lens test SMC Pentax 45-125mm f/4

caspert79 · Joined: 31 Oct 2010 Posts: 3230 Location: The Netherlands

The SMC Pentax 45-125mm f/4 has the same optics as its predecessor, the Super-Multi-Coated Takumar 45-125mm f/4 that was introduced in 1975. A pretty old zoom design in an unusual zoom range (which I find quite practical by the way). Despite its age, the lens has a pretty good reputation, at least under the Pentaxians on the Pentax forum. Let's put it to the test. Click on the images to see them in the intended quality.

@45mm:

test@45mm by devoscasper, on Flickr

@45mm, the lens is already sharp wide open. Even the corners are sharp at full aperture, but they improve a bit more when stopping down. CA's are clearly visible in the periphery, but those are easily corrected in PP.

@80mm:

test@80mm by devoscasper, on Flickr

PS focus it on the bricks.
Resolution is about perfect centrally at all apertures. Considering this is a 42.6mp image, I think the corner resolution is pretty good already wide open. It becomes about perfect @ f/8. CA's not really an issue at this focal length.

@125mm:

test@125mm by devoscasper, on Flickr
Very good resolution all over the frame at all apertures.
CA's not really an issue here.

Conclusion: for most trips, I would only need this lens + a wide angle of choice, which is very practical IMO. Resolution is very good at most apertures and focal settings. CA's seem to be an issue only at the wide end, but are easily corrected. Build quality and handling are great, and at 612 grams it's not very heavy either. I hope to share some more images as soon as the weather improves.