Question about weird DOF...

Can anyone tell me what the DOF issue is here?

http://www.pbase.com/image/62939916

Is this due to the angle of the shot? Why would the DOF in the
foreground look like that? FWIW, the set up is a D70s, 27.5mm PK-13 -
55mm Micro Nikkor, SB-800 w/ Lumiquest Softbox off camera at 9:00 in
the picture....

Any help is appreciated...

Ben

PS - No real processing was done; I'm more concerned with the blurry
ring.

wrote:
Can anyone tell me what the DOF issue is here?

http://www.pbase.com/image/62939916

Is this due to the angle of the shot? Why would the DOF in the
foreground look like that? FWIW, the set up is a D70s, 27.5mm PK-13
- 55mm Micro Nikkor, SB-800 w/ Lumiquest Softbox off camera at 9:00
in the picture....

Any help is appreciated...

Ben

PS - No real processing was done; I'm more concerned with the blurry
ring.


I don't see anything odd. What aperture were you using? Was there
enough available light to create a blurred image due to motion?

--
Joseph Meehan

Dia duit

Joseph Meehan wrote:

I don't see anything odd. What aperture were you using? Was there
enough available light to create a blurred image due to motion?

Aperture was relatively high, f/11 IIRC. At 1/320s there shouldn't,
and isn't, any blur due to motion in that picture. As you can see, the
closest wing is blurred due to DOF, but the other one is frozen by the
shutter speed and flash. It's just that I've never seen DOF like that
- a weird, perfect circle in the foreground...

wrote:
Can anyone tell me what the DOF issue is here?

http://www.pbase.com/image/62939916


PS - No real processing was done; I'm more concerned with the blurry
ring.

Looks like just another piece of bark in the foreground, very close to
the lens.

Kind of a cool looking fly, though.

Annika1980 wrote:
wrote:
Can anyone tell me what the DOF issue is here?

http://www.pbase.com/image/62939916


PS - No real processing was done; I'm more concerned with the blurry
ring.

Looks like just another piece of bark in the foreground, very close to
the lens.

Kind of a cool looking fly, though.

This is more than likely the case, as he was tucked away in the bark
creases, appearing occasionally. I had to snap quickly from wherever I
could. Yeah, I'd never seen a fly like this - speckled wings that were
moving constantly and the curious protrusion from the rear end...

wrote:
Can anyone tell me what the DOF issue is here?

http://www.pbase.com/image/62939916

Is this due to the angle of the shot? Why would the DOF in the
foreground look like that?

Depth of field is of course on a "flat" plane parallel to the
front of the lense. (It probably isn't actually flat though,
but...) The body of the insect is where the plane of focus is.
The bark where its far side legs are standing is at a greater
distance, and therefore out of focus. The bark in front of the
bug is at an equal distance, and is therefore in focus.

The wings appear to be such that one of them is almost parallel
to the lens, while the near one is pointing more or less at the
lense, and is therefore extending out of the range of focus.

It's just very difficult, without thinking about the depth of
field, to look at a two dimensional image such as that and
realize what the Z axis dimension is. The only key you have is
the depth of field...

It is interesting to keep in mind what "flat" means in terms of
focus too. Most lenses are not actually "flat", but instead
have sort of a curve much like the surface of the lense itself.
The outer edges of the image will be in focus slight closer to
the lense than the center. True macro lenses will probably be
better corrected for flatness, and while not absolutely flat,
the edges will be closer to the same plane as the center.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

It looks like a twig pointing at the lens and close enough to be OOF...

Guy

wrote in message
oups.com...
Can anyone tell me what the DOF issue is here?

http://www.pbase.com/image/62939916

Is this due to the angle of the shot? Why would the DOF in the
foreground look like that? FWIW, the set up is a D70s, 27.5mm PK-13 -
55mm Micro Nikkor, SB-800 w/ Lumiquest Softbox off camera at 9:00 in
the picture....

Any help is appreciated...

Ben

PS - No real processing was done; I'm more concerned with the blurry
ring.

My thoughts as well.

Kevin


Annika1980 wrote:
wrote:
Can anyone tell me what the DOF issue is here?

http://www.pbase.com/image/62939916


PS - No real processing was done; I'm more concerned with the blurry
ring.

Looks like just another piece of bark in the foreground, very close to
the lens.

Kind of a cool looking fly, though.

wrote:

It's just that I've never seen DOF
like that - a weird, perfect circle in the foreground...

It isn't quite a perfect circle - there is actually a good deal of
variation in the edges. My guess is there was some sort of large knot
or other knobby protrustion in the wood, which protruded enough to be
in front of the focus area, and that's what you're seeing.

--
www.ericschreiber.com

--
It looks like a good use of depth of field to create an interesting
photograph. The out of focus circle adds, not detracts, from the photo
in my opinion.
Bill in Lake Charles