Pentax smc DA 60-250mm f/4.0ED (IF) SDM Lens

Pros:
Sharp throughout the zoom range, even wide open it is great, by 5.6 it is simply astonishing
Versatile range (90-375mm Full frame equivalent, fairly close to 100-400mm)
Relatively Compact
Full weather sealing
Tripod mount with removable foot

Cons:
No zoom lock, could creep.
Some softness on one side of frame at 200-250mm and f/4 (rarely visible above f/4.5)
Tripod mount with removable foot

Verdict:
Superb lens worth the asking price. Image quality and bokeh is in league with most primes of similar range and aperture. Who should buy this lens? Anyone who needs an extra sharp, sports, wildlife, or general purpose lens with f/4 at the long end.

Review:
The lens is superb. SDM focus is silent and seems reliable with my K-7. It goes to its target and stops. It is not extremely fast, but not slow either. It seems to work well enough for some birds in flight tracking and other continuous focus activities. If you do use screw drive focus with this lens, it is fairly loud as typical of other DA* lenses running screw drive.

The sharpness of the lens never ceases to amaze me. Zooming in to 100% view and the pixels are still sharp, even on my K-7 which is 14.6 MP. It seems to peak about f/5.6, but is really very good from wide open. This behaves a lot like 70-200mm f/4 lenses in this regard. Since this is internal focus, the focal length is measured at infinity. It seems to be significantly less than that at close focus as typical of all IF lenses. Unlike some cheaper lenses this lens does not disappoint for distant subjects.

The lens is targeted for someone who is used to a 100-400mm for full frame. It has a tripod mount, and speaking of which, the foot of the tripod mount is easily removeable if you find it in the way (the ring remains on the lens), but I like to use the foot as the handhold when shooting, it makes a nice balance point. The ring has detents every 90 degrees so it is easy to rotate in 90 degree increments. My only word of warning is make sure you keep the tripod mount tightened, use a coin or something. If you only hand tighten the screw, it could work its way off, which would be unpleasant to say the least. The lens is actually not large if you are used to lenses like the Sigma 100-300mm f/4. It is small next to that lens. It is fairly close to a 70-200mm f/2.8, and maybe even a bit smaller.

Most of my minor complaints with this lens are mechanical. Don't get me wrong, it feels great, but it lacks a lock or anything to hold the extending barrel in place while you hike around. The weather seal helps keep the barrel from extending, but it doesn't take a lot to pull it out. There is also a small amount of barrel wobble (only if you push on it). There is also no focus limiter to help speed up focus, good thing it doesn't hunt often.

My minor issue with the left side being soft had me a slightly concerned initially, but it really only is noticeable in brick wall shots and appears to go away when stopped down at all. This mirrors what SLRGear saw with their review as well.

Optically, there is some visible green/magenta bokeh CA, but it is fairly minor and easy to correct in post. You will see some occassional fringing near the extreme edges of the frame too in high contrast situations, but it is still better than average in this regard and not to the point of systemically hurting contrast (like in most of the 70-300mm lenses). Overall contrast is superb with this lens.

The question I always hear is why should I buy this lens when I can buy the 55-300mm a quarter the price? Trust me, this lens is worth every penny. It really is in a different league than the 55-300mm, which is a great lens, but you do get what you pay for. Looking at uncropped images there will be only slight differences, but looking at 100% crops or large prints the difference is clearly visible.

I almost gave this lens 4 stars because of the minor complaints I had with mine, but the lens always makes me smile when I see the results. For that reason I had to give it 5 stars. This lens combined with the K-7 make one unbeatable all weather camera kit.

I owned one of these for about 14 months. It became my main day to day lens. It takes incredibly sharp, high quality images throughout the zoom range, sweet f-stop is about 4.5 or 5.6.

Our image standards are rather unforgiving: there is a 44" wide photo printer downstairs. Not every image can provide the data needed to hit 44" wide, but that is the target. My/our lesser zooms seldom make the grade. This lens does so, regularly.

This lens allows you to 'sample' frames out of a landscape, and produces zoomed in shots with breathtaking clarity and image quality. My other, lesser telephotos have a few settings that produce images with the quality obtained with a short lens, but by and large, you can immediately tell that the frame was shot with a long lens, zoomed in. In other words, a whole lot of files that never get sent to processing and printing. Not so with this puppy. Basically, if you are getting less than great clarity with this mounted on the front of camera, your problem is you are doing something wrong behind the camera.

This lens requires a tripod mount, careful stabilization, mirror lock up before shutter release, self timer or remote control trigger. Basic long lens protocol. Wind is your enemy. But get it rock steady between gusts and the results are simply: Wow!

Mine got totaled in an unfortunate hiking wipeout on Orkney. Smacked it into a rock with gusto. I am now buying another because my approach to outdoor photography now requires the capabilities of this lens.

The points made by other reviewers - it is a heavy lens, and has no zoom lock - are quite true. My left arm is pretty buff after spending 2 months in Scotland carrying this lens on a K-20 on a tripod up hill and down glen. Small price to pay for what it delivers.

You don't want one of the more "reasonably priced" long Pentaxs or a Tamron. You want this one.

Pros: Sharp from wide open, great color rendering, excellent construction, weather sealed

Cons: Heavy (as any good quality lens of this range), expensive, no focus limiter

This is an excellent lens for Pentax DSRL cameras. I have nothing but positive to say about it after one month of use with K-7.
Though it has no zoom locking, the barrel shows no creeping.
The tripod mount is easy to take out when not needed and collar has 90 degree locking points that you feel very clearly when turning the collar. Zoom ring does feel a bit sticky if you try to zoom out holding the lens up, but that's due to the weight of the barrel and glass. If you point it down the ring movement becomes soft.

The only little thing I can find is a small wobble of the barrel when zoomed fully out, but it seems to have no effect on the image quality.
The lack of focus limiter can cause slow focusing as the mechanism needs to make full travel if you do not pre-focus manually.