How truly useful are lightmeters?

[kevbo]

Hello all. I've been searching around the web for the answer to this question. I know what light meters are, I just can't find any discussions about why measuring ambient light is better than the metering on my 5d or the basically-spot metering on my m9.

I know that there are a few photographers whom I respect (Yanidel comes to mind) who openly admit to using a separate light meter and manual mode, I'm just having trouble understanding _why_.

My thanks to what is likely somewhat of a basic question. I searched through these fora as well for lightmeter but didn't find much.

 

[cosmonaut]

The meter in your 5D or M9 will be as accurate as anything else you could buy unless for some reason you need to get real serious. With modern DSLRs, LCD screens and Histograms I see little point in carrying extra equipment you don't need. A live histogram and the knowledge on how to read one would be better. IMO. Not to mention software like Lightroom.

 

[Jamie123]

In plain daylight with a camera that has decent metering (as most DSLRs have) a separate incident lightmeter doesn't offer many advantages. In difficult lighting conditions (e.g. snow) an incident meter can make things a bit easier and quicker but even then it's not crucial as you have the lcd and the histogram.
In a studio environment with more than one light I find it quite crucial, though, as you will want a way to meter the different lights separately in order to get the lighting ratio right.

 

[Pickett Wilson]

There are many good reasons to use incident, rather than reflected, light readings. I use a handheld for incident readings much of the time, even with my 5DII and 1DMkIV (with their excellent built in reflected light meters).

 

[Beemermark]

Don't know much about digital but a light meter in the camera measures reflected light. So if you outside and the sun is shining on your subject the camera is measuring the light reflected off the subject. Depending on how reflective your subject is can really influence the light meter. Also how much of you subject is the meter actually seeing? Is it the person's face? His whole body? The person and sky beyond? So it takes some experience to interpret what the built in meter is actually telling you the correct exposure should be.

Handheld meters can be either reflective or Incident. Incident meters actually measure the light falling on the subject. By measuring the light falling on the subject a much more accurate exposure measurement can be determined. If a subject is partially in the shadows you can get a high light and a shadow reading and compensate the exposure meter for what you, the photographer, consider what part of the subject is most important. Still not fool proof and still requires some experience but usually gives better results than a reflective meter.

The advantage of an in camera meter is that it is quick and easy to use. Most modern cameras, including film like Nikon's F100, F5, F6 ,etc, have built in computers to take a reflective reading, average the scene and deliver exceptional results.

The reflective meter is great if you have time to take reflect and take take the picture. I use one all the time with my 5x7 camera.

 

[Freakscene]

http://theonlinephotographer.typepad.com/the_online_photographer/a_simple_system.html

Any reflective light meter "sees" in 18% grey. An incident meter can get you around this. Both need to be used intelligently.

Marty

 

[ray*j*gun]

Light meters get you in the ball park but after that you need some trade craft to interpert the scene and incorporate your desired effects. Spot meters help but experience and training helps even more. Of course today's digitals do it all right.....?

 

[oftheherd]

If your camera has a good built in light meter, don't worry about it unless you just want to experiment and learn more. If your camera doesn't, then consider getting a light meter that does both reflective and incident. Then by reading and experience, learn how to use it properly.

Incident meters (ambient as you mentioned) have a better chance of giving consistent readings in general, but neither method is fool proof. Most agree incident is better for slide film, so probably for digital as well. I have both, and often prefer incident when I use a hand held meter, but not always.

A good place for information is Mr. Hicks' site at http://www.rogerandfrances.com/subscription/photo school index.html where you can scroll down and find a module on exposing negatives, and another on slides and digital.

 

[Roger Hicks]

http://theonlinephotographer.typepad.com/the_online_photographer/a_simple_system.html

Any reflective light meter "sees" in 18% grey. An incident meter can get you around this. Both need to be used intelligently.

Marty

Dear Marty,

Disputable. The original Kodak research indicated 12-14%, after all. No sources to hand but I'll try to look it up. The 18% Munsell mid-tone appears not to have been considered as a meter calibration standard until the 1950s -- and it's not clear, even then, whether it was ever used as a standard, except perhaps with some spot meters.

Cheers,

R.

 

[tlitody]

reflective light meters require you to know that what you point it at should be exposed at a certain level because it will try and make whatever you point it at a middle grey.
For example, if you point your camera with its meter at a black wall and just expose using the auto function, then the wall will turn out a middle grey.
If you do the same but with a white wall, then the result will be the same. i.e. a middle grey.
So you must know that if you are metering black you need to compensate and if you are metering white you must compensate. But most scenes are a balance of tones and the meter will get you in the ballpark. If its a bright area you are metering then you need to give more exposure than the meter indicates and if its a dark area you are meteriing then you need to give less exposure than the meter indicates. Effectively it measures the average brightness of what you point it at without knowing if that is predominately light or dark. Matrix metering tries to figure that out and adjusts accordingly but doesn't always get it right. You have to know your camera meter and how it works.

Then you have a spot meter which is very precise. BUT you have to be very precise in setting your compensation otherwise its no good.

Incident metering doesn't care about the brightness of your subject areas. It just knows that for your film speed the amount of light it measures requires a certain exposure. It will give you consistent exposures. So whether the wall is black or white it will give the same reading because you point it the light source. A reflective meter won't because you point it at the subject and as the subject brightnes/tone changes so wil the reading.

So it may seem like incident is always the way to go. Well not quite because there are situations where spot metering is superior. For example where your subject is not in the same light as where you are metering from. An incident meter often(not always) needs to be where the subject is. With a long lens photographing someone inside a doorway from distance can't be metered accurately with an incident meter unless you walk over to the doorway. But a 1 degree spot meter can nail it exactly if you know what you are doing. You might be able to get it right with an incident meter from distance with some guestimation but maybe not.

So if you know exactly the dynamic range of your film or sensor and use a spot meter you can always get it right. You can nearly always get it right with an incident meter. And your cameras meter will nearly always get it right but not as often as either a spot or an incident. But then your camera meter is a lot more convenient and will work faster than you can. So for sports photography with fast moving subjects you don't have time to meter everything with a spot or incident meter. You may be able to preset exposure if light is not changing using an incident meter but often the camera meter will do a better job.

As you can see the answer, as all the best answers do, begins with "it depends on what you are doing as to which is the best for that situation"

 

[tlitody]

Dear Marty,

Disputable. The original Kodak research indicated 12-14%, after all. No sources to hand but I'll try to look it up. The 18% Munsell mid-tone appears not to have been considered as a meter calibration standard until the 1950s -- and it's not clear, even then, whether it was ever used as a standard, except perhaps with some spot meters.

Cheers,

R.

The difference is so small as to be largely irrelevant. And besides if you calibrate film speed and development what the meter spec is also becomes irrelevant.

 

[kevbo]

What a wonderful treasure trove (so to speak) of new things to try to understand. My thanks everyone.

 

[Steve M.]

If you know a little about metering a $30 reflective meter will give you exposures as good as anything. This isn't figuring low light situations where a CDS cell will not be the best answer, hand held meter or in camera. I never saw the use of an incident meter as I have always been able to find a middle value to meter off. My hand is always attached to my arm (so far), and metering my palm is a fine middle value. If you're in sun and your subject is just in the shade an incident meter is useless. But as I said, you have to know a little about metering to avoid reflective objects that will throw off your readings.

I would much prefer an in camera meter that I trusted, because many cameras have a spot meter, and that will give you the best exposures in any situation. I have a nice expensive digital Sekonic meter now because I'm shooting meter less cameras, but the large spot meter in the Leicaflex SL I used to have is sorely missed.

 

[Roger Hicks]

Digital and slide exposures are 'keyed to' the highlights, i.e. to the maximum exposure you can give before the brightest areas 'blow' to an irrecoverable white.

You can measure the highlights in two ways: incident light (otherwise known as the 'artificial highlight' method) and spot. The former is normally much easier, unless you cannot measure the light falling on the subject.

Negative exposures are 'keyed' to the shadows, i.e. the least exposure you can give without their 'blocking up' to a irrecoverable black (clear film in the negative). The ONLY way to be sure of adequate exposure is with a spot meter.

Fortunately, there's quite a bit of latitude in the system, so almost any meter gives good results if used intelligently. On the other hand, 'used intelligently' is a lot easier if you understand the theory behind it all, then supplement that with experience.

Also, for a given film (transparency or standard-process C41 negative) or film/dev combination (in black and white) it takes precisely one test film to find out what index to use. In fact, it's easier than that. Around 99% of the time, you'll get excellent exposures if you set the actual ISO speed to IRE 1 (shadow index) or IRE 10 (highlight index).

To make life easier still, when you are using a true spot meter (1 degree or less -- most in-camera spot meters are a lot less useful, not least because of the larger and variable angle of coverage), assume that films are at or very close to their nominal ISO speed in middle-of-the-road developers; 2/3 stop slower in fine-grain developers; and 2/3 stop faster in speed-increasing developers. Thus, HP5 could be rated 250-400-650, depending on developer. Most manufacturers are pretty honest about ISO speeds: those who say otherwise are usually a bit unclear on what ISO speeds actually mean.

By all means give your negatives 1/3 or 1/2 stop more because you prefer the tonality, but don't confuse that with the ISO speed. And don't forget that with less precise metering techniques, films may appear slower because you aren't metering the shadows properly. Ansel Adams reputedly said that when he switched to a spot meter, his exposures increased by a stop.

Cheers,

R.

 

[dmr]

Your light meter is simply making a "suggestion" as to how to expose. 🙂

 

[thomasw_]

As I shoot BW film precisely 99.5% of the time, I find that all I require for satisfying exposures is a small hand held light meter like the gossen digisix. Over the years I think we develop our ways of compensating for our desired contrast, tonality etc. in the final printed negative; the initial light reading is of a certain relevance to a successful print, but also there are numerous other intermediate steps that can be manipulated to give us the desired look. Accordingly I find the initial exposure of any meter needs to be cross referenced with reason and experience; whether you do this in-camera or hand-held is just a matter of preference.

I have developed a strong preference for a VF without clutter, without flashing LEDs or containing info.; as such I prefer to meter hand held except in some social situations.

 

[furcafe]

I have nothing to add to the excellent posts by others here re: why you might want to go w/incident metering, but will point out that the meter on the M9 is not "basically-spot." The film Ms w/TTL metering do have semi-spot coverage (hence the little white metering circle on the shutter curtain), but the M8 & M9 have (center/slightly bottom-weighted, I believe) average coverage (hence the big gray section of the shutter), like the Hexar RF, Voigtlander Bessas, & Contax G1 & G2.

Hello all. I've been searching around the web for the answer to this question. I know what light meters are, I just can't find any discussions about why measuring ambient light is better than the metering on my 5d or the basically-spot metering on my m9.

I know that there are a few photographers whom I respect (Yanidel comes to mind) who openly admit to using a separate light meter and manual mode, I'm just having trouble understanding _why_.

My thanks to what is likely somewhat of a basic question. I searched through these fora as well for lightmeter but didn't find much.

 

[damien.murphy]

I find a meter quite useful for my b&w film shooting. A small incident meter serves to give me the basic exposure I dial into my M's and leave there until the light changes. A more advanced combined incident and spot meter gives me the metering tools to tap into the zone system when I am shooting more contemplatively.

I love my incident meter, but not sure it would be as useful for digital exposures, with the inherent narrower latitude of digital sensors. Beyond incident metering, if you have a spot meter built into your camera I would not see the point personally to have a seperate spot meter.

Lastly, one other benefit of a seperate meter is when you can turn off the metering in your camera, so as to remove the distraction. I found with my M6 those little red metering arrows were always distracting me, and it is liberating to shoot meterless cameras now, metering when needed with a handheld meter, focussing entirely on composition when I look through the viewfinder.

 

[ebino]

Every photographer should have an incident light meter.

 

[leicashot]

Nothing beats using an ambient meter shooting in manual. No in-camera meter can ever be 'consistently' accurate. Why? Because they only measure reflected light. They do not measure the light falling on the subject, which is much more accurate. In-camera meters are always confused and tricked by reflections and colors, making them untrustworthy. The argument against this is using 'exposure compensation'. This is backward thinking as you're guessing what you think the camera will do wrong then forcing it to compensate when you could do the same thing in manual, but with shot to shot consistency.

Nothing beats shooting in manual with an ambient meter in the hands of someone who understands light. Exposure isn't recket science. It's determining a certain amount of light chosen to be exposed for a certain amount of time. Shooting in manual is good because after a while you'll learn how to count f-stops and be able to recognize light changes and change exposure without always checking the light meter, and with digital, you can confirm just by checking the LCD. By measuring different zones and compensating using a spot meter is actually making metering much more complicated than it needs to be. A good photographer will be able to check the ambient light then decide whether they want to go with that or change it depending on the look they like, wether they want to make mor of a silhouette by giving it 'less' exposure, or blow out the unwanted highlights to make the subject po just by giving it 'more' exposure. Remember, also, aperture priority is NOT a manual or even semi-manual mode. It's auto. Just because you're selecting the depth of fiend outcome with the chosen aperture doesn't mean you're controlling the final exposure. The two are totally unrelated. It's just like shooting full auto, leaving the final look of the exposure in the hands of a computer - the camera's in-built meter.


This is the best advice any photographer can take on - well it's worked for me all my career and never let me down, except times I've dropped the ball...and I've never blamed my equipment because shooting manual makes me, the photographer totally responsible for the result, good and bad. I know that many don't share the same views as I, but many also don't rely on consistent photography for an income as I do. No doubt, the flaming will now come.