angle to mild telephoto zoom lens for digital single-lens reflex cameras with an EF-S lens mount. The field of view has a 35 mm equivalent focal length of 28.8-88mm, and it is the standard kit lens on Canon's consumer DSLRs.There have been four releases...

 or the 90-300mm lenses which have the characteristic rubber grip on the barrel. While retailing for around $100 less, these lenses have a decreased f-stop range and cheaper build quality (with a chrome-plated ring). The first 4-5.6 version has a DC motor for autofocus, while the second version uses a micro-USM, instead of ring USM that the 3.5-4.5 models use.

Specifications

Attribute	4.0-5.6	3.5-4.5
Image
Image stabilizer	No
Ultrasonic Motor	Yes
L-series	No
Diffractive Optics	No
Macro Macro photography Macrophotography is close-up photography, usually of very small subjects. Classically a macrophotograph is one in which the size of the subject on the negative is greater than life size. However in modern use it refers to a finished photograph of a subject at greater than life size...	No
Maximum aperture Aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are,...	4.0-5.6	3.5-4.5
Minimum aperture Aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are,...	22-32	22-27
Max. magnification	1:5.2
Weight	0.46 lbs. / 210 g	0.83 lbs. / 372 g
Diameter	2.6" / 6.7 cm	2.8" / 7.2 cm
Length	2.7" / 6.8 cm	3" / 7.5 cm
Filter diameter	58 mm
Horizontal viewing angle Angle of view In photography, angle of view describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view....	65° - 19° 20'
Diagonal viewing angle Angle of view In photography, angle of view describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view....	75° - 23° 30'
Groups/elements	9/10	12/15
# of diaphragm Diaphragm (optics) In optics, a diaphragm is a thin opaque structure with an opening at its center. The role of the diaphragm is to stop the passage of light, except for the light passing through the aperture...  blades	6	7
Closest focusing distance	1.57'	1.6'
MSRP Suggested retail price The manufacturer's suggested retail price , list price or recommended retail price of a product is the price which the manufacturer recommends that the retailer sell the product. The intention was to help to standardise prices among locations...  $	$140	$230