All Sony Lens need micro adjustment<<< is this normal?

[digitalxd1]

Hi
It's me again, a newbie in Sony DSLR.
I have a question regarding Sony lenses.
I bought
A900
Zeiss 24-70 F2.8
Zeiss 135.1,8 and
Sony 50/1.4

All of this lens are suffering from back-focus problem.
After carefully fine tuning each lens (using micro adjustment, more than 2 hours)
here are my results

Zeiss 24-70 F2.8 Need -10 micro adjustment
Zeiss 135/1.8 Need -9 micro adjustment
Sony 50/1.4 Need -17 micro adjustment

Now my lenses have 100% accurate focus
but, my question is
This is a normal behavior on Sony Lenses?? so weird...
Thx u

Andree

[zcf]

If all lens show sign of back focus, then it's more likely it's the body back focus instead of the lenses. Try a few more lens and see, if confirm back focus then need to send to Sony for adjustment, but you will need to re-do the micro adjustment after re-tuning

personnally I thinks 50mm f/1.4 is a lens tend to have more focus problem.

[boombox]

Yeap, in line with bro ZCF's thinking, i think the 50 1.4 suffers this more commonly, but for your case, it seems across the board...

Maybe you can have your lenses double checked with the rest of the guys here... they might be able to tell more.

[Galdor]

Quite unlikely that all 3 lenses you own have this issue. Like what the bros have mentioned, it could be a problem with the body. You may want to sent the body in for calibration. From what I know, SSC will calibrate the body using the 50mm f1.4.

[waiwah]

Micro adjustment..
how do u do tht ?

[Galdor]

Originally Posted by waiwah Micro adjustment.. how do u do tht ?

This feature is only available to the A900. Are you an Alpha user too?

[Mino]

Hi bro,

How do you fine tuning?
Using any standard chart?
a) Focal length (mm)
b) Selected f-stop like wide open
c) at various Subject distance;
e.g
c1) 1 to 1.1 of MFD
c2) 2 x MFD (+/-5%)
c3) 3 x MFD (+/-5%)
c4) ...con't
.... or like 30cm, 60cm, 100cm, 200cm, 300cm, 400cm, etc.....

Note that all these will give raise to difference reading in lens adjustments.
In today manufacturing technology, all lenses build shall have some or little back/front focus problem.
Thanks.

Originally Posted by digitalxd1 Hi All of this lens are suffering from back-focus problem. After carefully fine tuning each lens (using micro adjustment, more than 2 hours) here are my results Zeiss 24-70 F2.8 Need -10 micro adjustment Zeiss 135/1.8 Need -9 micro adjustment Sony 50/1.4 Need -17 micro adjustment Now my lenses have 100% accurate focus but, my question is This is a normal behavior on Sony Lenses?? so weird... Thx u Andree

[waiwah]

Originally Posted by Galdor This feature is only available to the A900. Are you an Alpha user too?

Yaya.
I'm using A700.

Very new member in Clubsnap.

[Galdor]

Originally Posted by waiwah Yaya. I'm using A700. Very new member in Clubsnap.

Warm welcome to you to the Alpha family. The A700 is a very solid cam. I enjoyed using it. Hope to see your great shots soon.

[Lai Ming]

Yep!

If after tuned, all pictures will be razor-shape, like...#1 & #25

http://www.hkmug.org/viewthread.php?...extra=page%3D1

[waiwah]

Originally Posted by Galdor Warm welcome to you to the Alpha family. The A700 is a very solid cam. I enjoyed using it. Hope to see your great shots soon.

Thnx man..
My 1st post picture was in "nature section" called "meeeeaow" ^^
C & C pls.

[ninelives]

not only sony, nikon and canon all the same.

[Rashkae]

The 24-70 and the 135mm are all sharp on my a900 without adjustments. The 50mm needed -2 but that's it.

[Agetan]

sems like its perfectly sharp on my version of CZ lenses on A-900 without the need of adjustment.

Hart