Why the 16 - 45?

Hi all,
still being relatively new and un-informed, what are the advantages of spending a lot on the Pentax 16 -50 (or 45) F2.8 for landscapes when most landscapes are shot at a higher F number for increased DoF? Is it simply because higher quality glass has a lower f stop anyway so it's the quality and not necessarily the larger aperture that is desired?

It's a good question. The 16-45mm f4 is already a very fine lens and the 16-50mm f2.8 will need to be equally good to make the extra money worthwhile. The extra stop does make it more expensive to make, more bulky, but offers a brighter viewing image and a slightly better low-light capability.

These days f2.8 is considered to be quite a fast lens, and in zoom terms it is.

I already have the 16-45mm and don't feel the need for a bulkier faster lens.

As your interest is landscapes I would think you might be better saving the cash and putting it towards somethings else. Another lens perhaps....

It's partly the better quality glass (the 16-45 F4 is much better optically that the kit lens, especially with regards to corner/edge sharpness) but also partly about versatility. Although the 16-45 F4 isn't much faster at the wide end than the 18-55 it's much better optically at wider openings.

In addition 16mm is significantly wider than 18mm (equivalent to 24mm v 28mm in the film days) which can also be fairly important depending on your type of shooting (it is for me).

It all adds up (for me at least) to the 16-45 F4 being a very useful lens compared to the 18-55 which I find largely useless.

Having said all that, and depending on your type of photography, I wouldn't necessarily consider the 16-45 or 16-50 if I was looking for primarily a landscape lens. The Sigma 10-20 I find a more useful landscape lens that the 16-45 F4 - and while I like both lenses (they're the two I use most) I find the Sigma is at least as sharp optically as suffers from less CA (not that it's bad on the 16-45) - in fact when I'm out with both lenses the quickest way I can tell later which one was used for a particular shot in the 16-20mm range is by CA, if it has some it's the Pentax, if not it's the Sigma.

Just to add another thought, it's not only wide angle lenses that are used for landscape photography. Distant mountain scenes, for example, can look very disappointing with a wide angle.

Moderate telephoto lenses have a place and the 50-200mm is inexpensive and excellent. We have been very happy with both of ours.

Unless you need the speed, I would pay half the price for the 16-45 and perhaps use the rest to get a good prime. You will find quite a difference.

Kim

Or... if you're into landscapes:
Get the 16-45 (which is excellent, BTW), and a set of decent ND grads (like the Cokin Z-Pro + Lee Foundation holder).
Matt