Sharpest f stops on 20mm?

Jamus

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Apr 18, 2010
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Peter Jamus
Just curious, I know some lenses have 'sweet spots', so I was wondering what f stops are particularly sharp on the 20mm f1.7.
Thanks.
:redface:
 

Jonas B

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I would say the lens is sharp enough from f/1.7-f/5.6. Maybe the sweet spot is around f/3.5 but then you are chasing that little extra which in this case is such a small extra that it doesn't matter. For real good center sharpness stick between f/2 and f/5.6.

Or, go play with the lens test widget at DPR here.

my cents,

/Jonas
 

vincechu

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Jan 22, 2010
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I tend to use it roughly arround f/3 where it seems sharpest to me but wide opens pretty sharp too - but its such a great lens I find i don't have to worry too much about sharpness - unless u're stopping down massively that is ;-)
 

PeterB666

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Probably around f/4 to f/5.6. Most lenses are pretty weak full-open and getting beyond f/8 you start to get the impact of defraction caused by the small aperture.

There are a number of reviews on the internet showing graphs of sharpness of this lens so if you want a more definitive answer, try Googling 'Panasonic 20mm reivew' or similar.
 

Iansky

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Traditionally and as I was taught when studying, the optimum aperture for sharpness on any lens is 2 full stops down from wide open.

The 20mm is an outstanding lens that if used carefully can produce some superb images with a great bokeh, the lens is very sharp wide open so much so that it is often just a case of deciding on depth of field requirements!
 

kwaphoto

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Jun 4, 2010
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I have found that f/2 yields a great results but I don't hesitate to use it wide open either. Otherwise, I just adjust based on the desired DOF rather than "sharpness" or a sweet spot. I shoot my images for the image sake and not the lens' desires :2thumbs:
 

Grant

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May 16, 2010
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Traditionally the teaching is that tie sweet spot is in the mid point of the f/range. From all the test I have read Panasonic has bumped there sweet spot closer to the wide side of the lens. My 20 mm is very good wide open although there is a softening further off axes, still not very bad. At 2.8 it seems to generally behave very well. My 20 mm is good even at f/16 but not perfect there. On the other hand my 14-45mm is almost too soft at f/16 although still usable.
 

BillN

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I always thought - use f8

the 20mm only needs around f3.5 - f4.5 ...... so it would seem
 

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