Compare lenses

Pentax smc DA* 16-50mm f/2.8 ED AL [IF] SDM vs Pentax smc DA 17-70mm f/4 AL [IF] SDM

The Pentax smc DA* 16-50mm f/2.8 ED AL [IF] SDM and the Pentax smc DA 17-70mm f/4 AL [IF] SDM side by side, computed from this guide's catalogue.

Which to pick

Pick the Pentax smc DA* 16-50mm f/2.8 ED AL [IF] SDM if you want a brighter f/2.8 (1.0 stops more light), for dim light and softer backgrounds. Pick the Pentax smc DA 17-70mm f/4 AL [IF] SDM if you want more reach (to 105mm equivalent).

Still torn? Ask the guide about the Pentax smc DA* 16-50mm f/2.8 ED AL [IF] SDM and the Pentax smc DA 17-70mm f/4 AL [IF] SDM

Specs side by side

Rows that differ are in full colour; the better value is marked where one is better by any measure.
Spec	Pentax smc DA* 16-50mm f/2.8 ED AL [IF] SDM	Pentax smc DA 17-70mm f/4 AL [IF] SDM
Maker	Pentax	Pentax
Focal length	16-50mm (zoom)	17-70mm (zoom)
Full-frame equivalent	24-75mm on APS-C	26-105mm on APS-C
Maximum aperture	f/2.8brighter	f/4
Made for	APS-C	APS-C
Mounts	Pentax K	Pentax K
Stabilised	no	no
Autofocus	yes	yes
Zoom range	3.1×	4.1×more range
Cameras it fits	20 in this guide	20 in this guide

Focal range, in full-frame terms

Pentax smc DA* 16-50mm f/2.8 ED AL [IF] SDM: 16-50mm on APS-C, like 24-75mm.

Pentax smc DA 17-70mm f/4 AL [IF] SDM: 17-70mm on APS-C, like 26-105mm.

Aperture

Pentax smc DA* 16-50mm f/2.8 ED AL [IF] SDM: f/2.8 wide open.

Pentax smc DA 17-70mm f/4 AL [IF] SDM: f/4 wide open.

Each opening drawn to scale against f/1.4: a smaller f-number lets in more light and blurs the background more.

Field of view

How wide each sees, at each end, on the sensor it was made for.

Cameras they fit

20 cameras in this guide take both, so either works on the same body.