Olympus-OM
[Top] [All Lists]

Re: [OM] IMG: Cape Neddick Lighthouse

Subject: Re: [OM] IMG: Cape Neddick Lighthouse
From: John Hudson <OM4T@xxxxxxxxxxx>
Date: Sun, 26 Oct 2014 12:29:58 -0300
Are your MPs per lens focal length per aperture numbers out the ether or do they have some source to which curious minds can refer ?

For instance, you state that for "this 16MP camera ........... f16 knocks the sensor resolution down to 8 MP on the green channel and 5MP on the red channel."

jh




On 10/26/2014 12:00 PM, Chuck Norcutt wrote:
Diffraction territory for this 16MP camera is about f/11 (for the green channel, I'm assuming that the monochrom uses all colors). f/11 would slightly reduce resolution in the red channel but f/16 is severe... it knocks the sensor resolution down to 8 MP on the green channel and 5MP on the red channel.

I can't tell what the shooting distance is for the foreground but it looks close enough to me that I wouldn't have tried it with a focal length longer than about 35mm. At f/11 on 50mm a hyperfocal shot's closest focus is about 11 feet (even at modest resolution). Using f/16 puts you seriously into diffraction territory for a 16MP camera. It knocks the green channel resolution down to 7MP and the red channel down to 5MP.

For this particular shot and focal length I have to agree that a composite of 2 images would be required... unless you had a tilt lens.

Chuck Norcutt


On 10/25/2014 11:56 PM, Moose wrote:
On 10/25/2014 12:07 PM, Chuck Norcutt wrote:
Some hyperfocal work by Tina.  Ask her how she did it.  She used f/8
at 90mm.  I suspect the lighthouse might be a bit soft at a larger
size. I'd have used f/11 and a shorter focal length if I could have
gotten close enough.  But maybe she couldn't get closer.

OK, lets look at another one, Prospect Harbor Lighthouse. Just as you
suggest, shorter FL and f11. <http://www.pbase.com/image/157906308>

And yet, the near foreground is quite OOF. It appears to me that the
lighthouse and tree were also a bit OOF, and sharpening has been used on
them. The result is slightly etched, artificial looking, to my eye.

Two shots, one focused near, one far, feathered together in the water,
would get everything in focus and better looking, overall.

Cropping and different compositions are possible, as with the following
horizontal shot. But to get the chosen shot, hyperfocal technique won't
do it without slipping into diffraction limited territory - not that
anyone would see it at this size.

Two for One Moose


--
_________________________________________________________________
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