Olympus-OM
[Top] [All Lists]

Re: [OM] Diffraction effects, was: New image with new(in part) gear

Subject: Re: [OM] Diffraction effects, was: New image with new(in part) gear
From: Mike Gordon via olympus <olympus@xxxxxxxxxxxxxxxxx>
Date: Sun, 31 Jan 2016 22:46:42 -0500
Cc: usher99@xxxxxxx
CN writes:

<<What Roger is actually saying is that resolution of 610 looks pretty good 
compared to 325 wide open. You have to close down 3 stops to f/4 to even equal 
the f/16 result. What his results do show is that <<diffraction has a very real 
effect and starts taking its toll about where theory says it should. 

Yes, agree with you  on everything to a point. Roger also demonstrated that the 
MTF decline by stopping down an extra stop was quite modest and that he would 
stop down more even to F16 for some landscapes.
It clearly depends on the image and the importance of critical sharpness at 
different distances.   Recall  from  Merklinger's article  that by focusing at 
infinity one gains 6 fold increase in resolution for distant objects and only 
loses 2X at the near limit of DOF. 
 
 http://www.trenholm.org/hmmerk/TIAOOFe.pdf          (about page 32)

 One easy solution, if circumstances permit, is to focus stack at a wider 
aperture and eliminate the  compromise (but introducing others). 

Now I know it is really mid-winter with a diffraction/dof thread, Mike  


-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz