Focus issues.

Not sure that my K10 is giving me dead sharp images. I take great care to watch for the indicator and then am disappointed with the results.
It is particularly noticable now with the 300mm lens.
If I invest in a Katseye screen, will I get the same dodgy results. In other words, what is it that tells the camera it is fully in focus? If the problem is in the camera will it fool the Katseye screen?

Not sure I have put that very clear but I know you good folks are brilliant at understanding what I am trying to say.

Thoramay.

The Katseye will only help with manual focus it has no influence on AF performance AFAIK.

John

The AF system is a seperate system on the camera, it's located on the underside of the camera so no where near the viewfinder, it even use his own mirror.
The Focus screen does have an effect on exposure metering though.

John already said the rest.

Had the same problem with my K10D

Thread HERE

Mike.
Have just read through the thread mentioned. I am not able to do the adjustment as you able folks have done. I'm stuck with the problem.
Would a Katseye split screen give me true focusing.
As mentioned, I have spent a whole morning lakeside taking pictures only to find that nearly all are out of focus. It is so frustrating.
It was mentioned that the K20 has the ability to be adjusted. Would that be a way forward? Is there somewhere that I can have my K10 put right?
Having spent a whole lot of cash on a 300mm lens, I'm kinda disappointed with Pentax. I know John's comment about the affect of use but I would expect a camera to have a system that is rugged. A poorly focusing camera is no use to any photographer,

Thoramay

Are you sure it is a focus problem and not camera shake?
What shutter speed are you shooting at and are you using a tripod?

AFAIK the in-camera focus adjustment only applies to AF, and on the K10D requires modified firmware to be loaded?

Both the K20D and K7 have AF adjustment as part of their standard menu.

Try some AF shots of the same subject with your 300mm at differant apertures and post the results here, together with the same shots taken with MF. Suggest you follow this sequence;

Set ISO to suitable fixed value to ensure reasonably high shutter speed at all apertures.

Put camera on tripod.

Select aperture. Focus on subject using AF.
Use timer/mirror up function to prevent camera shake.
Take shot. Immediately swith to MF. Re-focus.
Use timer/mirror up function to prevent camera shake.
Take shot.

Select new aperture...etc.

If you can complete the above within a few minutes that will hopefully eliminate/reduce any light level variation.

Make sure you don't lose the EXIF data in the process of posting the photos.

Posting shots as suggested will give the experts here a better chance of diagnosing what the issue is.

Preferably using a tripod and cable release/remote release to eliminate camera shake.

Regards,

John

Calling Mattmatic. What's needed is an earlier version of the firmware, modified so that the camera thinks it is later.

This will allow you to adjust the focus, but it is an overall adjustment, not lens-specific like the K20D adjustment.

What you have to hope is that the 300mm itself is not out of line with your other lenses.

This is a problem that affects all brands.

G

Thormay, three questions:

Have you experience AF issues with any other lens?
Were you using a tripod?
What shutter speed were you using?

There is every possibility that what your experiencing is the effect of camera shake, not AF issues, particularly if you've had no problems with other lenses.

Taking hand-held shots without shake with such a long lens will require a shutter speed in the region of 1/500 I think (correct me if I'm wrong though guys).

If you've got one, get the camera on a tripod and fire some shots (turn SR off first), that will help give a good indication whether it is a hardware or operator issue.

Try not to be disappointed with Pentax until the root cause of the problem has been identified.

I think the 'rule of thumb' is the reciprocal of the focal length, ie for a 300mm lens it would be 1/300 sec.

I had read somewhere (could be wrong) that you have to take the crop factor into account, so 1/450. I rounded to 1/500 for convenience.

To be honest, I've seen it written both ways, difficult to know what the truth is!

I am using a Monfroto 486RC2 tripod. The K10 with the 300mm is mounted on a monfrotto 454 macro adjusting rail. this allows me to set the weight balance over the tripod. This set up then allows the lens hood to sit tight on the rail and the whole arrangement is rock steady. I use a radio remote control.

I just wish my ability allowed me to post pictures on the Forum other than the Gallery.
My recent two pics of a juvenile adder on the Gallery are reasonable but not dead sharp.
My shaky hands means I always take pics on the tripod where possible.
Where would I be without this Forum.

Thoramay.

Careful Robbie - we could be straying into the 'focal length Vs field of view' battle ground

I'd like to know the answer though!