Which lens for Pentax K5?
I'm upgrading from the Nikon D70s to the Pentax K5. I've been studying photography for 3 years now and really want a new camera!
The photos I take are usually as close up as possible, so macro 70% of the time. However I do like capturing nice portrait photos which are not as close up. I really like to make the most of my lens and camera. I don't take landscape shots at all really.
These are the lenses i've been considering:
http://www.ebay.co.uk/...1438.l2649
http://www.ebay.co.uk/...1438.l2649
My advice would be to get the 18 - 55mm kit lens, it's heavily subsidised when you buy the camera and is the most overall useful focal lengths. Use it for a while to figure out which lenses would be helpful to you and then buy them as needed. There's no universal lens.
Avoid wide range zooms from any manufacturer, there are more compromises in their design almost to the point of them being useless for anything except bright light shots, even then image quality suffers.
The best lenses for image quality are primes, Pentax has a range of L series primes that can't be beat for image quality by any manufacturer, it's not a cheap option though. You may need to change the camera body due to improvements in technology, but good lenses last you whilst you use that lens mount, in the case of Pentax will probably be all your life. Lenses are far more important than camera for image quality. The camera body will be cheaper than lenses if you go for this kind of quality.
For a 'walk around' lens a wider aperture version of the kit lens is more useful especially for lower light levels (indoors or night photography), the wider aperture makes any lens more useful when lighting isn't as good as you would like, it also helps with 'selective focus' shots (where the subject is sharp, but the background blurred).
The Sigma 17 - 70 f2.8 - f4.5 is a good choice or the Pentax-FA 20-35mm F4 AL
Here's a list of most of the lenses made by Pentax with independent reviews from owners
http://www.pentaxforums.com/lensreviews/
Note that there are lots of quality lenses available from the film era for the Pentax K mount available cheaply, with good image quality, all will be image stabilised (as it's built into the camera), all will meter correctly and work as designed, some will not have auto focus, but that is all you will not have. For macro shots auto focus is of limited use as the depth of field is so small auto focus often focuses the lens where you don't want it.
A new manufacturer that makes exceptional lenses is Samyang
http://www.syopt.co.kr/eng/product/manual_zoom.asp
They are all prime wide aperture lenses at very reasonable prices, but with exceptional image and build quality. Some of these will auto focus on a Pentax camera.
With lenses buy quality and it will last you all your life and you will get the benefit in higher quality image during that time. Always buy the best lenses you can afford, but only buy lenses as the need arises.