incident or reflected meter readings?
Jim Waggener
lighting. Should I use incident or reflected meter readings for my
exposure?
Thanks
Tom Thackrey
incident
--
Tom Thackrey
www.creative-light.com
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Mike Marty
Incident because the color of your paintings might not average out to 18%
reflectence
Phil Stripling
Incident will give you an overall reading of 18% gray reflectance. That's
probably a good starting point, but you need to give some thought to
whether that averaged reading of the entire scene will give you the most
accurate reproduction of the range of each painting.
--
Philip Stripling | email to the replyto address is presumed
Legal Assistance on the Web | spam and read later. email to philip@
http://www.PhilipStripling.com/ | civex.com is read daily.
John Miller
> Incident will give you an overall reading of 18% gray reflectance. That's
> probably a good starting point, but you need to give some thought to
> whether that averaged reading of the entire scene will give you the most
> accurate reproduction of the range of each painting.
Phil, I think I know what you intended, but if you substitute the word
"reflected" for "incident" in the paragraph above, you will see that what
you have written is a perfectly good description of a reflected reading,
and the care that needs to be taken to ensure that the painting has a
reflectance that averages out to 18%.
An incident reading will result in blacks being black, and whites being
white, provided the range of the picture fits within the limits of a
particular emulsion (which is normally the case when copying a picture.)
It will also be the same as a reflected reading of an 18% grey card.
--
John Miller
I feel ... JUGULAR ...
Greg M
news:3q1xzzn...@shell4.tdl.com:
> "Jim Waggener" <ji...@visi.net> writes:
>
>> I am doing some flat copy work of oil paintings indoors with tungsten
>> lighting. Should I use incident or reflected meter readings for my
>> exposure?
>
> Incident will give you an overall reading of 18% gray reflectance. That's
> probably a good starting point, but you need to give some thought to
> whether that averaged reading of the entire scene will give you the most
> accurate reproduction of the range of each painting.
>
Incident meter readings measure actual light falling on subject. Therefore
18% reflectance does not apply (since you are not measuring reflected
light)
--
Remove uppercase letters for e-mail reply
------
Gregor Munro
Miramichi, N.B.
Canada
Phil Stripling
>SNIP<
> An incident reading will result in blacks being black, and whites being
> white, provided the range of the picture fits within the limits of a
> particular emulsion (which is normally the case when copying a picture.)
> It will also be the same as a reflected reading of an 18% grey card.
John, you're right. My intention was to raise the issue of whether the
painting is the equivalent of the 18% grey card. It _may_ be that the work
is not most accurately represented by the reflected reading of an 18% grey
card.
--
Phil Stripling
> Incident meter readings measure actual light falling on subject. Therefore
> 18% reflectance does not apply (since you are not measuring reflected
> light)
Hi, Greg,
My understanding of the incident meters I have had is that they read light
falling on them and give you the equivalent reading of a reflective meter
reading an 18% grey card. At least that's what the manual on my reflected
meter said. Did I misread?
Jim Waggener
> 18% reflectance does not apply (since you are not measuring reflected
> light)
>
> --
> Remove uppercase letters for e-mail reply
>
> ------
> Gregor Munro
> Miramichi, N.B.
> Canada
So the camera itself is only going to give me reflective readings correct?
Thats where a incident meter is the right tool for the job yes?
Jim Waggener
John Miller
> John, you're right. My intention was to raise the issue of whether the
> painting is the equivalent of the 18% grey card. It _may_ be that the work
> is not most accurately represented by the reflected reading of an 18% grey
> card.
You're absolutely right in that it may not, but -- although saying it this
way glosses over some details -- it doesn't matter. That's the beauty of
an incident reading (or reflected reading of an 18% grey card).
I'm sure you know the following, but just for the record...
...let's say you were copying an all-black picture and an all-white picture.
Neither is accurately represented by the reflected reading of an 18% grey,
card, and yet that single reading will give the correct exposure to make
the black picture come out black, and the white one, white (assuming once
again that those values can simultaneously be accommodated by the emulsion
in use).
Just pointing the reflected meter directly at the pictures will make them
both come out the same 18% grey, of course.
--
John Miller
Space tells matter how to move and matter tells space how to curve.
-- Wheeler
John Miller
> So the camera itself is only going to give me reflective readings correct?
Correct.
> Thats where a incident meter is the right tool for the job yes?
Yes, or, as a reasonable substitute, spot metering an 18% grey card
illuminated the same as the main subject.
--
John Miller
The whole of life is futile unless you consider it as a sporting
proposition.
Mike Marty
>
>
> So the camera itself is only going to give me reflective readings correct?
> Thats where a incident meter is the right tool for the job yes?
>
> Jim Waggener
>
>
Just get a Kodak grey card, put it under the same lighting, and use your
camera's meter to get a reading off of the card. Use that same reading
for all of your paintings.
Michael Quack
Jim Waggener says...
> I am doing some flat copy work of oil paintings indoors
> with tungsten lighting. Should I use incident or
> reflected meter readings for my exposure?
Nothing but incident. Include gray reference in your
pictures. Gray card, maybe also Kodak color control
swatches Q-13. If you need the paintings full frame,
shoot a separate reference image every time you change
your setup.
--
Michael Quack <mic...@photoquack.de>
Anytime terrorists want to scare the US, all they got to do is let
word get out they want to do something and the Bush administration
will do the terrorizing for them.
T.P
Greg M
> Greg M <mun...@Nnbnet.Nnb.Cca> writes:
>
>> Incident meter readings measure actual light falling on subject.
>> Therefore 18% reflectance does not apply (since you are not measuring
>> reflected light)
>
> Hi, Greg,
>
> My understanding of the incident meters I have had is that they read
> light falling on them and give you the equivalent reading of a
> reflective meter reading an 18% grey card. At least that's what the
> manual on my reflected meter said. Did I misread?
>
Hi Phil,
That's correct. As I understand it, when used properly, an incident light
meter is more accurate and easier to use since you don't have to estimate
the exposure adjustment. Of course, if you're an expert in the "Zone
System", one method is as easy as the other.
Greg
Rudy Garcia
"Jim Waggener" <ji...@visi.net> wrote:
If you know how to meter properly, either method will give you good
exposures.
--
Rudy Garcia
zilun
zilun
as a reference for measuring reflected light. Incident measures the actual
light hitting on the painting. How did the gray card issue get into this?
Also, why the hell you the painting need to average out as 18% gray?? If the
painting is mostly black, then, it's mostly black, capture the black; if the
painting is just a pure white canvas, then it's a pure white canvas, capture
the white.Why make it 18% gray? Make it as it truely is.
Incident, meaning, know how much light is hitting the surface, expose for
that amount of light.
18% gray is when you *don't* know how much light is hitting the surface and
had to guess, so you measure how much light is coming *from* the surface
reflected light ) by making an *assumption* that you composition averages
out to 18% gray.
"Jim Waggener" <ji...@visi.net> wrote in message
news:u6Wna.432$fb....@sydney.visi.net...
zilun
"Mike Marty" <mi...@cs.NOSPAMwisc.edu> wrote in message
news:b7pkbg$dno$1...@news.doit.wisc.edu...
>
> Just get a Kodak grey card, put it under the same lighting, and use your
> camera's meter to get a reading off of the card. Use that same reading
> for all of your paintings.
>
Wrong. Use an incident light meter, measure the light hitting the painting.
zilun
"Michael Quack" <mic...@photoquack.de> wrote in message
news:MPG.190a96acc...@news.cis.dfn.de...
> pictures. Gray card, maybe also Kodak color control
> swatches Q-13. If you need the paintings full frame,
> shoot a separate reference image every time you change
> your setup.
>
What does incident have to do with gray card? Incident will be the same at
the same position and direction, you can place a gray card or a white card
or a red card, or a black card or a light bulb or a neon bulb and it would
still be the same.
zilun
At the top of the mountain, a nice shot of the valley under the shadows of
the mountain. I'm not climbing down there to measure how much light is
hitting the valley. In the woods, a deer peeking out, the deer is not going
to stay still and let me walk up to it to measure how much light is hitting
it's skin. Statue of Liberty, yes, I climb up, measure, then, back down,
then a boat trip from the island back to NYC, but by the time I set up,
lighting is probably different. So on and so forth. That's when the gray
card comes in.
It's not really that diffcult to walk a few steps to the painting you just
setup in your own room, is it?
"Jim Waggener" <ji...@visi.net> wrote in message
news:u6Wna.432$fb....@sydney.visi.net...
Michael Quack
zilun says...
> > Nothing but incident. Include gray reference in your
> > pictures. Gray card, maybe also Kodak color control
> > swatches Q-13. If you need the paintings full frame,
> > shoot a separate reference image every time you change
> > your setup.
> What does incident have to do with gray card?
He's doing reproductions of paintings, dummy.
How do you think the lab or printer will know if they
reproduce the colors correct if they have no agreed
industry standard in the images to reference off?
Color control is the thing, not metering. That was taken
care of with the incident metering before color control
stepped in.
Mike Marty
> >
> > Just get a Kodak grey card, put it under the same lighting, and use your
> > camera's meter to get a reading off of the card. Use that same reading
> > for all of your paintings.
> >
>
> Wrong. Use an incident light meter, measure the light hitting the
painting.
>
What's the difference?
Mike Marty
"zilun" <zi...@pacbell.net> wrote in message
news:my3oa.258$Ha4.30...@newssvr21.news.prodigy.com...
> What's up with the gray card and incident light?? Gray card is for use
with
> as a reference for measuring reflected light. Incident measures the actual
> light hitting on the painting. How did the gray card issue get into this?
>
> Also, why the hell you the painting need to average out as 18% gray?? If
the
> painting is mostly black, then, it's mostly black, capture the black; if
the
> painting is just a pure white canvas, then it's a pure white canvas,
capture
> the white.Why make it 18% gray? Make it as it truely is.
>
> Incident, meaning, know how much light is hitting the surface, expose for
> that amount of light.
>
> 18% gray is when you *don't* know how much light is hitting the surface
and
> had to guess, so you measure how much light is coming *from* the surface
> reflected light ) by making an *assumption* that you composition averages
> out to 18% gray.
>
your camera's light meter is calibrated to give a proper exposure assuming
the scene reflects 18% of the light hitting it.
Taking a reading completely off of an 18% grey card using a reflective meter
would roughly be the same as using an incident meter.
Correct me if I'm wrong please. I'm only about 6 months into this hobby....
Jim Waggener
> your camera's light meter is calibrated to give a proper exposure assuming
> the scene reflects 18% of the light hitting it.
>
> Taking a reading completely off of an 18% grey card using a reflective
meter
> would roughly be the same as using an incident meter.
>
> Correct me if I'm wrong please. I'm only about 6 months into this
hobby....
>
>
>
Mike,
I believe what they are telling me is that a 18% gray card would work for a
reflective reading if the paintings averaged out to 18% with the colors
used. That is likely not the case because most of them have no neutral
colors in them at all. I don't know what the mix is to get 18% gray with
bold, vivid reds, blues, yellows etc. So my guess is a reflective reading
would not be appropriate for the copy work.
At least thats how I am reading the opinions expressed.
Thanks guys,
Jim
Eugene
Obviously an incident light meter would be ideal however a grey card should
also work perfectly well. An incident meter is calibrated to give you the
same exposure as a reflective meter reading from a grey card.
Eugene
> > > Just get a Kodak grey card, put it under the same lighting, and use
your
> > > camera's meter to get a reading off of the card. Use that same
reading
> > > for all of your paintings.
> > >
> >
> > Wrong. Use an incident light meter, measure the light hitting the
> painting.
> >
>
> What's the difference?
>
None, your original suggestion sounds reasonable to me.
Eugene
with printing.
Eugene
> Mike,
>
> I believe what they are telling me is that a 18% gray card would work for
a
> reflective reading if the paintings averaged out to 18% with the colors
> used. That is likely not the case because most of them have no neutral
> colors in them at all. I don't know what the mix is to get 18% gray with
> bold, vivid reds, blues, yellows etc. So my guess is a reflective reading
> would not be appropriate for the copy work.
>
> At least thats how I am reading the opinions expressed.
>
> Thanks guys,
>
> Jim
>
>
No, the grey card will work regardless of the colors in the original
painting. You could think of it as a substitute for an incident meter. Like
others have said, if you don't have an incident meter you can simply take a
reflective meter reading of the grey card (not the painting) to get the
correct exposure. In theory this should give you exactly the same reading as
the incident meter, the colors in the painting aren't really relevant as
using this technique should reproduce them exactly as they are.
Eugene
sun?
> Statue of Liberty, yes, I climb up, measure, then, back down,
> then a boat trip from the island back to NYC, but by the time I set up,
> lighting is probably different. So on and so forth. That's when the gray
> card comes in.
>
> It's not really that diffcult to walk a few steps to the painting you just
> setup in your own room, is it?
>
It's very important to be physically close to the subject to take the
reading when using studio lighting because unlike the sun, the inverse
square law is actually relevant.
zilun
Ever been to MOMA?
The paintings are not 18% gray when averaged out.
Actually, most paintings are not 18% gray when averaged out.
I used to paint. We have to exaggerate.
Painting is about illusion, not duplicating reality.
I do an abstract painting, it's a dark, dark, moody gray
with a bright orange, I don't think it's 18% gray.
Look at Margett's paintings, the city is at night, the sky is daylight,
I don't think its' 18% gray.
Look at Picasso's dark paintings, I don't think it's 18% gray.
look at his line drawings, just black lines on white canvas,
I don't think it averages out to 18% gray.
Look at the film Blade Runner, I don't think it's 18% gray.
When a painting mimics reality, there is no tension,
and there's no need to balance the tension,
there's no dynamics, there's no fun.
Paintings don't average out to 18% gray, please.
"Eugene" <eugene_NOS_...@yahoo.com> wrote in message
news:DD5oa.2252$e8.1...@nasal.pacific.net.au...
zilun
people associating gray cards to incident metering, dummy. I raised the
question because I don't see any relation, not because I don't understand
the relation, dummy.
"Michael Quack" <mic...@photoquack.de> wrote in message
news:MPG.190aef3f1...@news.cis.dfn.de...
> In article <iE3oa.260$qc4.30...@newssvr21.news.prodigy.com>,
> zilun says...
>
>
zilun
measure how much light is hitting your back. Is that it? Or do we just point
our meter to the sun? Do we point it up or down or towards the camera? Wait,
it's the same sun, doesn't really matter.
C'mon, I am just saying spot metering off gray cards are used when we don't
have the previlage to measure the incident light. And in the case of finding
out the exposure for the paintings, measuring incident light is actually
more accurate and easier than spot metering off a gray card.
"Eugene" <eugene_NOS_...@yahoo.com> wrote in message
news:NX5oa.2260$e8.1...@nasal.pacific.net.au...
zilun
incident light reading. Still, measuring incident light in this case, is
easier, and does not require a gray card.
"Mike Marty" <mi...@cs.NOSPAM.wisc.edu> wrote in message
news:rj5oa.1623$%_3.11...@newssrv26.news.prodigy.com...
Michael Quack
zilun says...
> " What does incident have to do with gray card? "
> was a question directed to people associating
> gray cards to incident metering,
Don't you think that it was a trifle lacking intelligence
to ask this in reply to *my* posting where the gray card
was explicitly suggested as *color reference* after incident
meter reading?
Maybe you should better have replied to a posting where
people _did_ associate gray cards with incident metering.....
zilun
"Michael Quack" <mic...@photoquack.de> wrote in message
news:MPG.190b23058...@news.cis.dfn.de...
Eugene
Why don't you go back and actually read the previous posts, no-one is
claiming that paintings have to average out to 18%, that would just be
stupid. Quite frankly the painting could be pink with white spots or black
with purple spots, I really don't care because it doesn't make the slightest
difference. The grey card is 18% grey and that's where the reading comes
from.
Just to refresh your memory, this is the post which you so fervently
disagreed with. Note the bit about getting a reading off the card.
>
> Just get a Kodak grey card, put it under the same lighting, and use your
> camera's meter to get a reading off of the card. Use that same reading
> for all of your paintings.
>
Kindly point out exactly what is wrong with what Mike has said here?
> No.
> Ever been to MOMA?
> The paintings are not 18% gray when averaged out.
> Actually, most paintings are not 18% gray when averaged out.
> I used to paint. We have to exaggerate.
> Painting is about illusion, not duplicating reality.
>
> I do an abstract painting, it's a dark, dark, moody gray
> with a bright orange, I don't think it's 18% gray.
> Look at Margett's paintings, the city is at night, the sky is daylight,
> I don't think its' 18% gray.
> Look at Picasso's dark paintings, I don't think it's 18% gray.
> look at his line drawings, just black lines on white canvas,
> I don't think it averages out to 18% gray.
> Look at the film Blade Runner, I don't think it's 18% gray.
>
> When a painting mimics reality, there is no tension,
> and there's no need to balance the tension,
> there's no dynamics, there's no fun.
> Paintings don't average out to 18% gray, please.
>
>
> > > > >
Eugene
> Okay, next time, when you do a scenery shot, just use an incident meter to
> measure how much light is hitting your back. Is that it? Or do we just
point
> our meter to the sun? Do we point it up or down or towards the camera?
Wait,
> it's the same sun, doesn't really matter.
>
You would point the meter towards the camera, it doesn't matter if you are
directly in front of the statue or a few hundred meters from it from it, the
reading will be the same because sunlight is the most even lightsource you
can get.
Having said that, incident light meters are often not suitable for
landscapes because there are other issues to take into consideration, like
the brightness of the sky. I was really just making the point that sunlight
doesn't vary a whole lot even over quite large distances, which means that
it isn't always nescessary to be physically close to the subject to take a
reading.
>
> C'mon, I am just saying spot metering off gray cards are used when we
don't
> have the previlage to measure the incident light. And in the case of
finding
> out the exposure for the paintings, measuring incident light is actually
> more accurate and easier than spot metering off a gray card.
>
True.
zilun
just that talking about gray card while suggesting incident metering got me
very mixed up.
again, my bad.
"Eugene" <eugene_NOS_...@yahoo.com> wrote in message
news:Lr8oa.2275$e8.1...@nasal.pacific.net.au...
T.P
No, Mike is right. If you don't have an incident meter, taking a
reflective meter reading off a grey card is almost as good. If the
grey card is held perpendicular to the lens axis (in other words,
ignore the advice of some ignorant people to tilt it upwards)) it
should give precisely the same reading as an incident meter.
After all, this is *exactly* what grey cards were designed to do.
T.P
>No.
>Ever been to MOMA?
>The paintings are not 18% gray when averaged out.
>Actually, most paintings are not 18% gray when averaged out.
>I used to paint. We have to exaggerate.
>Painting is about illusion, not duplicating reality.
>
>I do an abstract painting, it's a dark, dark, moody gray
>with a bright orange, I don't think it's 18% gray.
>Look at Margett's paintings, the city is at night, the sky is daylight,
>I don't think its' 18% gray.
>Look at Picasso's dark paintings, I don't think it's 18% gray.
>look at his line drawings, just black lines on white canvas,
>I don't think it averages out to 18% gray.
>Look at the film Blade Runner, I don't think it's 18% gray.
>
>When a painting mimics reality, there is no tension,
>and there's no need to balance the tension,
>there's no dynamics, there's no fun.
>Paintings don't average out to 18% gray, please.
With respect, what reflectance a painting has, and whether or not it
approximates to 18%, is of no relevance whatsoever to exposure.
The whole concept of incident light metering means that reflectance is
taken *completely out* of the exposure calculation. And if you don't
have access to an incident light meter, the Kodak grey card is, if
used correctly, an *excellent* substitute.
Perhaps you should buy a book on the basics of photography, read the
section in exposure and learn it, if only to avoid posting your
(albeit well-meaning) nonsense on here.
T.P
>What's up with the gray card and incident light?? Gray card is for use with
>as a reference for measuring reflected light. Incident measures the actual
>light hitting on the painting. How did the gray card issue get into this?
Because, as any competent photographer knows, an incident light meter
reading and a reflective light meter reading taken off a grey card
(used properly) should be *identical*.
Go buy a book on basic photography. Read the chapter(s) on exposure.
T.P
>Mike,
>
>I believe what they are telling me is that a 18% gray card would work for a
>reflective reading if the paintings averaged out to 18% with the colors
>used. That is likely not the case because most of them have no neutral
>colors in them at all. I don't know what the mix is to get 18% gray with
>bold, vivid reds, blues, yellows etc. So my guess is a reflective reading
>would not be appropriate for the copy work.
>
>At least thats how I am reading the opinions expressed.
Then either you are reading the wrong opinions,
or you are just *reading them wrong*.
Reflective readings off an 18% grey card used
properly, and incident readings, should be:
EXACTLY THE SAME.
If they aren't, you are doing something wrong.
T.P
>You are right about the calibration, yes, the exposure will be very close to
>incident light reading. Still, measuring incident light in this case, is
>easier, and does not require a gray card.
If you don't have an incident light meter,
the ONLY way you can take incident light
readings is with a reflective light meter
and a grey card, used properly.
T.P
>
>You would point the meter towards the camera, it doesn't matter if you are
>directly in front of the statue or a few hundred meters from it from it, the
>reading will be the same because sunlight is the most even lightsource you
>can get.
Wrong. If the subject is surrounded by areas of different reflectance
than the areas surrounding the photographer, you can get a very
different incident light reading.
An incident light meter measures the light falling on the subject not
only from the primary light source (in this case, the sun) but also
secondary light sources including sunlight reflected off the ground,
trees and bushes and constructed objects such as buildings and
streets. If the photographer is not in surroundings that are exactly
comparable with the subject's, an incident reading taken at the camera
position can only differ from that taken at the subject position.
All these problems can easily be solved by learning about exposure and
what it means. It's worth buying a book on the basics of photography
and reading the chapter on exposure, or getting some basic tuition
(you really cannot get more *basic* than this!), or both.
Matt Clara
"Phil Stripling" <phil_st...@cieux.zzn.com> wrote in message
news:3qfzofm...@shell4.tdl.com...
> Greg M <mun...@Nnbnet.Nnb.Cca> writes:
>
> > Incident meter readings measure actual light falling on subject.
Therefore
> > 18% reflectance does not apply (since you are not measuring reflected
> > light)
>
> Hi, Greg,
>
> My understanding of the incident meters I have had is that they read light
> falling on them and give you the equivalent reading of a reflective meter
> reading an 18% grey card. At least that's what the manual on my reflected
> meter said. Did I misread?
>
> --
Phil,
You've got it right, you're just confusing two things: the incident light
meter says this _light_ at these settings is 18% grey, while the reflected
meter says this _subject_ at these settings is 18% grey. If your subject
was very dark or very light the reflected reading would be different from
the incident reading.
If you depend on a reflected meter and don't manually compensate, a light or
dark subject will come out medium grey. If you depend on an incident meter,
a light or dark subject should come out respectively light or dark. If the
number of stops between medium grey and light or dark exceeds your film's
latitude, those light or dark subjects will have no detail in them at all.
In other words, some compensation may be in order whether you are using
incident or reflected, depending on your desired results.
zilun
incident light.
I have already apologized for the mixed up. But since the original question
asks, " Incident or Reflected ", it's given that the person who asks this
has an incident meter. So we don't need to worry that if he can't do this,
then the only other option is this. He is already asking, ' I have 2
options, well, which? ' And it's obvious that measuring incident in this
case, is faster than spot-metering off a gray card. And almost in every
reply, the suggestion is meter incident, then goes on to talk about the gray
card. I just read the thread and stopped to post comments. There were
replies of worries and assurances if 18% gray as a good representations,
comments that incident will meter an 18% gray value, I jump in, and replied
to the wrong posts.
Phil, " Incident will give you an overall reading of 18% gray reflectance."
Phil, " My intention was to raise the issue of whether the painting is the
equivalent of the 18% grey card. It _may_ be that the work is not most
accurately represented by the reflected reading of an 18% grey card."
Still, no offense, Phil, and again, sorry, Mike, Michael, Eugene.
"T.P" <T...@noemailthanks.com> wrote in message
news:bm92av8325o9o3d99...@4ax.com...
zilun
Sorry, Jim.
"T.P" <T...@noemailthanks.com> wrote in message
news:bq92avcpvrkek4he2...@4ax.com...
zilun
"Matt Clara" <no.e...@this.guys.expense> wrote in message
news:7yaoa.308739$yn2....@post-03.news.easynews.com...
Matt,
Incident has nothing to do with whether the subject is light or dark.
Incident meter is pretty dependable.
You and Phil got it backwards.
Incident meters are not set out to match the 18% gray.
The 18% gray system was created as a solution to match the incident
metering.
Incident measures light hitting the subject, regardless of subject matter.
But, to take readings from refeccted light,
manufacturers agreed to meter off 18% gray as correct exposure,
so, if your compostion is 18% gray,
the reading of the reflected lights will be close to the incident value.
But, 18% gray will not work in every situation,
so, here comes the gray card, and it will work for this situation,
becuase the card is exactly 18% gray,
this ensures the reflected reading will match the incident's..
They could have made the card-meter system work with 90% gray,
just that if they did do so, without the card, most of the time,
metering reflected lights directly from the subject won't work.
You don't need to manually compensate for either case.
Your light-dark latitue issue only comes in if you spot meter
your overall compostion with the zone system.
I had already caused enough trouble and confusion,
this just adds more.
Matt Clara
"zilun" <zi...@pacbell.net> wrote in message
news:DVaoa.322$GO5.36...@newssvr21.news.prodigy.com...
I'm sorry, but you have no idea what you're talking about.
T.P
>I don't need a book to know I don't need a gray card if I am measuring
>incident light.
There is only one thing worse than a profoundly ignorant person, and
that is a profoundly ignorant person who has a pathological fear (or
hatred) of knowledge.
May your God help you.
Rudy Garcia
T.P <T...@noemailthanks.com> wrote:
There is no magic in incident vs. reflected metering. They both assume
the subject will be 18% gray, but in different ways.
A reflective reading measures the light reflected from the subject and
assumes the subject's reflectance averages out to 18% gray. It then
computes the exposure accordingly.
An incident reading measures the light falling on the subject and then
computes the exposure value that would be correct, if the subject's
reflectance was 18% gray.
Over most subjects, an incident reading will tend to give more "correct"
exposures, particularly for those users that are not familiar with how
the different meters operate.
--
Rudy Garcia
Rudy Garcia
T.P <T...@noemailthanks.com> wrote:
Actually, you should hold the card in such a way that it doesn't result
in specular reflections being reflected back to the meter. This normally
requires positioning the card at some angle to the light and or lens
such that the specular reflections are not directed to the meter.
--
Rudy Garcia
John Miller
> There is no magic in incident vs. reflected metering. They both assume
> the subject will be 18% gray, but in different ways.
I'm afraid there's been a misunderstanding...
> A reflective reading measures the light reflected from the subject and
> assumes the subject's reflectance averages out to 18% gray. It then
> computes the exposure accordingly.
Yep.
> An incident reading measures the light falling on the subject and then
> computes the exposure value that would be correct, if the subject's
> reflectance was 18% gray.
Introducing 18% grey into the operation of an incident meter merely confuses
the issue. A subject's reflectance is irrelevant to an incident meter.
Whether you're metering light falling on a coal bin or a snow bank, the
exposure given by an incident meter will be the same. (The foregoing in no
way conflicts with the fact that an incident reading will be the same as a
reflected reading from an 18% grey card.)
> Over most subjects, an incident reading will tend to give more "correct"
> exposures, particularly for those users that are not familiar with how
> the different meters operate.
And that's one of the key advantages of incident metering.
--
John Miller
A man who turns green has eschewed protein.
T.P
>Actually, you should hold the card in such a way that it doesn't result
>in specular reflections being reflected back to the meter. This normally
>requires positioning the card at some angle to the light and or lens
>such that the specular reflections are not directed to the meter.
If specular reflections are a problem, there is something wrong with
your grey card.
zilun
incident light meter???????????????????
"T.P" <T...@noemailthanks.com> wrote in message
news:hcl2av0lhjrfuertn...@4ax.com...
zilun
What makes you think I hate knowledge?
How often do you watch TV?
Come to my place and there's no TV, just a wall of books.
Saying I fear knowlege makes you an expert?
So I don't think any book will tell me how to use a gray card with my
incident meter properly, that translate to me hating knowlege and need my
God's help?????? Why don't you be an expert and just correct me and tell me
how to use a gray card with an incident light meter?????????
The time you spent saying I am ignorant and fear knowlege and get a boook,
etc, you could have said, take out your incident light meter, take out your
gray card, do this, and do that.
Okay, tell me now. I'm brave enough to accept knowlege now.
"T.P" <T...@noemailthanks.com> wrote in message
news:hcl2av0lhjrfuertn...@4ax.com...
zilun
source, compensation, or actually, finding somewhere in between the range is
in order. We would need your careful approach. For this case, to photograph
a flat painting, with one light source, we just need to place the incident
meter in front of the paiting, pointing towards the camera, I don't think we
need to compensate for anything.
As far as incident meter's reading is 18% light at the right exposure, I
don't believe so. Incident just states there's this much light. Phil's
question on incident meter giving the reading of a reflective meter of an
18% gray card, though it is true, it is not because incident is measuring
18% light. The reflective meter is setup to measure 18% gray as the right
exposure, so placing a card in front makes the whole scene 18% gray, taking
that exposure then becomes the correct exposure. Correct exposure will mean
knowing how much light is falling onto the subject, thus equavalent to
incident reading, not equivalent to exposing at 18% light. The manufacturers
could have easily setup a meter so that when you place a 85.8% Red card, it
will give a correct exposure, which would mean, matching the incident meter.
The reason they settled for 18% gray because they took a bunch of photos,
and most averages out to 18% gray, so, if there were no gray card, the meter
could work, assuming most photos are 18% gray. 18% gray because "what if
there were no incident meter and no exposure reference card for the
reflective meter", not because 18% gray is correctly lit scene.
"Matt Clara" <no.e...@this.guys.expense> wrote in message
news:Foboa.311532$yn2....@post-03.news.easynews.com...
Rudy Garcia
Both metering cells are measuring the light incident on them (thus, in a
way, they are both incident meter readings).
Neither meter is reading out in units of light but in units of exposure.
The computation carried out by the incident meter to convert from light
to exposure value implicitly assumes an 18% reflectance of the subject.
--
Rudy Garcia
Rudy Garcia
T.P <T...@noemailthanks.com> wrote:
Most commercially available gray cards have a finish that will result in
such reflections if the angles are just right. Perhaps glare reflection
is more appropriate in this case than specular.
--
Rudy Garcia
Rudy Garcia
"zilun" <zi...@pacbell.net> wrote:
> Matt, if we are talking about metering a scene, with more than one light
> source, compensation, or actually, finding somewhere in between the range is
> in order. We would need your careful approach. For this case, to photograph
> a flat painting, with one light source, we just need to place the incident
> meter in front of the paiting, pointing towards the camera, I don't think we
> need to compensate for anything.
>
> As far as incident meter's reading is 18% light at the right exposure, I
> don't believe so. Incident just states there's this much light. Phil's
> question on incident meter giving the reading of a reflective meter of an
> 18% gray card, though it is true, it is not because incident is measuring
> 18% light. The reflective meter is setup to measure 18% gray as the right
> exposure, so placing a card in front makes the whole scene 18% gray, taking
> that exposure then becomes the correct exposure. Correct exposure will mean
> knowing how much light is falling onto the subject, thus equavalent to
> incident reading, not equivalent to exposing at 18% light. The manufacturers
> could have easily setup a meter so that when you place a 85.8% Red card, it
> will give a correct exposure, which would mean, matching the incident meter.
> The reason they settled for 18% gray because they took a bunch of photos,
> and most averages out to 18% gray, so, if there were no gray card, the meter
> could work, assuming most photos are 18% gray. 18% gray because "what if
> there were no incident meter and no exposure reference card for the
> reflective meter", not because 18% gray is correctly lit scene.
Lets break it into basics to demistify this.
The metering cells of both types of meters measure incident light. That
is, light that is incident on them.
A reflective meter is meant to be used to measure the light that
reflects from the subject. When properly used, the light incident on the
meter's cell is the light reflected from the subject.
An incident meter is meant to be used to measure the light incident on
the subject.
Since we are talking about photographic meters, we don't want to have a
reading in terms of luxes or some such units. We want to have a reading
of Exposure Values, or preferably, aperture and shutter speed.
To get this kind of reading, both meters need to do a little math to
produce the results.
They will both need to know the ISO rating of the film used. Armed with
the amount of light incident on the meter cell (or diffusing dome) and
the ISO rating, the reflective meter cranks through an equation that
causes the exposure to render the subject 18% gray on the exposure. The
constants in the equation it solves assumes that the subject was 18%
gray in the first place.
The incident meter also needs the ISO rating and given the incident
light, it computes what exposure value is required to render the subject
as 18% gray IF the subject was 18% gray to begin with.
Neither meter can really tell if the subject is 18% gray or not. They
can only measure the light incident on their cells and solve an equation
with some additional constants.
Since they are used differently, it is not surprising that the results
are different for different subject reflectances.
--
Rudy Garcia
Jim Waggener
I appreciate your explanation. Very concise. I guess my question still is
from my original post, do I use incident or reflective for copy work and how
would I (or the meter) know if oil paintings are 18% gray? Just take the
reading either way and bracket? I don't have a gray card so that leaves me
with incident at the present.
Jim
zilun
"Rudy Garcia" <ru...@jps.net.invalid> wrote in message
news:rudyg-057F1F....@nnrp01.earthlink.net...
> In article <76joa.60$nt7.5...@newssvr21.news.prodigy.com>,
> "zilun" <zi...@pacbell.net> wrote:
>
> Lets break it into basics to demistify this.
>
> The metering cells of both types of meters measure incident light. That
> is, light that is incident on them.
>
> A reflective meter is meant to be used to measure the light that
> reflects from the subject. When properly used, the light incident on the
> meter's cell is the light reflected from the subject.
>
> An incident meter is meant to be used to measure the light incident on
> the subject.
>
> Since we are talking about photographic meters, we don't want to have a
> reading in terms of luxes or some such units. We want to have a reading
> of Exposure Values, or preferably, aperture and shutter speed.
>
> To get this kind of reading, both meters need to do a little math to
> produce the results.
>
> They will both need to know the ISO rating of the film used. Armed with
> the amount of light incident on the meter cell (or diffusing dome) and
> the ISO rating, the reflective meter cranks through an equation that
> causes the exposure to render the subject 18% gray on the exposure. The
> constants in the equation it solves assumes that the subject was 18%
> gray in the first place.
>
True. So far.
> The incident meter also needs the ISO rating and given the incident
> light, it computes what exposure value is required to render the subject
> as 18% gray IF the subject was 18% gray to begin with.
>
No, I can place an incident light meter in front of a black object, pointing
towards my camera, take the aperture and shutter speed reading based on my
ISO, and the object will not render 18% gray according to the exposure. It
will render black. If I replace it with a white object, the exposure
readings do not change.
> Neither meter can really tell if the subject is 18% gray or not. They
> can only measure the light incident on their cells and solve an equation
> with some additional constants.
>
Yes. Incident meter can not tell if anything is 18%, light or subject, and
does not care about anything related to 18% gray. Spot meter, which is
reflective meter fom your camera, if pointed to an object, any object, and
you use its suggested exposure, the object will appear 18% gray. So, place
an 18% gray in front of it, and everything will appear as they are.
> Since they are used differently, it is not surprising that the results
> are different for different subject reflectances.
>
No, if used correctly, both should yield the same suggested sets of aperture
and exposure. Both are set to expose the subject correctly.
zilun
"Jim Waggener" <ji...@visi.net> wrote in message
news:Hcloa.437$fb....@sydney.visi.net...
Jim,
Just use incident metering. Place your incident meter in front of your
painting, pointing towards your camera, use the reading. If your paiting is
black, it's black, if your painting is 30% orange, it's 30% orange. Forget
about the reflected meter and the 18% gray. If you are really curious about
the 18% gray, then, place an 18% gray card in front of your painting, so
that the card gets the same light as the painting, then, use your camera's
spot meter to meter off the gray card, and lock the exposure. Now, throw
away the gray card and use the locked exposure to shoot your painting. If
your paiting is black, it's black, if your painting is 30% orange, it's 30%
orange. Your painting will not need to be 18% gray. But see how silly spot
metering off a gray card in this situation is?
If you don't have an 18% gray reference card, and you spot meter the dark
areas of your paitning, you spot meter the midtone of your painting, you
spot meter the highlights of your painting, and take those readings and
manually set a aperture-shutter in the middle range, and the photo of your
painting comes out great, then your painting is 18% gray. But I am sure your
paintings are not 18% gray. Just worry about the light that's hitting your
paiting and going through your lens. For this case, forget that anyone ever
said anything about 18% gray.
Jim Waggener
Jim
Stefan Patric
> I am doing some flat copy work of oil paintings indoors with
> tungsten
> lighting. Should I use incident or reflected meter readings for my
> exposure?
In 30 years of commercial photography, I've always used a incident
meter, at the subject, and bracketed that exposure + and - 1 stop in
half or 1/3 stop increments to get the "best" chrome. The "best"
exposure is not always the technically "correct" exposure.
I also include a Kodak Color Separation target in the shot to help
with printing, color separations, etc.
Be sure to use tungsten film and lights with new 3200K lamps,
otherwise, your color will be off.
--
Stefan Patric
too...@yahoo.com
T.P
>
>Most commercially available gray cards have a finish that will result in
>such reflections if the angles are just right. Perhaps glare reflection
>is more appropriate in this case than specular.
If you use the grey card in the proper manner, with the card on - and
exactly perpendicular to - the lens axis, you will not have any
problems with reflection.
T.P
>Okay, will you be so kind and tell me how ro use a gray card with my
>incident light meter???????????????????
Why on earth would you want to do that?
Have you ever thought of a new career as a stand-up comic?
T.P
You are sooooooooo beyond help.
T.P
Jim,
Just use an incident meter at the same position as the painting, point
it exactly at the camera and take a reading. Then use that reading.
End of story.
Tony
Rudy Garcia
T.P <T...@noemailthanks.com> wrote:
Not quite. You also need to insure that the location of the light source
will not result in glare from the card surface being seen by the lens.
--
Rudy Garcia
Rudy Garcia
"Jim Waggener" <ji...@visi.net> wrote:
You can always take a reflected reading from the palm of your hand and
open up 1 stop from the reading.
If you are not quite sure on how to compensate a meter reading then by
all means use an incident reading.
--
Rudy Garcia
Rudy Garcia
"zilun" <zi...@pacbell.net> wrote:
You didn't quite grasp what I wrote. The meter gives an exposure reading
to render a gray subject as gray on the film. It doesn't know your
subject is black and it doesn't care. If your subject is black, it will
be rendered as black, because it is darker than the gray tone that is
built into the equation the meter uses.
> > Neither meter can really tell if the subject is 18% gray or not. They
> > can only measure the light incident on their cells and solve an equation
> > with some additional constants.
> >
>
> Yes. Incident meter can not tell if anything is 18%, light or subject, and
> does not care about anything related to 18% gray. Spot meter, which is
> reflective meter fom your camera, if pointed to an object, any object, and
> you use its suggested exposure, the object will appear 18% gray. So, place
> an 18% gray in front of it, and everything will appear as they are.
>
> > Since they are used differently, it is not surprising that the results
> > are different for different subject reflectances.
> >
>
> No, if used correctly, both should yield the same suggested sets of aperture
> and exposure. Both are set to expose the subject correctly.
They will read the same IF AND ONLY IF the subject is a gray tone and
the meters are calibrated to the same standard card (tone). Beyond
that, and adjustments to the reading will be needed, depending on what
you want to artistically capture on film.
--
Rudy Garcia
zilun
Just tell me how to use the gary card with my incident light meter as you
had suggested.
"T.P" <T...@noemailthanks.com> wrote in message
news:a325avo3rh3joh418...@4ax.com...
zilun
Becuause you told me I should get a book and look it up on how to do it, and
if I don'tget a book, I'll need my god's help to overcome my fear of
knowledge. Stop the crap and tell me how to use a gray card with an incident
light meter.
Frank Pittel
: okay. my bad.
: just that talking about gray card while suggesting incident metering got me
: very mixed up.
: again, my bad.
I've noticed that TP is good at getting things confused. In the end either
incident or reflective with a gray card will work. Use which ever you feel
most comfortable with and what your meter will allow.
: "Eugene" <eugene_NOS_...@yahoo.com> wrote in message
: news:Lr8oa.2275$e8.1...@nasal.pacific.net.au...
:> You missed the point entirely.
:>
:> Why don't you go back and actually read the previous posts, no-one is
:> claiming that paintings have to average out to 18%, that would just be
:> stupid. Quite frankly the painting could be pink with white spots or black
:> with purple spots, I really don't care because it doesn't make the
: slightest
:> difference. The grey card is 18% grey and that's where the reading comes
:> from.
:>
:> Just to refresh your memory, this is the post which you so fervently
:> disagreed with. Note the bit about getting a reading off the card.
:>
:> >
:> > Just get a Kodak grey card, put it under the same lighting, and use your
:> > camera's meter to get a reading off of the card. Use that same reading
:> > for all of your paintings.
:> >
:>
:> Kindly point out exactly what is wrong with what Mike has said here?
:>
:>
:> > No.
:> > Ever been to MOMA?
:> > The paintings are not 18% gray when averaged out.
:> > Actually, most paintings are not 18% gray when averaged out.
:> > I used to paint. We have to exaggerate.
:> > Painting is about illusion, not duplicating reality.
:> >
:> > I do an abstract painting, it's a dark, dark, moody gray
:> > with a bright orange, I don't think it's 18% gray.
:> > Look at Margett's paintings, the city is at night, the sky is daylight,
:> > I don't think its' 18% gray.
:> > Look at Picasso's dark paintings, I don't think it's 18% gray.
:> > look at his line drawings, just black lines on white canvas,
:> > I don't think it averages out to 18% gray.
:> > Look at the film Blade Runner, I don't think it's 18% gray.
:> >
:> > When a painting mimics reality, there is no tension,
:> > and there's no need to balance the tension,
:> > there's no dynamics, there's no fun.
:> > Paintings don't average out to 18% gray, please.
:> >
:> >
:> > > > > >
:> > > > > > Just get a Kodak grey card, put it under the same lighting, and
:> use
:> > > your
:> > > > > > camera's meter to get a reading off of the card. Use that same
:> > > reading
:> > > > > > for all of your paintings.
:> > > > > >
:> > > > >
:> > > > > Wrong. Use an incident light meter, measure the light hitting the
:> > > > painting.
:> > > > >
:> > > >
:> > > > What's the difference?
:> > > >
:> > >
:> > > None, your original suggestion sounds reasonable to me.
:> > >
:> > >
:> >
:> >
:>
:>
--
Keep working millions on welfare depend on you
-------------------
f...@deepthought.com
Frank Pittel
: "zilun" <zi...@pacbell.net> wrote in message
: news:DVaoa.322$GO5.36...@newssvr21.news.prodigy.com...
:>
:> "Matt Clara" <no.e...@this.guys.expense> wrote in message
:> news:7yaoa.308739$yn2....@post-03.news.easynews.com...
:> >
:> > "Phil Stripling" <phil_st...@cieux.zzn.com> wrote in message
:> > news:3qfzofm...@shell4.tdl.com...
:> > > Greg M <mun...@Nnbnet.Nnb.Cca> writes:
:> > >
:> > > > Incident meter readings measure actual light falling on subject.
:> > Therefore
:> > > > 18% reflectance does not apply (since you are not measuring
: reflected
:> > > > light)
:> > >
:> > > Hi, Greg,
:> > >
:> > > My understanding of the incident meters I have had is that they read
:> light
:> > > falling on them and give you the equivalent reading of a reflective
:> meter
:> > > reading an 18% grey card. At least that's what the manual on my
What makes you say that??
Frank Pittel
: Rudy,
If you have an incident meter use it. Hold the meter as close to the
painting as you can with the sensor pointed to the lens of the camera.
Since you're going to be in front of the lights be careful of shadows and
use the reading the meter gives you. Don't worry about 18% gray.
Frank Pittel
: "Jim Waggener" <ji...@visi.net> wrote in message
: news:Hcloa.437$fb....@sydney.visi.net...
:> Rudy,
:>
:> I appreciate your explanation. Very concise. I guess my question still is
:> from my original post, do I use incident or reflective for copy work and
: how
:> would I (or the meter) know if oil paintings are 18% gray? Just take the
:> reading either way and bracket? I don't have a gray card so that leaves me
:> with incident at the present.
:>
:> Jim
:>
:>
: Jim,
: Just use incident metering. Place your incident meter in front of your
: painting, pointing towards your camera, use the reading. If your paiting is
: black, it's black, if your painting is 30% orange, it's 30% orange. Forget
: about the reflected meter and the 18% gray. If you are really curious about
: the 18% gray, then, place an 18% gray card in front of your painting, so
: that the card gets the same light as the painting, then, use your camera's
: spot meter to meter off the gray card, and lock the exposure. Now, throw
: away the gray card and use the locked exposure to shoot your painting. If
: your paiting is black, it's black, if your painting is 30% orange, it's 30%
: orange. Your painting will not need to be 18% gray. But see how silly spot
: metering off a gray card in this situation is?
In this situation anything but an incident meter is going to make things a lot
more complicated then they need to be.
: If you don't have an 18% gray reference card, and you spot meter the dark
: areas of your paitning, you spot meter the midtone of your painting, you
: spot meter the highlights of your painting, and take those readings and
: manually set a aperture-shutter in the middle range, and the photo of your
: painting comes out great, then your painting is 18% gray. But I am sure your
: paintings are not 18% gray. Just worry about the light that's hitting your
: paiting and going through your lens. For this case, forget that anyone ever
: said anything about 18% gray.
To complicated and prone to error. Use an incident meter. :-)
I normally use a spot meter and the zone system for determining exposure
and in this situation wouldn't even consider using anything but an
incident meter.
Frank Pittel
: Phil Stripling <phil_st...@cieux.zzn.com> wrote in
: news:3qfzofm...@shell4.tdl.com:
:> Greg M <mun...@Nnbnet.Nnb.Cca> writes:
:>
:>> Incident meter readings measure actual light falling on subject.
:>> Therefore 18% reflectance does not apply (since you are not measuring
:>> reflected light)
:>
:> Hi, Greg,
:>
:> My understanding of the incident meters I have had is that they read
:> light falling on them and give you the equivalent reading of a
:> reflective meter reading an 18% grey card. At least that's what the
:> manual on my reflected meter said. Did I misread?
:>
: Hi Phil,
: That's correct. As I understand it, when used properly, an incident light
: meter is more accurate and easier to use since you don't have to estimate
: the exposure adjustment. Of course, if you're an expert in the "Zone
: System", one method is as easy as the other.
I do use the zone system and could get an exposure with a spot meter and
no gray card, but why? An incident meter will give me what I want in this
situation. I'm assuming contrast control isn't a concern. :-) (this is
flame bait but please leave it alone:-))
NickC
I'm offering just a casual comment concerning reflective and incident light
meter readings. If either system were to provide perfect (or near perfect)
picture taking exposures, there would be no need for using the practice of
bracketing. In the end analysis, the photographer must rely upon experience
and knowledge of the equipment being used.
Nick
zilun
Oh, really???
When I said, " I don't need a book to know I don't need a gray card if I am
measuring incident light. "
Your reply was, " There is only one thing worse than a profoundly ignorant
person, and that is a profoundly ignorant person who has a pathological fear
(or hatred) of knowledge. May your God help you. "
Now, according to you, that's not end of story, shouldn't I get a book to
overcome the fear of learning using a gray card with my incident light
meter?