Although I am still learning, I am starting to undertand the settings on my camera.
That said, I want to see if a better lens will result in clearer pictures.
So obviously, I have been taking a lot of landscape photos. I would like a lens adept at this (is this subjective?). What should I be looking for in terms of Pentax lenses, as well as general lens parameters?
Bobby kindly included the pentax kit lens which is 15-55m. So I find myself slamming it as far as possible to get landscapes, but I think I am running out of runway quick when framing shots? Rogue, in another thread explained lens sweet spots.
So... if I am correct in this thinking, what are your brand, features, and/or things to avoid?
I have a modest budget, but am also adept at manual focus.
Generally speaking (there are always exceptions).
Prime lenses (non zoom - single focal length lenses) are sharper than Zoom lenses.
Zooms with a limited range (e.g. 27-70), are sharper than those with a huge range (24-300) - especially at the outer edges of that range.
"fast glass (wider than f2.8 for zooms, or f1.8 for primes) " is nice but usually not what the majority of shooters need to bother with, especially if you are after sharpness, since you'll have to stop the lens down to 5.6 or so anyway. So I wouldn't worry about the extra expense, generally - unless the lens is a significantly better performer for your needs.
recommendations are not easy to make... lenses that are well suited to landscape, like the DA 12-24/f4 are nice, sharp lenses. But not cheap, I think that one clocks in at $850 or so.
The fixed 15mm f4 isn't much cheaper at $650.
There are lots of good KA mount Pentax lenses out there, but there have been significant improvements in the optics over the years, so it will really come down to what level of performance you are after. But for ultrawides (anything wider than 20mm is considered an ultrawide lens), since those were mostly developed for 35mm film, you are not going to find much in the under 17mm range.
If you want to look at third party lenses... I've had good luck with Tokina, as being better made than Sigma or Tamron, and a better performer. (Edit, tho it looks like Tokina actually makes some of the Pentax lenses, and does not make their own in pentax mount... so you're stuck with Sigma/Tamron). Neither one is necessarily better than the other - they each have some strong lenses, and some weak ones. shrug If I could afford it, I'd probably stick with the Pentax lenses. DA and DA*
worth considering, Pentax can take older manual focus lenses - which you can pick up for far less than AF lenses on eBay.
Originally posted by: arigato worth considering, Pentax can take older manual focus lenses - which you can pick up for far less than AF lenses on eBay.
Very true, but if he's regularly finding himself at 15mm for landscapes, he's not going to find much.
Oh well I cited 15 since it was what I was shooting at. I would be perfectly ok with something a little higher. What I am trying to do is get down in that vicinity without losing the sweet spot, as you say.
I see.
Well, this lens:http://www.keh.com/camera/Pentax-Manual-Focus-Fixed-Focal-Length-Lenses/1/sku-PK06009016533N?r=FE
at $225 for an EX version, with a nice return policy (KEH is very trustworthy), is not too bad. And frankly, I have bought several BGN grade lenses from them, they are pretty conservative in their ratings, and will take it back, no questions asked, if you are not happy.
24mm on a crop sensor may not be wide enough for you, but it should WAY outperform the 15-55. On a full frame sensor, 24, is a Go-to landscape lens. On your sensor it will feel more like a 35mm, but that's not a bad thing, still a very natural looking wide.
You will probably be able to find it cheaper on the bay.
Pentax also made a 20mm f4, but it's harder to find. http://www.bdimitrov.de/kmp/lenses/primes/ultra-wide/M20f4.html
Everything wider than that, is fisheye, I think. The 17/4, and old pattern 15mm ($1200 - which, frankly, you shuold buy the new $600 15/4 DA, before getting that one).
What causes a a lens to "feel" different on different sensors?
:noob:
mostly the relative size of the sensor. Since the size of image circle and angle of view projected by the lens remains fixed, a smaller sensor will view less of it, effectively cropping the lens from what you would see with the size sensor the lens was designed for. Making a lens slightly longer by a given factor, usually referred to as the crop factor. Most dSLRS that number is between 1.5 and 1.3. (so a 35mm lens x 1.5 = effectively a 52mm lens - you've gone from what would be considered a wide angle lens, to a normal lens, just by changing sensor size, not the focal length).
Thank you for the explanation!
would this be terribly far off?
I know it's a cheapie, i just can't spend 600 bucks on a lens. There's some 50s. Am I reaching into wide angles needlessly? WOuld a cheaper, more local 50mm make more sense.
Lenses are confusing.
My recollection is that Bell and Howell lenses were rebadged Pentax originals, with a different coating.
90 + shipping doesn't sound bad at all. If you like the focal length, or decide you want wider, you haven't invested so much that you can't walk away from it. 
Looks like a winner to me.
ok thanks for the encouragement and all the help. Awesomeness.
:notworthy
I think it's on its way. I will post results.
Thanks for the help gentlemen.
ok, how bout a minolta to pentax adpater?
The minolta is a mid eighties era sitting in an attic, but has a bunch of lenses with it.
Minolta has a shorter registration distance to the sensor/film, than pentax. Which means you could adapt Pentax lenses to a Minolta camera, but not back the other way.
As far as I know you also cannot use the manual focus minolta lenses in the autofocus minolta/sony bodies, for the same reason.
The exceptions are for uber-close focus macro stuff. That will work. You just won't be able to get infinity focus. I do not know if there is a readily available adapter made (given the above). You could probably get an M42 screw mount adapter for the lenses, and then get M42-pentax... but that's getting a bit nasty.
All that said.
If you ever get an M4/3 camera (olympus pen, Panasonic GH-1) - you will be able to adapt those lenses to that, so they are not totally scrap (and of course, you can always run film in the minolta).
Yeah! the person offering all the minolta stuff said i could have the whole bag of stuff for nothing, so I might grab some film and try some fun.
Depending on which camera it is, some of them are fairly valuable. the XD-11 for instance usually runs about $200 still, and was one of the best manual focus film 35mm cameras ever made. Top 10 easy.
it was owned by a professional photographer. it's an all black X-700 bought in the early 80s. It weighs a ton. Where there's been paint-wear I'd swear the thing is made out of brass. I am not to worried about the value. I understand the pure technical capability diminishing the value. I was looking to see if it was a cheap way to get some lenses, and or have some fun with some film - take what I ahve learned from chimping and see if I can apply it to some committed shots.
the X-700 is also good. It does have a brass body. enjoy!