Tag Archives: Light

Is your metering method causing you problems?

Following on from my previous post on comparisons between meters, I thought it important to point out that HOW you use your meter has a significant effect on the exposure you get on the film. There are basically two ways to meter a scene, but a few variations on how those measurements are actually taken and interpreted;

The two main ways of taking a light reading are Reflective and Incident. Reflected readings are measurements of how much light is falling ON THE SCENE and Incident readings are measurements of how much light is falling ON THE METER. Spot meters measure small areas, but are still reflective types and when you take a reading through the camera lens (TTL metering), you are also taking a reflected reading. The trouble is, your choice of subject, or the angle that you shoot from, will influence the brightness that the camera reads. For instance, If I point my camera at a bunch of trees from thirty feet away, I will probably get a reasonable reading from the camera. If I then walk up to the nearest tree and lie underneath it, pointing the camera up through the branches at the sky, I will get quite a different reading, even though the light levels are the same.

In another scenario; I have in front of me two garage doors. One of them is painted black, and the other is white. If I stand some distance away, my reflective reading will average out the lights and darks, giving me an exposure somewhere in between. If I then walk towards the garage doors and take a reading from each, I will have TWO OTHER readings, even though the light levels are still the same.

This kind of subject influenced reading happens on sunny beaches, snowy landscapes, stage photography, night photography, or whenever you photograph any object, scene or person with a predominance of dark tones, or light tones. Given the infinite range of everyday lighting situations and possibilities for error, it is amazing that most shots come out at all. The reason they do, is because film is so forgiving, especially if you are scanning from your negatives and working on the images in photo-editing software. When I say film, I am referring to black and white, or colour negative films. Colour transparency film is far less forgiving and needs more careful metering.

The other method of metering  I mentioned was the incident reading. With this, there is usually a white plastic cone which goes over the light cell and this then allows the meter to read the light falling on the meter, and this is not affected by the tone of the subject. Incident readings are a quick and very accurate way of establishing a reading and are correct in most situations. If used in a back lighting situation, they will favour the shadow tones and give you an exposure which will show the lit areas as overexposed, so use them intelligently.

There is one rule when taking incident readings, and that is that you must point the cone from the scene towards the camera, -not towards the light source. The reason the white thing is a cone, and not a flat disc, is so that in side lighting, one side will be lit and the other shaded, the meter can then average them out. If you point the meter at the light source, it will not take shaded areas into account and you will have an underexposed shot.

Screen Shot 2015-08-31 at 16.57.05

If you have a meter with the facility for taking both types of reading, you can take two readings beginning with an incident, then decide if the reflective is giving you a proper mid tone. I usually take an incident and check that against a reflective reading off the grass, or tarmac on the road, both of these are very close to mid grey.

In certain weather conditions, fog for instance, or snow scenes on a grey day, the light remains constant for a number of hours and one meter reading will be sufficient for many shots. Take one incident reading and the light will be the same for every shot.

Screen Shot 2015-08-31 at 16.51.51

Spot metering. The spot meter is an excellent invention, but needs careful thought when being used. Typically it will take a reflected reading from a small area, indicated by a circle in the viewfinder of the meter. Anything outside of this area will not be metered, though they do pick up a bit of stray light if you have areas of brightness nearby, or are pointing into the light.

Some people think that all you have to do is take one reading from the shadows, and another from the highlights and put your setting right in the middle. This can be done, but it will depend on how high your bright areas go. Are you reading off a white painted door, or the clouds nearest to the sun? A far more accurate way to do it is to read the exposure for the darkest tone that you would like detail in and underexpose from that reading by two stops.

The important thing to remember is that exposure determines shadow detail and development determines highlight detail.

Just let that sink in a bit; Exposure determines shadow detail and development determines highlight detail. There is no shadow detail that can’t be rendered on film if given enough exposure. Leave the shutter open long enough and the film will record light that your eyes cannot detect. Okay, we’ve got that, but what about contrast? Well, if you have exposed so that the shadow detail will produce some pale greys on the negative, but you have areas where a lot more light reached the film, say for instance, a gap in dark woodland with a sunlit area beyond, this area will have obviously received an excess of light. This will only become unprintable if you keep it in the developer long enough for it to go to black. You don’t want that, you want a dark grey that you can print through, so the answer is to cut back the developer so that this doesn’t happen. I’ll be covering this subject in my next post.

Metering through the camera lens (TTL). This is a quick and practical way to get your exposures pretty close to correct as long as you understand a few things; What you point the camera at for the picture, doesn’t have to be exactly the same thing you point it at to take a reading. For instance, if you were shooting tall buildings in the city from ground level, you would most likely be pointing the camera up and getting lots of sky. Point the camera at the building, excluding sky, take the reading and use that for the up shots. If you are shooting a band on stage, exclude the lighting rig from the frame when you take the reading, then set it and fire away.

For street shooting, a 35mm camera is ideal, but you won’t have time to take a reading as you compose the shot. Think about the tonality of the scene, take a reading from something typical, then set it and forget it.

Metering in low light.

Metering in situations where there is low, even light only requires a good incident reading, a reciprocity chart and a tripod. Metering in situations where there are areas of deep shadow, coupled with hotspots of intense light, such as a concert needs a different approach. Uprating is commonly used in these situations, but this creates negatives of higher contrast, requiring very careful metering. Whenever I see images online and the photographer is claiming that the film was rated at 12500 ASA / ISO or some such high number, my first thought is; Yes, but where did you meter from? If the shots are taken at a concert, or some dark restaurant or club, there will be areas of deep shadow and very bright spots of light. In that kind of situation, a 12500 ASA reading from dark clothing in the corner of the room will give pretty much the same exposure settings as a 400 ASA reading from a well lit face. TTL metering will give you a result, but if the shot is important, then a carefully taken incident reading would be better.

Outdoors in changeable weather conditions: If you have one of those days when the sun is in and out every two minutes messing up your readings, remember that the exposure will only drop by one to one and a half stops when a small cloud comes over. Proper storm clouds will take much more light away, but a typical British summer day with fleeting clouds is easy to meter; If you meter the grass for the sunny areas, the shadows from the clouds will be 1.5 – 2 stops darker than mid grey, but if you meter for the grass when the cloud comes over, the sunny patches will be 1.5 – 2 stops brighter than mid grey. Meter the scene according to the look you are after.

Go out and try these methods and let me know how you get on. If there are any other lighting situations you are having difficulty with, then please leave a comment or question.

 

Demystifying photography

  Today’s blog post is taken from my book ‘Home Photography’ Published By Argentum in 2003.

The quality of photography that you produce is dependent on the amount of time that you are willing to devote to it. So the obvious question is: are you shooting enough? A possible reason for not producing many good pictures is that you are probably not taking enough — the more you do it, the better you get. I don’t mean pick up the camera once a month and run off a number of films at a sporting event or whatever. Shoot every day, think about pictures every day, use the camera every day.

eiffel-tower-collection

The ability to see pictures comes from exercising that part of your mind as much as possible; any period of abstinence causes you to become ‘rusty’. It is definitely not like riding a bike, the ability does not stay with you unless you use it. One way to keep it functioning well is to look at the work of good and great photographers. Avoid looking at the work of poor photographers, as this will also influence your vision. Seek out high quality photography and think carefully about how it was done. Many times there are big clues in the picture. For instance, ask yourself where the light is coming from, are there two or more sources of light? If so, then how has that been achieved, by the use of artificial light, or reflectors? Is there a hard edged shadow or a very soft one, is it midday sun or late/early in the day when the sun is lower? Can you estimate the focal length of the lens used? Is it a wide angle shot or standard? Perhaps a longer lens? Has it been shot on 35mm or a larger format?

fish-and-chips

Look closely and see if there is plenty of depth of field throughout the photograph, indicating a small aperture. Perhaps the picture shows very little evidence of depth of field, indicating a wide aperture and probably a fast shutter speed. If there is subject movement in a shot displaying shallow focus, then this would suggest low light or a very slow film. There are many more ways to extract the information from photographs, but to list them would get boring. You must work it out for yourself. This is a useful exercise which helps to demystify photography. Asking these questions puts you next to the photographer at the moment of exposure. The important thing to bear in mind after the technical information has been extracted is: it is essential that you ask yourself whether this picture would have worked if any of these details had been different. Would the picture have been poorer had a larger or smaller format been chosen? And so on. Once the essential points have been established, you have a valuable reference point for creating strong images in a similar situation. This kind of detective work saves a lot of wasted film and can be a fascinating exercise which can be enjoyed whilst reading a magazine or watching a film. Old black and white films are rich in such details.

Reciprocity failure

Recently I have been doing a lot of pinhole photography, and due to that I have had to explain to a number of people (unfamiliar with the more technical parts of photography) what reciprocity failure is.

Reciprocity is the relationship between shutter speeds and apertures, which means that as you reduce exposure with a change in, lets say the shutter speed by one stop, then increase the exposure by one stop with the aperture, you will have exactly the same exposure. Each one-stop adjustment of the shutter speed, is equivalent to a one-stop adjustment of the aperture. This holds true throughout the normal use of the camera in most lighting situations.

This linked relationship begins to slip away with exposures longer than one second, and the longer the indicated exposure, the more of a difference there is between the indicated exposure and what is actually needed. Many years ago I included in my book on night photography, a chart for working out the amount of exposure correction you might need in situations where exposures were between 1 second and 17 minutes. I have been referring to this chart for my extended pinhole exposures, and I include a link to a word document here which shows the full chart:

https://dl.dropboxusercontent.com/u/88621650/Reciprocity%20chart.doc

Winter light

I love the low sun and long shadows that are a feature of winter days. Shadows have been a fascination of mine for many years and will continue to be I expect. Every sunny winter morning the light shines directly into our kitchen and on this occasion I placed a piece of driftwood on the table to explore the distorted and extended shadows.

Long shadows

Using light meters intelligently

First posted 21 April 2011

Looking at an analogue or digital hand meter for the first time can be very confusing, there are many options and often an overload of information. There are multi metering modes on advanced modern digital types which I find confusing even after using meters for thirty years, so I thought I might write a little about how to simplify matters and ensure consistent results.
Firstly, whatever you point a light meter at is read by the meter as a mid grey. It does this so that the whites are white and the blacks are black and to do that, it puts the exposure in the middle. To make this work, there must either be a range of brightness in the scene, or something which is already a mid grey.

Any and all light meters do this, and this is why when shooting in snow the hurried metering method often gives grey and underexposed areas where white should be the predominant tone. Another common mistake amongst beginners is to take shots looking up at trees or buildings without thinking of how bright the sky is. This causes the meter to read far too much brightness in the scene and the subjects end up as silhouettes against a grey sky. Even when a hand meter is used, false readings can arise from simple mistakes, such as having your shadow over the meter.

So let’s look at the different ways of metering; Reflected, Incident, Spot and Average.

Reflected is simply pointing a meter at something and seeing how bright it is, how much light is reflected from it. The problem though, is that if you point it at something rather dark, you will get an overexposed shot and pointing it at something light will give an underexposed shot.

Incident is a method which reads how much light is falling ON THE METER. This avoids the problems above. When using a hand meter, taking an incident reading will produce an excellent negative 99% of the time (it’s not much good with backlit subjects).
An incident reading is when a white plastic cone is fitted over the light cell allowing the meter to read light falling on the meter, rather than light reflected off the subject. The important thing is that the meter should be pointed towards the camera from the position of the subject, not pointed at the light source. If you are unable to stand in the position of the subject then simply point the meter in the same direction, but from a manageable position. As long as the direction of the light is the same where you take the reading and in the scene, the exposure will be the same.

One of the most reliable methods is spot metering. Not for taking a number of readings to average out the exposure as some meters permit you to do, as this can often lead to an incorrect reading (Because the important brightness is always two stops up from deep shadow, not half way between deep shadow and bright white). Finding the all important deep shadow tone, ( Zone III ) takes practice. If you can identify this tone in a scene and read it, you then underexpose that reading by two stops, which gives you zone V – which is two zones along. This may seem confusing, as the explanation is more complicated than the doing.

A simpler method is to set the spot meter to a film speed two stops higher than you are actually using, take a reading from deep shadow, set the camera accordingly and shoot. The film rating is not actually changed, so no alteration of dev time is necessary.

Because the meter is set two stops higher, it reads the shadows brighter than they are, the meter then suggests a faster shutter speed/smaller aperture. Shooting at this exposure causes the deep shadows to be two stops underexposed (from mid grey) which is exactly where you want them.

The explanation as I say often seems complicated, but in practice it is quite easy. give all methods a go and see which works best for you.

5 Comments

  1. Posted 02/05/2011 at 7:03 pm

    Thanks for this explanation. Although I’ve been using an old-fashioned hand-held meter for years, I did not really understand all the implications of this, and I guess I’ve just been lucky with my shots (though it does explain a few overexposed anomalies now), or fortunate to have been using film with a wide exposure latitude. My recent move into shooting slide film will probably be more telling!
    As my meter is so old, I’m guessing it’s measuring reflected light rather than incidental light – it doesn’t have one of those cones. Maybe I’ll have to start thinking about an upgrade to my kit.

  2. mark lacey
    Posted 06/07/2011 at 12:49 am

    For black and white your technique of spot meter deep shadow and open two stops is dead right, I’ve been doing that for 30 years and my negs have always been really easy to print, which to me is the point of the exercise. Don’t know anout colour, I don’t use the stuff! All good advice, it’s nice to see it expressed simply, some people turn the zone system into rocket science and I suspect in the process forget to take a good photograph.

  3. Posted 07/10/2011 at 9:35 pm

    I read Mark’s comment, and I had to stop and think about it for a moment. You wouldn’t OPEN two stops from the meter reading if you’re metering a deep shadow. The meter would look at that shadow and (as you explain so succinctly) give a reading to render it a middle gray – which would require either a slower shutter speed or wider aperture. Either way, in order to properly render the deep shadows properly using the spot meter technique described, you would STOP DOWN two stops – not open up… Your explanation of “underexpose that reading by two stops” is the same way of looking at the situation.

    I just wanted to clear it up because I put up a link to this great article, and then some questions as to whether the proper thing to do is OPEN the aperture – or stop down…

  4. Posted 05/04/2012 at 5:34 pm

    Thank you. These are some good insights.

  5. Philp Toal
    Posted 15/08/2012 at 5:29 pm

    I usually take a spot reading of the shadow area and over expose by 1-2 stops and develop N-1/-2 (depending upon the shadow area I want to show up), and then print down to Z3 because Z´s 1 – 3 expose as black on any paper unlike the the wider Zone range of say 1-18 of all films. Paper in general, barely goes beyond Z10 and with N development Z3 would render only black as well.

Seeing

First posted 1 October 2009

Looking around on the web I see many, many photographers who are producing sharp, well exposed shots and many of them are very competent photographers.
Often though, there is something missing; Too many of the shots are just BORING.
Making an image which is sharp and well exposed is the easy part, making an image which affects people, which has that certain ’something’ is another matter.

Screen Shot 2015-01-10 at 22.00.17

Kitchen table and sunlight

So how do you develop (I know it’s a pun) a way of seeing?

Well, that depends on a few things; Where you are, what there is to photograph there and what you are interested in. Are you new to it and enthusiastic, or set in your ways?

Seeing is an important part of it, although not the full story -but I’ll come back to that in a minute…
What are you looking for? perhaps you have been looking in the wrong place?

The most common mistake is to concentrate too much on ‘what it is’ -the subject matter, the thing or person in front of the lens.
That may seem like a perverse statement, but let me expand on that.

The single most important element in Photography is Shape, not the subject matter. It doesn’t matter what it is, as long as the shape looks good. If you get too fixated on the subject you lose sight of that. The second most important element in photography is Light. As I sit writing this I can see some interesting light on the curtains and I know it would make a decent shot. Curtains are not an interesting subject in themselves, but the way the light plays across them just now makes them so.
The third most important element is Tone, how the tonal range is distributed over the frame.
Photography (and this applies to monochrome mainly) is about shapes and tones within a delineated area, whether that be a square, a rectangle or even a circle. If you pay attention to that, you can photograph anything.
Go and look at some really good photography now and see it in the terms I have described, you will begin to see things very differently.
There is one other thing that I need to mention; To be able to see the good stuff you need to be able to spot the bad stuff! You need to cultivate a highly developed sense of the naff, the corny and tasteless, the boring and cliched. If you can spot it quickly you can avoid photographing it.

I said that seeing is important, but not the whole story, the missing part is presentation. I could show you my best shot, but if it was on poor quality paper and badly mounted in a crap frame it wouldn’t merit a second glance. Conversely, I could show you a simple image as a beautiful platinum print, mounted and framed professionally and it would be far more desirable.
It doesn’t have to be platinum, it could be a print on a good quality Fibre Based paper or an art paper ink-jet. It does however need to be presented as an object of beauty, so don’t use poor quality materials. One of my pet hates is seeing a low quality RC print with glaring whites in a cream coloured mount -Yuck!

Dried noodles

There are plenty of good papers out there, both darkroom and digital, though what is great for one type of image, might look wrong for another. choose your paper to suit the picture.

Think about how the space around the image helps to present it. Narrow borders make you look at the centre of the image, very wide borders make you look at the edge of the image. If you get the proportion right, the full area is taken in by the eye.
Make sure your quality control is high, don’t make do with unfinished prints, make sure your borders are properly square not wonky and don’t think that people won’t notice dust marks on your pictures, – they will. Your laziness will be noticed by others and their impression of you will go down.

Screen Shot 2015-01-10 at 22.07.10