Pictures taken with Sony 70-200/f4 (A7II) not so sharp

[beunky]

Do try it with a shutter release cable or a 2-second timer release, that way you completely shut out any movement from your end.

[Username]

......... I thought this lens was as sharpest aroung 5.6 and up?

 

.............   

 

    

On a 4.0 lens, 5.6 is only one stop down. Certainly 

will be better than wide open, but it's only the first 

incremental improvement. The best IQ begins at 

about 2 stops down, with more improvement at 3 

and sometimes 4 stops down. Then it deteriorates 

if you stop down much more, due to the small iris 

opening beginning to approximate a pinhole "optic" 

[iQ loss due to diffraction].  

   

Altho there's a stop or two of improvement beyond 

f/8.0, to see that difference you'll hafta idealize all 

other variables [magnificent tripod, low ISO, truly 

accurate focus, etc etc]. OTOH, given half decent 

technique, you should easily detect the difference 

between f/5.6 and 8.0 by "zooming in".  

[UglyBob]

On a 4.0 lens, 5.6 is only one stop down. Certainly 

will be better than wide open, but it's only the first 

incremental improvement. The best IQ begins at 

about 2 stops down, with more improvement at 3 

and sometimes 4 stops down. Then it deteriorates 

if you stop down much more, due to the small iris 

opening beginning to approximate a pinhole "optic" 

[iQ loss due to diffraction].  

   

Altho there's a stop or two of improvement beyond 

f/8.0, to see that difference you'll hafta idealize all 

other variables [magnificent tripod, low ISO, truly 

accurate focus, etc etc]. OTOH, given half decent 

technique, you should easily detect the difference 

between f/5.6 and 8.0 by "zooming in".  

 

Ok, thanks, will keep that in mind also...

[twokey]

On 5/2/2017 at 12:12 AM, UglyBob said:

 

Ok, thanks, will keep that in mind also...

Hi UglyBob,

Did you figure out what was wrong? I have a similar issue with the kit lens 28-70 and Sony a7 body.

Thank you,

[tinplater]

This thread is two years old, unlikely OP is still watching.  Having said that, I have this lens and it is very sharp.  Folks forget that at increasing focal lengths faster shutter speeds are necessary.  I try to use shutter speed of 1/1000 or faster and let the camera adjust ISO automatically.