24mm Summilux focus shift question

[jaeger]

Advertisement (gone after registration)

I just wanted to verify if focus shift is a design flaw on 24mm Lux or something it can be fixed by adjustment.

Since this lens has forgiving depth of field so the focus shift will only noticeable at the following conditions....

1) at close subjects that's less than 1.5 meters, please set yours at 0.7 meter on the barrel to test.  (don't push all the way, some lenses might go below 0.7m that your viewfinder doesn't)

2) provided your lens and camera are perfectly calibrated, which supposed to be no issue wide open at f/1.4 at any range.   The focus shift will happen started from half click increment.  Greater than f/2.8 will stop seeing focus shift just simply becoz this lens has very wide DOF.

I use this lens for close subject intensively so please don't tell me how to use it or how you use it -- thank you in advance.  I start noticing all my pictures are out of focus between 0.7 to 2m when aperture is set to f/2 plus or minus half stop.  So I did a test at home to confirm my copy does have focus shift between f/1.8, f/2 and f/2.4 (I include half click).  My lens @f/1.4 is perfect at any range, every click closing (not step) will result in two inches back focus,  @f/2 is worst at about 5 inches total.  Beyond that range like f/2.8 is fine, it starts to recover a wide range of DOF - some called it zone focusing. 

If it's not a design flaw, then I need to speak to a Leica technician who is going to fix this lens.  Thank you very much.

 

 

Edited November 3, 2019 by jaeger

[Joakim]

I performed a quick test using my M10 and on reviewing the images, shot at 1.4 - 2 - 2.8, I can not see any obvious focus shift.

[lct]

Did you use an EVF to check your findings? If not, you may wish to do it in order to exclude other causes like the RF as possible culprits.

[jaeger]

1 hour ago, Joakim said:

I performed a quick test using my M10 and on reviewing the images, shot at 1.4 - 2 - 2.8, I can not see any obvious focus shift.

Thank you sooo much Joakim.  That's mean the focus shift isn't design flaw but something fixable.

[jaapv]

Quick handheld test on mine: no obvious focus shift.

[jaeger]

1 hour ago, jaapv said:

Quick handheld test on mine: no obvious focus shift.

appreciate that.  more case studies to proof that it's not a design flaw.  It definitely needs to be addressed. 

[jaapv]

Advertisement (gone after registration)

The cause may well be in the floating elements. In that case it can only be adjusted by Leica.