I had no idea these blossoms were so tiny. Given the image with the
flower in your hand my guess is that the total width of the flower image
is perhaps 4-5" (100-125mm). To get that size using a 50mm lens on a
4/3 camera the image plane of the camera had to be only about 12" (30cm)
from the flowers. At a marked f/11 the effective aperture is actually
about f/13.9 since the lens has to be extended about 13mm past its
infinity focus. DoF for that (using the more stringent CoC for 4/3)
would only be about 14mm. Using the less stringent 35mm CoC (or assuming
only a small print like 4x5) the DoF is still only double that at 28mm.
A tough nut to crack even if your focus point was spot on at about 1/2
way into the total DoF. To double these DoF numbers you'd have to shoot
at a marked f/22.
The hyperfocal distance for 50mm at f/11 is off in the range of 7-14
meters depending on how stringent you want to make the CoC. Macro
distances and hyperfocal just don't go together.
Chuck Norcutt
On 12/9/2011 7:42 AM, Brian Swale wrote:
>
> Chuck advised on relative focus etc.
>
> I have added another shot which gives a good idea of the size of these
> flowers ( see URL below).
>
> http://www.brianswale.com/zuikoholics/October-2011/Oct-2011.htm
>
> The flowers have long gone - the photos were taken on 1st October - if my
> memory of the EXIF is correct. It was really tricky to get good light, subject
> not moving in the wind, and the correct lighting (none) on the backdrop
> cloth.
>
> I had nearly the max DOF I could extract from that lens. Maybe I didn't
> guess the hyperfocal distance well enough.
--
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