Proximity Puzzle: Using a 300mm lens I focussed on the BMW number plate. The car was approximately 300 feet from the camera, but the bush which appears to be behind the number plate...

Searcher Loc: Kent, England

Using a 300mm lens I focussed on the BMW number plate.

The car was approximately 300 feet from the camera, but the bush which appears to be behind the number plate and the car lamps was at least 10 feet nearer to me.

Can anyone offer an explanation as to why the bush appears behind the plate and the lamps appear in front of the bush?
1/160 sec, f/5.6, ISO 400

(Download)

jerryc41 Loc: Catskill Mts of NY

Searcher wrote:

Using a 300mm lens I focussed on the BMW number plate.

The car was approximately 300 feet from the camera, but the bush which appears to be behind the number plate and the car lamps was at least 10 feet nearer to me.

Can anyone offer an explanation as to why the bush appears behind the plate and the lamps appear in front of the bush?
1/160 sec, f/5.6, ISO 400

We've had members post several optical mysteries like that, and sometimes people have an answer. I wonder if this would have happened with film.

kenbar Loc: middlesbrough uk.

I think the photo is correct. The number plate is in front of the car's front bumper but the bonnet and lights are behind the bumper. Hence a small gap for the bush.

oldtigger Loc: Roanoke Virginia-USA

jerryc41 wrote:

We've had members post several optical mysteries like that, and sometimes people have an answer. I wonder if this would have happened with film.

Kenbar is correct and in addition
bush is reflected in finish of car.
license does not reflect.

Searcher Loc: Kent, England

Thanks guys, the light has changed significantly in the last hour and the reflection has gone.

Just for a fleeting moment I thought I had invented a new form of 3D photography.

Morning Star Loc: West coast, North of the 49th N.

kenbar wrote:

I think the photo is correct. The number plate is in front of the car's front bumper but the bonnet and lights are behind the bumper. Hence a small gap for the bush.

No! Searcher says the shrub is 10 feet nearer the camera than the car. So how come the right hand edge of the license plate appears to be in front of the branch of that bush. That's some weird gymnastics either the plate or the bush needs to do for this photo to be correct!

If you enlarge the photo, you can also see that the headlight (left for the car, right for the viewer), appears to be in front of the shrub. This looks to me like the same effect I got when I took a photo of an aircraft through a mesh fence. The aircraft was tack-sharp, but the fence totally out of focus and in places looked to be in front of the mesh fence.

Searcher Loc: Kent, England

Morning Star wrote:

No! Searcher says the shrub is 10 feet nearer the ... (show quote)

Now I am going to have to walk across and look close up. :-D

Searcher Loc: Kent, England

Changed perspective, the bush (shrub) is further away from the car than I thought, about 25 feet, so I am back to square one.

It looks as though I was shooting through the bush in the original photo, (similar to Morning Star and the chain link fence).

Its cold out, so there is a little camera shake (shiver)

(Download)

gdwsr Loc: Northern California

Searcher, I believe it has to do with detraction through the lens elements. We see this phenomena all the time with bokeh. We never question the overlap of two bokeh lights where the same thing is happening. If I may post a picture here I took one like that recently.

Searcher Loc: Kent, England

gdwsr wrote:

Searcher, I believe it has to do with detraction through the lens elements. We see this phenomena all the time with bokeh. We never question the overlap of two bokeh lights where the same thing is happening. If I may post a picture here I took one like that recently.

Please do post

gdwsr Loc: Northern California

In the Bokeh lights image the lights don't really overlap of course. (I believe that effect is called the circle of confusion and changes with aperture) If one of them was in sharp focus, one of the blurred ones would overlap it. But because it is in sharp focus we see it as being in front of the blurred overlap.

In the Foreground branch photo there is a very blurred diagonal branch in the foreground (camera left side of image) but the sharp focused branch appears to be in front rather than being seen through.

Make sense?

Bokeh lights

(Download)

Foreground branch

(Download)

Searcher Loc: Kent, England

gdwsr wrote:

In the Bokeh lights image the lights don't really ... (show quote)

So the light has been refracted around the branches, or in my image around the twigs?

Morning Star Loc: West coast, North of the 49th N.

gdwsr wrote:

In the Foreground branch photo there is a very blurred diagonal branch in the foreground (camera left side of image) but the sharp focused branch appears to be in front rather than being seen through.

Make sense?

Makes perfect sense! Hadn't thought about it till now, but I believe it is the same principle used, when you want to take a photo of animals in a zoo that are behind chain link fence or bars.
That is, make sure you're close enough to the chain link and also make sure there is space between the chain link and the animal. Focus on the animal and if the focus and distances are just right, the chain link will not show in your photo.
Step back from the fence and/or decrease the distance between fence and animal and the fence will become visible in the photo, just like these branches.

gdwsr Loc: Northern California

Yes, I believe so. In my Foreground branch image the sharp focused dove blocks the blurred house behind it. All of the reflected light from the bird falls within the Circle of Confusion limits (ie. all the pixels are filled only with light from the bird) and therefore, completely blocks and thing behind it, blurred or not. However, the foreground branch has the reflected light spread out so not all the pixels are occupied by the light from the branch -- some of the focused branch gets through. Enough that we perceive it as sharp (even though if we zoomed in to the pixel level we could see that some pixels are from the foreground branch and some from the more concentrated light of the focused branch).

I don't know if this site clarifies it any but there are some graphics:
http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

gdwsr Loc: Northern California

Actually, in that situation, wouldn't it make sense if you could occupy the entire image with the very dispersed (blurred) image of one wire on the fence. The whole image would have a muted look that could be more easily dealt with in post -- especially if your subject was dark and the wire bokeh was light?

Morning Star wrote:

Makes perfect sense! Hadn't thought about it till ... (show quote)