Questions about G1 exposure

Yang Hong · Jul 1, 2001

I found I'm having a hard time to deal with G1's exposure/metering system. Does anybody know exactly when G1 does the over/under-expsoure?

Anyway, here is what I found/did:

1. under bright sunlight, I found compensation of -1/3 does a pretty good job to prevent overexposure in center weighted mode. I did this when I was shooting the SF Pride parade and most pictures look fairly bright and well constrast with -1/3 compensation.

2. During those golden light moments (dusk or dawn), I found it's very tricky. Sometime the camera overexposes, sometime it underexposes severely. I just can't find a way to tell exactly how the camera decides the exposure.

3. When shot at low night conditions, then camera seems to tend to slightly overexpose.

Anyway, the reason I want to rant here is that today I shoot 45 pic around San Francisco marina around 7-8PM with bright sunset light. I put exposure compensation to -1/3 but to my dismay this time nearly all pix came out badly underexposed.

I remember I had similar underexpsoure problem with my previous Kodak DC4800. So does sea water surface fool G1's metering system, possibly due to the reflection? But I was not shooting with backlit at all.

Also, if you use G1's spot metering mode, do you still want to compensate? Or normally G1 will do a pretty accurate metering in spot mode?

I apologize for a disorganized post. I'm starting to loose my confidence on G1's metering systyem. I'd appreciate any advice on how to properly set G1's exposure. I just don't want to accept the fact that I have to do exposure bracketing for every single shot. That'll be nightmare for me since I only have 128+64MB cards and I shot in RAW.

Yang

Peter T44178 · Jul 1, 2001

Here's a link that you shoud find useful:
http://www.cliffshade.com/dpfwiw/exposure.htm

Pete49571 · Jul 1, 2001

Peter T said:
Here's a link that you shoud find useful:
http://www.cliffshade.com/dpfwiw/exposure.htm

I can;t help you but I'd like to agree with you on every point you made. I'm having a lot of trouble too and am beginning to doubt that I can ever rely on the exposure system of this camera. It's my third week and I still can't figure it out. I've used an old practica, nikon 801 slr, Contax g1 before and never had any of these problems.. I'm using P mode mainly, exposure compensation set at -1/3 or more, UV and polarizing filters etc

Do all digital cameras have these problems? Exposure is so important....I haven't read about the sony people having these issues...but that could be chance

Thanks for advice!

Pete

koumou29739 · Jul 1, 2001

Hello Yang,

I've had my G1 for 6 months nad I've been through what you are experiencing.

The center weighted metering of the G1 is doing exactly what it is ment to do.

I very strongly recomend that you go here:
http://www.cliffshade.com/dpfwiw/exposure.htm
and try to understand what the camera's metering is trying to do.

The camera is set to meter correctly of a medium grey card that reflect
18% of light.This grey sits right in the midle of a brightness zone where

black is the min. and white the max.Do the following test and you will understand how the camera behaves.

Take a picture of a black piece of paper that fills the frame and the camera will render this as grey.Do the same with a white peice of paper,again the camera will render this as grey.Now if you take an exposure reading of a medium grey card and keep those setting and take a picture of the black and white paper they will be rendered correctly.Now ,the objects we take pictures of, although colored, fall somewhere in between the black and white I mentioned in the brightness zone.Now if an object falls above the medium grey,it will be under exposed,if it falls below,it will be overexposed.

Take a red rose for example,that a poster in this forum has been complaining that the G1 is over exposing.This hapens because the brightness of a red rose falls below that of a medium grey.If you take a picture of lots of snow it will be rendered grey unless you over expose a litle.A picture of a black car will be over exposed ,the car will be grey.
Now what center weighted metering does is take readings of objects in

certain zones while giving more emphasis in the centre and comes up with an average exposure .This works sometimes but gets fulled easily in some situations. This is an area where Nikon and some other digi cams do better due to their more modern and sophysticate multi zone metering systems.

Personally I find that the best way to deal with exposure in the G1 is:

1.Get a medium grey card and use it whenever possible
2.Learn to recognise objects or areas in a picture that have an average grey
brightness and mesure exposure of them.The palm of my hand for intance
is almost as bright as a grey card.

3.I have found that if the correct exposure is used,AWB is spot on.So I use this the other way round, to ensure I have the correct exposure.If the colors are right in the Lcd then the exposure most probably is correct also.

Hope All this helped.

Koumou

Yang Hong said:
I found I'm having a hard time to deal with G1's exposure/metering
system. Does anybody know exactly when G1 does the
over/under-expsoure?

Anyway, here is what I found/did:

1. under bright sunlight, I found compensation of -1/3 does a
pretty good job to prevent overexposure in center weighted mode. I
did this when I was shooting the SF Pride parade and most pictures
look fairly bright and well constrast with -1/3 compensation.

2. During those golden light moments (dusk or dawn), I found it's
very tricky. Sometime the camera overexposes, sometime it
underexposes severely. I just can't find a way to tell exactly how
the camera decides the exposure.

3. When shot at low night conditions, then camera seems to tend to
slightly overexpose.

Anyway, the reason I want to rant here is that today I shoot 45 pic
around San Francisco marina around 7-8PM with bright sunset light.
I put exposure compensation to -1/3 but to my dismay this time
nearly all pix came out badly underexposed.

I remember I had similar underexpsoure problem with my previous
Kodak DC4800. So does sea water surface fool G1's metering system,
possibly due to the reflection? But I was not shooting with backlit
at all.

Also, if you use G1's spot metering mode, do you still want to
compensate? Or normally G1 will do a pretty accurate metering in
spot mode?

I apologize for a disorganized post. I'm starting to loose my
confidence on G1's metering systyem. I'd appreciate any advice on
how to properly set G1's exposure. I just don't want to accept the
fact that I have to do exposure bracketing for every single shot.
That'll be nightmare for me since I only have 128+64MB cards and I
shot in RAW.

Yang

Yang Hong · Jul 1, 2001

Hi Koumou,

Thanks a lot for the reply and it reallys helps me to understand more about G1's metering.

I have to add here that most time I'm satisfied with G1's exposure. It's just now that when I'm trying to make it perfect by setting exposure compensation then I got severely burned yesterday...

If I'm not going to use a gray card, then is there certain rules for exposure compensation? Say, when taking a picture with a large area of ocean I should up the exposure a little bit? To camera maybe the sea surface is lot brighter than it's to human eyes. I guess what I'm struggling now is to learn when and how I should adjust G1's exposure, to know in which cases G1 will do a good job, and in which cases I should kick in to do the adjustment.

I guess I should practice more. A good thing about digital camera is the EXIF information.

Yang

koumou said:
I've had my G1 for 6 months nad I've been through what you are
experiencing.

The center weighted metering of the G1 is doing exactly what it is
ment to do.

I very strongly recomend that you go here:
http://www.cliffshade.com/dpfwiw/exposure.htm
and try to understand what the camera's metering is trying to do.

The camera is set to meter correctly of a medium grey card that
reflect
18% of light.This grey sits right in the midle of a brightness zone
where
black is the min. and white the max.Do the following test and you
will understand how the camera behaves.

Take a picture of a black piece of paper that fills the frame and
the camera will render this as grey.Do the same with a white peice
of paper,again the camera will render this as grey.Now if you take
an exposure reading of a medium grey card and keep those setting
and take a picture of the black and white paper they will be
rendered correctly.Now ,the objects we take pictures of, although
colored, fall somewhere in between the black and white I mentioned
in the brightness zone.Now if an object falls above the medium
grey,it will be under exposed,if it falls below,it will be
overexposed.
Take a red rose for example,that a poster in this forum has been
complaining that the G1 is over exposing.This hapens because the
brightness of a red rose falls below that of a medium grey.If you
take a picture of lots of snow it will be rendered grey unless you
over expose a litle.A picture of a black car will be over exposed
,the car will be grey.
Now what center weighted metering does is take readings of objects in
certain zones while giving more emphasis in the centre and comes up
with an average exposure .This works sometimes but gets fulled
easily in some situations. This is an area where Nikon and some
other digi cams do better due to their more modern and sophysticate
multi zone metering systems.

Personally I find that the best way to deal with exposure in the G1
is:

1.Get a medium grey card and use it whenever possible
2.Learn to recognise objects or areas in a picture that have an
average grey
brightness and mesure exposure of them.The palm of my hand for intance
is almost as bright as a grey card.
3.I have found that if the correct exposure is used,AWB is spot
on.So I use this the other way round, to ensure I have the correct
exposure.If the colors are right in the Lcd then the exposure most
probably is correct also.

Hope All this helped.

Koumou

Yang Hong said:

I found I'm having a hard time to deal with G1's exposure/metering
system. Does anybody know exactly when G1 does the
over/under-expsoure?

Anyway, here is what I found/did:

1. under bright sunlight, I found compensation of -1/3 does a
pretty good job to prevent overexposure in center weighted mode. I
did this when I was shooting the SF Pride parade and most pictures
look fairly bright and well constrast with -1/3 compensation.

2. During those golden light moments (dusk or dawn), I found it's
very tricky. Sometime the camera overexposes, sometime it
underexposes severely. I just can't find a way to tell exactly how
the camera decides the exposure.

3. When shot at low night conditions, then camera seems to tend to
slightly overexpose.

Anyway, the reason I want to rant here is that today I shoot 45 pic
around San Francisco marina around 7-8PM with bright sunset light.
I put exposure compensation to -1/3 but to my dismay this time
nearly all pix came out badly underexposed.

I remember I had similar underexpsoure problem with my previous
Kodak DC4800. So does sea water surface fool G1's metering system,
possibly due to the reflection? But I was not shooting with backlit
at all.

Also, if you use G1's spot metering mode, do you still want to
compensate? Or normally G1 will do a pretty accurate metering in
spot mode?

I apologize for a disorganized post. I'm starting to loose my
confidence on G1's metering systyem. I'd appreciate any advice on
how to properly set G1's exposure. I just don't want to accept the
fact that I have to do exposure bracketing for every single shot.
That'll be nightmare for me since I only have 128+64MB cards and I
shot in RAW.

Yang

Click to expand...

sarbos · Jul 2, 2001

Hello!

Yang Hong said:
If I'm not going to use a gray card, then is there certain rules
for exposure compensation?

You need to get the idea of "grey", Koumou is right, and I'll try to say the same in another way

The meter dosen't know anything about colors, everything it sees is grey 18% (the grey card); so:

When it sees white piece of paper, it thinks that is a grey paper 18% (as always) but in a VERY BRIGHT place, so bright that even the grey looks white... so it "recomends" to close down the aperture because the amount of light. ==> You get an underexposed white paper, that is, a "grey" picture of a white paper.

When it sees a black piece of paper, it reacts just the same way, it's a grey paper in a VERY DARK place... so it opens the diafragm in orther to get more light in such a dark place... so you get a overexposed black, that is, a
"grey" picture of a black paper.

So, you, the inteligent "thing"

in charge, have to tell the camera that it is black or it is white, how? setting the over/underexposure yourself.

With clear subjects (sand, snow, white walls...) you will need to overexpose... Yes! OVER, you may think:

-what! it is clear and I have to give even more light?!?

Yes, because he dosen't know it is clear... and would think it's just grey with a lot of light.

You must also overexpose if shooting reflective surfaces, like water, windows... if an strong source of light (sun or lamps) reflects on them.

With dark subjects you must do the same, but underexposing. (black cats, coal...).

Take care of not misunderstand subject "lightness" with enviromental light.

If you are in a dark place, with normal subjects, and you want to "see" more than you do, you must overexpose, and if you are in a bright place with normal subjects, and you don't want a "washed" picture you must underexpose...

But that's when you don't want the right exposure... but one that suits your creativity...

Koumou said:

Yang Hong said:
The palm of my hand for intance is almost as bright as a grey card.

It depends of each one's skin colour, mine is one point clearer than the grey card, a friend of mine is "overexposed" by 1.5 (he is swedish) and my cousin is spot on! you should check your colour

and then you could use your hand to set the right exposure...

Select the overexposure for your colour, aim the camera to the hand so it fills the LCD (or the center if using the pseudo spot [] ) (if outdoors, pay attention not to block the sunlight with your shadow) press , so the exposure is took, aim to your subject and shot...

The exposure should be perfect...

My two cents,

Yang Hong · Jul 2, 2001

Very nice! thank you and koumou so much for making this matter much clear to me. I'll certainly keep what you said in mind next time I use my G1. I have yellow skin since I'm asian, so I'll test to see if my hand is of 18% grey. What a nice trick!

Also thanks to Peter for that URL. I remember I read it once ago but was in a hurry so I didn't remember too much it said. I'll readi it again.

Yang

sarbos said:
Yang Hong said:

If I'm not going to use a gray card, then is there certain rules
for exposure compensation?

Click to expand...

You need to get the idea of "grey", Koumou is right, and I'll try
to say the same in another way

The meter dosen't know anything about colors, everything it sees is
grey 18% (the grey card); so:

When it sees white piece of paper, it thinks that is a grey paper
18% (as always) but in a VERY BRIGHT place, so bright that even the
grey looks white... so it "recomends" to close down the aperture
because the amount of light. ==> You get an underexposed white
paper, that is, a "grey" picture of a white paper.

When it sees a black piece of paper, it reacts just the same way,
it's a grey paper in a VERY DARK place... so it opens the diafragm
in orther to get more light in such a dark place... so you get a
overexposed black, that is, a
"grey" picture of a black paper.

So, you, the inteligent "thing" in charge, have to tell the
camera that it is black or it is white, how? setting the
over/underexposure yourself.

With clear subjects (sand, snow, white walls...) you will need to
overexpose... Yes! OVER, you may think:

-what! it is clear and I have to give even more light?!?

Yes, because he dosen't know it is clear... and would think it's
just grey with a lot of light.

You must also overexpose if shooting reflective surfaces, like
water, windows... if an strong source of light (sun or lamps)
reflects on them.

With dark subjects you must do the same, but underexposing. (black
cats, coal...).

Take care of not misunderstand subject "lightness" with
enviromental light.

If you are in a dark place, with normal subjects, and you want to
"see" more than you do, you must overexpose, and if you are in a
bright place with normal subjects, and you don't want a "washed"
picture you must underexpose...

But that's when you don't want the right exposure... but one that
suits your creativity...

Koumou said:

sarbos said:

The palm of my hand for intance is almost as bright as a grey card.

Click to expand...

It depends of each one's skin colour, mine is one point clearer
than the grey card, a friend of mine is "overexposed" by 1.5 (he is
swedish) and my cousin is spot on! you should check your colour
and then you could use your hand to set the right exposure...

Select the overexposure for your colour, aim the camera to the hand
so it fills the LCD (or the center if using the pseudo spot [] )
(if outdoors, pay attention not to block the sunlight with your
shadow) press , so the exposure is took, aim to your subject and
shot...

The exposure should be perfect...

My two cents,

Diane B · Jul 2, 2001

sarbos said:
Yang Hong said:

If I'm not going to use a gray card, then is there certain rules
for exposure compensation?

Click to expand...

You need to get the idea of "grey", Koumou is right, and I'll try
to say the same in another way

Thank you you two--that is a WONDERFUL explanation and really helped me understand exactly what is happening. I did understand in a theoretical way, but this made me see it in 'real life' terms and I understand it much much better. Thanks again to both of you.

Diane

Diane B · Jul 2, 2001

Diane Fields said:
sarbos said:

Yang Hong said:

If I'm not going to use a gray card, then is there certain rules
for exposure compensation?

Click to expand...

You need to get the idea of "grey", Koumou is right, and I'll try
to say the same in another way

Click to expand...

Thank you you two--that is a WONDERFUL explanation and really
helped me understand exactly what is happening. I did understand
in a theoretical way, but this made me see it in 'real life' terms
and I understand it much much better. Thanks again to both of you.

Diane

Just wanted you to know (see Pete's new post) THAT I bought gray cards and now understand this even better. Besides which--regardless of what aperture setting I've given the camera, it has been right on after metering with the gray card.

Ray Hussey · Jul 2, 2001

Excellent explanation for normal pictures. Does this principal hold for flash. I have the 420ex and have been running into overexposures. Especially when the subject is up close.

Steve D50919 · Jul 2, 2001

Why are so many people having exposure problems with the G1? I have a G1 and find thnat it is a wonderful camera. Although I never use the auto mode, I find that I need to make minimal adjustments in the 'p' mode to get excellent results. Also, when I take a picture of people.. (portraits), using the portrait setting does a fabulous job.. including opening up the f stop to provide little depth of field (desireable). Similiarly, using Landscapre provides terrific depth of field.

I have learned lots about using exposure compensation settings from this forum., but I simply haven't had many exposure problems. Wonder why! Perhaps it is partially because I enjoy digitally editing most important photos anyway. By the way, Paint Shop pro is every bit as good as Photoshop 6.0 (one man;s opinion).

Also.. the canon case for the G! is fabulous. It screws into the tripod hole and fits liek a glove. It alone is worth the price of admission.

Steve

Yang Hong said:
I found I'm having a hard time to deal with G1's exposure/metering
system. Does anybody know exactly when G1 does the
over/under-expsoure?

Anyway, here is what I found/did:

1. under bright sunlight, I found compensation of -1/3 does a
pretty good job to prevent overexposure in center weighted mode. I
did this when I was shooting the SF Pride parade and most pictures
look fairly bright and well constrast with -1/3 compensation.

2. During those golden light moments (dusk or dawn), I found it's
very tricky. Sometime the camera overexposes, sometime it
underexposes severely. I just can't find a way to tell exactly how
the camera decides the exposure.

3. When shot at low night conditions, then camera seems to tend to
slightly overexpose.

Anyway, the reason I want to rant here is that today I shoot 45 pic
around San Francisco marina around 7-8PM with bright sunset light.
I put exposure compensation to -1/3 but to my dismay this time
nearly all pix came out badly underexposed.

I remember I had similar underexpsoure problem with my previous
Kodak DC4800. So does sea water surface fool G1's metering system,
possibly due to the reflection? But I was not shooting with backlit
at all.

Also, if you use G1's spot metering mode, do you still want to
compensate? Or normally G1 will do a pretty accurate metering in
spot mode?

I apologize for a disorganized post. I'm starting to loose my
confidence on G1's metering systyem. I'd appreciate any advice on
how to properly set G1's exposure. I just don't want to accept the
fact that I have to do exposure bracketing for every single shot.
That'll be nightmare for me since I only have 128+64MB cards and I
shot in RAW.

Yang

sarbos · Jul 2, 2001

Hello!

Ray Hussey said:
Excellent explanation for normal pictures. Does this principal
hold for flash. I have the 420ex and have been running into
overexposures. Especially when the subject is up close.

You are right, G1 uses to overexpose flash, at least for my taste. I use to set the flash level to underexpose from 1 to 2 points, and some times I miss a -3 adjustment. (Some times I use a sto-flen filter on the flash because it difuses the light and decreases its power...)

About the "work-flow" with grey cards, it also works for flash, with a BUT:

The distance from the sun to your hand is the same than from the sun to your subject... but it isn't true with flash, obviously

So, you need to read the light bounced back from the subject.eh...let's take a portrait:

You place the model, set the lights, props... etc...
then you give her the grey card,
and you go back to where you want to take the photo from,
aim the camera to the grey card with spot metering [],
and use the zoom (normal or digital) to fill the spot with the card,
press ,

the flash will pre-fire and the right amount of flash and enviromental flash will be "locked"...

tell the model to throw the card out of sight, recompose, and shot (before 6 seconds or you will lose the settings).

It should produce the right exposure.

By the way, you don't need to aim the flash to the model, it works with bounced flash, and I like it much more than direct... I use a big unexpensive cardboard from any paper-shop, you can get golden, silver and white cardboards at very low prices... and since they are cheap and "paper" you can cut them on the field if needed... (I also carry a black cardboard to stop light bouncing from places I don't want it to).

My two cents,

hope it helps! ;-)

Steve D50919 · Jul 3, 2001

Thanks koumou

Let me see if I have this right. Are you saying that in bright sunlight I might have to do the OPPOSITE of what is intuitively obvious? That is.. I should RAISE the ev setting?.. the theory being that the G1 thinks that the object I'm focusing on is really lighter than it really is, and will therefore underexpose?

Also, when using AE lock the manual says to press the shutter half way down and then hit the . This is incredibly cumbersome. It seems to work by aiming the camera where i want to set the exposure and just hitting the , without pressing the shuuter halfway. THEN I aim and press the shutter to get the focus I want. Am I wrong?

koumou said:
I've had my G1 for 6 months nad I've been through what you are
experiencing.

The center weighted metering of the G1 is doing exactly what it is
ment to do.

I very strongly recomend that you go here:
http://www.cliffshade.com/dpfwiw/exposure.htm
and try to understand what the camera's metering is trying to do.

The camera is set to meter correctly of a medium grey card that
reflect
18% of light.This grey sits right in the midle of a brightness zone
where
black is the min. and white the max.Do the following test and you
will understand how the camera behaves.

Take a picture of a black piece of paper that fills the frame and
the camera will render this as grey.Do the same with a white peice
of paper,again the camera will render this as grey.Now if you take
an exposure reading of a medium grey card and keep those setting
and take a picture of the black and white paper they will be
rendered correctly.Now ,the objects we take pictures of, although
colored, fall somewhere in between the black and white I mentioned
in the brightness zone.Now if an object falls above the medium
grey,it will be under exposed,if it falls below,it will be
overexposed.
Take a red rose for example,that a poster in this forum has been
complaining that the G1 is over exposing.This hapens because the
brightness of a red rose falls below that of a medium grey.If you
take a picture of lots of snow it will be rendered grey unless you
over expose a litle.A picture of a black car will be over exposed
,the car will be grey.
Now what center weighted metering does is take readings of objects in
certain zones while giving more emphasis in the centre and comes up
with an average exposure .This works sometimes but gets fulled
easily in some situations. This is an area where Nikon and some
other digi cams do better due to their more modern and sophysticate
multi zone metering systems.

Personally I find that the best way to deal with exposure in the G1
is:

1.Get a medium grey card and use it whenever possible
2.Learn to recognise objects or areas in a picture that have an
average grey
brightness and mesure exposure of them.The palm of my hand for intance
is almost as bright as a grey card.
3.I have found that if the correct exposure is used,AWB is spot
on.So I use this the other way round, to ensure I have the correct
exposure.If the colors are right in the Lcd then the exposure most
probably is correct also.

Hope All this helped.

Koumou

Yang Hong said:

I found I'm having a hard time to deal with G1's exposure/metering
system. Does anybody know exactly when G1 does the
over/under-expsoure?

Anyway, here is what I found/did:

1. under bright sunlight, I found compensation of -1/3 does a
pretty good job to prevent overexposure in center weighted mode. I
did this when I was shooting the SF Pride parade and most pictures
look fairly bright and well constrast with -1/3 compensation.

2. During those golden light moments (dusk or dawn), I found it's
very tricky. Sometime the camera overexposes, sometime it
underexposes severely. I just can't find a way to tell exactly how
the camera decides the exposure.

3. When shot at low night conditions, then camera seems to tend to
slightly overexpose.

Anyway, the reason I want to rant here is that today I shoot 45 pic
around San Francisco marina around 7-8PM with bright sunset light.
I put exposure compensation to -1/3 but to my dismay this time
nearly all pix came out badly underexposed.

I remember I had similar underexpsoure problem with my previous
Kodak DC4800. So does sea water surface fool G1's metering system,
possibly due to the reflection? But I was not shooting with backlit
at all.

Also, if you use G1's spot metering mode, do you still want to
compensate? Or normally G1 will do a pretty accurate metering in
spot mode?

I apologize for a disorganized post. I'm starting to loose my
confidence on G1's metering systyem. I'd appreciate any advice on
how to properly set G1's exposure. I just don't want to accept the
fact that I have to do exposure bracketing for every single shot.
That'll be nightmare for me since I only have 128+64MB cards and I
shot in RAW.

Yang

Click to expand...

sarbos · Jul 3, 2001

Hello!

Steve H said:
Let me see if I have this right. Are you saying that in bright
sunlight I might have to do the OPPOSITE of what is intuitively
obvious? That is.. I should RAISE the ev setting?.. the theory
being that the G1 thinks that the object I'm focusing on is really
lighter than it really is, and will therefore underexpose?

No, you get it wrong, but almost right...

You should RAISE the ev setting if the subject is lighter than the grey card, it has nothing to do with the amount of light in the scene.

A very bright scene with the exposure value metered from a grey card will give you a correct bright scene... a dark scene with exposure from a grey card will produce a dark scene...

If you want a dark scene clearer (or a bright scene not so bright) then you don't want the REAL value, but one that you choose for your taste... then is up to you to over/underexpose.

Steve D50919 said:
Also, when using AE lock the manual says to press the shutter half
way down and then hit the . This is incredibly cumbersome. It
seems to work by aiming the camera where i want to set the exposure
and just hitting the , without pressing the shuuter halfway. THEN
I aim and press the shutter to get the focus I want. Am I wrong?

I think you are right, the * alone is enough for exposure locking.

Hope it helps,

Sarbos

James49642 · Jul 3, 2001

Wow, wow, wow! Excellent explanation of the G1's (and others') metering system! I have to read this over and over. Makes perfect sense. I'll have to practice with this.

Regarding the * button that you press to get the exposure. Is this in P mode? Or are you talking about setting the white balance? I have to look at the manual again.

Thanks so much to everyone!

Diane B · Jul 3, 2001

James said:
Wow, wow, wow! Excellent explanation of the G1's (and others')
metering system! I have to read this over and over. Makes perfect
sense. I'll have to practice with this.

Regarding the * button that you press to get the exposure. Is this
in P mode? Or are you talking about setting the white balance? I
have to look at the manual again.

Thanks so much to everyone!

The * button is right above the white balance, etc. button. I guess I need to read the manual too LOL--but believe its in P, Av, Tv. I use Av.

koumou29739 · Jul 4, 2001

Steve H said:
Thanks koumou

Let me see if I have this right. Are you saying that in bright
sunlight I might have to do the OPPOSITE of what is intuitively
obvious?

Yes thats exactly what I am saying.It depends on what you are photographing.If it is snow,for example, it will come out grey if you don't over expose a litle.
That is.. I should RAISE the ev setting?.. the theory

Steve D50919 said:
being that the G1 thinks that the object I'm focusing on is really
lighter than it really is, and will therefore underexpose?

Also, when using AE lock the manual says to press the shutter half
way down and then hit the . This is incredibly cumbersome. It
seems to work by aiming the camera where i want to set the exposure
and just hitting the , without pressing the shuuter halfway. THEN
I aim and press the shutter to get the focus I want. Am I wrong?

koumou said:

I've had my G1 for 6 months nad I've been through what you are
experiencing.

The center weighted metering of the G1 is doing exactly what it is
ment to do.

I very strongly recomend that you go here:
http://www.cliffshade.com/dpfwiw/exposure.htm
and try to understand what the camera's metering is trying to do.

The camera is set to meter correctly of a medium grey card that
reflect
18% of light.This grey sits right in the midle of a brightness zone
where
black is the min. and white the max.Do the following test and you
will understand how the camera behaves.

Take a picture of a black piece of paper that fills the frame and
the camera will render this as grey.Do the same with a white peice
of paper,again the camera will render this as grey.Now if you take
an exposure reading of a medium grey card and keep those setting
and take a picture of the black and white paper they will be
rendered correctly.Now ,the objects we take pictures of, although
colored, fall somewhere in between the black and white I mentioned
in the brightness zone.Now if an object falls above the medium
grey,it will be under exposed,if it falls below,it will be
overexposed.
Take a red rose for example,that a poster in this forum has been
complaining that the G1 is over exposing.This hapens because the
brightness of a red rose falls below that of a medium grey.If you
take a picture of lots of snow it will be rendered grey unless you
over expose a litle.A picture of a black car will be over exposed
,the car will be grey.
Now what center weighted metering does is take readings of objects in
certain zones while giving more emphasis in the centre and comes up
with an average exposure .This works sometimes but gets fulled
easily in some situations. This is an area where Nikon and some
other digi cams do better due to their more modern and sophysticate
multi zone metering systems.

Personally I find that the best way to deal with exposure in the G1
is:

1.Get a medium grey card and use it whenever possible
2.Learn to recognise objects or areas in a picture that have an
average grey
brightness and mesure exposure of them.The palm of my hand for intance
is almost as bright as a grey card.
3.I have found that if the correct exposure is used,AWB is spot
on.So I use this the other way round, to ensure I have the correct
exposure.If the colors are right in the Lcd then the exposure most
probably is correct also.

Hope All this helped.

Koumou

Yang Hong said:

I found I'm having a hard time to deal with G1's exposure/metering
system. Does anybody know exactly when G1 does the
over/under-expsoure?

Anyway, here is what I found/did:

1. under bright sunlight, I found compensation of -1/3 does a
pretty good job to prevent overexposure in center weighted mode. I
did this when I was shooting the SF Pride parade and most pictures
look fairly bright and well constrast with -1/3 compensation.

2. During those golden light moments (dusk or dawn), I found it's
very tricky. Sometime the camera overexposes, sometime it
underexposes severely. I just can't find a way to tell exactly how
the camera decides the exposure.

3. When shot at low night conditions, then camera seems to tend to
slightly overexpose.

Anyway, the reason I want to rant here is that today I shoot 45 pic
around San Francisco marina around 7-8PM with bright sunset light.
I put exposure compensation to -1/3 but to my dismay this time
nearly all pix came out badly underexposed.

I remember I had similar underexpsoure problem with my previous
Kodak DC4800. So does sea water surface fool G1's metering system,
possibly due to the reflection? But I was not shooting with backlit
at all.

Also, if you use G1's spot metering mode, do you still want to
compensate? Or normally G1 will do a pretty accurate metering in
spot mode?

I apologize for a disorganized post. I'm starting to loose my
confidence on G1's metering systyem. I'd appreciate any advice on
how to properly set G1's exposure. I just don't want to accept the
fact that I have to do exposure bracketing for every single shot.
That'll be nightmare for me since I only have 128+64MB cards and I
shot in RAW.

Yang

Click to expand...

Click to expand...

Peter T44178 · Jul 4, 2001

sarbos said:
A very bright scene with the exposure value metered from a grey
card will give you a correct bright scene... a dark scene with
exposure from a grey card will produce a dark scene...

What? If you shoot a grey card under different light intensities, each shot will look the same.

Some people say that a meter assumes everything is like a grey card reflecting 18% of the light. But that's not an accurate way of putting it. What a meter does is make whatever you are shooting average out to a middle tone. Or if using a spot meter, it makes the area you are metering a middle tone.

sarbos · Jul 4, 2001

Peter T said:
sarbos said:

A very bright scene with the exposure value metered from a grey
card will give you a correct bright scene... a dark scene with
exposure from a grey card will produce a dark scene...

Click to expand...

What? If you shoot a grey card under different light intensities,
each shot will look the same.

Right, that's what I'm saying... if you shot in a dark place with a grey card you will get a correct dark scene. If you shot in a light place with a grey card it will produce the correct exposure for the light scene....

Peter T44178 said:
Some people say that a meter assumes everything is like a grey card
reflecting 18% of the light.

That's precisely what it does. nothing else...

Sarbos

Peter T44178 · Jul 4, 2001

sarbos said:
Right, that's what I'm saying... if you shot in a dark place with a
grey card you will get a correct dark scene. If you shot in a light
place with a grey card it will produce the correct exposure for the
light scene....

I guess I'm not sure what you mean by a correct dark scene. It sounds to me that you are saying if you meter a grey card in a dark scene that the resulting exposure will look like what you are seeing.

Questions about G1 exposure

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