F.A.O. Shim

Ok m8
Did a few more with the 50mm, f1.4, Tripod, focus chart at 45 degrees, close focus as i could with the 50mm, Circle in Viewfinder perfectly lined up with the circle in the focus chart.


First is Minus 10
[IMG]http://i271.photobucket.com/albums/jj132/CraigF1969/private/50mmminus10.jpg[/IMG]

This one is Plus 10
[IMG]http://i271.photobucket.com/albums/jj132/CraigF1969/private/50mmplus10.jpg[/IMG]

This one is 0
[IMG]http://i271.photobucket.com/albums/jj132/CraigF1969/private/50mm0.jpg[/IMG]

Now from what i can see here and the other tests done earlier then i either have 3 lenses which all need adjustment between minus 8 and minus 13 or i have indeed got another faulty camera.

I would find it incredibly unlucky if it were indeed the 3 lenses that were off especially with one being a prime.

I didn't follow the other threads but is your camera still in warranty? If so I would send it in for adjustment.
I would accept a -5 or +5 adjustment in the body but this is off by quite a bit which makes me think that it needs a re-adjustment of the focussing system.

When I recently bought my Bigma and I wasn't really satisfied with it I did a lot of tests as well with all my lenses and there was clearly a problem with the Bigma because it was the only lens that was off by a huge amount.

Did you allso try out these charts with manual focus to see if you get a clear image that way (so bypassing the whole AF system completely)?

Did it with manual also m8 but its exactly the same.
I bought my K20D around a month ago and had to send it back, got a replacement which went "South" after 2 weeks and this is my 3rd one in the space of a month.
I dont know whether to laugh or cry in all honesty.
Im thinking back through my entire life to try and think what i did to deserve this.

I feel really sorry for you.
This is very unusual. Did you get new bodies or did they give you refurbished ones?
I would demand a new body at this stage if it were refurbished ones.

But shouldn't the images taken with manual focus be correct no matter where the focus adjustment is at? Focussing manual and not looking at the "in focus hexagon" should allways work. If you focus manually and wait for the in focus light to come on then you are basically using the AF system which might be focussing to the wrong point.
Your 50mm f1.4 is that an AF lens or a manual focus one?

They were all New Bodies, 50mm is the AF one.
I will try that theory of yours by not using the light as a guide to infocus and let you know what happens.
I assume there is a way to turn that light off?
Or is it simply just putting everything on manual?

Here is the manual shots with the 50mm @ 0, -10 and +10.
Doesnt seem to be any difference in all three.

[IMG]http://i271.photobucket.com/albums/jj132/CraigF1969/private/50mmmanual1.jpg[/IMG]


[IMG]http://i271.photobucket.com/albums/jj132/CraigF1969/private/50mmmanual2.jpg[/IMG]


[IMG]http://i271.photobucket.com/albums/jj132/CraigF1969/private/50mmmanual3.jpg[/IMG]

i found that when i adjusted my focus on the k20 it made no difference. also do you know anyone else with a k20d you could try the lenses on.

Unfortunately i dont know anyone.

well to be honest i would get back on to srs and say that its out on all your lenses, and see what they say,

In all honesty im at the point where i am seriously thinking of just sending everything back and just let them deal with it.
Ive emailed Pentax for their thoughts and once i receive a reply will consider whether its worth contacting whatever consumer body deals with cases like this.
Im just sick to the back teeth of all the hassle.

If you fill in your location details in your profile there could be a forum member close to you who might be willing to help.

Good Point.
Updated.

Hi Craig, sorry I've been out and only just got back. The one at -10 above looks OK. I use a K10D so I'm not sure about the K20D adjustments, but I understand that you can set one for each lens, so I would set that one to -10.

It's very often the lenses that cause this adjustment to be necessary for some reason. Some of my lenses are spot on, unfortunately the one that I need to be right for manual focusing a 50mm A f/2.8 macro is about 8mm out at .45m and if I give it the minimum amount of adjustment it goes out the other way. The mind boggles at why manual focus is out on one lens.

Sadly all digital cameras have these focusing problems, possibly due to the small size of the sensor and focusing screens. The position of the manufactures, particularly Canon is that the focus should fall within the depth of field before they will accept that it's out. Before Fleet St. even use a camera it gets sent to a specialist to check and adjust the focusing and they still aren't perfect.

I'm not happy with any of them A4 printed focus tests. If I were you with the Sigma I'd photograph the cornflake box and then move it back 3 inches, do it again and then do it 3 inches in front of the original position and see which was sharpest then try a few +- adjustments and repeat it. Alternatively set 3 boxes or batteries up staggered and photograph them. If you have any railings nearby you could set up at 45deg to them and focus on a post and then see which rail is in focus.

shim

It's probably worth recapping at this point just to ensure you have your camera set correctly before attempting these adjustments.

First, print these charts and read the author's blog, cut out the first 2 and fold them as shown. Set them on a flat surface.

Your camera needs to be set as follows:-

1: Mounted on a tripod
2: Shake Reduction turned off
3: Select 2 second timer mode (mirror lockup)
4: Select centre spot focus point
5: Set Focus mode switch to AF-S
6: Set Exposure mode switch to Av
7: Adjust the height of the camera and lens so that the centre of the lens is the same height as the centreline of the chart(s).
8: Level the camera as best you can.

Finally, position the chart such that it's front face is parallel (horizontally) with the sensor plane of your camera.
Align the centre of your viewfinder with the centre of the chart. Physically move or adjust the tripod to maintain the camera level.

Now try again with your tests. Use a cable release and before pressing the shutter release to focus, set the lens's focus barrel at infinity.
Repeat this infinity to focus step three times taking a shot each time.
Now take three more shots but setting the lens's focus barrel to minimum focus before each shot.

At this point you need to stop and check each of the six images and ensure that each of them has focussed to the same point, even if it is the wrong point. If not, there's a problem. It is quite possible that due to manufacturing tolerances, there may be a slight difference between the focussing point of the first 3 compared to the second 3 images. That's normal, but if it's a large difference, there's a problem.

Assess how much adjustment you might need, set it, or just try an adjustment, and repeat by taking 6 more images in the same way. Repeat these exposeure and adjustment steps until the focussing is as you would like it, or as best as you can get it. Once adjusted, take some 'real world' shots to verify the setting.

On the K20D, these steps need to be repeated for each lens (up to 20) if you find they give different results. You can apply one setting for all lenses if that's appropriate. I don't know if these adjustments are cumulative, that is, a + 10 adjustment for all lenses and a +10 adjustment for an individual lens might not result in a +20 adjustment.

On the K10D I'm afraid you have only a 'one adjstment for all' option. Some forums claim that you can set 4 lenses individually on the K10D. I can't confirm or refute that.

And don't give up, we'll get to the bottom of it.

@Peter
You should make a nice new topic about this and let the admins make it sticky just like some of the nice topics from Matt.
Your explanation above is very good.