DA 12-24mm vs Sigma and Tamron 10-24mm Comparison

Design and Handling

The Pentax DA 12-24mm f/4 was introduced in 2005. It is designed for digital cameras and as such cannot be used on film cameras. The lens, like most Pentax DA’s, is built to tight tolerances utilizing both a metal mount and plastic components. The zoom ring is rather large and it is approximately 1/4 turn from 12mm to 24mm. The focus ring is at the front of the lens and it is a little over 1/4 turn from the minimum focus distance of one foot to infinity. The focus ring is a little small and does turn when you utilize the cameras auto focus. The lens, like most DA lens, does allow Quick-Shift Focusing which permits you to manually focus the lens at any time. The front element does not rotate because of the internal screw drive focus. The Pentax DA 12-24mm f/4 is designed with a maximum aperture of F4.0 which is constant throughout the zoom range. The petal shaped lens hood attaches via a bayonet mount and can be reversed to save space. The front element uses a 77mm filter. However, if you use a filter be sure to get an ultra-thin one to prevent vignetting, which can occur at the 12mm zoom setting. The lens is longest at the two extremes of 12mm and 24mm. The Pentax lens does not have an external aperture or depth of field scale. At the front of the lens is a small tick mark that indicates the focus distance.

The Sigma DG 12-24 f/4.5-5.6 was introduced in 2003. It is designed for a full frame 35mm camera. According to the specifications, the angle of view is 122 – 84 degrees. On the other hand, because of the crop factor of the APS-C sensor the angle of view is more like the Pentax 12-24mm. The lens is well built and has a metal mount with plastic components. The zoom ring is well proportioned to the lens, well dampened, and it takes approximately 1/8 of a turn from 12mm to 24mm. The focus ring is at the front of the lens and it takes a little less than 1/4 turn from the minimum focus distance of 11 inches to infinity. The focus ring is the same size as the zoom ring which makes it easy to adjust. The Sigma focusing ring is different from both that of both the Pentax and Tamron lenses because it turns clockwise from infinity. The focus ring cannot be used when the camera is in autofocus mode but works when the camera is in manual focus. Between the zoom and focus ring is the depth of field scale. The lens maximum aperture varies from F4.5 at 12mm to F5.6 at 24mm. At the back of the lens is a manual aperture ring. Once the ring has been moved off the “A” setting, it is possible to turn the aperture ring. Because of the location and placement it is very difficult to manually use the aperture ring.

The Sigma DG 12-24 f/4.5-5.6 has a built in lens hood to protect the front element. Although the front element does not rotate, it does move in and out quite a bit. From the pictures below you can see the movement from 24mm to 12mm.

The Sigma lens will not accept a front filter, although it might be possible to install a filter on the adaptor ring which is 82mm. The lens is designed to accept gelatin type filters. The filters are cut to size using the included guide plate as a pattern. Seen in the picture below is the filter holder at the back of the lens.  

The Tamron SP AF 10-24mm f/3.5-4.5 DI II was introduced in 2008. It is designed for digital cameras. The Tamron is well built with a metal mount and plastic components. The zoom ring is as large as that of the Pentax 12-24mm and it takes approximately 1/4 turn from 10mm to 24mm. The focus ring is slightly smaller than that of the Sigma 12-24mm and takes a little more than 1/4 turn from the minimum focus distance of nine inches to infinity. The focus ring cannot be used when the camera is in autofocus mode but works well when the camera is in manual focus. The Tamron's maximum aperture varies from F3.5 at 10mm to F4.5 at 24mm.The front element does not rotate nor does it move out like the Sigma. The petal shaped lens hood attaches via a bayonet mount which can be reversed to save space. The Tamron does accept a front 77mm filter. The lens is longest at the 24mm zoom range when it is focused at infinity. The lens does not have an external aperture or depth of field scale. At the front of the lens is a small tick mark that indicates the focus distance. It should be noted that the Tamron has the widest zoom range of the three lenses.