[ross]

I recently bought a K5 and the kit lens 18-55mm WR but I had focus issues with the lens, at 18mm the right side of the photo was always blurry at other focal lengths the lens was OK. So I got a refund and have on order a Tamaron 17-50mm f2.8 lens. But in the mean time I have been anxious to start using my camera so I bought a Pentax-A 50mm f2.0 manual focus lens, I was all eager to see the results but I have been very dissapointed all my photos don't seem focussed and pretty blurry, when I look through the viewfinder I turn the focus ring until the center looks sharp then I check the distance on the lens but still no luck.
When I turn the camera on it shows a screen "Imput Focus Length" i select 50 and hit OK, is there any other thing I need to do with the camera.
Here's a sample of what I mean.

Attached Images

 

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Last edited by ross; 11-29-2011 at 03:28 PM.

[areidjr]

...when I look through the viewfinder I turn the aperature ring until the center looks sharp then I check the distance on the lens but still no luck.

Aperture ring to focus? Is this a typo?

[sterretje]

The matte screen in your viewfinder might need shimming (adjustment with shims); mine seems to be pretty accurate, but that is not guaranteed to be the case.

When you use the green hexagon, be aware that there is a bit of 'play' in the AF. Coming from nearby while turning the focus ring, the green hexagon will light up to indicate focus. Continue to turn the focus ring and the green hexagon will stay on till the AF decides that it is out of focus. Same when coming from infinity. Based on the green hexagon there should be a range of what is in focus but that can't actually be the case

You need to determine if you get correct focus with the green hexagon when you're coming from nearby or from infinity. And if you have to turn the focus ring a tad further or not.

The best solution is a third party split prism screen; it also might need shimming but once correctly adjusted it's a pleasure to work with and solve your problems.

[DogLover]

The best solution is a third party split prism screen; it also might need shimming but once correctly adjusted it's a pleasure to work with and solve your problems.

Actually, the best solution is a Canon s-type screen, as virtually everyone who has tried one will attest. The splits simply cannot compete with the s-type when it comes to accurately focusing at shallow DoFs. Plus, it doesn't play havoc with metering like a split will.

I can't help but wonder if the OP's problem is more his technique, though. Are you really using the aperture ring to dial in focus?

[adpo]

the tree in the center looks good and sharp to me

[philippe]

Is there an other area than the one you focussed on that IS sharp? The picture you showed is not large enough to see that.
Where on did you focus? What was the shutter speed and at what aperture?
To my own experience, the 'older' analogue lenses like the SMC-M and the SMC-A, are not that ' vividly sharp' as the digital dedicated lenses, particularly on a demanding camera like the K5.
On the K10 there was 'no problem', on the K20 I wasn't that pleased anymore and and on the K5, but, perhaps, I am the one that is to demanding...
Some time ago, just out of curiosity, I compared the SMC-A 50mm 1.4, the FA 50 mm 1.4 and the FA 43 mm 1.9 Ltd on my K5, and the FA 43 mm Ltd, all tough a non digital lens but of a more recent design, was clearly the winner.
So, I think that a digital dedicated lens should do even better. Wait an see what that Tamron will do and then make your conclusions.

[mrjamesabels]

If you want to manual focus and use the view finder, then get a new focusing screen and adjust with shims til perfect. Try focusing in live view in the mean time. That will work perfectly but stinks for moving subjects.

[mrjamesabels]

Use info inside of live view to zoom in a step or 2 then turn the focus ring til sharp. Be sure to use a fast enough shutter speed TaV f/2.0 (1/30-1/125th) and hold steady. Good luck!

[cali92rs]

If you want to manual focus and use the view finder, then get a new focusing screen and adjust with shims til perfect. Try focusing in live view in the mean time. That will work perfectly but stinks for moving subjects.

Thats the method I currently use...but in addition to it being crappy for moving subjects, its also a battery sucker.

I do plan on getting a proper focusing screen, but am nervous of the whole trial and error shimming process.

[jatrax]

I turn the aperature ring until the center looks sharp then I check the distance on the lens but still no luck.

First I assume you mean the focusing ring, not the aperture ring, right? Do you have the lens in the 'A' position or are you setting the aperture manually? Either way, what aperture are you using?

To test, set up on a tripod and focus on something flat with detail, like a brick wall. You should be able to get a good focus at any aperture since there is no depth of field to matter. Try one shot using the viewfinder and another using live view, compare the results.

Remember, if you are using the lens wide open the depth of field will be very small. Something in your photo is probably in focus but I cannot tell, maybe the yellowish shrub? At f/2 the depth of field at 10 feet is about 1 foot. At 20 feet it is about 4 feet. Hard to assess this without knowing the aperture used.

[Ron Kruger]

Looks to me like you may have forgotten to adjust the diopter?

[ross]

Thanks for your help and excuse the typo about aperture/focus ring.
I think unless I get another focussing screen that using the viewfinder is too hard, but live view worked a treat and being able to use the info button to zoom in really helped, except once you start zooming using the info button I couldn't workout how to get back to normal view. I think once I get my Tammy the 50mm lens will go into storage but for $22 it at least lets me use the camera until my lens arrives. I'm quiet impressed with the IQ of the in-camera jpegs from the K5, with my Nikon D300s I usually shoot RAW. I always wanted a smaller camera that when I want to go hiking or travelling I could just chuck it into my bag without too much weight looks promising so far.Here's my latest test shots done this morning.
PS. just had a look at the uploaded photos the IQ looks terrible compared to the originals