Help - Exposure Questions

[Nikkofan]

OK, this is such a newbie (read: stoooopid) question, but if anyone can help, I'd be grateful. A while ago, I decided to go back to basics and try to mainly use Manual rather than AP, because I'd like to be able to analyse lighting situations as much as possible by myself and so (I think) become a better photographer. While I decided to do this a while ago, the recent Dee Why dawn shoot just reinforced to me that I need a greater understanding of EV's and light situations.

My dumb question/s is/are:

1. Is "Zero EV" (as discussed in several websites that I've looked into) always the beginning point? One site said "Zero EV is defined by the combination of an aperture of f/1 and a shutterspeed of 1s at ISO 100". So, is this always the common denominator in photography? ie: ALL cameras start with Zero EV at this point (f/1 and 1s at iso 100) and everything from this point on - ie: all adjustments to aperture, shutterspeed and iso and even EV +/-adjustments - is based on this?

2. Is there a "common" understanding about lighting situations or the range of EVs for different lights? eg: Would a darker day be in a particular recognised EV range, a brighter day in another particular recognised EV range, etc? I guess another way of saying this is: is there a recognised "scale" of sorts, that rates light into particular EV ranges? Is this where the Kelvin scale comes in? Or is the Kelvin scale only for measuring the colour in light? God, as you can see - I need help with this!

Sorry, I know this is probably as confuddled as anything but I can't really explain it any better. I really hope someone can make sense of what I'm asking!

Part of the reason I'm asking this is because I'm trying to make up a chart or table for myself to understand the combinations of aperture, shutter & iso under different lighting conditions, which I intend to refer to and amend as experience dictates. Lighting is one thing which fascinates about me about photography but I don't know enough about it so I'd really like to develop this skill much further, rather than having to rely on AP when I'm not sure.

Thanks for your help - hope someone can understand this post (and I hope someone else would like to know about this besides me!)

Lynn

[wendellt]

Lynn

it's important to get the technical explanation of all your questions,

even now i can't perfectly explain if there is a reference point in the ev scale

i can simply tell you the way i judge light situations is to shoot
1. a bright sunny day with no clouds in the sky
I stuck to f8 which is standard good depth of field then stayed on ISO 100
and used a shutter of 1/250, this produced a pretty well exposed shot, i just played with different shutterspeeds to see what they produced,then put them to memory.

did the same thing on an overcast sky

kelvins is the metric value for measuring colour temperature of a scene nothing to do with ev and exposure
you can play with colour temperature to balance the colour rendition of your images or add warm or cool moods to them

now discussing how you balance iso with shutter speed that's more complex leave that up to someone more techncially experienced on the forum to answer

I think it is more important to experiment and find a balance between that and knowing a technical ev table, the balance between both are important.

[stubbsy]

Lynn

To be blunt I see no logic in switching to manual in an attempt to improve your photography. You have a camera with a whole stack of built in smarts to assist with things like focussing and exposure and the like that is based on years and years of experience. Switching all that off is like saying you'll stop using a calculator or computer program to do complex maths for you until you master the intricacies of doing it by hand using pen and paper.

I'd suggest you use either A or S (or even P) mode so that you can focus on one aspect. eg use A mode so you can play with the effect the aperture settings has on things like DOF and let the camera work out the optimal shutter speed. Or use S mode to play with the effect shutter speed has on freezing motion while the camera works out the right aperture size for the exposure.

And when it comes to analysis of exposure a great starting point is to use and learn to understand the histogram that your camera displays for images after they are taken.

[Nikkofan]

Thanks Wendell, I'm glad to see you could understand my confuddled post and really appreciate your response.

I agree that experimenting and just shooting is the way to go, but I want to understand and what I'm doing and why. I guess it's a remnant of my uni days, but I find I learn and remember things much more if I've put them down on paper and can refer to them - and my memory's not getting any better, I can tell you! (good thing I'm not at uni now!) For instance, I read somewhere that a "high EV means bright conditions" and "a low EV means darker conditions", hence my 2nd question about any existing scale of EV's, because I was wondering if there was any sort of universal law or understanding about ev's equating particular light conditions and, if so, what's the base line to start from (hence my 1st question).

I intend to use the technical table as a starting point to understanding it all and heavily supplementing it with lots of practice, until it's redundant.

Any other technical explanations, if anyone has the time?

Thanks guys. I really appreciate being able to ask questions like this on this wonderful forum and getting your help.

Lynn

[MCWB]

Lynn, I'd have to say that I agree with Peter. I see no reason to learn the zone system (EVs) and guess when you have one of the best metering systems available to you right in your camera! Using manual mode with matrix metering is almost the same as using A, S or P modes, only with easier exposure compensation (you do it via altering the command dials for shutter and aperture rather than using the exposure compensation buttons).

If you're using spot metering and manual mode then yes, I can see the point in learning the zone system... but why make life harder for yourself? Do you manually focus, or do you use autofocus? I think a better way to go is to learn what each of the metering modes can do for you, and when it might be advisable to use them.

[myarhidia]

Hi Lynn,
if you chose to shoot in manual mode then a technique I suggest you use is to switch your camera to spot meterering. "Guess" what the AP&SP will be then use the spot metering in your camera to show you if the spot you're metering will be over/under exposed & adjust accordingly.

As Stubbsy suggested, your camera has a lot of smarts and it's best to use them.

[Nikkofan]

Lynn

To be blunt I see no logic in switching to manual in an attempt to improve your photography. You have a camera with a whole stack of built in smarts to assist with things like focussing and exposure and the like that is based on years and years of experience. Switching all that off is like saying you'll stop using a calculator or computer program to do complex maths for you until you master the intricacies of doing it by hand using pen and paper..

Sorry you feel like that Peter, but as I said, I want to understand, not just do it and leave the camera to rely on it. What's the difference with that and a mechanic who likes to play with cars, stripping it down piece by piece?

I'd suggest you use either A or S (or even P) mode so that you can focus on one aspect. eg use A mode so you can play with the effect the aperture settings has on things like DOF and let the camera work out the optimal shutter speed. Or use S mode to play with the effect shutter speed has on freezing motion while the camera works out the right aperture size for the exposure.

Yes, and I'm doing that too, particularly S mode for sports.

And when it comes to analysis of exposure a great starting point is to use and learn to understand the histogram that your camera displays for images after they are taken.

And doing that too, but - sorry, Peter - still want to understand the why's. Guess I'm just too curious for my own good!

Thanks for your comments.

Lynn[/quote]

[Nikkofan]

Last point ... interesting that some of you have mentioned the Zone system, because I've been reading Ansel lately and perhaps that's where the interest in understanding light comes from, subliminally. hmmmm....

[wendellt]

Thanks Wendell, I'm glad to see you could understand my confuddled post and really appreciate your response.

I agree that experimenting and just shooting is the way to go, but I want to understand and what I'm doing and why. I guess it's a remnant of my uni days, but I find I learn and remember things much more if I've put them down on paper and can refer to them - and my memory's not getting any better, I can tell you! (good thing I'm not at uni now!) For instance, I read somewhere that a "high EV means bright conditions" and "a low EV means darker conditions", hence my 2nd question about any existing scale of EV's, because I was wondering if there was any sort of universal law or understanding about ev's equating particular light conditions and, if so, what's the base line to start from (hence my 1st question).

I intend to use the technical table as a starting point to understanding it all and heavily supplementing it with lots of practice, until it's redundant.

Any other technical explanations, if anyone has the time?

Thanks guys. I really appreciate being able to ask questions like this on this wonderful forum and getting your help.

Lynn

yeah Lynn

i'm not a tech head i have my own understanding of EV which makes sense to me, i don't have format trainign in photography me self taught and got advice on the forum

Leigh Nnnsic is one of the trained photographers here, or ask Gary Stark they can talk tech and explain it more correctly than me

regardign peters comments, totally fair enough, you pay heaps for all this metering tech so may as well use it

but sometimes manual is good when you want to shoot with more control over artistic direction, for example shooting dark all the time to get moody shots, instead of relying on the technically perfect what you see is what you get exposure that a camera program may give you

[MCWB]

Wendell: surely intentionally underexposing using exposure compensation will give the same result as doing it in manual mode? I agree of course that it's easier in manual.

Lynn, you may already be aware of it (probably are by the sounds of it), but anyway, here's the zone system + a there are a zillion other sites about it on Google for your reading pleaasure.

I guess my point is this: if we had no in-camera metering and only spot handheld light meters then the zone system is very useful. We do however have very sophisticated in-camera metering that takes into account exposure from different parts of the scene and probably 95% of the time gets it bang on what you want. The other 5% is easy to predict as long as you understand what you're looking for in the shot and how each metering mode works.

[olrac]

Lynn,

you could review the exif on a bunch of your shots and work out each ones EV and see if the pic is an overcast day or bright day or indoor ect and form your scale that way.

You could probably even do a similar thing with the photos posted on this site.


That would give you a fair amount of sample data to create your graph/scale.

[wendellt]

Trent

curiosity what is the best metering mode to use when photographing moving objects like cars or people in say a sunny day but under the shade(lower light)

my D2X on any metering mode always gives me incorect exposure I get blurry images even when skillfully holding the camera strill when taking the shot

either my camera is broken or this sophisticated metering system ain't that smart

[Nikkofan]

Wow. I almost feel like I've offended some people with my comments about using Manual mode for a while. Or, actually, perhaps I didn't mention that it would only be for a while, ie: until I have a greater understanding of it all. And after that, for selective purposes only.

Like Wendell said, there's a lot of creativity that can be achieved with Manual and I'd like to explore it.

Yes, the camera has some fantastic features built into it and I utilise them very heavily, but I just want to explore more avenues hence the questions re manual usage and ev.

Really sorry if it's bothered anyone to think that someone in this day and age would use Manual on a D70, but there you go. We're all individuals and that's what makes this forum interesting, isn't it?

Thanks for the suggestions & responses.

Lynn

[losfp]

Lynn, I guess you are doing this purely for interest's sake?

I know that I cannot possibly judge the light level even half as well as my camera's metering systems could, so I wouldn't see any value in compiling any graphs/etc giving values for a certain set of conditions

probably 75% of the time, my D70s is set on AP mode, I stick it on f/8 most times as a balance between sharpness and light, unless I deliberately want more light or a certain amount of DOF. If I need a certain shutter speed for speed blur, or freezing action, then out comes SP mode. I really only put it on manual for a couple of reasons: locking the exposure where I want it so that the metering won't change it constantly (ie: doing a series of shots for a pano), or if I want to deliberately under/over expose shots on the fly. Even when I'm using M, I do it like a "manual AP" or "manual SP" - I decide which of aperture or shutter speed is more important, then set it. Then dial in the other until the light meter tells me it's nicely exposed. If I can't do it at that ISO setting, bump it up gently until it works.

My feeling is that it's all well and good saying "this setting works great in sunlight" . But what sort of sunlight? In shade? How much shade? Just saying that it would be the biggest chart in the world!!!

I don't mind using manual every now and then, but I do it as I've described above...

Not sure if any of my rambling is useful or relevant to you, but that's how I do it

[MCWB]

curiosity what is the best metering mode to use when photographing moving objects like cars or people in say a sunny day but under the shade(lower light)

Wendell,

All my motorsport photography uses matrix metering. Unless there's a different effect you want, for 'normal' fast action shooting it simply can't be beat. Not sure how the D2X works with respect to this though!

With people in the shade on a sunny day, I use TTL-BL fill-flash with matrix metering. Alternatively if you have to do it sans flash, spot metering off the face is pretty good (although of course you'll blow out the background).

Lynn, you haven't offended me at all, sorry if it came over that way. If you're going to be using manual mode and spot metering for learning purposes that's cool, good for you. I do find manual mode great for low-light + flash work (to balance the flash and natural light), and also for low-light night shots (spot metering so as not to blow the lights out).

[stubbsy]

Wow. I almost feel like I've offended some people with my comments about using Manual mode for a while.

SHeeesh Lynn Only thing that would offend me would be that someone thought I was offended at them choosing to use manual

I guess the point being made by Trent & myself is shooting in manual with a modern camera is like tieing an arm behind your back. But it's your choice - far be it from me to say you shouldn't do it. See my tag line below

[gstark]

Lynn,

First of all your question is not a stupid, nor a newbie question. The concept of exposure and light is one of the basics that we used to have to master in the days BC.

Since the mid 70s it's been getting a lot easier, but tools like a handheld meters are still quite helpful in assisting one to get not just a better exposure for an image, but also a better understanding of ths whole thing.

Most of what you're asking here is really quite simple, but perhaps confused a little bit because there are so many technical terms and different concepts to get one's head around.

Let's start with a couple of those terms.

EV : relates to a specific light value. Always.

A given quantity of light falling on a subject will, for that constant value of light, always yield a given EV.


It's probably not too important to worry too much about any absolute EV as such, but to think of one EV in relation to others, and while these are regular and graduated steps, they represent a doubling of the available light as you progress from one EV to the next.

I've never given any thought to what zero EV actually might be, and given that I've been taking photos for something in excess of 35 years (or thereabouts) and the fact that that question has never actually raised its head, perhaps it's not that important a concept to grasp.

At the end of the day, the EV will be expressed in terms of a combination of related shutter speeds and apertures, susch as 1/250 @ f8. I guess that's an answer to one of your questions.

Whether there's a "common" understanding about lighting situations and EVs depends upon whom you ask. One recently departed (from this forum) ex-member seemed to hold the view that the answer to this question would be "no", but that would be a view I would challenge.

Inside many film packs - even today - manufacturers provide a basic guide to exposure, for the film purchased, in certain condtions. These guides are based upon what is generally known as the "sunny 16 rule", and it holds that, for certain lighting situations, you would use the reciprocal of your film speed (approx) as a shutter speed, with the following apertures:

- Bright Sun: f16
- Hazy Sun: f11
- Open shade or bright but cloudy: f8
- Dull f5.6

So, for ISO 200, use 1/200 (or perhaps 1/250); ISO 400 you'd use 1/400 , and so on.

Clearly, these are know and identifiable light values, and once you have a starting point, it really doesn't take too much effort or thought to extrapolate from these values into other lighting conditions.

You do need to exercise some caution however, as our eyes are very flexible, and provide us with a "compensated" view of a scene when it comes to poorly lit situations. Just copmare what you might see in a poorly lit room with what your camera's meter might suggest the EV is.

That said, it is possible to "read" the light and make some pretty good judgements once you gain experience in this stuff.

A couple of people mentioned the Zone system. While I'm certainly no expert on this (I suspect that Matt K will be able to add some real value here) my understanding is that a primary concept behind the zone system is to place a given part of a scene into a given contrast level (from a very solid, rich black, through a variety of greys, to pure white) so that - particularly for B&W images - the photographer produces images that cover the whole contrast spectrum.

That's probably more than enough to digest at the moment, but please feel free to ask any further questions.

I agree with you that a good understanding of this concept will assist you in making better images, if only because it will help you to better identify difficult exposure situations that may not be ideally metered by your camera.

[gstark]

either my camera is broken or this sophisticated metering system ain't that smart

None of the above: it's what's known as "operator error".



In many outdoor shooting situations, especially if you're at a racetrack shooting racecars, the chances are that your exposure needs are failry simple, and will often be static for a given scene.

Let's presume that it's a bright sunny day. If the correct exposure is f16 and 1/250 (say) for the current lighting conditions you're encountering, what other factors are there to consider when making your exposure?

I'm talking about pure exposure right now, and the answer is "not a whole lot".

Of course, shooting racecars is not as easy as it looks - they have been known to move rather quickly at times - and there's a multitude of other things to consider when making these images.

How fast are they travelling, and in which direction, relative to you, is this travel occurring? What sort of images do you want? Do you want to freeze action? Or do you want to impart a sense of movement in your images?

The answers to these questions are at least as important as the correct exposure, but they will have a severe impact upon what exposure settings you may decide to use in making your images.

Note that cars moving towards you may be easier than panning with a car moving across your plane, but it's more difficult to impart a sense of movement in that type of image.

I've not even begun to canvass the areas of focus, where there are just as many variables that need to be considered, and you should note that your comment that you always get "blurry images" is strongly suggestive to me that your problem is one of focus, rather than an exposure related one.

And finally, as you get closer to trackside, the degree of difficulty increases.

[gstark]

I guess the point being made by Trent & myself is shooting in manual with a modern camera is like tieing an arm behind your back.

I would have to disagree with this.

I think that the metering systems on modern cameras is truly great, but there are times and circumstance where it can - often and easily - be fooled.

I think that it's by learning and understanding the basics of exposure that you can begin to recognise the sorts of situations that might fool your meter, and then you can do something that can help increase your keeper rate.

[stubbsy]

I guess the point being made by Trent & myself is shooting in manual with a modern camera is like tieing an arm behind your back.

I would have to disagree with this.

I think that the metering systems on modern cameras is truly great, but there are times and circumstance where it can - often and easily - be fooled.

I think that it's by learning and understanding the basics of exposure that you can begin to recognise the sorts of situations that might fool your meter, and then you can do something that can help increase your keeper rate.

Was waiting for you to come along Gary

[wendellt]

yup agreed user error maybe
also totally agree that modern metering systems can be fooled more often than once in any given scene, by a number of factors, even on the allmighty D2X!

So Lynn Gary has explained it here hope that answers all your questions.

[MCWB]

SHeeesh Lynn Only thing that would offend me would be that someone thought I was offended at them choosing to use manual

Hi Pete.

[olrac]

I always thought that 0 ev was
f1
1 sec
ISO-100

[stubbsy]

SHeeesh Lynn Only thing that would offend me would be that someone thought I was offended at them choosing to use manual

Hi Pete.

Trent - bad bad boy

[avkomp]

I echo the stuff already mentioned here re exposure.
These days when photographing birds etc I pick the aperture I might need and set the camera in aperture priority. I usually take note of the shutter speed being offered and decide whether I believe it is right for the task.
If I have a 400mm lens on for instance and have f8 selected, if the shutter speed is 1/100 I might decide that it wont be fast enough to avoid camera shake and increase the iso.
for landscape stuff I just about always use manual mode.

Understanding of the sunny 16 rule will certainly help because it will let you have a fair idea of what exposure you should expect to see in given circumstances.

your exposure meter can mislead you under certain circumstances and it is worthwhile knowing when to believe the meter.

nnnnsic posted a few links last week with tutorials and this one
http://www.fredparker.com/ultexp1.htm

explains the basis of how exposure works and how you might learn to determine it manually yourself.
I recommend visiting this site and grabbing a copy and get a handle on what is going on.

in time you do get a feel for what exposure to use.
I remember many years ago doing tests where you would for practice pick a scene, decide on the exposure without the meter and take some shots. I wouldnt do this for vital once in a lifetime things, but by all means have some practice. digital is free right?? try it in the backyard for instance. determine exposure in your head. perhaps check it with the meter. take some shots and see how you did.

Steve

[Aussie Dave]

Quite an interesting thread to read. Good on you Nikkofan for posting your questions, as that's what we are all here for.....to help one another.

Personally, I almost always shoot in Manual mode as I prefer not to use the D70's exposure compensation abilities. Not because they aren't any good, but because that's one more setting that I can forget to change back (similar to ISO).

You may also like to remember that even shooting in manual mode, you are still utilising the D70's metering system to obtain your correct exposure. As a result, there is NO difference between using manual in this fashion and using A or S mode and dialling in exposure compensation. They all lead you to the same settings for a given scene.

As for EV, I'm not sure you can harness that knowledge in a table. There are so many varied lighting situations, each with their own subtle nuances, that it is something you really need to have a "feeling" for (IMHO).

As a little project, go outside and flick your D70 to manual. Set the metering mode to Matrix (to begin with) then choose an aperture that you want to shoot at (lets say f5.6). From here, fiddle with the shutter speed until you bring the exposure bar (inside the viewfinder) back to the very centre.
Done ? You have now just done what the camera would automatically do for you in A mode.
The question to ask yourself now is, "Is this shutter speed suitable to what I'm shooting ?"
If it is, all is good. If not (eg. 1/10sec. handheld - will produce soft images), then you have to negotiate your aperture (or ISO) settings in order to give you a shutter speed that is useable.

If you were to switch your metering mode to "spot", you could meter on a certain part of the scene (either a light or dark part) and expose from that. However, you should note that if there is a considerable difference in brightness throughout the scene, you will either come away with overexposed or underexposed areas (depending on what you metered for) - or potentially both, if you metered for a middle tone !.

If you play around with the camera in this way for a week or two, you will soon start to see what is going on and what is bringing you the best results.

Hope this is useful info....

PS... Look out for an exercise that will be posted in a few weeks on this forum, which will be right up your alley !

[gstark]

So Lynn Gary has explained it here hope that answers all your questions.

I doubt it. We're just starting down a road where one answer will lead to another ten questions.

[gstark]

SHeeesh Lynn Only thing that would offend me would be that someone thought I was offended at them choosing to use manual

Hi Pete.

[gstark]

I always thought that 0 ev was
f1
1 sec
ISO-100

Carlo,

It may well be; I really don't know.

Nor do I care: the bottom line is, though, really, is does it matter?

I'm not trying to flame you nor trying to ask an inflammatory questio. I'm simply asking that you consider when you last needed to use that information, and why.

[elffinarts]

I found that in order for me to shoot effectively in the nightclub where I shoot the most I must shoot manual. With club strobes constantly playing havoc with my exposure every shot is a lucky dip and I only use the auto functions out in the day (which is SO not my natural environment) to give me a guide for light conditions that I am least familiar with.

but then I am still pretty new to photography and dont experiment with the functions anywhere near as much as I should to understand it.

[Nikkofan]

Thanks so much everyone for your comments and sharing your experience & expertise - really appreciated.

As to the table, maybe I should clarify this: I have no intention of following it to a "T", ie: consult the table, shoot, consult the table for the next shot, then shoot, etc. It would hardly be conducive to spontaneous photography, would be ridiculous and a pain to compile and, as you said, losfp, it would have to be the biggest table in the world! I just want to get some basic idea of the EVs roughly relevant to basic lighting conditions. From there, it would be just experience, with the additions of EV compensation, iso adjustments, etc, all intended to eventually be able to "read the light", as Gary mentioned.

I really really do appreciate everyone's help & suggestions - Thanks again!

Lynn

[dooda]

Funny, as I've become fairly adept at taking pictures with available light, I'm finding that I'm becoming better at guessing what the variable will be. I think that there is some value to understanding exposure, as it's a skill that your brain will begin to understand and adapt to, and give you atleast some control over the experience. My wife likes to exercise control over...etc etc.

So now I know when F8 at 10 seconds when the scene is directly lit by more than one streetlight. Generally 1 minute or so if it's directly reflected light, and a little bit of residue light leeking in, 2-3 minutes if it's in the shade, but lots of light around it. Of course it always needs slight tweeks depending on what Apeture I feel like, but I like that my brain is beginning to know what to do, and of course everyone knows that metering at night is mostly useless.

[Matt. K]

Hi Lynn
If you're looking for a kind of standard as a beginning to understanding exposure then perhaps this may help. Consider your camera is on a tripod and you have a large light. This light is shining on a KODAK 18% gray card....which is a standard that represents the reflection from a average daylight scene. It is also totally colour neutral...IE, it has no colour bias whatsoever. Let's also presume that the camera, in auto mode, has chosen f8 @ 1/60 as the correct exposure. Then in theory and in practice the camera should capture an image that accurately reproduces the tone and colour balance of that card. F8 @ 1/60 is also an EV or exposure value. The experianced photographer will know that he or she could change the cameras setting to f5.6 @ 1/125 and this exposure will allow the same amount of light to enter the camera as our original exposure. It has the same EV. Other "same" EV's for our scene would be f4 @ 1/250 or f2.8 @ 1/500 or f11 @ 1/3o of a second. All of these settings are correct for out gray card subject.
Now...let's see what happens if we remove our gray card and insert a white card. The camera will now choose an exposure of f16 @ 1/60 because it presumes........what?...................It presumes you have moved the light much closer to the gray card! The camera will always presume you are metering from a gray card....or average daylight scene. But you have not increased the intensity of the light therefore the exposure is incorrect. The correct exposure for the white card is the same as that for the gray card! And the same thing happens if we insert a black card. The camera will now choose f4 @ 1/60 because it presumes??? You have moved the light away from the gray card.
So...as a general rule if your metered scene is brighter than average then, (white suit in snow), you should add 1 or 2 stops of exposure compensation and if it is darker, (black cat against black wall), then subtract 1 or 2 stops of exposure compensation.
Having said the above, I believe the Nikon matrix metering does compensate a little in the right direction because it is a very smart meter. However it can be fooled and that's when you should take control.

[digitor]

Hi Lynn,

I'm one of those who uses manual most of the time, as I find that the auto modes can change your carefully set exposure for you just when you least expect it, even though the lighting conditions haven't changed, but the composition of the scene has. Matrix metering is pretty good at this, but shooting in contrasty conditions is still a bit too much for it in my opinion.

I could use one of the auto modes and exposure comp., but I don't, as you've still got to fiddle with a dial (and also hold a button down) and it's one less thing to remember to reset for the next shot.

I've never really thought about the absolute value of EV0, I think the use of the EV concept is that it makes it easy to express relative exposures, without using a specific speed/aperture combination. Knowing an absolute EV for a scene is not going to be much use to you unless you then convert that to a speed/aperture/iso value. Getting used to estimating the exposure for a scene in terms of the camera setting is useful, however. You can then think in EV about relative exposures for that scene, I suppose, but I just think in terms of stops, which is the same thing as EV really. So if I took a series of exposures of 1 stop difference, I might change the speed, the aperture, or the iso setting, or a combination of these, depending on the circumstances.

It's not really too hard to estimate exposure, just start with the tried and true rules Gary has written above. I've got a couple of manual lenses I use regularly on my D70, and can usually nail an exposure on the first shot without too much trouble. The histogram gives instant feedback, making it a lot easier to check your estimate!

Cheers