Zone system/ EV question

steveo_mcg

steveo_mcg

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Steven
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Right technical question and I think this will be a different answer depending on film choice or digi sensor but here goes.

If I meter a scene and the point I want to be about black is EV10 what EV setting would I want to dial in the camera?
 
Make sure you are not confusing EV (exposure value) with LV (light value).

EV is purely a function of shutter speed and aperture. LV is a meausure of light.

At ISO 100 the numbers are the same.

If what you are referring to as black at EV10 is the darkest point you want to see detail in then I think about two and a half stops less exposure so EV 12.5


Steve.
 
Says EV on my light meter, that's the top and bottom of my knowledge on the subject. :)

I'll rephrase as I don't think I explained that right. I'm using a spot metre on a scene, it has a range of values and the area of shadows I want to be black measures as EV10 you reckon shooting at an EV of at least 12.5 would render that black?
 
I think so. If you meter something black and the meter tells you it needs EV10 for correct exposure (the meter can tell you EV numbers as you will have set the ISO on it).

If you used EV 10, it would render it as a mid (18%) grey. In order to make it black, you would need to under expose it by about two and a half stops, hence the suggestion for EV 12.5

EDIT: Actually, you might need to under expose a little bit more. Perhaps 3 to 3.5 stops. It's difficult to ascertain as you wouldn't normally meter on something black. It's more usual to meter on the darkest part of the scene in which you want to retain detail - which will not be totally black.

http://www.alanrossphotography.com/category/tech/zonesystemandmetering/

It was decided that that middle gray represented a neutral color reflecting 18% of the light falling on it. Photoshop-wise – that works out to a black set at about 55% opacity.

In photography, this works out fine so long as your meter (or camera) is reading an equal mix of lights and darks, or you are metering something that is itself middle-gray in brightness.

• But what if you are photographing a white horse in the snow? The meter thinks it is looking at something gray – and thus will give you the correct exposure to make that horse and snow GRAY! The solution is to give MORE exposure to your film or image sensor so that the scene is given enough light to look like a textured white in the image.

With film, this is about 2.5 to 3 stops more light than your meter reading.

With digital, this may be only 1.5 to 2 stops more light than the meter reading.

• Conversely, if you are photographing something dark in a dark surround, the opposite approach comes into play. The meter will tell you how to expose to make that DARK scene a middle gray! You then need to give LESS exposure to force that scene to look dark.

With film: a 2 to 3 stop reduced exposure will run you from a textured dark to nearly black.

With digital: a 1.5 to 2.5 stop reduction will typically run you from a textured dark to nearly black.
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Steve.
 
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I agree with Steve.

Your spotmeter reading of ev10 is basically a reading in Zone V (the meter giving a mid gray 18% reading etc). IMO what you want however is for your ev10 to be in zone II (being the darkest part of the image that you want some detail to show) or Zone III (average dark materials) and therefore if you shoot at ev12 or ev13 this will acheive this.
 
I used to find this all terribly confusing but then found a zone chart that I stuck on to my pentax Spotmeter. Now I simply take the spot reading and line that up with the zone that I want this to fall in on the zone chart and can see from the chart the reading that I need to set the camera to.

Are you using a Pentax spotmeter? If so, I'll see if I can find the link to the chart mentioned above.
 
Cheers Steve, makes sense.

David its a Soligor Spot Sensor II, little pistol gripped meter but a chart is good idea I'll have a look for one.
 
So, Steven, this thread has been all theory and numbers (and the other two threads included spreadsheets as well). Did you go so far as to take any photos using your version of the Zone System? And how did they turn out?

I'm beginning to think I need a much better understanding of exposure, especially if I'm ever going to be successful at taking transparencies, but even with negative film. I keep getting situations where things I can see (eg people making their way up a trail on Arthur's Seat) are not appearing in my pics, as I've let the exposure be dominated by the sky behind... OK, that's a fairly easy one, but you get the picture.

I keep reading and re-reading books on exposure and tracts about the Zone System. Maybe little bits of it are percolating into my brain (I was using exposure compensation on my Pentax ME today, for example), but too often my mind gets boggled.

Anyway, I wondered how successful you'd been?
 
I've not really got a feel for it intuitively but I've been trying to force my self to think a bit more rather than metering for V and fixing it in post.

This one I wanted the top of the tower to be just this side of blown since it was sticking out the canopy and in the late evening sun whilst the rest of it was relatively dark. I metered off the highlights and dialed that into my meter then notched it down two or three stops to put it into zone 8 (ish). I did another quick check off the darker bits of the tower to make sure they'd not be too dark then shot. Didn't take too long though.
 
ChrisR said:
I'm beginning to think I need a much better understanding of exposure
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See if you can find a copy of this book.

exp_man3e.jpg


This will answer all of your questions (and many more).


Steve.
 
dont they say expose for the shadows and devlop for the highlights. So what i do is meter the darker areas of the scene, that gives me Zone V then i knock it down 2 or 3 stops to put the shadows on Zone 2 or 3. This naturally pulls all the highlights down 2 or 3 stops too so when i develop i leave it developing for longer to push them back out, the longer develop time doesnt affect areas of film with shadow as much as areas of film with highlights so your shadows are still safe.

Get a good 1 degree spot meter and youre off to a good start. I use the minolta spotmeter F

Get Ansel Adams "The Negative" and "The Camera" , you can get "The Print" too if you like. They're pretty much bibles on exposing / developing film
 
Yeah you're probably right, though the develop for the highlights applies more to sheet shooters. As i'm sure you know its more difficult to adjust development for rolls of film, that extended develop might blow out another frame for example. Plus its another excellent rule that tends to drop out of my head when I'm shooting, there are many!
 
Thanks Steves and Essex... I have a copy of "the photographic guide to exposure" by Chris Weston, from the library. It kind of makes sense when I'm reading it but...

Plus its another excellent rule that tends to drop out of my head when I'm shooting, there are many!
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I think of this as a kinaesthetic adrenaline rush, so I can feel better about being such a prat! I really need to try some painstaking studies, possibly book in hand... Did someone mention 10,000 hours?
 
If you haen't seen them possibly these links to Roger Hicks film school articles might be helpfull.


exposing negative films

exposure for slides and digital

the zone system


THE EVOLUTION OF THE GOSPEL ACCORDING TO ST. ANSEL


With slide film I think people get uneccessarilly hung up on trying to make their lives more complicated than required.

Is there a nice white fluffy cloud ? meter on it and give one and a half more stops of exposure.

No convienant fluffy cloud, pick a suitable mid tone in your pictuure could be tree bark or stone work for example.
 
ChrisR said:
I think of this as a kinaesthetic adrenaline rush, so I can feel better about being such a prat! I really need to try some painstaking studies, possibly book in hand... Did someone mention 10,000 hours?
Click to expand...

The number of times I fire off a frame, usually the last one, then one of the useful guidlines pops into my head to remind why that last shot will probably be mince. I think its a matter of drilling and forcing oneself to remember these rules even if it takes longer to make the shot, I suppose thats the dicipline the diji boys wan't when they say shotting film makes you better and we want when we say shooting LF makes you better. In either case ones failures just get exponentially more expensive... maybe thats where the dicipline comes from :thinking:


10,000 hous isn't that the mtf of a photographer?
 
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H'mm why doesn't anybody follow the "grey card" rule i.e. if your exposure reading on the subject is the same as a Kodak grey card then it must be correct for the film. Of course the problem is getting a grey card reading for something in the shadows in the distance, well things that are dark grey like shrubs, dark green grass etc are equivalent to Kodak grey, so you would have to spot meter those....things in bright sunshine? well just do the same and expose on a a shrub or something grey nearby.
Once you have the separate exposure readings in the above example, you can then decide what is more important i.e. shadows or highlights or just choose the simple way of selecting an exposure reading in the middle.
 
I was thinking about this last night. Apparently Jim Richardson said "If you want to be a better photographer, stand in front of more interesting stuff". Once upon a time, long, long ago (are you sitting comfortably), that is what I was able to do, but it didn't make me a better photographer! I didn't worry about it, though; I trusted my camera and film, used whatever compositional skills I had, and fired away. Many of the results were satisfying... and that was largely (but not entirely) down to the "more interesting stuff".

So what's happened since? The camera is the same (or at least one of them), the films are better. I don't get in front of such extremely interesting stuff very often, but I do find some pretty good stuff.

I guess my expectations of myself have increased. I want a higher hit rate. When I find interesting stuff, I trust my compositional skills, but I want my technical skills to support me in making really good images.

To some extent, that seems to come down to understanding how the camera system (including the film) can deal with the stuff in front of me. Can I let it get on with its job and concentrate on composition? Or is the interesting stuff beyond the camera system's ability to render as I'd like it to (and if so, in what ways)? Can I (should I) override the meter etc or adjust the stuff in some way to get a better result?

And that understanding presumably is part of what people are getting at with the 10,000 hours. It's not enough to have an intellectual understanding; it has to get ingrained in my sub-conscious processes so that it's not overridden by that kinaesthetic adrenaline rush.

(When I was younger, a friend helped me learn to dive, over many lunch-time sessions in Reading's open-air pool. He patiently kept telling me what to do, in different ways. I kept patiently trying to do it, and achieving a belly-flop. Then one day everything went right; I surfaced and said excitedly "ah, NOW I see what you mean!". Words are pretty inadequate sometimes...)

Which is why I keep asking these darn-fool questions, and trying to understand short-hand codes like the Zone System!

(BTW thanks abbandon, will check out those references!)
 
but why do you expect a higher hit rate, maybe what youre doing is perfectly good already. Wasn't it Cartier-Bresson who said "the first 10,000 shots are the worst" Meaning , i guess, that even the masters didn't produce classics on every shot. Im sure even Osh's recycle bin has the odd image in there!

We can only point the camera at what the universe puts in front of us on the day and you cant polish a whotsit.
 
Well, there are little clues like when I took a photo of a large group of people climbing the path on Arthur's Seat, and ended up with nice clouds behind the mountain and a dark hillside! Just one example, quite a few other disappointments. And I want to start using more transparency film, and it's just too expensive as well as less forgiving...
 
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