Thought this was interesting? (1 Viewer)

KenM · Jun 1, 2020

Caught this in a shutter-burst this am. Interesting that an essentially all dark bird should at a given angle show white reflection on the almost flat under-wing surfaces and tail, and not even a glint off the barrelled body.
Presume there must be a ''physics/material'' answer to this?

Cheers

Richard Prior · Jun 1, 2020

Can’t help with the scientific reason but bright sunlight on the darker plumaged birds makes the wings ‘shine‘ to our eyes, I have a few silver-winged Ravens here!

Farnboro John · Jun 1, 2020

Different textures and physical structure of body and wing feathering. Very common effect in photos.

John

KenM · Jun 1, 2020

Richard Prior said:
Can’t help with the scientific reason but bright sunlight on the darker plumaged birds makes the wings ‘shine‘ to our eyes, I have a few silver-winged Ravens here!

Yes dark clouds and corvids often have a silver lining...and yet the “barrelled body” doesn’t appear to reflect any glare. :eek!: :t:

Richard Prior · Jun 1, 2020

KenM said:
Yes dark clouds and corvids often have a silver lining...and yet the “barrelled body” doesn’t appear to reflect any glare. :eek!: :t:

I think that's what John was alluding to, the body is a mass whereas the wing feathers are err, light as a feather (no blood, organs etc) and at times transparent at times reflective:t:

Farnboro John · Jun 1, 2020

Richard Prior said:
I think that's what John was alluding to, the body is a mass whereas the wing feathers are err, light as a feather (no blood, organs etc) and at times transparent at times reflective:t:

Body feathering is a lot less structured as well. Much of it is quite loose and multi-directional fibres reflecting light in multiple directions and for that matter allowing some to pass through and be lost in inner layers.

Flight feathers are highly organised rows of barbs zipped together forming a surface that is effectively designed to reflect in only a few particular directions if hit by light at a particular angle. When that angle applies a lot of light is reflected in a fairly focused manner.

John

KenM · Jun 1, 2020

Yes thanks all, a very odd looking Swift, it’s the white forked tail with the black centre spine that looks to my eye at least quite unusual.

Cheers

Deb Burhinus · Jun 1, 2020

KenM said:
Yes thanks all, a very odd looking Swift, it’s the white forked tail with the black centre spine that looks to my eye at least quite unusual.

Cheers

Well not an ‘odd looking Swift’ as such, but an odd looking photo of a Swift -

in addition to what others have said about the natural phenomena of light on black plumage, I think a certain amount of overexposure when taking a shot (ie where light strongly hits one surface more than the rest of the frame) can also burn out subtle colour and detail so can produce odd artefacts in a photo.

It is interesting (and a cautionary tale for ID purposes!)

PYRTLE · Jun 1, 2020

KenM said:
Yes thanks all, a very odd looking Swift, it’s the white forked tail with the black centre spine that looks to my eye at least quite unusual.

Cheers

But it isn't that monochrome effect all the time though Ken, just certain angles and light reflection as Deb and others have explained. I would hazard a guess that other frames in your "burst" show a bird that has dark wings and tail concolorous with the body. It is a snapshot and we know how just one image can deceive, play tricks or even suggest it is something else.

KenM · Jun 1, 2020

Remiss of me, I failed to state the obvious...ie it’s the image and NOT the Swift that’s odd looking!
I was looking at it from an “impressionistic” point of view, whilst also considering the science (dynamics of light and mass) producing such an image.

Cheers

Britseye · Jun 2, 2020

KenM said:
Remiss of me, I failed to state the obvious...ie it’s the image and NOT the Swift that’s odd looking!
I was looking at it from an “impressionistic” point of view, whilst also considering the science (dynamics of light and mass) producing such an image.

Cheers

Na. I understood what you meant. I agree it's interesting as an illusion. I also like John's summing up of the physics behind the snapshot. I never forget that photography essentially means 'writing with light' and how the camera was a doorway for me to become interested in the phenomenon of light in and of itself.

Deb Burhinus · Jun 2, 2020

KenM said:
Remiss of me, I failed to state the obvious...ie it’s the image and NOT the Swift that’s odd looking!

Cheers

Are you being overly sensitive Ken ? There was a wink after my comment - I was just being being pedantic |

|

KenM · Jun 2, 2020

Deb Burhinus said:
Are you being overly sensitive Ken ? There was a wink after my comment - I was just being being pedantic ||

Me sensitive Deb?....Nah!...got skin like a rhino.

:t:

RafaelMatias · Jun 3, 2020

In addition to what others have said, the underside of the flight feathers is remarkably glossy on Common Swift (with an almost waxy feel to the feathers), while its body feathers are more matte (hence the strong contrast on your pic: part of the plumage reflects light, while other part absorbs light). See here for example: http://blascozumeta.com/wp-content/uploads/aves-aragon/no-passeriformes/277.apusapus.pdf

Farnboro John · Jun 3, 2020

KenM said:
Me sensitive Deb?....Nah!...got skin like a rhino. :t:

Moisturise daily

John

Richard Prior · Jun 3, 2020

Farnboro John said:
Moisturise daily

John

He does, with 60% proof, but that’s internally ( and purely for medicinal purposes of course)

KenM · Jun 3, 2020

RafaelMatias said:
In addition to what others have said, the underside of the flight feathers is remarkably glossy on Common Swift (with an almost waxy feel to the feathers), while its body feathers are more matte (hence the strong contrast on your pic: part of the plumage reflects light, while other part absorbs light). See here for example: http://blascozumeta.com/wp-content/uploads/aves-aragon/no-passeriformes/277.apusapus.pdf

Thanks Rafael....if only I could read Spanish. :t: :-C

Farnboro John said:
Moisturise daily

John

Am currently doing just that John! due to the “soddingly high” pollen count!

Richard Prior said:
He does, with 60% proof, but that’s internally ( and purely for medicinal purposes of course)

Twice a week only Richard and at just 11% alcohol!....anything stronger could impede my performance “out doors”.

Andy Adcock · Jun 3, 2020

KenM said:
Thanks Rafael....if only I could read Spanish. :t: :-C

Am currently doing just that John! due to the “soddingly high” pollen count!

Twice a week only Richard and at just 11% alcohol!....anything stronger could impede my performance “out doors”.

Are these the days (daze) when we get the 'odd' birds by any chance?

Richard Prior · Jun 3, 2020

andyadcock said:
Are these the days (daze) when we get the 'odd' birds by any chance?

Yesh, after my pre dinner Pastis (51% alcohol, water with it of course) I thought I saw a Pink eared Duck yeshterday

RafaelMatias · Jun 3, 2020

KenM said:
Thanks Rafael....if only I could read Spanish. :t: :-C

I meant the photos Ken (especially those in page 6, showing the underwing, that you can magnify), nothing relevant in the text for this thread. :t:

Thought this was interesting? (1 Viewer)

Well-known member

Attachments

Halfway up an Alp

Well-known member

Well-known member

Halfway up an Alp

Well-known member

Well-known member

Used to be well known! 😎

Old Berkshire Boy

Well-known member

Well-known member

Used to be well known! 😎

Well-known member

Unknown member

Well-known member

Halfway up an Alp

Well-known member

Worst person on Birdforum

Halfway up an Alp

Unknown member

Similar threads

Users who are viewing this thread