F/ number in relation to the sensor size

[bobn2]

An image file itself has no brightness, only data levels. A given image file (set of data) can result in a final image of virtually any brightness depending on how it is processed or post processed or manipulated by the controls of the output medium.

It's also worth noting that 'brightness' at the output (more technically called 'lightness') is a completely different sort of thing to 'exposure' at the input. Talking physically, exposure is luminous energy density, it is a physical quantity that has a unit associated with it, the lux second. 'Lightness' on the other hand is not a physical quantity. It is just a position on a scale running from black to a bit whiter than white. It has no physical reality until you use it to control an output device (be it screen, projector or print). It is that device, its settings and the viewing conditions that determine what is the luminous energy density at the surface of the viewed image. It has no direct connection with the original exposure, except that relative exposure from the darkest to brightest parts of the image projected by the lens control the grey scale. That's why there is no requirement for any 'amplification' as part of this processing chain. What is required is to measure the exposure from point to point as accurately as possible. Electrical amplification sometimes is a means to that end, but it is not the end in itself.

 

[Moti]

I'm just amazed at how off base some of you are. It's like you are trying to fit the facts to a predetermined argument.

ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER!!! Hello! That's what exposure is!

Nope. There's a very clear definition of what exposure is. The fact that you choose to ignore it and make up your own stuff does not really change that.

But whatever. This is pretty common here, so you're in good company.

Just for curiosity, So you are saying that exposure is not a way of making an image brighter or dimmer?

Exposure does indeed affect the brightness of the final image,

of course, every photographer with a bit of knoledge knows that.

but it is not part of the brightening processes applied in creating that final image.

every photographer with a bit of knoledge knows that too because once the film or sensor is exposed, exposure cannot be changed anymore hence, brightening can only be controlled during processing phase.

So if a guy like Lumigraphics comes and says ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER, he is not that wrong as you guys make out of him. His only crime maybe is coming from film photography, where exposure and brightness used to be synonyms and the these terms get now sometimes mixed in daily language.

That said, I agree that exact and accurate definitions of things is important but I also believe that trying to understanding what people actually meant to say when they say something, trying to read between the lines and trying to be more open minded, IS much more important. And when it comes to this, some of the guys here have still a long way to go.

Moti

 

[Great Bustard]

I'm just amazed at how off base some of you are. It's like you are trying to fit the facts to a predetermined argument.

ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER!!! Hello! That's what exposure is!

Nope. There's a very clear definition of what exposure is. The fact that you choose to ignore it and make up your own stuff does not really change that.

But whatever. This is pretty common here, so you're in good company.

Just for curiosity, So you are saying that exposure is not a way of making an image brighter or dimmer?

Exposure does indeed affect the brightness of the final image,

of course, every photographer with a bit of knoledge knows that.

but it is not part of the brightening processes applied in creating that final image.

every photographer with a bit of knoledge knows that too because once the film or sensor is exposed, exposure cannot be changed anymore hence, brightening can only be controlled during processing phase.

So if a guy like Lumigraphics comes and says ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER, he is not that wrong as you guys make out of him. His only crime maybe is coming from film photography, where exposure and brightness used to be synonyms and the these terms get now sometimes mixed in daily language.

That said, I agree that exact and accurate definitions of things is important but I also believe that trying to understanding what people actually meant to say when they say something, trying to read between the lines and trying to be more open minded, IS much more important. And when it comes to this, some of the guys here have still a long way to go.

Lumigraphics' crime was how he responded to correct information. He insisted, over and over, to his right to be willfully ignorant, insulting those trying to explain things to him. This is all to common a crime on DPR (and probably anywhere else).

The bottom line is that he could have come out a bit more knowledgeable than he came in but chose instead to repeatedly punch himself in the face only to eventually walk away thinking he won a fight,

 

[gollywop]

I'm just amazed at how off base some of you are. It's like you are trying to fit the facts to a predetermined argument.

ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER!!! Hello! That's what exposure is!

Nope. There's a very clear definition of what exposure is. The fact that you choose to ignore it and make up your own stuff does not really change that.

But whatever. This is pretty common here, so you're in good company.

Just for curiosity, So you are saying that exposure is not a way of making an image brighter or dimmer?

Exposure does indeed affect the brightness of the final image,

of course, every photographer with a bit of knoledge knows that.

but it is not part of the brightening processes applied in creating that final image.

every photographer with a bit of knoledge knows that too because once the film or sensor is exposed, exposure cannot be changed anymore hence, brightening can only be controlled during processing phase.

So if a guy like Lumigraphics comes and says ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER, he is not that wrong as you guys make out of him.

Of course it's wrong. That's just like saying that the recording level is all a way of making the listening volume louder or softer.

His only crime maybe is coming from film photography, where exposure and brightness used to be synonyms

For a guy who, I must suppose, comes from film days, that's a pretty ignorant statement. What I did to expose the film in camera and what I did to process and print that image in the dark room hardly allowed exposure and brightness to be synonymous – any more so then than now.

and the these terms get now sometimes mixed in daily language.

As well they should.

--
gollywop
I am not a moderator or an official of dpr. My views do not represent, or necessarily reflect, those of dpr.
http://g4.img-dpreview.com/D8A95C7DB3724EC094214B212FB1F2AF.jpg

 

[Dennis]

So if a guy like Lumigraphics comes and says ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER, he is not that wrong as you guys make out of him.

You're down in the guts of the conversation at this point. It all started with his reply to the OP, stating:
"Equivalence is a false idea. If you factor in depth-of-field, then exposure changes and vice versa. You cannot and will not get the same results from different sensor or film sizes."

I've read a few posts by lumigraphics in a couple of threads recently and he's apparently out to loudly rant about how equivalence is dumb without saying what's supposedly dumb about equivalence or taking the time to reply directly to points people are making when they patiently take time to explain to him what equivalence is (and what it isn't).

He seems to be (from his website) an extremely capable photographer who has no need or use for equivalence* but inexplicably feels the need to disparage it without understanding it.

*Few people have any need for equivalence and its best use as a handy tool for quickly comparing capabilities across systems. Here on the forums, it's most often used to counter misinformation (like when people claim that Fujifilm 56/1.2 is a cheaper, smaller, lighter version of the Canon 85/1.2).

• Dennis
  --
  Gallery at http://kingofthebeasts.smugmug.com

 

[Moti]

I'm just amazed at how off base some of you are. It's like you are trying to fit the facts to a predetermined argument.

ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER!!! Hello! That's what exposure is!

Nope. There's a very clear definition of what exposure is. The fact that you choose to ignore it and make up your own stuff does not really change that.

But whatever. This is pretty common here, so you're in good company.

Just for curiosity, So you are saying that exposure is not a way of making an image brighter or dimmer?

Exposure does indeed affect the brightness of the final image,

of course, every photographer with a bit of knoledge knows that.

but it is not part of the brightening processes applied in creating that final image.

every photographer with a bit of knoledge knows that too because once the film or sensor is exposed, exposure cannot be changed anymore hence, brightening can only be controlled during processing phase.

So if a guy like Lumigraphics comes and says ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER, he is not that wrong as you guys make out of him.

Of course it's wrong. That's just like saying that the recording level is all a way of making the listening volume louder or softer.

His only crime maybe is coming from film photography, where exposure and brightness used to be synonyms

For a guy who, I must suppose, comes from film days, that's a pretty ignorant statement. What I did to expose the film in camera and what I did to process and print that image in the dark room hardly allowed exposure and brightness to be synonymous – any more so then than now.

now we are getting to what came first, the egg or the chicken debate. You are right, I come from long time film photography and exposure was actually the going term we used then as relation to brightness. A too bright image was called overexposed and a dark one was called underexposed. Do you think people have used these terms then because they haven't met you yet? Or maybe was there another reason.

So before calling someone ignorant as you very often do to anyone who has a different opinion or a different experience than you, maybe you should look a bit in the mirror from time to time.

And last but not least, even that you are probably an ace of photography science, bear in mind that when it comes to real world photography, some of those you call ignorants, can still teach you some lessons about how to take good photos because what they have already forgotten, you haven't yet started to learn. And this is the only thing that really counts.

Moti

--
http://www.musicalpix.com

 

[Astrotripper]

now we are getting to what came first, the egg or the chicken debate. You are right, I come from long time film photography and exposure was actually the going term we used then as relation to brightness.

So, are you actually trying to defend a statement that a photograph of the same scene at the same f/number but at a different shutter speed will result in the same exposure?

Because it is this statement that sparked this "debate". So if you insist that this statement is true, than I guess you can join lumigraphics in the "I don't know what exposure is" club. And contrary to what you say, this is not a matter of opinion. Facts and definitions do not change because you have an opinion about them.

 

[Moti]

now we are getting to what came first, the egg or the chicken debate. You are right, I come from long time film photography and exposure was actually the going term we used then as relation to brightness.

So, are you actually trying to defend a statement that a photograph of the same scene at the same f/number but at a different shutter speed will result in the same exposure?

That is your own imaginary interpretation. I've never said anything like that, but if this helps you to win an argument, be my guest.

Because it is this statement that sparked this "debate". So if you insist that this statement is true, than I guess you can join lumigraphics in the "I don't know what exposure is" club. And contrary to what you say, this is not a matter of opinion. Facts and definitions do not change because you have an opinion about them.

I invite you to look at the photos in my web site and then come back and tell me that I don't know what closure is.

Moti

 

[Pan X]

May I set the table, and you please define what's on the plate for me?

My old, hand held light meter, and the Golden Rule suggests: f16 * 1/125 * ISO 100, shooting at noon, outside, no clouds, no shadows, should equal a well "Exposed" photograph, either on film or digital.

Are "Exposed", or "Exposure" or "Exposure Settings" the right term(s) to describe the three camera settings my light meter gives for pretty good photographic results??? If not, then what is the correct term?

Can this photograph be said to have "Good Exposure"??? If not, then what is the correct term?

If I then change the camera settings to: f11 * 1/250 * ISO 100 (same light), did I change the "Exposure",or "Exposure Settings"?? If not, then what is the correct term for the change?

One more.

Then (same light) I change to: f11 * 1/500 * ISO 200 (employ a "times two" amplifier to the image device output signal), did I change the "Exposure", or "Exposure Settings" ???

If not, then what is the correct term for the addition of the signal amplifier?

Thanks for helping with the correct terms I should use.

 

[gollywop]

I'm just amazed at how off base some of you are. It's like you are trying to fit the facts to a predetermined argument.

ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER!!! Hello! That's what exposure is!

Nope. There's a very clear definition of what exposure is. The fact that you choose to ignore it and make up your own stuff does not really change that.

But whatever. This is pretty common here, so you're in good company.

Just for curiosity, So you are saying that exposure is not a way of making an image brighter or dimmer?

Exposure does indeed affect the brightness of the final image,

of course, every photographer with a bit of knoledge knows that.

but it is not part of the brightening processes applied in creating that final image.

every photographer with a bit of knoledge knows that too because once the film or sensor is exposed, exposure cannot be changed anymore hence, brightening can only be controlled during processing phase.

So if a guy like Lumigraphics comes and says ITS ALL A WAY OF MAKING THE IMAGE BRIGHTER OR DIMMER, he is not that wrong as you guys make out of him.

Of course it's wrong. That's just like saying that the recording level is all a way of making the listening volume louder or softer.

His only crime maybe is coming from film photography, where exposure and brightness used to be synonyms

For a guy who, I must suppose, comes from film days, that's a pretty ignorant statement. What I did to expose the film in camera and what I did to process and print that image in the dark room hardly allowed exposure and brightness to be synonymous – any more so then than now.

now we are getting to what came first, the egg or the chicken debate. You are right, I come from long time film photography and exposure was actually the going term we used then as relation to brightness. A too bright image was called overexposed and a dark one was called underexposed. Do you think people have used these terms then because they haven't met you yet? Or maybe was there another reason.

Ignorance is clearly not just a modern-day phenomenon. Nor, apparently, is it something that some can reverse – even over a long period of time.

But let's look at those good ol' days:

Exposure = Intensity x Time *

Brightness . . . A subjective interpretation of Luminance. **

* Adams, Ansel, p. 2, "The Negative: Exposure • Development," Morgan and Morgan, NY, 1966.

** Adams, Ansel, p. vi, "The Negative: Exposure • Development," Morgan and Morgan, NY, 1966

It's one thing to be wrong; it's altogether another to take pride, and perhaps even pleasure, in the condition.

So before calling someone ignorant as you very often do to anyone who has a different opinion or a different experience than you, maybe you should look a bit in the mirror from time to time.

Oh, I do, I do. And it's funny that, in circumstances like this, the reflection apears to be blurred beyond recognition, and seems to be trying to picture someone else.

And last but not least, even that you are probably an ace of photography science, bear in mind that when it comes to real world photography, some of those you call ignorants, can still teach you some lessons about how to take good photos because what they have already forgotten, you haven't yet started to learn. And this is the only thing that really counts.

Absolutely. And lumigraphics is a good example of that: someone who, I readily grant, is a talented photographer and who demonstrates that one doesn't need to know what's really going on to make good photographs. His value as a teacher, if it exists at all, would be via mute demonstration and not by verbiage, either spoken or written.

--
gollywop
I am not a moderator or an official of dpr. My views do not represent, or necessarily reflect, those of dpr.
http://g4.img-dpreview.com/D8A95C7DB3724EC094214B212FB1F2AF.jpg

 

[Astrotripper]

now we are getting to what came first, the egg or the chicken debate. You are right, I come from long time film photography and exposure was actually the going term we used then as relation to brightness.

So, are you actually trying to defend a statement that a photograph of the same scene at the same f/number but at a different shutter speed will result in the same exposure?

That is your own imaginary interpretation. I've never said anything like that, but if this helps you to win an argument, be my guest.

Well, I never wrote you did. I just asked why are you seemingly insisting on backing up this statement?

So let me ask you again. Do you agree with lumigraphics, that a photograph of the same scene at the same f/number but at a different shutter speed will not result in different exposure?

And if you do not agree, than what are you exactly arguing here about?

 

[gollywop]

May I set the table, and you please define what's on the plate for me?

My old, hand held light meter, and the Golden Rule suggests: f16 * 1/125 * ISO 100, shooting at noon, outside, no clouds, no shadows, should equal a well "Exposed" photograph, either on film or digital.

Are "Exposed", or "Exposure" or "Exposure Settings" the right term(s) to describe the three camera settings my light meter gives for pretty good photographic results??? If not, then what is the correct term?

Exposure is the correct term to describe the trio of the the scene luminance, the relative aperture (f-ratio), and the shutter speed. See here.

Your camera's exposure settings for the given scene are the f-ratio and the shutter speed. Your camera's settings include the ISO.

Can this photograph be said to have "Good Exposure"??? If not, then what is the correct term?

Your (reflective) light meter, if it's like most, does not provide you with three settings. Rather it expects you to set the ISO (relevant to film but not digital), and then it provides you with exposure settings (f-ratio and SS) "appropriate" to an "average" scene for that ISO.

In practice, it is impossible to tell whether the indicated exposure will be "good." It depends on the nature of the scene (particularly its DR relative to that of the camera's) and just how you measure the scene.

With a digital camera, one tends to be better off forgetting the meter readings and employing the technique of ETTR. See here. Scenes unable to be properly exposed using ETTR tend to require HDR techniques.

If I then change the camera settings to: f11 * 1/250 * ISO 100 (same light), did I change the "Exposure",or "Exposure Settings"?? If not, then what is the correct term for the change?

The exposure has not been changed, but your exposure settings have.

One more.

Then (same light) I change to: f11 * 1/500 * ISO 200 (employ a "times two" amplifier to the image device output signal), did I change the "Exposure", or "Exposure Settings" ???

You have now changed the exposure settings to lower the exposure by one stop, but altered the camera settings to compensate so as to result in an LCD image of the same brightness. This compensation may or may not be reflected in the raw data, depending on the camera. In most cameras it will.

If not, then what is the correct term for the addition of the signal amplifier?

It may or may not involve an amplification, but you have reduced the exposure and increased the in-camera ISO.

Thanks for helping with the correct terms I should use.

--
gollywop
I am not a moderator or an official of dpr. My views do not represent, or necessarily reflect, those of dpr.
http://g4.img-dpreview.com/D8A95C7DB3724EC094214B212FB1F2AF.jpg

 

[johnierebel]

May I set the table, and you please define what's on the plate for me?

My old, hand held light meter, and the Golden Rule suggests: f16 * 1/125 * ISO 100, shooting at noon, outside, no clouds, no shadows, should equal a well "Exposed" photograph, either on film or digital.

Are "Exposed", or "Exposure" or "Exposure Settings" the right term(s) to describe the three camera settings my light meter gives for pretty good photographic results??? If not, then what is the correct term?

Can this photograph be said to have "Good Exposure"??? If not, then what is the correct term?

Hard to say, did you take your lens cap off? It is depended upon what the scene is & what you are giving emphasis to

If I then change the camera settings to: f11 * 1/250 * ISO 100 (same light), did I change the "Exposure",or "Exposure Settings"?? If not, then what is the correct term for the change?

An equal amount of light will be captured as per 1st example, with reduced DOF & refraction

One more.

Then (same light) I change to: f11 * 1/500 * ISO 200 (employ a "times two" amplifier to the image device output signal), did I change the "Exposure", or "Exposure Settings" ???

You have reduced the total light that can be captured by 1/2. Your ISO setting does not affect exposure, it affects captured light once it is discharge from the pixel well.thus the image will be brighter as per your example.

If i haven't worded this correctly 'G' Bob, Golly will be along to school me again,

If not, then what is the correct term for the addition of the signal amplifier?

Thanks for helping with the correct terms I should use.

 

[Dennis]

May I set the table, and you please define what's on the plate for me?

My old, hand held light meter, and the Golden Rule suggests: f16 * 1/125 * ISO 100, shooting at noon, outside, no clouds, no shadows, should

If I then change the camera settings to: f11 * 1/250 * ISO 100 (same light), did I change the "Exposure",or "Exposure Settings"?? If not, then what is the correct term for the change?

You have the same exposure, but different exposure settings.

Then (same light) I change to: f11 * 1/500 * ISO 200 (employ a "times two" amplifier to the image device output signal), did I change the "Exposure", or "Exposure Settings" ???

You have less exposure and you compensate for the underexposed image by brightening it through the ISO setting.

• Dennis
  --
  Gallery at http://kingofthebeasts.smugmug.com

 

[bobn2]

it affects captured light once it is discharge from the pixel well.thus the image will be brighter as per your example.

If i haven't worded this correctly 'G' Bob, Golly will be along to school me again,

Sorry, I will. You're doing well but it shows how difficult it is to get rid of entrenched, false ideas. One of the false mental models that people have seems to be that there is some kind of light pipe in a photographic system. The model seems to be that light goes in one end and comes out the other and if you want the output to be 'brighter' than the input you have to 'amplify' it some way. It just isn't so. No light is 'discharged' from the pixel. The pixel makes a measurement of the amount of light that it has collected. It does this by generating a charge that is proportional to the amount of light. The electronic design problem is to make this measurement as precise as possible. Once the measurement is made, there is no more light in the system, just a set of numbers representing amounts of light pixel by pixel. Conceptually, what ISO does is set a palette of tones against that list of numbers. As you change the ISO the palette is shifted so that low light counts match lighter tones in the palette. When it comes to an output image the tones defined by the palette might be represented by pain, ink, a mask over a light source or a set of lamps, depending on your display device. As I said earlier, no 'light' comes out of the system, so nothing gets amplified. The only reason for 'amplification' is an engineering detail to make the measurements as accurate as possible.

 

[bobn2]

May I set the table, and you please define what's on the plate for me?

My old, hand held light meter, and the Golden Rule suggests: f16 * 1/125 * ISO 100, shooting at noon, outside, no clouds, no shadows, should equal a well "Exposed" photograph, either on film or digital.

Are "Exposed", or "Exposure" or "Exposure Settings" the right term(s) to describe the three camera settings my light meter gives for pretty good photographic results??? If not, then what is the correct term?

Exposure is the correct term to describe the trio of the the scene luminance, the relative aperture (f-ratio), and the shutter speed. See here.

Your camera's exposure settings for the given scene are the f-ratio and the shutter speed. Your camera's settings include the ISO.

Can this photograph be said to have "Good Exposure"??? If not, then what is the correct term?

Your (reflective) light meter, if it's like most, does not provide you with three settings. Rather it expects you to set the ISO (relevant to film but not digital), and then it provides you with exposure settings (f-ratio and SS) "appropriate" to an "average" scene for that ISO.

In practice, it is impossible to tell whether the indicated exposure will be "good." It depends on the nature of the scene (particularly its DR relative to that of the camera's) and just how you measure the scene.

With a digital camera, one tends to be better off forgetting the meter readings and employing the technique of ETTR. See here. Scenes unable to be properly exposed using ETTR tend to require HDR techniques.

If I then change the camera settings to: f11 * 1/250 * ISO 100 (same light), did I change the "Exposure",or "Exposure Settings"?? If not, then what is the correct term for the change?

The exposure has not been changed, but your exposure settings have.

One more.

Then (same light) I change to: f11 * 1/500 * ISO 200 (employ a "times two" amplifier to the image device output signal), did I change the "Exposure", or "Exposure Settings" ???

You have now changed the exposure settings to lower the exposure by one stop, but altered the camera settings to compensate so as to result in an LCD image of the same brightness. This compensation may or may not be reflected in the raw data, depending on the camera. In most cameras it will.

If not, then what is the correct term for the addition of the signal amplifier?

It may or may not involve an amplification, but you have reduced the exposure and increased the in-camera ISO.

People seem obsessed by this 'amplification'. There really is never any 'amplification' of 'signal'. What there is is an internal scaling (sometimes) in the internals to make the measurement system more accurate. If the 'signal' is the levels of light measured in the pixel, it never ever gets amplified. Just the internal representations within the black box might change. It's engineering detail and really nothing whatsoever to do with 'ISO'.

Thanks for helping with the correct terms I should use.

 

[johnierebel]

it affects captured light once it is discharge from the pixel well.thus the image will be brighter as per your example.

If i haven't worded this correctly 'G' Bob, Golly will be along to school me again,

Sorry, I will. You're doing well but it shows how difficult it is to get rid of entrenched, false ideas. One of the false mental models that people have seems to be that there is some kind of light pipe in a photographic system. The model seems to be that light goes in one end and comes out the other and if you want the output to be 'brighter' than the input you have to 'amplify' it some way. It just isn't so. No light is 'discharged' from the pixel. The pixel makes a measurement of the amount of light that it has collected. It does this by generating a charge that is proportional to the amount of light. The electronic design problem is to make this measurement as precise as possible. Once the measurement is made, there is no more light in the system, just a set of numbers representing amounts of light pixel by pixel. Conceptually, what ISO does is set a palette of tones against that list of numbers. As you change the ISO the palette is shifted so that low light counts match lighter tones in the palette. When it comes to an output image the tones defined by the palette might be represented by pain, ink, a mask over a light source or a set of lamps, depending on your display device. As I said earlier, no 'light' comes out of the system, so nothing gets amplified. The only reason for 'amplification' is an engineering detail to make the measurements as accurate as possible.

--
Bob.
DARK IN HERE, ISN'T IT?

Yes , I am aware light is not discharge from the well, my bad. Yes when photons slam ( NOT FALL ) into the photo diode dislodging electron in to the well, that process has a term which escapes me right now ( have sinus infection ).

Question: is it 'gain' that is added to change data's relationship to the tonal scale?

I appreciate your input, I do sometimes take short cuts & don not get many opportunities to discuss this topic & keep it fresh in my thoughts. Thanks Bob!

 

[Pan X]

Thanks for the answers so far, good stuff.

Should I consider what the image device size is in my camera?

For "Exposure" purposes, does it matter what size the device is, once my light meter determines/suggests the correct incident light exposure settings to use??

With the ISO and Shutter already fixed, will I need to figure out a different f stop by the correct crop factor than what the meter indicates because of the "equivalent" discussion above?

.

 

[bobn2]

Thanks for the answers so far, good stuff.

Should I consider what the image device size is in my camera?

For "Exposure" purposes, does it matter what size the device is, once my light meter determines/suggests the correct incident light exposure settings to use??

The question you're not asking yourself is why does your light meter suggest this 'correct' exposure? The only reason is that you told it what the 'correct' exposure would be by choosing an ISO in the first place. What you have essentially done is guessed what exposure should be right and told the camera to use it - there really is no 'correct' about it.

So, the point to ask, is how did you make the decision about what would be the 'correct' exposure in the first place? In my experience, there are two criteria people usually use. One is how big an exposure your camera will cope with. You tell the camera to use that by dialling in 'base ISO'. The second is how much noise you're willing to suffer, which is why you set higher ISOs. Which higher ISO depends on a guesstimate of what will be the EV you end up with and whether that's likely to satisfy your requirements with respect to DOF and camera shake.

With the ISO and Shutter already fixed, will I need to figure out a different f stop by the correct crop factor than what the meter indicates because of the "equivalent" discussion above?

Why have you decided that ISO should be fixed? You have the freedom to change it aver a wide range on a digital camera.

 

[Steve Bingham]

Hey, Gollywop. What does DPReview Contributor mean? I see the wrench but have no idea what it means.

--
Steve Bingham
www.dustylens.com
www.ghost-town-photography.com
Latest postings are always at the bottom of each page.