Dynamic Range of Negative Film

[chris_antidote]

<p> I've heard with modern scanners, the full range of a scanned negative is about 15-19 stops.... </p>

[lex_jenkins]

<p>A reference to the source might assist an informed discussion.</p>

[tom_mann1]

<p>It probably was Chris' Anecdote. ;-)</p>

<p>On a serious note, Googling {"dynamic range" "negative film"} turned up 226,000 hits, with 1600 of them right here on photo.net. In other words, there has been a *LOT* of previous discussion of this topic, so perhaps the OP can let us know what he feels wasn't covered adequately in these previous discussions.</p>

<p>Tom M</p>

<p> </p>

[bobatkins]

<p>I've heard Elvis was sighted last week in Nashville, but I don't always believe what I hear.</p>

[dave_s]

<p><finger to temples>I foresee crayons . . . lots of crayons . . .</p>

[marc_bergman1]

<p>What did crayons ever do to you? They should bring you joy of a simpler, less complicated time.</p><div></div>

[yog_sothoth]

<p>The zone system would have more zones if that was true. Nine or ten is more in line with my experience. </p>

[yog_sothoth]

<p>I should have addded "Using standard development times." Actually, if you overexpose and underdevelop you can get a couple more out of tmax 400. </p>

[James G. Dainis]

Zones 1 to 9 are the printable ranges. A band of sunlight striking a bride's lacy white dress will appear as pure white on a photo. Looking at that black area on the negative, one could see some lace texture, sort of like writing on a black sheet of paper with a black magic marker. Trying to burn in that area of blocked highlights will get some of the lace texture to show at the cost of having that area of dress turn gray. No good. That texture is there on the negative and the scanner may pick it up but trying to print it is the problem - nice white band of sunlight showing with lace texture but the rest of the dress is dark gray.

[Alan Marcus]

<p>The dynamic range of film has not changed much since the days of the daguerreotype (mid 1800's) which slightly exceeds today's films. <br>

Key to this discussion is the lens aperture adjustment (f/#) by convention, each increment is a 2X change in light energy at the film plane.<br>

Likely, Ansel Adams put forth the best definition<br>

Below is loosely translated from his 5 book Basic Photo Series<br>

His ten zones remain valid today thus the dynamic range of film is:<br>

2x2x2x2x2x2x2x2x2x2 = 256 (typical dynamic range of films process to specification)<br>

Zone 0 Maximum black void of detail exposure units 1/2<br>

Zone I First visible step of tone above maximum black exposure units 1<br>

Zone II First impression of texture in shadows exposure units 2<br>

Zone III Satisfactory value for shadow detail exposure units 4<br>

Zone iV Average value shadows in portraits and vista exposure units 8<br>

Zone V Middle gray (gray card) 18% exposure units 16<br>

Zone VI Human Caucasian skin 36% reflectivity exposure units 32<br>

Zone VII Light gray objects very pale human skin exposure units 64<br>

Zone VIII Very light gray objects (textured whites) exposure units 128<br>

Zone IX Pure white no detail exposure units 256</p>

[yog_sothoth]

You could expose for the groom and develop for the sunlit white dress, but the skin may wind up somewhere odd and the

rest of the picture would be kind of blah. Dodging and burning can improve things, but heavily dodged and burned areas

can get grainy. Multiple scans of the same negative can get you some "HDR" effect, but with extra grain.

 

I had a mishap with a flash photo using porta 400. I underexposed by two or so stops. There was shadow detail, but the

image was clearly affected by the under exposure. You could call that a success or a failure depending on how you look

at it. If you put important exposure ranges in the shallow wings of the exposure/density curve the picture quality will

suffer.

[lauren_macintosh]

<p>Alan Marcus: Thank you very much for this bit of Information negative tones of grey :<br>

now I have a better understanding of the zone system : Thanks a Lot:</p>

[chris_antidote]

<p>Look, I'm not talking about printable ranges or dark room enthusiast like Ansel Adams. The films today have so much latitude, Kodak Portra is rated well beyond the usable scale of zones. Which is why you can over and under expose and normally get a good shot. If you had a hasselblad scanner, drum scanning at 4.9 D-max, individually recording every tone variable with remarkable accuracy; you're still blowing away modern day digital cameras. Which by the way, most modern day digital camera companies, claim more dynamic range than your zone system. Nikon d800!? Obviously everyone born today is limited by printing. We can't escape that, just yet. </p>

[tom_mann1]

<p>Exactly why did you start this thread, Chris?</p>

<p>Tom M</p>

[Brad_]

>>> I've heard with modern scanners, the full range of a scanned negative is about 15-19 stops....

 

And still, even with that, ho-hum photographs will still be produced from ho-hum captures, snapped without

enough cowbell.

[chris_antidote]

<p>@ Tom Mann, Because I thought it was just as irrelevant as "How do you hold your camera when shooting vertically?" And, "Is bokeh strictly a function of the lens?" lol. No, I'm really advertising for Kodak Films, Because I don't want them to go bankrupt. And I want to shove film in all the faces of digital snap shooters who walk around with a bulge in their pants that isn't an extra roll of film. Hehe, No. I'm completely obsessed with enthusiast who love rambling on about all this nonsense in blogs, instead of going out and shooting photos. Actually, I do shoot film, I'm a purist, but I use a digital scanner. No no, Really, it's all about art and form and composition. It doesn't matter what you shoot as long as you shoot entirely with your minds' heart in focus. Unless you have arterial plaque. which is why you're not out in the world shooting photos because you're afraid of the heart attack that might ensue. Nonetheless, I'm completely sure of everything I've said. </p>

[yog_sothoth]

Did you impress yourself with your own cleverness? In that case you have likely achieved uniqueness, which I am sure

you consider a good thing.

[chris_antidote]

@stephen cumblidge, are you admitting I'm clever? I just

don't want to be fat or boring.

[bobatkins]

<p>Keep it civil or this thread will close and offending accounts may be suspended.</p>

<p>If you must disagree, do so with some civility. </p>

[chris_antidote]

@admin, who's not being civil?

 

On a better note..., As it may be.. Ansel

Adams and a colleague essentially

invented the zone system laws. He

also stated in his literature books that a

new technology would change the

rules. And was aware of a digital

frontier as well as color photography as

a new art form. What he neglected to

say is that eventually his laws of zones

would change too.

[john_a5]

<blockquote>

<p>Zones 1 to 9 are the printable ranges.</p>

</blockquote>

<p>and then</p>

<blockquote>

<p><br /><br />Zone 0 Maximum black void of detail exposure units 1/2<br />Zone I First visible step of tone above maximum black exposure units 1<br />Zone II First impression of texture in shadows exposure units 2...</p>

</blockquote>

<p>These discussions of the zone system have a bit more to do with making a print--in the wet darkroom-- than the dynamic range of a film itself. Films can record, different films have different results, substantially more "zones" than are usable, without modification, in a print and definitely more than what most wet darkroom process can record effectively. But many processes in photography, like printing- out- paper printing, relied on substantially more "zones" (zones that were from much thicker, contrasty negatives) than what a silver gelatin or color printer would even consider for that sort of wet darkroom work. Linda Connor, who printed all her work on POP paper until it disappeared, famously talks about one image that took several days to print while many only an hour or so. That first one had zones on it way beyond anything most of us will ever see.</p>

<p>A high quality scanner can dig out detail within a negative that might be well below an acceptable zone 3 if we were printing in the traditional darkroom. I actually got a print out of a negative that was so underexposed (from a Holga) that it looked totally clear unless it was at just the right angle to the light--it was in my portfolio and on my website for years--and sold for stock several times. Likewise, a good scanner can bring back what otherwise might be blown highlights which were beyond "burning in" in the wet darkroom. Again, I experienced a situation where I could never get a darkroom print (silver gelatin) from a seriously overexposed negative until I finally scanned it on my Imacon/Hasselblad scanner. It is in my portfolio now.</p>

<p>Prints, digital or otherwise, have always been limited--and still are--to a finite number of zones--probably 7 to be generous--it is just the nature of most reflective media. Even in the wet darkroom we had tools to tame a negative that had more than that through dodging and burning--and contrast controls with b/w printing--into a print. (or expanding the captured zones with higher contrast papers) Scanning, and digital darkroom work, allows access to even more zones through selective outputs for highlight and shadow areas that can then be blended (without HDR) to create a full range, and tamed, print. I will often consider exposing color film normally when 11-12 stops are metered on location--although I certainly prefer less. Beyond that, I will start to make more specific decisions on where I will let things go--highlights or shadows, based on the scene--or bracket. I know I can get more than that out of a film scan, but often the parts beyond this range, over or under exposed, don't yield the same quality image as those within that range. Unless, of course, as with that blank negative, you like a bit rougher look in the resulting image because it works with the subject matter.</p>

[Alan Marcus]

<p>It's easy to confuse exposure latitude with dynamic range. Exposure latitude is the range of exposure levels above and below specification that a film can tolerate and still yield an acceptable image. Exposure latitude decreases as subject contrast, film contrast, or development contrast increases. For negative films, the latitude is greater in the overexposed direction whereas positive materials have greatly reduced latitude. </p>

<p>As to dynamic range: The best I have ever seen is a 21 step gray scale produce in a laboratory. I am referring to a gray scale made in 1/2 stop increments. The first step is clear film plus fog (no exposure) measures 0.05 density units, the last step (maximum black) this typically measure measures 2.40 density units. Each 0.30 density units = a 2X change = 1 f/stop. The dmax is is achieved at step 21, that’s 10 f/stops elevated from zero exposure.</p>

<p>When this film is viewed by transmitted light (projected on an enlarger eases). The original luminance range of 1024:1 is compressed and we see a range of only 256:1 (8 f/stops) math 2.40 ÷ 8 = 0.30. In other words, optic flare, film turbidity and the film's response curve works against us and we get an image that compresses the tonal range captured on film. Consider a slide reproducing sunlit vista, if reproduces with faithfully and projected, we would be more comfortable viewing the movie wearing sunglasses.</p>

<p>Please note, we view negative film and transparencies by transmitted light. The light makes one pass through the film. Now when printed, the print emulsion sits atop a white base called the baryta. This is a white reflective base of barium sulfate in gelatin. To view a print in all its glory, light from a nearby lamp plays on the print paper. The light transverses the emulsion, hits the bayta and reflects back to the viewer (true for b&w and color. We view prints by light that makes two (2) transits through the emulsion. The result is, the dynamic range of paper is at best 64:1 (6 f/stops).</p>

<p>In other words, the best we can do with film and photo paper is to take a picture with a scene range of 1024:1 and reproduce it on film and achieve a brightness range of 256:1 we print this on paper to get a print range of 64:1. Such values are only achievable if camera exposure, film developing, print exposure and print developing are on target. A miss anywhere reduces the dynamic range of the resulting image.</p>

<p>Now it may be that digital cameras and digital displays exceed film and print. Technology marches on. I have seen remarkable digital images made by juxtaposing many images of the same scene to achieve a dynamic range never realized by chemical films and papers. I know that future cameras and future display methods will beat the pants off the old chemical ways. </p>

[KenPapai]

<p>For "true" film purists the answers also lie here:</p>

<p><a href="../film-and-processing-forum/00Zvnj">http://www.photo.net/film-and-processing-forum/00Zvnj</a></p>

<p>(warning: harsh stuff there about "digi-snappers" ;)</p>

[john_a5]

<p>Alan, I don't take issue with most of your analysis, which is very technical and theortetical, but practical test indicate results that are somewhat different.</p>

<p>As to dynamic range and exposure latitude, especially when it is then coined as zones or stops as the OP did, they really are very similar concepts. The biggest issues have to do with, as you point out, the difference between transmission and reflective viewing characteristics. But digital scanning and digital post do change things quite a bit. I don't know that we can see more on a digital screen, but with scanning, we can use a far great amount of information captured within a negative than we can with more conventional analog methods.--maybe even more in the absolute, but I honestly never took the organic process that far. I just know that in more conventional terms, digital scanning can allow for the extraction of information from a negative that far exceeds what one could achieve in most "normal" wet darkroom processes.</p>

[yog_sothoth]

<p>Kodak publishes the development curves for their films. They tend to show around 3 decades of sensitivity with some films giving a bit more. This would amount to 10-11 stops and is consistent with Alan's tests.</p>

<p>Where are there tests that show other levels of dynamic range?</p>