Metering with film

[Tom Cross]

hi all, I've googled this but am even more confused after that.

When I am metering with film I have heard the term "meter for shadows, develop for highlights". Some say rate the film at half box speed, meter for shadow detail and back off negative development time by about 15%, to stop the highlights developing too much.

In practice, this will surely result in a highly over-exposed image?? I would have thought that metering for shadow detail at the box speed, or taking an ambient reading at half the box speed would have similar results, but both together would over expose?

 

[Ian Grant]

Get yourself a copy of The Negative by Ansel Adams. Everything is explained clearly. It's about doing your own personal tests to achieve the negatives that suit your purposes.

That maybe shooting at half the ox speed but that doesn't necessarily lead to over-exposed images because the final negative is a result of exposure and appropriate development. It's about getting the balance right, when you do you have negatives that are easy to print (or scan).

Ian

 

[Tom Cross]

The last time I read anything about the zone system I found it even more confusing!

 

[David Allen]

The term "meter for shadows, develop for highlights" refers to the fact that exposure controls how much shadow detail you will record and development controls how much contrast you will achieve.

In practical terms with negative film the phrases ‘over-exposure’ and ‘under-exposure’ are misleading because it implies that there is an ‘ideal, universal norm’ exposure for any given scene. There is an IDEAL exposure for each scene but this is not governed by some form of universal norm but rather it is governed by how you wish to present your image.

For example, if you want to make prints that have a full range of tones from deep shadows with detail through to sparkling highlights with detail then there is a minimum of exposure required to capture the shadow detail and a fixed development time to ensure that your contrast and bright highlights are correct. For a certain set of photographers they would describe this as over-exposure in relationship to how they prefer to expose and develop their films.

If, however, you prefer your images to look more like the work of Dead Link Removed or Daido Moriyama you would not expose for the shadows (preferring to loose this detail) and would increase development to obtain a full range of tones from what information the film has recorded. For a certain set of photographers they would describe this as under-exposure and push-processing in relationship to how they prefer to expose and develop their films.

The only true answer is what do you wish to achieve. Whichever approach you decide is correct for your image making will determine whether "meter for shadows, develop for highlights" or “Sunny 16” or “meter a mid-tone at box (or higher) speed and then extend development to compensate” is the correct approach for you.

Once this is clear then you have the second set of decisions to make:

• Do I want more/less grain in my images
• Do I want more/less sharpness in my images
• Do I want more/less accutence in my images
• Do I want more/less contrast in my images

So to sum up, there is no ideal for you to follow but rather a range of choices that are determined by what kind of images you wish to make and how you want them to look.

If you have a type of photography or photographer that you would like to emulate (or use as your starting point) you could start a new thread asking how you can achieve a particular look (giving the name of a particular photographer would help a lot) and there are many here on APUG who could then suggest how you can achieve this.

All the best for your photography,

David.
www.dsallen.de

 

[Frank53]

The last time I read anything about the zone system I found it even more confusing!

Then why not try exposing at box speed and following the instructions for the developer you use?
Frank

 

[baachitraka]

There are two difference schools. One who use reflected meter(spot or average meter) and the other the incident one.

"meter for shadows and develop for highlights" is rather metering with the spot meer the most important shadow on the scene where you want to retain details on negative and place it on an appropriate zone. And then metering the hightlight where you want to retain details will give you scene brightness range. Based on testing will give you the appropriate development times.

 

[Doremus Scudder]

Tom,

It seems you don't want a really technical answer, so I'll try to give you just the essentials without the technical substantiation, which means that you'll just have to believe me

First, negative film has much more leeway on the side of overexposure than underexposure, hence the admonition to meter so that you get shadow values you want on the film and don't inadvertently underexpose (a real danger). A couple of stops overexposure with modern films makes practically no difference in print quality.

Second, longer development gives you a larger overall range of densities on the negative (contrast). Therefore the practice of nailing down developing time to give you the highlight densities you want. If your negs are consistently too contrasty, then reduce development and vice-versa.

Many take advantage of these facts by erring on the side of overexposure and then underdeveloping a bit. Contrast can be increased at the printing stage if needed.

However, if you're not into learning an exposure/development system like the Zone System (which is really only practical for sheet-film users anyway) and don't trust the seemingly contradictory practices of others, why not just use the manufacturers' suggestions? Kodak, Ilford and Fuji have spent millions developing and testing their products and want their consumers to have the greatest possible success rate. Their suggestions are your best starting point.

As for metering (your original question): It depends on the meter you have! If you use an in-camera meter (your avatar has a 35mm camera in it, so I suppose you do), then by all means use it. It is likely an averaging meter of some kind, maybe center-weighted. At any rate, set the box speed ISO, and go out and shoot. 80% of your shots will be well-exposed. There are only a few situations when this technique will underexpose the film, so...

If you want to refine your metering technique, then you have to learn to recognize situations that "fool" your meter into underexposing. These include scenes that are high-key (i.e., all lighter values like the white cat in the snow)*, backlighting (where the meter sees all that background light and averages it in, but you really want full exposure of the shadowed foreground) and high-contrast situations (where the meter averages extremes that are too far apart and comes up with a wrong middle value). Recognize these situations and give one or two stops more exposure for them depending on the severity of the lighting difference. Heck, you could just give 2 stops every time you encounter a situation like these and at worst only be a stop overexposed. That should increase your rate of accuracy tremendously.

*Note that you don't have to worry about the opposite situation, low-key (the black cat in a coal bin) because the meter will just overexpose this, which is in the film's "safety zone" or latitude and won't adversely affect print quality much.

And, since you're using roll film, you can just bracket when in doubt: shoot a frame at the meter reading and then one 2 stops over when you're not sure. One of the negs will have a 99% chance of making a good print. Remember, it's underexposure that's your enemy and overexposure that's your safety valve when in doubt.

Develop according to the manufacturers' directions (use a recommended developer, time and temperature) and you'll be way in the ball park. For many, this is all that's ever needed. If you want to delve further into the nuances and creative possibilities of exposure and development controls in the future, you will already have a good basis.

Have fun,

Doremus

 

[Ian Grant]

There are two difference schools. One who use reflected meter(spot or average meter) and the other the incident one.

"meter for shadows and develop for highlights" is rather metering with the spot meer the most important shadow on the scene where you want to retain details on negative and place it on an appropriate zone. And then metering the hightlight where you want to retain details will give you scene brightness range. Based on testing will give you the appropriate development times.

Are there really two different schools ? Personally I disagree completely and I use both spot meters and incident meters, It's all about knowing how to use and interpret you meters particularly in extremes of light conditions.

Ian

 

[Tom Cross]

Thanks Doremus (and everyone), I mainly use 120 with a handheld meter (capable of spot and incident). When I send negatives off for commercial processing I tend to rate the film at half box speed and either use the meter in camera with my little Prakticas or with 120 an ambient reading. From these replies and after briefly revisiting "the negative" this is a highly "more luck than judgment" method!

I will continue re-reading "the negative" also experiment, using a grey card and also possibly metering off of objects which I might want to be 18% grey in the final image.

I've only revisited film in the last 12 months, after probably 10 years of digital. With digital you can meter for the highlights and boost in post processing. I much prefer film, and am keen to refine my technique and use it more. I use a Hasselbad 501cm and a Mamiya RZ ProII. For lazy days, I take my Praktica with its built in meter!

 

[Doremus Scudder]

Tom,

Just so you know: I'm an LF shooter and use sheet film. I use my adaptation of the Zone System and a spotmeter. I have development schemes for three different films from N-3 through N+2. That said, when I shoot roll film, I use an average reading and err on the side of overexposure and or bracket when needed. I don't think this is particularly "more luck than judgement," but rather "playing it safe."

Doremus

 

[David Allen]

Thanks Doremus (and everyone), I mainly use 120 with a handheld meter (capable of spot and incident). When I send negatives off for commercial processing I tend to rate the film at half box speed and either use the meter in camera with my little Prakticas or with 120 an ambient reading. From these replies and after briefly revisiting "the negative" this is a highly "more luck than judgment" method!

I will continue re-reading "the negative" also experiment, using a grey card and also possibly metering off of objects which I might want to be 18% grey in the final image.

I've only revisited film in the last 12 months, after probably 10 years of digital. With digital you can meter for the highlights and boost in post processing. I much prefer film, and am keen to refine my technique and use it more. I use a Hasselbad 501cm and a Mamiya RZ ProII. For lazy days, I take my Praktica with its built in meter!

Tom,

one thing to note is that meters are not calibrated for 18% grey. You are far better off learning to identify which part of the scene you wish to record as dark shadow with detail and meter that and place on Zone III or, in non Zone System language, take the meter's reading and stop down two stops.

Have fun.

David.
www.dsallen.de

 

[NJH]

Sounds like you were using ETTR (Expose To The Right) for digital, basically exposing just under the point where you have clipped highlights. Honestly I think the thing is to start by keeping it simple, shoot box speed and set exposure on a mid tone. I read through a lof forums in the past and had the odd experience that when I started shooting slide film I was getting much more consistent exposures than with B&W where I have tended to over expose on bright scenes but get thin negatives in doors in very flat scenes. I have the AA book Ian mentions and it is really good. What I am starting to do now is utilise how I have tended to scan a scene to find my exposure when shooting slides to give me an exposure adjustment for B&W, basically to get better balance across a mixed roll so the flat lit scenes get more exposure and the high contrast ones slightly less. I guess this is slightly inverting the process sheet films users would follow where the exposure and contrast control parts are separated but eventually all of us just have to accept compromises with roll film that have a mixture of scene types on a roll. RobC is one the few people I have seen talk about this sort of stuff on the forums a lot, I find his posts really useful if you can find them.

 

[removed account4]

hi all, I've googled this but am even more confused after that.

When I am metering with film I have heard the term "meter for shadows, develop for highlights". Some say rate the film at half box speed, meter for shadow detail and back off negative development time by about 15%, to stop the highlights developing too much.

In practice, this will surely result in a highly over-exposed image?? I would have thought that metering for shadow detail at the box speed, or taking an ambient reading at half the box speed would have similar results, but both together would over expose?

hi tom

get yourself a couple of rolls of film and do this:

set your meter to whatever the iso of the film might be
expose 3 exposures for each view: one as the meter says, one 1 stop more, 1 one stop less.
process in whatever developer you use, at the time the recommended.
then do the same routine ( 3 exposures ) at 30% more development,
and another 30% less exposure.
make 3 contact sheets or scans or whatever your method of reversing negative to positive
and see which exposures hold the best highlight or shadow or midtone or whatever it is you want
then notice was it 1 stop more, 30% less? or box speed 30% more?
expose a whole roll like that (whatever it ended up being ) and enjoy.

be prepared for a bunch of people suggesting film tests, books, devices
and any sort of test to get better knowledge of your exposure/development practices
to be a waste of time &c, and others will give you more tests and procedures.
take what you need and enjoy yourself, maybe it is all a waste of time? who knows.
good luck figuring it out !
john

 

[paul ron]

read the little yellow book, the zone system by minor white. do the tests he recomends for rating and adjusting exposures.

you can google zone system and find many articles that may simplify it to better understand the system.

 

[ic-racer]

Meter for the shadow only works if you have a spotmeter. Use average metering and put the safety factor back in the film. That is, expose at 1/2 box speed. When printing, if you need to regularly use contrast grades higher or lower than #2 then you can adjust negative development for future rolls.

The difficulty is that you need experience (or some help) to know if your negatives are OK and to know what a good print looks like.

 

[Ian Grant]

Meter for the shadow only works if you have a spotmeter. Use average metering and put the safety factor back in the film. That is, expose at 1/2 box speed. When printing, if you need to regularly use contrast grades higher or lower than #2 then you can adjust negative development for future rolls.

The difficulty is that you need experience (or some help) to know if your negatives are OK and to know what a good print looks like.

You can use any meter to take shadow readings you don't need a spot meter. Ansel Adams discusses this in the negative.

Ian

 

[pentaxuser]

Thanks Doremus (and everyone), I mainly use 120 with a handheld meter (capable of spot and incident). When I send negatives off for commercial processing I tend to rate the film at half box speed and either use the meter in camera with my little Prakticas or with 120 an ambient reading. From these replies and after briefly revisiting "the negative" this is a highly "more luck than judgment" method!
!

Given that commercial labs generally use the manufacturer's development times and you use half box speed I'd say that you are following the non-technical advice given to give you OK negs 90% of the time. It then remains to recognise the exceptional scenes that fool the camera's meter and if in doubt bracket as has been suggested.

Are you dissatisfied with more than a few of your prints in every roll? If so you might want to show us examples of these "not OK " negs so we can comment on what might be going wrong

pentaxuser

 

[Richard S. (rich815)]

I think maybe you're confused by the "meter for the shadows" part. This does not mean set your film speed and point your spot meter at the shadows and use the resulting setting. It means meter for the shadows "correctly" and let the highlights and rest fall where it may. My metering for shadows "correctly" mostly means take a meter reading in the darkest shadows I still want detail and then closing down two stops from the meter's reading. And yes, I also typically rate the film at 1/3rd to a full stop stop less than box depending on the contrast overall and then develop for 15-20% less than typical start times. The less development time prevents an "over-exposed" negative. Well, actually prevents an an over-developed negative...

 

[Gerald C Koch]

Anyone serious about B&W photography should have at the very least a copy of Ansel Adams "The Negative" and probably also "The Print." They are well worth the expense for the amount of information they contain. They are often sold as a package.

Speaking generally I am concerned by the number of people on APPUG who obviously have never read a good book on photography. The net is useful for specific questions but very poor in providing the overall information that a book does. So consider a good book on photography as a necessary companion to your camera.

 

[David Allen]

You can use any meter to take shadow readings you don't need a spot meter. Ansel Adams discusses this in the negative.

Ian

+1 - where did this spot meter idea come from? Most spot meters use a lens that also introduces a optical flare element not present in the taking stage.

Bests,

David.
www.dsallen.de

 

[RobC]

To the OP...

18% being middle is a myth (well most of the time but not always).

each stop is twice/half as bright as next/previous stop

so units of reflected light for each zone starting at zone 0 of 1/2 a unit...

0=1/2
1=1
2=2
3=4
4=8
5=16
6=32
7=64
8=128
9=256
10=512
11=1024
12=2048

now if you do the maths to find out what percentage of each brightness range the middle point is you will find that from zone 0 to zone 5 the middle point is 18%. i.e. a 5 stop range has zone 5 reflecting 16 units and the mid point is zone 2 1/2 which reflects 3 units which is approc 18% of 16 units of reflected light.
But if you calculate the percentage of middle point units of light from zone 0 to zone 10 you will find its about 3.125%. i.e. Zone 5 in a 10 stop range is far from 18% and in fact 18% on a 10 stop range is around zone 7.5 which is 2.5 stops less than the 10 stops brightness range.
The more astute may notice that on a 5 stop brightness range 18% is 2.5 stops less than the 5 stop brightness range.

AND

if you take a 12 stop brightness range 18% is 2.5 stops less than the 12 stop brightness range. And in fact 18% reflectance is always 2.5 stops less than the total brightness range of your subject. i.e. the mid point of SBR is not fixed. It varies with SBR.

The average subject (not that such a thing exists) is only 7 or so stops in brightness range. Excluding the brightest and darkest end you are left with a 5 stop range you are really interested in so 18% will work for your average Subject Brightness Range but its a ball park reading . But take a landscape with bright clouds and deep shadows in the foreground and 18% will be way off if your subject is 9, 10 or 12 stops range.

So I never assume 18% reflectance is a middle point because mostly I'm not shooting average brightness range subjects.

AND

for those AA followers who find this hard to believe, if zone 5 is 18% reflectance, then zone 6 is 36% reflectance, zone 7 is 72% reflectance and zone 8 is 144% reflectance. So 18% being the middle of any subject brightness range is just plain wrong except in the one case where your subject brightness range is 5 stops ( which 9 times out of 10 it won't be). It therefore follows that basing your exposure on a kodak grey card will not put your exposure in the middle of the film curve unless your development is tailored to capture a 5 stop range into the full useable negative density range (1.3log density range).

Since film ISO standard is designed to capture 7 1/3 stops subject range onto film in useable 1.3log film density range, the middle point reflectance of that from above would be middle percentage of 85 units of reflected light which is 7 units of reflected light and 7 units is 8 percent of a 85 units (7 1/3 stop range).

So in short, a grey card is as much use as a concrete parachute for normal black and white film exposure calculation when using ISO box speed and manufacturers recommended development.

Trust what your meter is telling you and you won't go wrong. A simple method of dealing with this when using a spot meter, ISO speed and manufacturers recommended dev is to treat each zone from zone system as 0.7 stops and not 1 stop. (0.7 being 1/10 of 10 stops) Then all you need to do is to meter something you want any zone and adjust assuming the metered reading is zone 5. So if you want to place exposure on zone 3 then meter your zone 3 area and close down 2 zones which 0.7 x 2 = 1 1/2 stops. Same principal if you want to place something on zone 7. Meter your zone 7 area and open up two zones so 0.7 x 2 = 1 1/2 stops.
My preference is to meter for and expose for highlights which gives much more consistant negative densities and therefore more consistant print times with easier contrast adjustments when actually printing.

And surprise surprise, a K factor of 12.5 results in 8% from what is metered which is the middle of a 7 1/3 stop range so your meter is calibrated to that 8% whether people like to hear it or not. Doesn't matter one iota how that K Factor is arrived at becasue its what effect it actually has that is the proof of the pudding.

So to the OP, forget about grey cards. What you really need to know for practical photography, is how many stops of range your film development is calibrated for relative to the calibration of your meter. Your spot meter is (I think) using a K Factor of 12.5 which equates to 8% of 7 1/3 stop subject range which puts it bang in the middle of the film curve when using ISO speed (for B&W film) and manufacturers recommended dev.
Once you start changing EI and/or dev then things change and you need to know what so be wary of changing from manufacturers recommendations because if you do then you need to do some serious testing to find where your meter will put its metered value on the curve.

If you want to calibrate dev to 10 stops range then see:

(there was a url link here which no longer exists)

Finally, you need to be aware that paper has a limted contrast range. I don't mean grade, I mean it will only print to a density of approx 2.1log print density. You can NOT increase that significantly and it implies that if you compress a subject of a high contrast range to fit into it, then the resulting print will have a lack of separation between high contrast areas you saw in the original subject. For this reason your best prints (most expressive) will usually come from subjects which have 7 or less stops of contrast in them to start with. You can do somersaults in the darkroom to get a decent print from high contrast subjects but something somewhere will be compromised since you can not fit a square peg into a round hole. For that reason I am very picky about what I actually photograph and avoid very high contrast subjects if at all possible. Other people seem to think its a desirable to compres contrast to make it fit the paper but their prints usually look flat and all increasing print contrast will do is to block out detail from what they got on film. i.e. there is no kudos in capturing 15 stops of subject contrast onto film since all it will do is make producing a good print a real bugger.

 

[David Allen]

Everyone here is assuming that the OP wants to achieve the 'classic' tonal range but the OP is asking if the "meter for shadows, develop for highlights" is the correct approach and whether it would lead to over-exposed negatives. The OP is coming from digital where the key thing (just like transparencies of old) is to work against over-exposure. In the world of negative films the opposite is true - under-exposure is the biggest problem if you wish to achieve the 'classical' tonal range in your prints.

The REAL question is how do you the OP wish your prints (or scans) to look. This was the central idea of my post #4. What the OP had originally asked is impossible to answer without knowing what kind of images the OP wants to create.

When we have this information, then we (as a forum with great and diverse experience) can advise further.

Anyone serious about B&W photography should have at the very least a copy of Ansel Adams "The Negative" and probably also "The Print." They are well worth the expense for the amount of information they contain. They are often sold as a package.

I completely agree Gerald BUT only if the OP wants to achieve this type of tonal reproduction of the scene - many do not want this. Also many people find the (what for me and others so simple to understand is) Zone System so impenetrable as to be useless as a guide to further development. Hence why we have such sites as this.

Bests,

David.
www.dsallen.de

 

[RobC]

well since he's using roll film then he can't develop for highlights since he's likely to have subjects of varying SBR. So something has to be compromised. The question is what? The link I provided above is one way of doing it. However, if OP is doing mostly studio work then I would stick with ISO speed and adjust lighting in studio to get the results you want. And use an incident meter if working in studio.

Expose for the shadows and develop for highlights is best reserved for sheet film use IMO.

 

[Tom Cross]

I did a test film today, using varying metering, and they all came out pretty well but some more defined testing is definitely needed.

One of my main problems in home development is resolving detail. More often than not images look at bit soft, where similar images with the same camera/lens/film but commercially processed appear with much greater detail.

 

[pentaxuser]

One of my main problems in home development is resolving detail. More often than not images look at bit soft, where similar images with the same camera/lens/film but commercially processed appear with much greater detail.

You are saying that the commercially processed negs look sharper? This might be possible if you were using a fine grain developer such as Perceptol and the lab was using say Rodinal but even then and unless you have a very large magnification loupe this seems unlikely to show up

Show us an example of the commercial neg and one you have processed at home. It will help if the two negs are of a similar scene and lighting conditions but this isn't essential.

Scans of two prints will help as well

pentaxuser