John Whittingham wrote:
Its filter size is 72 mm. and although it isn't particularly big or heavy, the Pentax 28-105 3.2-4.5 looks really small when compared to this Tamron. If small size and SMC are important for you, and you don't need the extra focal length range, I would say that the Pentax is a better choice.
The filter size is the only negative side for me I'd prefer 67mm or even 77mm, size and weight probably no bigger or heavier than some of my older Pentax lenses, I used a Pentax-A 35-105 f/3.5 for years until recently when I use the Pentax-FA 28-105 Power zoom. I'd love the focal length range for a walkabout lens.
Well, you're in luck, because whoever said it has a 72mm filter size is wrong. The size is 58mm. Check the Pentax website for confirmation. That's what it says on the Pentax site, and that's also the specification that MY lens has when I look at the number printed on the front... and it's the size of the filter I've got on the camera. ;)
People are often confused by the fact that there are three 28-105 lenses in the Pentax lineup:
SMC Pentax-FA 28-105 f/4-5.6 PZ - The original Power Zoom model
SMC Pentax-FA 28-105 f/4-5.6 AL[IF]- The "probably made by Tamron" model
SMC Pentax-FA 28-105 f/3.2-4.5 AL[IF]-The one we're talking about today.
