Questions re: Photo Vision Target

[R_Fredrick_Smith]

Originally Posted by Stecyk

Hi Roger,

I thought you wanted to use incident for a black dress. Reflective would give you the wrong reading, because it is not 18% grey. My understanding is that a reflective reading would try to make the black dress 18% gray. An incident reading, on the other hand, doesn't care about whether you are shooting a white bride's dress or a black dress.

You can see a more detailed description of that here at Sekonic's site:

http://www.sekonic.com/classroom/classroom_2.asp

Look at the first example with the white, gray, and black plates with incident metering. And then look at similar examples below with reflective metering.

All that said, I recently photographed a model in a black dress and I overexposed. I did something wrong somewhere.

If I have a misunderstanding, please correct me.

Best regards,
Kevin

Keep in mind that I started by talking about the zone system and then moved into the black dress example. You take a spot reading to see where the black dress is (which would give a reading that would make it 18%) gray and then you modify that reading based on the zone you want to put the black in. So the meter would give a reading and that tells you what you need to make black zone 5. But suppose I want black to be in zone 2, then I would modify the result of my spot reading on the black in the scene (in digital I would then check where that is going to put the highlights in my scene). I would then shoot RAW, because I can recover problems on the highlight side much more easily than on the shadows side. In the zone system you exposed for the shadows and then processed based on the difference between the shadows and highlights. Naturally we can't do that for digital, so we use the histogram when taking the photo to make sure the highlights are not blown and then use the RAW converter to recover any highlight problems. And keep in mind, when you get to RAW, you set the black and white point using the blacks and exposure slider. So in other words, you are forcing the blacks into the zones you want them to be in. Now let's say we use an incident meter for the scene. Then we get the amount of light that is falling on the blacks and the whites. This does not take into consideration how much light each of them reflect. So we still end up having to compensate. One way or the other we have to make choices based on what our vision is for the scene.

So the reflective readings give me information about the amount of light being absorbed or reflected by different objects in my scene and the incident meter gives me information about how much light is "falling" on the scene.

All the above being said, if you were in a studio you would almost always use incident light metering. But then you would compensate based on the lightness or darkness of the primary subject in the scene.

But out of doors, especially for landscapes you almost always have to use reflective. It is wise to gain a good understanding of both techniques, however.

Does this make any sense?

Anyway, it is more of a "feel" thing, when it comes right down to it. You play with the technical aspects of exact exposure evaluation, and through experience you learn what works and what doesn't and you eventually reach a point where you often guess exactly what the exposure should be just by glancing at a scene. Then a test shot, a glance at the histogram, and a final zeroing in.

Cheers,
rfs

[Stecyk]

Originally Posted by R_Fredrick_Smith

Keep in mind that I started by talking about the zone system and then moved into the black dress example. You take a spot reading to see where the black dress is (which would give a reading that would make it 18%) gray and then you modify that reading based on the zone you want to put the black in. So the meter would give a reading and that tells you what you need to make black zone 5. But suppose I want black to be in zone 2, then I would modify the result of my spot reading on the black in the scene (in digital I would then check where that is going to put the highlights in my scene). I would then shoot RAW, because I can recover problems on the highlight side much more easily than on the shadows side. In the zone system you exposed for the shadows and then processed based on the difference between the shadows and highlights. Naturally we can't do that for digital, so we use the histogram when taking the photo to make sure the highlights are not blown and then use the RAW converter to recover any highlight problems. And keep in mind, when you get to RAW, you set the black and white point using the blacks and exposure slider. So in other words, you are forcing the blacks into the zones you want them to be in. Now let's say we use an incident meter for the scene. Then we get the amount of light that is falling on the blacks and the whites. This does not take into consideration how much light each of them reflect. So we still end up having to compensate. One way or the other we have to make choices based on what our vision is for the scene.

So the reflective readings give me information about the amount of light being absorbed or reflected by different objects in my scene and the incident meter gives me information about how much light is "falling" on the scene.

All the above being said, if you were in a studio you would almost always use incident light metering. But then you would compensate based on the lightness or darkness of the primary subject in the scene.

But out of doors, especially for landscapes you almost always have to use reflective. It is wise to gain a good understanding of both techniques, however.

Does this make any sense?

Anyway, it is more of a "feel" thing, when it comes right down to it. You play with the technical aspects of exact exposure evaluation, and through experience you learn what works and what doesn't and you eventually reach a point where you often guess exactly what the exposure should be just by glancing at a scene. Then a test shot, a glance at the histogram, and a final zeroing in.

Cheers,
rfs

Hi Roger,

Thank you for your explanation. I hadn't taken into consideration your discussion about the zone system, something which I know very little about.

My understanding is that incident reading are generally more accurate because you are measuring the light that is falling on the subject as opposed to light that is reflected from the subject. So with incident readings, blacks are black and whites are white. With reflective readings based on 18% gray, you have to adjust: reduce exposure for blacks and increase exposure for whites.

You mentioned in your post that in a studio with incident light metering, you compensate depending on the lightness or darkness of your subject. I no studio experience to guide me. I am struggling though. Wouldn't the incident reading be the correct reading? If you subject is a white dress, isn't the incident reading correct? Or similarly for a black dress? Doesn't the incident light reading provide the exposure reading to yield proper tones? If you could elaborate on what I am missing, I would greatly appreciate it.

Furthermore, I read that outdoor landscapes scenes are simply too far away to get incident readings. You can't go walking up the mountain, get your incident reading, walk back down the mountain and take your photograph. By that time, the light has changed anyway. So you use reflective readings.

Again, thank you for your assistance.

Best regards,
Kevin

[RobArtLyn]

Originally Posted by Stecyk

Wouldn't the incident reading be the correct reading? If you subject is a white dress, isn't the incident reading correct? Or similarly for a black dress? Doesn't the incident light reading provide the exposure reading to yield proper tones? If you could elaborate on what I am missing, I would greatly appreciate it.

The incident reading will give you the correct reading for a mid tone and anything close too it. However, if the scene has highlights and/or shadows that go beyond the contrast range of your film/digital sensor then you will have blown highlights or shadows without details. A meter reading is always just a starting point. You then need to decide if adjustments are necessary based on the full tonal range of the scene and the characteristics of your film/sensor. This is why photographers will often take multiple readings of different parts of a scene. They determine the scene's overall contrast range and decide if they will sacrifice highlight or shadow detail if there is too much contrast to record in a single shot.

[Stecyk]

Originally Posted by RobArtLyn

The incident reading will give you the correct reading for a mid tone and anything close too it. However, if the scene has highlights and/or shadows that go beyond the contrast range of your film/digital sensor then you will have blown highlights or shadows without details. A meter reading is always just a starting point. You then need to decide if adjustments are necessary based on the full tonal range of the scene and the characteristics of your film/sensor. This is why photographers will often take multiple readings of different parts of a scene. They determine the scene's overall contrast range and decide if they will sacrifice highlight or shadow detail if there is too much contrast to record in a single shot.

Hi Rob,

Great explanation, thank you. I soaked on your message for a while and now understand why the mid tone object is important. If it is bright, it is blown out. If it is dark, then is simply too bright, but not blown.

Again, thank you!

Best regards,
Kevin

[RobArtLyn]

Originally Posted by Stecyk

I soaked on your message for a while and now understand why the mid tone object is important. If it is bright, it is blown out. If it is dark, then is simply too bright, but not blown.

I am not quite following what you mean here. An incident reading will never cause a dark tone to appear too light (for a uniformly lit scene). If the dark tone is within the contrast range of the film/sensor under the current lighting, it will record correctly. If not, it will record too dark with some degree of loss of shadow detail.

Perhaps you are thinking of using a spot meter to take a reflective reading. Whatever you point the meter at will be recorded as an 18% mid tone and everything else in the scene will be lighter or darker relative to that, within the limits of the film/sensor.

[R_Fredrick_Smith]

Here is a link that will clarify things a bit more:

http://www.kodak.com/cluster/global/...f9/index.shtml

In particular, consider this quote:

The exposure determined by an incident-light meter should be the same as reading a gray card with a reflected-light meter. Fortunately, many scenes have average reflectance with an even mix of light and dark areas, so the exposure indicated is good for many picture-taking situations. However, if the main subject is very light or very dark, and you want to record detail in this area, you must modify the meter's exposure recommendations as follows:

• For light subjects, decrease exposure by 1/2 to 1 stop from the meter reading.
• For dark subjects, increase exposure by 1/2 to 1 stop from the meter reading.

Cheers,
rfs

[Stecyk]

Originally Posted by RobArtLyn

I am not quite following what you mean here. An incident reading will never cause a dark tone to appear too light (for a uniformly lit scene). If the dark tone is within the contrast range of the film/sensor under the current lighting, it will record correctly. If not, it will record too dark with some degree of loss of shadow detail.

Perhaps you are thinking of using a spot meter to take a reflective reading. Whatever you point the meter at will be recorded as an 18% mid tone and everything else in the scene will be lighter or darker relative to that, within the limits of the film/sensor.

Hi Rob,

When I read my message over, I agree with you. It doesn't make sense.

Let's try this:

Uniformly lit scene.

Under these conditions, an incident meter should read the same everywhere since the scene is uniformly lit.

Dark object: should record dark

Mid tone object: should record mid tone.

Bright object: should record bright.

This is very much like the Sekonic information here:
http://www.sekonic.com/classroom/classroom_2.asp (see white, gray, and black plates)


Variable lit scene.

Range: difference in exposure between highlights and shadows.

If the range exceeds the camera's capability, then photographer must decide whether highlight or shadow detail is more important.

Assuming photographer chooses highlights and exposes for highlights:

In the shadows:
Light object: still some detail (guessing)
Dark object: loss of detail

Assuming photographer chooses shadows and exposes for shadows:

In the highlights:
Light object: loss of detail (blown)
Dark object: overexposed but still detail (guessing)

Does this message make more sense?

Best regards,
Kevin

[Stecyk]

Originally Posted by R_Fredrick_Smith

Here is a link that will clarify things a bit more:

http://www.kodak.com/cluster/global/...f9/index.shtml

In particular, consider this quote:
Cheers,
rfs

Hi Roger,

Thank you for the link. Yes, I am aware with reflected readings that you must increase for bright (snow) and decrease for dark (black cats) because the meter is believes everything is 18% gray.

I need to simply practice more. Compare my actual shots to what I thought I shot.

Best regards,
Kevin

[RobArtLyn]

Originally Posted by Stecyk

Thank you for the link. Yes, I am aware with reflected readings that you must increase for bright (snow) and decrease for dark (black cats) because the meter is believes everything is 18% gray.

You need to follow the link and read it. The adjustments that he quoted are from the section for using an incident meter, not a reflected meter.

Uniformly lit scene.

Under these conditions, an incident meter should read the same everywhere since the scene is uniformly lit.

Dark object: should record dark

Mid tone object: should record mid tone.

Bright object: should record bright.

Under perfect world conditions, this would be all that you would need to worry about. However, even in a uniformly lit scene, you could have a bright object and/or a dark object that fall outside the tonal contrast range that your film/sensor can record in one shot without lost details in either the highlights, shadows or both. This is why you sometimes make an adjustment from the incident reading even if the scene is uniformly lit, as described in the document linked above.

[Stecyk]

Originally Posted by RobArtLyn

Under perfect world conditions, this would be all that you would need to worry about. However, even in a uniformly lit scene, you could have a bright object and/or a dark object that fall outside the tonal contrast range that your film/sensor can record in one shot without lost details in either the highlights, shadows or both. This is why you sometimes make an adjustment from the incident reading even if the scene is uniformly lit, as described in the document linked above.

Rob,

I read the article. Thank you for your patience.

Best regards,
Kevin