aaa salisbury, north carolina and vicinity Starry-eyed Cars and the Tall, Dark Stranger

Street photo--sort of. Comments welcome.

--Lannie

Hi Lannie,

Well shot my friend.

I really like the diffraction effect from the iris used at F/8.

Best Regards,  Mike

to risk rating, i mean.  4.37 with my six included.  i only ask for rating when i want an excuse to delete something nowadays.  every once in a while i get surprised.  i liked rating when the population liked my pictures better and you could see the distribution of individual numbers.  that's important to me, because surely ones, twos, threes, and fours all mean exactly the same thing.  Now, it's not possible to discount them because you can't tell what numbers you've been given.  (2, 2, 6, 6) is a great set of ratings.  (4, 4, 4, 4) is miserable, but the average is identical.

Oh yeah.  The picture.  Ken Rockwell, who has a great camera review site, loves diffraction stars.  I always thought that was juvenile, but they do provide information about how bright light sources are, even though the light sources themselves are too bright to be recorded accurately.  Still a scientist.

Oh yeah.  The picture.  Sorry.  I like it.  The man is interesting, and the blur is nice, apart from the highway signs, which render strangely.  best, j

Thanks, Mike and Jamie.

Yes, it's a weird picture, Jamie.  I didn't know what to do with it, and so I posted it. . . .

I was a bit taken aback by the "stars" myself, but it was too late to do anything about that.

--Lannie

Diffraction at straight edges of aperture blades creates the bright lines.  (The black lines I added to my horribly contrast-enhanced detail suggest nine blades.)   The wave properties of light cause the lines.  The light occluded by the straight edges is exactly the light that would have cancelled out the bright lines, believe it or not.

Even weirder, if you looked at at just that occluded light, it would look the SAME as the bright lines you ended up with!  This is because that light would have the same intensity but opposite phase.  We are not able to see phase, so the light would look exactly the same.  Wave optics is hard to get your head around!

Many claim the light is damaged somehow by the aperture, causing lines and diffraction blur.  This theory is absolutely incorrect, but easier to conceptualise, so the idea persists.  What I said earlier should make this clear.  If we added the light which had gone through your aperture to light that had gone through a slightly larger circular aperture with your aperture blacked out, we would have the exact image from the larger circular aperture, with no lines.

The more you stop down, the brighter they will be because the un-diffracted image becomes darker more than they do (area vs. circumference).  The brighter the light sources are, the brighter they will be because that energy is spread into the lines.  best, jamie

p.s.:  It would be interesting to compare my Leica 280/2.8.  I'm not sure how many blades it has.  Too lazy to get it out.  No pertinent info in my books.

I like Mike and other comments as they provide interesting info. The man is your relative Lannie as we belong to the family of humanity, we are all connected. Look you took an image of him totally on your free will! Ha! Warm regards.