Colour Negative / Slide and the Zone System

[Photo Engineer]

Do I have to post this again?

Here is a series of negatives scanned identically using Portra 160. The exposures range from ISO 25 to ISO 400.

PE

 

[Bill Burk]

Ok - I appreciate the length of responses but I still cannot see how this fits into outdoor photography. I should have made it apparent that I only use reflected light / spot meter to measure the scenes that are far from the camera, as I am using film to photograph landscapes / cities on MF, LF (6x12 on 120) and street and city scenes.

I don't print, I scan, so another variable removed. If I don't get the exposures correct there are colour shifts and excessive shadow noise when scanned

Ok here is a straightforward scene - how would you meter this with a spot meter? There was masses of bright reflected light coming straight at the

It was taken last week in London with an 85year old Rolleiflex Old Standard on expired Portra 400NC

View attachment 165877 .

Looks like whatever you did worked fine.

I'd meter the sunlit white side of the building - maybe not the brightest sheets but a little to the left of the real bright parts. In "Zone System" terminology, I would "place" a high value where I wanted to see some detail on "Zone VII". (You might be able to read some points that will go up to Zone X in the brightest sheets of plastic, but those extremely bright points aren't necessarily the best place to judge a meter reading)

Then I would check the darkest reading I could get on the left side of the building and see where it "falls". I think in your scene it wouldn't fall much below "Zone IV" so I'd take note of the planned exposure and make a few more notes.

[Here is where you could just as well take the darkest reading and "place" it on Zone III and "see" where the white parts of the sunlit side of the building "fall"]

I'd read white cloud, gray cloud and blue sky and just "see" where they "fall". If gray cloud wasn't right on "Zone V" I would get suspicious. But if it was "Zone V" that would be enough confirmation for me.

So this scene, say that except for the really bright points, might have metered a range of five or six stops, which you could expose anywhere in the range of exposures from -3 to +12.


For example I would probably try to expose it at "-2 to +4"

But you could pick "-3 to +3" or "0 to +6" or "+4 to +10" and the color negative material, because it can record up to fifteen stops of detail, would be able to record your picture - and you would be able to get a fairly good print out of it.

[Like PE just showed, a scene of about 7 stops subject luminance range (from the dark shadow under the chair... to the white patch on the color checker card), can be exposed over a wide span of choices for exposure as long as you avoid underexposure]

 

[Bill Burk]

Color slide material is more finicky because people watching your slide show expect to see the white sheets on the side of the building... as white... and without the negative-positive process available to give you a chance to adjust brightness, you have to get the brightness (as it will show projected up on a screen) correct in the camera.

You're shooting color negative film though, so you have a wide range of adjustments that you can make after you get the negatives back.

 

[Bill Burk]

DavidClapp,

A couple more thoughts

The default clipping points on the L-758DR are pretty good for starting points if you don't want to do all the testing...

It never hurts to take a quick incident reading just to double-check you are not making a crazy decision based on the spotmeter readings (Don't expect incident and spotmeter readings to be the same, they often differ by a stop. Just expect them to make some kind of reasonable sense).

 

[Leigh B]

Don't expect incident and spotmeter readings to be the same, they often differ by a stop.
Just expect them to make some kind of reasonable sense.

Ain't that the truth.

The two readings will match under VERY tightly controlled conditions.

You're not likely to find any surface in real life that has a true 18% reflectance with zero specularity.
That's what a reflectance meter wants to see. Any deviation from that ideal results in reading errors.

- Leigh

 

[Bill Burk]

Ain't that the truth.

And I'm not even talking about the 18% rabbit-hole...

I get different results just because the different ways of taking meter readings... lead to different answers.

Except somehow, in bright sun, no matter how I meter, I always get the "Sunny 16" equivalent.

 

[Leigh B]

Except somehow, in bright sun, no matter how I meter, I always get the "Sunny 16" equivalent.

That's because "sunny 16" matches the way film speed is defined in the first place.

Film speed = reciprocal of shutter speed @ f/16 required to achieve proper exposure in sunlight.

- Leigh

 

[Poisson Du Jour]

Shoot slides using incident metering.
That is the best training you can get.

Actually I take the view that is not good training. The reason is that an incident reading does not take into account any of the range of luminances within the scene, and their individual values. The incident assumes the entire scene is the same single value, irrespective of shadow and highlights. For slide film I have seen how this (incident metering without explicit measurement) has resulted in more strife than any other single task in the execution of a photograph. Yes, there is a role for incident metering in specific presenting backlight situations, but it is largely problematic in the wider landscape format where there are critical elements that slide film depends on to get right -- there and then, in-camera, not in Fauxtoshoppe.

Transparency film delivers excellent results spot metered, and when the meter has been calibrated to the known characteristics of one or two particular films (this might be a problem with David Clapp not achieving consistent results, but I think there are bigger troubles about). The image posted by David of the building against a blue sky is underexposed, certainly it does not fit an expected "correct exposure" expectation. The subsequent image posted by derelict cannot be commented on beyond the image obviously having some post work applied. The palette is incorrect for Velvia 100F.

[...]If you are not getting those sorts of results, your problem is with the digital parts of your workflow, and APUG isn't the place to discuss that.

That's right, I think that digital workflow is the cause of many problems (scanning changes a lot!), but I also think there is a deficit in metering capacity, analysis and circumstantial change. I really do not know for sure. What I do know is that image at the top is underexposed, and is a very surprising result for an advanced meter such as the L758D, spot or incident. As for "how to meter this scene", spot it in 5 places (do not meter the sky), average, then provide +1.0 to +1.5 additional.

Somebody mentioned clipping points on the L758D; I agree fully the defaults are fine as valid reference points and generally do not require any shifting. Typically Velvia is one, sometimes two points less than shown. It will vary with lighting conditions, which must be taken into account when using contrasty film such as RVP50, the lesser Provia 100F and lesser again Rollei CR 200 (this film is a quirk that does not require special attention for shadows).

 

[Leigh B]

Shoot slides using incident metering.
That is the best training you can get.

Actually I take the view that is not good training. The reason is that an incident reading does not take into account any of the range of luminances within the scene, and their individual values.

You conveniently neglected to quote the two sentences following that exerpt, thus:

Shoot slides using incident metering.
That is the best training you can get.

You train your eye to recognize situations where the standard incident exposure may not be appropriate. In such cases you adjust up or down half a stop or even a full stop as needed.

I very strongly resent your intentional mis-quote.

- Leigh

 

[Poisson Du Jour]

I don't need to read any further than the first silly statement.

 

[Leigh B]

I don't need to read any further than the first silly statement.

Perfect example.

- Leigh

 

[Chris Livsey]

The incident assumes the entire scene is the same single value, irrespective of shadow and highlights.

Strangely we expose the whole scene at one single value

 

[Chris Livsey]

Alan, you have highlighted the whole point of this thread, a shifting in colours, hues and exposure. .

But that's not what you said in your first post, that was all about placing the exposure within the constraints of the film.
If you had talked about colour shifts and hues we would have moved quickly on to the scanning, or rather referred you elsewhere for expert help, PE has posted the answer to that question.

 

[pdeeh]

It started rather complicated sorting out dynamic range from latitude and I apologise for that.

No need for apologies, that was one of the most succinct but lucid explanations of the interrelation that I've read, anywhere

 

[derelict]

You also don't know how many shots he took to get the "right" one.

PE

True. I do not. I just know that it was slide film and I like the results. I would meter it using incident most likely. Or, if that is not possible, spot metering the bright part of the door which would have been my focal point.

I am going to shoot it at box speed and incident meter for the highlights.

 

[Bill Burk]

That's because "sunny 16" matches the way film speed is defined in the first place.

Film speed = reciprocal of shutter speed @ f/16 required to achieve proper exposure in sunlight.

- Leigh

True, fitting the age-old Sunny 16 rule of thumb was a chief requirement for the arbitrary number that was ultimately picked in the definition of film speed.

That wouldn't explain why meters all agree in sunlight... I think the real reason is that I'm just storytelling at this point... I only had one meter Saturday when my careful Zone System metering with the Weston Master III of a daylight scene only confirmed Sunny 16

I agree with you that it is a good learning exercise to experiment with color slide film and check it by projecting the slides...

That's because with a positive-negative system, the printmaking process gives you a chance to correct any exposure deviations from optimum... while with slides, if it doesn't look right when projected... it is because you did not choose the correct camera exposure.

And an incident meter will likely give that one correct exposure for color slides. But for a positive-negative process (color or black and white) there are judgement calls to be made and there is a saying for positive-negative processes... "the least, if it is enough, is often the best"...

But I like just a little more exposure since I want to make sure it is enough.

 

[Chris Livsey]

No need for apologies, that was one of the most succinct but lucid explanations of the interrelation that I've read, anywhere

Your generous comment is appreciated.

 

[DREW WILEY]

Whenever I'm confronted with an unfamiliar new color neg film, I do exactly what PE showed in a post above: Grab a Macbeath color chart and a roll
film or 35mm camera, and shoot a series of frames all the way from serious underexposure clear up through serious overexposure. With transparency film you can simply look at the results on a lightbox. With color neg you can order a contact sheet and/or a basic scan. This at least gets you to first base in terms of real-world latitude and what is apt to happen if you're way off in parts of an image due to excessive contrast or
an exposure error.

 

[faberryman]

I only had one meter Saturday when my careful Zone System metering with the Weston Master III of a daylight scene only confirmed Sunny 16.

Please explain your careful Zone System metering with an incident meter.

 

[DavidClapp]

But that's not what you said in your first post, that was all about placing the exposure within the constraints of the film.

The thread evolved somewhat...

 

[Bill Burk]

Please explain your careful Zone System metering with an incident meter.

Although I have the attachment for incident metering with the Weston Master III, I didn't use it. The meter is naturally a large area reflected light meter.

I metered my outstretched hand and set the dial on Zone VI, then I aimed at different parts of the world around me... the sky, the grass, shaded side of car I got out of... and each meter reading corresponded to a print value that I would be happy with.

My meter has a sticker like this: (photo is of my Weston Master II, but I made a sticker similar for the Master III - advantage of Master III... it has ASA speed instead of Weston speed)

 

[Bill Burk]

The thread evolved somewhat...

Did you make any progress towards understanding exposure?

 

[faberryman]

I metered my outstretched hand and set the dial on Zone VI, then I aimed at different parts of the world around me... the sky, the grass, shaded side of car I got out of... and each meter reading corresponded to a print value that I would be happy with.

With a 30 degree angle of view, you must take close up readings of the reflective areas you are metering.

 

[Bill Burk]

With a 30 degree angle of view, you must take close up readings of the reflective areas you are metering.

It's very practical, and turns picture taking into an immersive experience... to walk around the area you are considering taking a picture and checking the reflected light readings of different parts of the picture...

But when I went to Yosemite last summer, I smashed the glass on my Weston Master II (the one in the picture but I've since repaired it)... Then I was forced by circumstances to rely on a Pentax Spotmeter V.

A spotmeter makes Zone System metering much more practical than the Weston Master series.

 

[Adrian Bacon]

I've not read the whole thread yet, but seeing as you're shooting film to scan it and I'm a hybrid guy, I'll chime in. For color negative film, most reasonably good film scanners can see and digitize the full density of the film, so the only thing you have to care about is getting what's important in the scene exposed with enough density that the important stuff isn't lost in the film fog. The red, green, and blue channels have different densities, and different density ranges from each other, so once it's developed and scanned in (ideally as a 16 bit positive transparency with gamma 1.0), you get to invert it and choose where stuff goes with photoshop levels and curves. That's the beauty of digital, you get to choose and can change it as much as you want. Once you do your initial baseline density correction so that the red, green, and blue have the same density and density ranges and any remaining color casts have been removed with curves, you'll have an image that looks flat and ugly. It's at this point that you can start to think of the zone system.

In digital, even though you scanned in at 16 bits, your display is only 8 bits and actually a lot like paper. At gamma 2.2 (which is what the vast majority of displays are), you can encode about 12 stops into those 8 bits. It's not linear, but you know what? It doesn't really matter. There's a much simpler way to deal with it that is shockingly like the zone system.

Percentages of luminance. Black is 0%. White is 100%. Divide that range up into 10% blocks, and what do you get? 10 zones. OK, so where does stuff go? This is totally subjective and up to you where you put stuff, but what I generally do is put an exposed 18% exposure gray card at 46.6% through an exposure adjustment layer, then apply a curve layer to place the other things (at that point, if I exposed reasonably well, they're already close unless the scene is really high contrast). Some general rough rules: 90-100%, light sources. 80-90%, specular highlights. 70-80%, reflected white. 50-70%, most skin tones, darker skin can dip down into the 35-50% range. Middle gray: 46.6%. 10-40%, darker tones and shadows. You start to lose discernible detail above 90%, and below 10%, so put your important stuff between those two points.

This is all very fast and easy to do with a simple curve layer in PS and results in an image that looks good and has good contrast. From there, you can add more or less contrast, warm it up or cool it down, pretty much do whatever you want with it to get the aesthetic you're going for. For exposure, I don't bother with a light meter. I use the sunny 16 rule, and when in doubt, err on the side of more exposure.

Granted, none of this really applies if you're 100% analog, but if you're scanning it in, it can be helpful.