What the reviewers don't view...

I took another look at different pictures the same time and guess what? It's
WAY OFF!

Much more difference in scene, but the values are the same:
http://photos-of-portugal.com/Canon3.JPG
http://photos-of-portugal.com/Canon4.JPG

Here less difference in scene, but one at 1/500 sec and f7.1, the other
1/500 and f8
http://photos-of-portugal.com/Canon5.JPG
http://photos-of-portugal.com/Canon6.JPG


Here much more difference, but the same values:
http://photos-of-portugal.com/Canon7.JPG
http://photos-of-portugal.com/Canon8.JPG

All in all, I think the problem is, that Canon (or at least the sample of
the 40D that I had) hates direct sunlight.
Other pictures of the same place at early evening before sundown are OK.
I checked similar pictures I took with the Nikon D40 and D300 and the Sony
A350, but they don't have any problems like this.

Maybe it's time to put a big sticker on the box:

"KEEP OUT OF DIRECT SUNLIGHT"


--
Focus

The OP wrote that the pix were taken in the same light.
Looks to me the first was in hazy light and in the second the sun had
come through fully.

Nope. Not a cloud in the sky. look at where there's a space between the
houses. Right above there's a bush with shadow. looks the same in both
pics, but of course less bright. Same at the front of the ship. There's a
little reflection from the top and a little lower. Same in both.

The light on the building and boats is clearly different, look at the
highlights and shadows. Exposure can't create that.




Now let's estimate the amount of movement.
The two boats do not show movement. The have about the same distance in both
pictures. They are fairly close together and look moored. So I assume that
they do not move.

Behind the right boat an extra car is visible in one of the picture. (Two
cars between the boat and the red car in one picture, only one and a part on
the other). The difference in distance is about 3 meters extra. A very rough
estimate is the the relative distance from the cars to the boat and from the
boat to the observer is about 5 times as much.
(This is a very crude estimate). If the cars have not moved and the boot has
not moved and the distance between the cars and the boat is about 1/5 of the
distance between the cars and the camera, the camera must have moved about
15 meters.

According to the exif data the pictures are taken 3 seconds from eachother.
This would give a speed of 15 meters for 3 seconds. or 5 meter a second.
that's 3600/1000*5 = 18 km/hour. Quite some speed to take pictures in. Maybe
during the measuring the camera was pointed and something different in on of
the pictures.

From the pictures I do see the movement at a lot of places, so it's not only
the boats that show the movement. But's it's difficult to estimate the
relative distances, with the boat and cars, the distances can be estimated
(very roughly), that's why I have used those. But there is movement from my
calculation even movement at some speed. So the pictures must have been
taken in 'Haste', then consistent results should not be expected.

Maybe the OP can clearyfy what realy happend. I detend movement, I estimate
speed (roughly). But might be completely wrong in estimating the distances.
(and therefore the speed).


Ben

"ben brugman" wrote in message
bel.net...


The OP wrote that the pix were taken in the same light.
Looks to me the first was in hazy light and in the second the sun had
come through fully.

Nope. Not a cloud in the sky. look at where there's a space between the
houses. Right above there's a bush with shadow. looks the same in both
pics, but of course less bright. Same at the front of the ship. There's
a little reflection from the top and a little lower. Same in both.

The light on the building and boats is clearly different, look at the
highlights and shadows. Exposure can't create that.




Now let's estimate the amount of movement.
The two boats do not show movement. The have about the same distance in
both pictures. They are fairly close together and look moored. So I assume
that they do not move.

Behind the right boat an extra car is visible in one of the picture. (Two
cars between the boat and the red car in one picture, only one and a part
on the other). The difference in distance is about 3 meters extra. A very
rough estimate is the the relative distance from the cars to the boat and
from the boat to the observer is about 5 times as much.
(This is a very crude estimate). If the cars have not moved and the boot
has not moved and the distance between the cars and the boat is about 1/5
of the distance between the cars and the camera, the camera must have
moved about 15 meters.

According to the exif data the pictures are taken 3 seconds from
eachother. This would give a speed of 15 meters for 3 seconds. or 5 meter
a second. that's 3600/1000*5 = 18 km/hour. Quite some speed to take
pictures in. Maybe during the measuring the camera was pointed and
something different in on of the pictures.

From the pictures I do see the movement at a lot of places, so it's not
only the boats that show the movement. But's it's difficult to estimate
the relative distances, with the boat and cars, the distances can be
estimated (very roughly), that's why I have used those. But there is
movement from my calculation even movement at some speed. So the pictures
must have been taken in 'Haste', then consistent results should not be
expected.

Maybe the OP can clearyfy what realy happend. I detend movement, I
estimate speed (roughly). But might be completely wrong in estimating the
distances. (and therefore the speed).

Ahum, very accurate Sherlock!
As I don't have floating shoes, it might be evident I took the shots from a
ship.
And likely the speed is correct.
Still doesn't come close to explain the difference.
Your turn, Sherlock!


--
Focus

"ben brugman" schreef in bericht
bel.net...

Maybe the OP can clearyfy what realy happend.

The OP is a troll.

"Focus" schreef in bericht
...

"ben brugman" wrote in message
bel.net...


The OP wrote that the pix were taken in the same light.
Looks to me the first was in hazy light and in the second the sun had
come through fully.

Nope. Not a cloud in the sky. look at where there's a space between the
houses. Right above there's a bush with shadow. looks the same in both
pics, but of course less bright. Same at the front of the ship. There's
a little reflection from the top and a little lower. Same in both.

The light on the building and boats is clearly different, look at the
highlights and shadows. Exposure can't create that.




Now let's estimate the amount of movement.
The two boats do not show movement. The have about the same distance in
both pictures. They are fairly close together and look moored. So I
assume that they do not move.

Behind the right boat an extra car is visible in one of the picture. (Two
cars between the boat and the red car in one picture, only one and a part
on the other). The difference in distance is about 3 meters extra. A very
rough estimate is the the relative distance from the cars to the boat and
from the boat to the observer is about 5 times as much.
(This is a very crude estimate). If the cars have not moved and the boot
has not moved and the distance between the cars and the boat is about 1/5
of the distance between the cars and the camera, the camera must have
moved about 15 meters.

According to the exif data the pictures are taken 3 seconds from
eachother. This would give a speed of 15 meters for 3 seconds. or 5 meter
a second. that's 3600/1000*5 = 18 km/hour. Quite some speed to take
pictures in. Maybe during the measuring the camera was pointed and
something different in on of the pictures.

From the pictures I do see the movement at a lot of places, so it's not
only the boats that show the movement. But's it's difficult to estimate
the relative distances, with the boat and cars, the distances can be
estimated (very roughly), that's why I have used those. But there is
movement from my calculation even movement at some speed. So the pictures
must have been taken in 'Haste', then consistent results should not be
expected.

Maybe the OP can clearyfy what realy happend. I detend movement, I
estimate speed (roughly). But might be completely wrong in estimating the
distances. (and therefore the speed).

Ahum, very accurate Sherlock!
As I don't have floating shoes, it might be evident I took the shots from
a ship.

Why not from the opposite shore ? The pictures do not reveal that. The hight
you are on is about the same as the shore where the cars are standing. If
you stand close enough to the edge and with a 85 mm you do not even have to
be close, you do not get any 'shore' line of your side.

And likely the speed is correct.
Still doesn't come close to explain the difference.
Your turn, Sherlock!

From the pictures I can not see from what or were the pictures where taken.
My first assumption was that they where taken from the opposite on the
shore. The two pictures do not reveal that. The speed indicates for me
something faster that walking. Could be a bike, a car or something else.
Floating shoes did not come to my mind, but yes a ship would be able to do
18 km/hour.
One of the pictures is not as wel sharp as the other, (movement or not
focused correctly), so one possibility would be that moving the camera
around you could take pictures of almost the same scene but measuring
something else.

(I have made pictures where the exifs shows the same focal length, but the
pictures show completely zoomed in and completely zoomed out, so working
fast enough, it can be that the measurement (exif) does not correspond with
the pictures. Because of the movement this is not exactly a repeateble
experiment).

But if in general the camera does produce pictures where the results are not
consistent there is a problem because you can not anticipate enough as a
fotographer.
Total consistency can not be expected. But if you can reproduce this
difference (it's less than a stop), with a more stable situation (tripod)
and a fixed framing. I would say that the variation of 2/3's of a stop is a
bit to much for a decent camera.

Can't exactly see were the sun is in the pictures, could be that you might
benefit from a good sunshade (on the lens or external). If the sun is
hitting the lens directly or by a reflexion (possible on a ship) this might
be the cause. The reflexion could even be happening during the metering and
not effect the picture. So again reproducing this with a more fixed setting,
would indicate that the camera is wrong.

So from the shown pictures I can not say that the camera made the
difference, this could wel be but the pictures are not enough proof for
this.

So the difference is not explained, but because of the circumstances
(unstable), the conclusion that it must be the camera, is not correct. Yes
it could be the camera, but these pictures on their own are not conclusive.

I hope for you that you can not reproduce this and thereby proof that this
was just a fluke. Otherwise you have to accept this or change your camera.

ben







--
Focus

"ben brugman" wrote in message
bel.net...

"Focus" schreef in bericht
...

"ben brugman" wrote in message
bel.net...


The OP wrote that the pix were taken in the same light.
Looks to me the first was in hazy light and in the second the sun had
come through fully.

Nope. Not a cloud in the sky. look at where there's a space between
the houses. Right above there's a bush with shadow. looks the same in
both pics, but of course less bright. Same at the front of the ship.
There's a little reflection from the top and a little lower. Same in
both.

The light on the building and boats is clearly different, look at the
highlights and shadows. Exposure can't create that.




Now let's estimate the amount of movement.
The two boats do not show movement. The have about the same distance in
both pictures. They are fairly close together and look moored. So I
assume that they do not move.

Behind the right boat an extra car is visible in one of the picture.
(Two cars between the boat and the red car in one picture, only one and
a part on the other). The difference in distance is about 3 meters
extra. A very rough estimate is the the relative distance from the cars
to the boat and from the boat to the observer is about 5 times as much.
(This is a very crude estimate). If the cars have not moved and the boot
has not moved and the distance between the cars and the boat is about
1/5 of the distance between the cars and the camera, the camera must
have moved about 15 meters.

According to the exif data the pictures are taken 3 seconds from
eachother. This would give a speed of 15 meters for 3 seconds. or 5
meter a second. that's 3600/1000*5 = 18 km/hour. Quite some speed to
take pictures in. Maybe during the measuring the camera was pointed and
something different in on of the pictures.

From the pictures I do see the movement at a lot of places, so it's not
only the boats that show the movement. But's it's difficult to estimate
the relative distances, with the boat and cars, the distances can be
estimated (very roughly), that's why I have used those. But there is
movement from my calculation even movement at some speed. So the
pictures must have been taken in 'Haste', then consistent results should
not be expected.

Maybe the OP can clearyfy what realy happend. I detend movement, I
estimate speed (roughly). But might be completely wrong in estimating
the distances. (and therefore the speed).

Ahum, very accurate Sherlock!
As I don't have floating shoes, it might be evident I took the shots from
a ship.

Why not from the opposite shore ? The pictures do not reveal that. The
hight you are on is about the same as the shore where the cars are
standing. If you stand close enough to the edge and with a 85 mm you do
not even have to be close, you do not get any 'shore' line of your side.

And likely the speed is correct.
Still doesn't come close to explain the difference.
Your turn, Sherlock!

From the pictures I can not see from what or were the pictures where
taken. My first assumption was that they where taken from the opposite on
the shore. The two pictures do not reveal that. The speed indicates for me
something faster that walking. Could be a bike, a car or something else.
Floating shoes did not come to my mind, but yes a ship would be able to do
18 km/hour.
One of the pictures is not as wel sharp as the other, (movement or not
focused correctly), so one possibility would be that moving the camera
around you could take pictures of almost the same scene but measuring
something else.

(I have made pictures where the exifs shows the same focal length, but the
pictures show completely zoomed in and completely zoomed out, so working
fast enough, it can be that the measurement (exif) does not correspond
with the pictures. Because of the movement this is not exactly a
repeateble experiment).

But if in general the camera does produce pictures where the results are
not consistent there is a problem because you can not anticipate enough as
a fotographer.
Total consistency can not be expected. But if you can reproduce this
difference (it's less than a stop), with a more stable situation (tripod)
and a fixed framing. I would say that the variation of 2/3's of a stop is
a bit to much for a decent camera.

Can't exactly see were the sun is in the pictures, could be that you might
benefit from a good sunshade (on the lens or external). If the sun is
hitting the lens directly or by a reflexion (possible on a ship) this
might be the cause. The reflexion could even be happening during the
metering and not effect the picture. So again reproducing this with a more
fixed setting, would indicate that the camera is wrong.

So from the shown pictures I can not say that the camera made the
difference, this could wel be but the pictures are not enough proof for
this.

So the difference is not explained, but because of the circumstances
(unstable), the conclusion that it must be the camera, is not correct. Yes
it could be the camera, but these pictures on their own are not
conclusive.

I hope for you that you can not reproduce this and thereby proof that this
was just a fluke. Otherwise you have to accept this or change your camera.

ben

I already changed to a Sony A350 that doesn't have this problem with the
same time of day, same ship and same shore.
You can look at the other pictures in the posting below.
Should be more then evident, there's something wrong.
But I don't really care anymo the Sony is very good at metering and
rarely gets it wrong.
It reminds me very much of the Nikon D300, as far as metering goes.
You're right about the fact that they can't be expected to be dead on
always. But 95% would be nice ;-)


--
Focus

Focus wrote:
It's warm and cozy in the perfectly lit studios of most reviewers, but do
you really get a really good "buying advise"?

I don't think so. The 40D Canon I had, seemed OK at first. Trouble started
when I tried to make pictures with any kind of sunlight: the WB was all over
the place and the difference between some shots with the same light,
aperture and subject, sometimes differ as much as one stop!

Here's a picture of the south bank of the river:

http://photos-of-portugal.com/Canon1.JPG

Here's another, exactly the same place and time, just 3 secs apart:

http://photos-of-portugal.com/Canon2.JPG

Now you would think, that the second picture is lighter, because the camera
is more turned to the sun.... BEEP! It's actually turned away from the sun.
But all smart people already understood that, since the picture is of the
south bank ;-)
The exposure increased form 1/400 to 1/250. Close to 1 stop, and the sky is
washed out, including some masts on top of the hill.

Case in point: not one review shows this, because they all use the studio
set-up.
So you'll just have to take a camera out for a spin, before you decide which
is good and which is not.
This one clearly is not.


You don't say anything about the lens you used. Was it a Canon lens, or
a third-party job?

I have seen lenses where the aperture closes down differently each time,
or doesn't open fully after, upsetting the exposure measurement. Whether
it was sticky blades or crappy construction wasn't clear.

When the camera calculates the exposure and sends the aperture data to
the lens, the aperture is expected to close down accurately - if it
doesn't, you get the exposure variation you have in your shots.

One further possibility is if you allow stray light into the viewfinder,
it will shorten the exposure. Wearing glasses that sit some distance
from the eye can be a subtle source of variable exposure, by letting
light in from the side. This is an often overlooked problem when the
camera is on a tripod and the VF is not covered.

I think blaming the camera here is just a little premature.

Colin D.
** Posted from http://www.teranews.com **

"TRoss" wrote in message
...
On Thu, 22 May 2008 19:13:31 +0100, "Focus" wrote:


"TRoss" wrote in message
. ..
On Thu, 22 May 2008 14:21:40 +0100, "Focus" wrote:

It's warm and cozy in the perfectly lit studios of most reviewers, but
do
you really get a really good "buying advise"?

I don't think so. The 40D Canon I had, seemed OK at first. Trouble
started
when I tried to make pictures with any kind of sunlight: the WB was all
over
the place and the difference between some shots with the same light,
aperture and subject, sometimes differ as much as one stop!

snip

Just curious. Is the camera set up for auto exposure bracketing?
Shooting in Aperture Priority with a 1-stop AEP will give you the
results you got.


LOL! I think I would remember going thru the menu and putting it on AEB.

I think I would remember, too. But on more than one occasion I've set
the AEB and forgot to reset when it was no longer needed. It isn't as
as bad as forgetting to reset exposure compensation, which doesn't
reset on my camera when it's turned off, but it can still make a mess
of things.

Besides, then I would have 3 different ones.

Not necessarily. If the drive is set to one shot, you have to press
the release to move through the brackets. You could have taken two of
the three shots in the bracket.

OK, to be absolutely clear about it. I KNOW it wasn't in bracketing, because
I NEVER use bracketing.
Clear enough?


--
Focus

"Colin_D" wrote in message
...
Focus wrote:
It's warm and cozy in the perfectly lit studios of most reviewers, but do
you really get a really good "buying advise"?

I don't think so. The 40D Canon I had, seemed OK at first. Trouble
started when I tried to make pictures with any kind of sunlight: the WB
was all over the place and the difference between some shots with the
same light, aperture and subject, sometimes differ as much as one stop!

Here's a picture of the south bank of the river:

http://photos-of-portugal.com/Canon1.JPG

Here's another, exactly the same place and time, just 3 secs apart:

http://photos-of-portugal.com/Canon2.JPG

Now you would think, that the second picture is lighter, because the
camera is more turned to the sun.... BEEP! It's actually turned away from
the sun.
But all smart people already understood that, since the picture is of the
south bank ;-)
The exposure increased form 1/400 to 1/250. Close to 1 stop, and the sky
is washed out, including some masts on top of the hill.

Case in point: not one review shows this, because they all use the studio
set-up.
So you'll just have to take a camera out for a spin, before you decide
which is good and which is not.
This one clearly is not.


You don't say anything about the lens you used. Was it a Canon lens, or a
third-party job?

I have seen lenses where the aperture closes down differently each time,
or doesn't open fully after, upsetting the exposure measurement. Whether
it was sticky blades or crappy construction wasn't clear.

When the camera calculates the exposure and sends the aperture data to the
lens, the aperture is expected to close down accurately - if it doesn't,
you get the exposure variation you have in your shots.

One further possibility is if you allow stray light into the viewfinder,
it will shorten the exposure. Wearing glasses that sit some distance from
the eye can be a subtle source of variable exposure, by letting light in
from the side. This is an often overlooked problem when the camera is on
a tripod and the VF is not covered.

I think blaming the camera here is just a little premature.

It was a 400.- Canon 17-85 IS lens. Hardly a piece of crap, I think, but I
don't know how much Canon charges for crappy lenses ;-)

The "stuck blades" theory would be something, but I don't think so.
Stray light is so far fetched: I don't wear glasses and then it should be
evident in other photo's with other camera's, which is not the case...

Blaming the camera is the only option after ruling all others out.
You do know what "trial and error" means, don't you?


--
Focus

Focus wrote:


OK, to be absolutely clear about it. I KNOW it wasn't in bracketing, because
I NEVER use bracketing.
Clear enough?

I've used the 40D and all the latest slew of released DSLRs except the
1Ds MkIII.

Focus is reporting something which happens when the focus point shifts
in matrix metering. Focus may decide it is on a dark area, or a light
area, which happen both to be at a distant point (like cliffs/sea).
Depending on which focus sensor is locked on, even if the focus does not
change, the exposure can change.

In my experience, especially with the Canon 400D, the result can be
extreme. It is as if the camera is using a spot metering from the
selected point. The 40D is not as extreme in effect and nor is the 450D.
The Sony/Minolta system is more like a gentle bias, it does still affect
the exposure but is weights it rather than changes it. Also, the Sony AF
module is less volatile in trying to find the right focus point, and
sticks more stubbornly to the obvious central spot.

The Nikon D300 and D3, when put into 51-zone or 15-zone modes, are also
prone to unexpected changes in exposure as a subjecty moves across the
field of view, depending on how well the tracking works.

If you want consistent exposurem, don't use matrix/evaluative/multizone
metering as small changes in composition can make big changes in exposure.

David