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Please, why is sky washed out?

 
 
David Harper
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      06-08-2006

"Scott W" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
>

<snip>

> The sky is simply blown out, a lower exposure and or shooting raw could
> bring it back. You might then have a very dim forground but there are
> software adjustments that can help greatly there.


In the picture at:

http://celestart.com/images/publiques/15.jpg

....the general consensus seems to be that the sky is blown out. When I do
that in "AUTO" mode the sky is 255,255,255 (pure white). This picture shows
the sky at a uniform 239,239,239. Why is that? What in-camera or
post-processing did this? I have never seen that before. To me "blown" is
255 all the way.

- David Harper

 
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oj
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      06-08-2006

Celcius wrote:
> Hi everyone!
>
> Why is the sky washed out while my wife with a point and shoot gets blue
> skys?
> It seems to me the sky was quite blue when I took this photo:
> http://celestart.com/images/publiques/15.jpg
>
> Any ideas? Recommendations?
>
> Thanks,
>
> Marcel


While everyone is intent in pointing out the sky is overexposed, they
missed the point of the question, and I've thought the same thing
sometimes. I can point my old Canon Powershot P/S at a scene, and the
sky is blue and white shirts aren't overexposed, but my DSLR doesn't
seem to be able to capture the same range. Either the sky is blown
out, or the subject is dark.

Weird, huh.

oj

 
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Celcius
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      06-08-2006

"Pat" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
> King Sardon wrote: "The house and trees are in bright sun"
>
> No they are not. Are we looking at the same picture?
> http://celestart.com/images/publiques/15.jpg
>
> The house is in TOTAL shadow. Look at the driveway. You have bright
> sunlight and shadow where the tree is. Then you have a distinct shadow
> line right next to the garage door, maybe a foot out from the door, and
> the shadow line crosses the concrete slab that makes up the porch. The
> only part of the house in bright sun is about a 1 foot strip across the
> edge of the room that separates the brick above the garage door from
> the vinyl as well as the primary roof.
>
> Further, you can see through the crank-out window on the second floor.
> If it was bright sun, that would almost definately have glare.
>
> Notice the light next to the garage door. No shadow -- because it is
> IN a shadow.
>
> I don't know what time of day it was taken, but it appears to be
> mid-day because the shadows aren't too long. Assuming the house is in
> the northern hemisphere, then if the OP had waited a little bit, most
> of the house would have been well lit, but they he would have had to
> deal with shadows across the house.
>
> Finally, look athte trees, esp. the more distant ones. Notice the
> distortion of the leaves as the light wraps around them.
>
> The house is definately backlit. The OP is shooting into the sun.
> That's why the sky is burned out.
>
> His best bet, other than some filters, would be to wait for a
> semi-cloud day. Wait until the house is in shadow and there's some
> interesting clouds in the sky. But still, filters would help
> significantly.
>


Hi Pat!
Thanks for your answer.
Actually, I live in Ottawa, Canada. The front of the house is facing the
river (North). The right side of the house, when you look at the photo is
west, and of course the back side is south. The photo was taken at 14h38
(2:38PM). The sun must have been overhead, slightly right if you look at the
shadow of the tree. I thought the sun was immaterial since I was shooting in
the direction of the house and wanted mostly to show the house and trees. I
never thought the sky would look that way. I took some photos in Cuba in the
sun by the swimming pool and it never turned out that way:
http://celestart.com/images/publiques/pool.jpg
Marcel


 
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Pat
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      06-09-2006
Ottawa? Isn't that the place that the Canadians use to separate Quebec
from Ontario so they don't throw down their gloves and go at it?

Before I comment, an off-topic aside. I am just outside of Buffalo,
ie, Toronto, so our weather forcasts are in both Far. and Celcius (or
as we say, Canadian). I was at Christmas mass. "Gloria" was on the
song list. So I say to my mother "what exactly does "In Excelcius
mean"?" Before she could answer, my 11-year-old (who was sitting
between us) shot back, "That how they measure the temperature in
Canada".

Here's what I guess happened. First, you shot into the sun. In that
circumstance, the sky is really a light source, so you were shooting
into a light. Now look at your other picture. Sun was behind you.

For whatever reason, either your, your camera, or your software took
the image and adjusted for the shadow (the house) and did a good job
burning out the sky. To compound it, somewhere the image adjusted for
the blueness and took out some blue, leaving the sky a slight gray.

There is a fairly easy fix. Just delete the sky and put in a cloudy
sky, like in your other picture. Clouds can add interest. Otherwise,
consider shooting on a cloudy day when the sun puts the whole area into
the shade, but you'll still lose part of the sky. Otherwise, filter
will help. Shooting in late evening as the sun is setting will also
help.






Celcius wrote:
> "Pat" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed) ups.com...
> > King Sardon wrote: "The house and trees are in bright sun"
> >
> > No they are not. Are we looking at the same picture?
> > http://celestart.com/images/publiques/15.jpg
> >
> > The house is in TOTAL shadow. Look at the driveway. You have bright
> > sunlight and shadow where the tree is. Then you have a distinct shadow
> > line right next to the garage door, maybe a foot out from the door, and
> > the shadow line crosses the concrete slab that makes up the porch. The
> > only part of the house in bright sun is about a 1 foot strip across the
> > edge of the room that separates the brick above the garage door from
> > the vinyl as well as the primary roof.
> >
> > Further, you can see through the crank-out window on the second floor.
> > If it was bright sun, that would almost definately have glare.
> >
> > Notice the light next to the garage door. No shadow -- because it is
> > IN a shadow.
> >
> > I don't know what time of day it was taken, but it appears to be
> > mid-day because the shadows aren't too long. Assuming the house is in
> > the northern hemisphere, then if the OP had waited a little bit, most
> > of the house would have been well lit, but they he would have had to
> > deal with shadows across the house.
> >
> > Finally, look athte trees, esp. the more distant ones. Notice the
> > distortion of the leaves as the light wraps around them.
> >
> > The house is definately backlit. The OP is shooting into the sun.
> > That's why the sky is burned out.
> >
> > His best bet, other than some filters, would be to wait for a
> > semi-cloud day. Wait until the house is in shadow and there's some
> > interesting clouds in the sky. But still, filters would help
> > significantly.
> >

>
> Hi Pat!
> Thanks for your answer.
> Actually, I live in Ottawa, Canada. The front of the house is facing the
> river (North). The right side of the house, when you look at the photo is
> west, and of course the back side is south. The photo was taken at 14h38
> (2:38PM). The sun must have been overhead, slightly right if you look at the
> shadow of the tree. I thought the sun was immaterial since I was shooting in
> the direction of the house and wanted mostly to show the house and trees. I
> never thought the sky would look that way. I took some photos in Cuba in the
> sun by the swimming pool and it never turned out that way:
> http://celestart.com/images/publiques/pool.jpg
> Marcel


 
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Jack Mac
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      06-09-2006
On Thu, 8 Jun 2006 07:34:13 -0400, "Celcius" <(E-Mail Removed)> wrote:

>
>"Jack Mac" <(E-Mail Removed)> wrote in message
>news:(E-Mail Removed).. .
>> On Wed, 07 Jun 2006 23:48:16 GMT, "JohnR66" <(E-Mail Removed)> wrote:
>>
>> >The solution in a situation where the subject was dark on a sunny, clear

>day
>> >was to use a polarizer filter and dial in -1 of exposure (under expose by
>> >one stop). Using RAW too would have helped as the sky was still not as

>blue
>> >as I wanted.
>> >John
>> >
>> >"Celcius" <(E-Mail Removed)> wrote in message
>> >news:e66jnf$da3$(E-Mail Removed)...
>> >> Hi everyone!
>> >>
>> >> Why is the sky washed out while my wife with a point and shoot gets

>blue
>> >> skys?
>> >> It seems to me the sky was quite blue when I took this photo:
>> >> http://celestart.com/images/publiques/15.jpg
>> >>
>> >> Any ideas? Recommendations?
>> >>
>> >> Thanks,
>> >>
>> >> Marcel
>> >>
>> >>
>> >

>> You say your wife's point and shoot camera gets blue sky.
>> Why not just use her camera? Is the DSLR really worth all
>> the extra effort?
>> Jack Mac
>>

>Good question, Jack.
>
>However, I bought a DSLR to use it and to learn photography. Otherwise, I
>would have bought a P&S. This is also why I come to this forum as well as
>alt.photography, rec.photo.digital.slr-systems, to learn and to seek help
>from more knowledgeable than I.
>
>I find this pastime quite interesting. It also allowed me to work with
>Photoshop (7.0, CS1 and now CS2). When I think that so many retired people
>hang around shopping centers for lack of something better to do....
>
>Take care,
>
>Marcel
>


Marcel,
My post was really intended to be tongue-in-cheek meaning that if the
wife's point and shoot camera can capture a blue sky, your Rebel XT
should be able to do it too..... and without all the filters etc.
It will be a learning experience for you.
I also have a Rebel XT and still have a lot to learn about it.
This has been an interesting thread!

Jack Mac
 
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Floyd L. Davidson
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      06-09-2006
"oj" <(E-Mail Removed)> wrote:
>Celcius wrote:
>> Why is the sky washed out while my wife with a point and shoot gets blue
>> skys?

....

>While everyone is intent in pointing out the sky is overexposed, they


For a reader with sufficient experience, pointing out that the
sky is over exposed tells pretty much the whole story. Of course
if the whole significance of a washed out sky is *not*
understood, then it isn't half enough of the story!

However, you have pointed out something that, at least to techie
types, is even more interesting. Newer cameras might use
computer analysis of the data to automatically adjust exposure
in much the same way that a photographer would... or not,
depending...

That confuses the issue, because instead of getting the results
one would expect from a simple metering system, the results are
what one would expect when the photographer chooses some rule of
thumb to compensate for a simple metering system.

>missed the point of the question, and I've thought the same thing
>sometimes. I can point my old Canon Powershot P/S at a scene, and the
>sky is blue and white shirts aren't overexposed, but my DSLR doesn't
>seem to be able to capture the same range. Either the sky is blown
>out, or the subject is dark.
>
>Weird, huh.


Nah, just the expected results of the toys we like to play with!

Back in the good ol' days, Through-The-Lense light meters were
simple and there were just three kinds. It was either 1)
average a reading from the whole screen, or 2) from a small spot
on the screen, or 3) use a weighted response that gave more
emphasis to some known area, like the center.

With that kind of a meter we can set the exposure for the whole
scene, for example, but the bright sky will skew the average and
cause the desired part of the image to be in deep shadows. That
will still work /if/ the photographer manually sets Exposure
Compensation to +1 or +2 in order to cause more exposure. Hence
you get your "Either the sky is blown out, or the subject is
dark."

Another way is to use a spot meter or weighted area to eliminate
or greatly reduce the effects of the bright sky on the metered
value. This is essentially just another manual method of
correcting the exposure as above, and the results are typically
the same.

Given the above, an older or less complex camera when simply
pointed at the scene and the shutter released, will under expose
the shadow areas and allow for at least some texture in the sky,
which would allow it to be blue. (The OP's wife's P&S...)

However, a modern DSLR might well have a much more complex light
metering system, and will make the manual corrections described
above automatically! Instead of averaging the entire screen or
just a spot or some set weighting pattern, the meter might take
readings from several spots in the scene, do a computer analysis
to decide what is appropriate, and then adjust the weighting
pattern to match what it assumes the image most likely is.

In this case it can tell that 1/2 of the upper part of the image
is very very bright (it might even know it is blue!), while the
rest seems to be just the right amount less to be a shaded area.
In particular the center appears to be a shaded area. The
camera's computer program decides this is a sunlight scene with
bright sunlight and deep shadows with a lot of sky. So it
compensates by calculating the exposure based *only* on the
lower half of the image... which results in totally washing out
all of the sky, but providing a fairly good exposure for areas
in the shadows in the center of the image.

Don't want that? Use spot metering or turn off the
"multi-segment" metering mode to get a full scene average, and
use your own Exposure Compensation to get the exposure desired.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) http://www.velocityreviews.com/forums/(E-Mail Removed)
 
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Richard Kettlewell
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      06-09-2006
"David Harper" <(E-Mail Removed)> writes:
> In the picture at:
>
> http://celestart.com/images/publiques/15.jpg
>
> ...the general consensus seems to be that the sky is blown out.
> When I do that in "AUTO" mode the sky is 255,255,255 (pure white).
> This picture shows the sky at a uniform 239,239,239. Why is that?
> What in-camera or post-processing did this? I have never seen that
> before. To me "blown" is 255 all the way.


It does seem a little odd. There are points on the path where it goes
up to (for instance) 242,239,234. Though I notice the mean of that
triple is nonetheless still below 239. Perhaps whatever converted it
to JPEG included some poor decisions about the maximum?

--
http://www.greenend.org.uk/rjk/
 
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2
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      06-09-2006
<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...

> King seems to be wrong. Washed sky is usually the result of open
> aparture.


Nonsense. Aperture alone has nothing to do with this case. Stopping down
does not extend the range of sensor sensitivity. Aperture and shutter speed
together determine correct exposure.

There are only two applications of aperture which effect exposure: 1) when
one opens wide enough to cause flare (in a lens so susceptible), and that's
generally not considered a good thing and 2) when focusing close enough to
throw the brighter background far out of focus because a focused image is
(generally) less bright than a focused one.

In this case the range is too great for the sensor or the image was
underexposed.


 
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mike.engles@btinternet.com
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      06-09-2006

Celcius wrote:
> Hi everyone!
>
> Why is the sky washed out while my wife with a point and shoot gets blue
> skys?
> It seems to me the sky was quite blue when I took this photo:
> http://celestart.com/images/publiques/15.jpg
>
> Any ideas? Recommendations?
>
> Thanks,
>
> Marcel

Hello

It is nothing to do with metering and all to do with really bad
processing in camera which does not cope with the dyanmic range. I have
a 5D and the first thing I noticed was how the highlights just burn out
if the general foreground is correctly exposed. My 5D overexposes by at
least one stop. The only way I have found to get the correct tones is
to process from RAW. Even this will not do the job unless one expands
the tones using a lighten shadows tool as in Photoshop, having first
underexposed the image by about 1 stop, so that no highlight is
clipped. This should give a image whuch looks washed out, but with all
the tones. A final going over with a curves tool, with a long S curve
will give the needed result.

After much fiddling about in Photoshop and processing RAW, I have
managed to capture the tones I saw when I photographed the scene.
Still does not really explain why expensive DSLRs cannot give an in
camera result like a point and shoot camera.

Mike Engles

 
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