[BethC]

Is that possible?

I used my 50 - 135 lens on my K 10 body and it backfocused... a lot!! Tried the same lens on my K5 and it seemed fine. Is that possible? To backfocus on one body but not another? Or is it most likely a problem with my K10 body? I did try a different lens on my K10 and it seemed okay though. I'm just not sure what to think.

[Docrwm]

Yes, it is possible. I just uploaded a picture from my K-5IIs + Tamron 70-200 that has NO AF adjustment but on my K-5 that lens needed adjustment. It's the fit between the lens and camera and even two of the same model of camera can require different adjustments with the same lens.

[BethC]

Yes, it is possible. I just uploaded a picture from my K-5IIs + Tamron 70-200 that has NO AF adjustment but on my K-5 that lens needed adjustment. It's the fit between the lens and camera and even two of the same model of camera can require different adjustments with the same lens.

I'm not sure how to adjust a lens, but I'm going to look into that. But if I adjust the lens for the K10 will it not be right on my K5 then?

[JimJohnson]

actually you will be adjusting the body for the lens, not the lens for the body. There is a fine focus adjustment in the 'C' part of the menu. Exact location will likely vary between body models.

Do an autofocus test-
Using Moire' Interference Patterns to Test DSLR Auto Focus

It is fast and easy for testing. But if this test determines autofocus is off, I suggest the tool here to adjust it-
PENTAX DSLRs: Front or Back Focusing Problems? Free test (Lens Alignment) charts for Pentax, Nikon, Canon, Sony, Olympus.

[BethC]

actually you will be adjusting the body for the lens, not the lens for the body. There is a fine focus adjustment in the 'C' part of the menu. Exact location will likely vary between body models.

Do an autofocus test-
Using Moire' Interference Patterns to Test DSLR Auto Focus

It is fast and easy for testing. But if this test determines autofocus is off, I suggest the tool here to adjust it-
PENTAX DSLRs: Front or Back Focusing Problems? Free test (Lens Alignment) charts for Pentax, Nikon, Canon, Sony, Olympus.

Thank you so much for that information! I will definetly do that. Okay, so if I asjust the camera for that lens, will it affect how that camera works with other lenses?

[VisualDarkness]

There is a tolerance when it comes to measurements when manufacturing. and extremely small tolerances costs too much, so almost every consumer product has these kind of variations. Even things like air pressure and temperature will affect things. Sometimes both the body and the lens are within set tolerances but at the different ends of it, creating problems like miss-calibrated focus. It's more about luck than something actually wrong, or we would have to pay even more for the products.

A nice read of the case of calibration to ease you mind.
LensRentals.com - "This lens is soft" and other myths

Edit: K-5 can do both single lens and all lenses calibration.

[BethC]

There is a tolerance when it comes to measurements when manufacturing. and extremely small tolerances costs too much, so almost every consumer product has these kind of variations. Even things like air pressure and temperature will affect things. Sometimes both the body and the lens are within set tolerances but at the different ends of it, creating problems like miss-calibrated focus. It's more about luck than something actually wrong, or we would have to pay even more for the products.

A nice read of the case of calibration to ease you mind.
LensRentals.com - "This lens is soft" and other myths

Edit: K-5 can do both single lens and all lenses calibration.

Thanks for that info. I'll read that article too.

So, if I think the lens if actually backfocusing on both bodies, is it most likey a lens problem? Or still just that my cameras need to be adjusted. I was just outside messing around with the lens on both bodies and now I'm thinking it may be a problem on both camera's. Going to test it out some more later (Gotta run and do that Mother's Day family "stuff" )

[GabrielFFontes]

It's a body-lens thing...if you can correct if within the +-10 range, it's okay...if you have to goo further, it can be a problem, because you'll have to use the debug mode, etc. etc...
Most K-30 users say that there is no need for adjustment, but i still have to adjust some lenses...my recently bought 24mm 1.8, for example, is still going through the testing procedure, and it looks like it needs a bit of adjustment, like -3...basically if its still correctable its fine.

[BethC]

This lens has worked fine on both these cameras for the past year and a half, just now started back focusing. Is it normal for a lens to stop focusing right all of the sudden?

[Docrwm]

You said you tried another lens on the K10 body, was it SDM as well?

[BethC]

No, it was not another SDM lens that I tried on the K10. It was a Tamron 17 - 50 mm F2.8 lens. I need to get both camera bodies and all my lenses back out tomorrow when I have more time. Today was a hectic day and I tried testing it all real quick between visiting family etc... But I think the 50 - 135 is back focusing on both my K10 and my K 5 and I'm just not sure what to do about it.

[Spodeworld]

There are 2 forms of adjustment, at least on the K20D there are, so I assume it is about the same.

You can do a global adjustment that would impact every lens that you attach to the camera.

Or, you can assign the adjustment on a per lens basis. You can do up to 20 specific assignments, and when you put that lens back on it will work accordingly.

So, if all the lenses seem off, you might try the global adjustment. If only one is off, select the adjustment so that it only affects that one lens.

Thank you so much for that information! I will definetly do that. Okay, so if I asjust the camera for that lens, will it affect how that camera works with other lenses?

[Parallax]

You can't adjust the K10D for back/front focus unless you are using the hacked firmware.