Positive vs. Negative Film

I am getting back into large format photography after many years of working with just

35mm. In making transparency tests I am seeing the the shadows block up quite a bit. I

am testing with Velvia 50 & 100F, Astia 100F, and Kodak Ektachrome 100G. I can

understand that shadow areas will block up if the film is underexposed. Will color negative

film give me more latitude and detail between shadow and highlights?

 

Thanks, Fred

Yes, negative films have a much longer useful exposure range. To see this, download datasheets for the films that you are considering and compare the characteristic curves. The exposure range between the shoulder and the toe of a transparency film will be about 1.5 decades or 5 stops. In comparison, the characteristic curve that Kodak plots for Portra 160NC shows an almost straight line above the toe for 3.0 decades or 10 stops. The Kodak graph for that film ends before a shoulder appears. A transparency film will have problems with either underexposure or overexposure; a negative film will have problems with underexposure but will tolerate considerable overexposure.

Hey Michael.

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Given the wider range of negative film - if one is developing a body of work in large

format in color, isn't as simple as shoot negative film?

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I saw a mention on some thread or other that scanners are sometimes challenged to scan

color negatives, and do better overall on slides.

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Any thoughts on how to view this space? What the important points, pluses and minuses

are to decide on which film (type) to do color image capture in large format

where digital post processing is the end goal (and long term reuse of raw image library)?

For a given luminosity range in the scence, the density range of a color negative is much less than the density range of a transparency film. Using two "random" datasheets as examples, an exposure range of two decades for Kodak E100S leads to a density range of 3.0 in the film; an exposure range of two decades for Portra 160NC leads to a density range of about 2.0. The reduced density range of the negative materials _should_ make them easier to scan. Many photographers report that transparencies are easier to scan -- my guess is that this a market-based result rather than a technical one -- more people scan transparencies and the makers of scanners have done more work on the software for transparencies. Scanning negatives might require more effort from the user to get the color balance correct. My experience with scanning is only for images for the web. I get good color balance for this purpose just by setting the black and white points in each channel.

 

Professionals have traditionally preferred transparencies. A major advantage was that the photographer could tell the press operator or darkroom technician to make the reproduction look just like the transparency when the transparency was viewed on a light table with a standard color temperature bulb. An amateur doing their own printing can make technical or artistic judgements of the print itself.

<I>Will color negative film give me more latitude and detail between shadow and highlights?</i><P>Depends on the method of reproduction. I can't see as to how Astia would produce blocked shadows with a decent scan.

As Michael has pointed out, color negative film has much greater latitude than transparency film. As he also points out, in principle scanning color negative film should be easier with any modern scanner because of the lower maximum density. With a properly exposed negative, you shouldn't have any problem in scanning with either shadows or highlights, if you go about it properly.

 

Transparency film might have two advantages when scanning. First, you can compare the color balance of the scan to what you see in the transparency on a light table. However, keep in mind that there is no reason to believe that what you see on the light table is an accurate rendition of the colors in the scene. A second advantage is that you may be able better to fit the dynamic range of the source to the capability of the scanner. When you spread out the negative's lower range (about 2.0) you may separate out tones and produce gaps in the histogram. However, as Michael pointed out, if the transparency is not properly exposed and the dynamic range of the scene is too high, you won't have recorded what you want on film in the first place.

 

I work primarily with negative film in color and black and white. I don't have any problems with separation of tones. I don't see any difference between negatives and transparencies in this respect. I also have managed to figure out ways to produce a good color balance and I don't find that any easier with transparencies.

 

Finally, remember that transparency film was not designed originally for making prints. It was designed for either direct viewing by transmitted light or for projecting in a darkened room on a screen. For making prints, color film was always the preferred medium. One problem with transparencies is that there are defects in the dyes. That isn't a problem when viewing as intended, but it causes problems when making prints. The orange dye in color negative film compensates for these deficiencies. If you scan, you may be able to correct for the deficiencies, so they may be less of an issue.

 

Transparencies became the dominant medium because of the needs of commercial users of photography. It was much easier to submit a tranparency, and that became the accepted method.

<i>When you spread out the negative's lower range (about 2.0) you may separate out

tones and produce gaps in the histogram.</i><br><br>

This was a huge strike against negatives on older scanners that only had 8-bit internals.

On modern scanners with 12 bits or more internally it's a non-issue.<br><br>

<i>I can't see as to how Astia would produce blocked shadows with a decent scan

</i><br><br> It depends on what you're shooting--if you've got high scene contrast,

something that'd call for n-1 or n-2 in the zone system, even Astia will get in trouble,

especially if your exposure isn't dead on. A decent scan is far from a given, especially with

large format, where resolution on consumer flatbeds is reasonably close to good enough

but handling of high density areas is still pretty bad.

I love the way that Transparency film pops....

 

BUT I have gotten into trouble a couple of times with it. I was recently shooting a street

portrait with TriX and Provia loaded into Hassy backs. I was "thinking" B&W when I

composed the shot and metered.

 

I took basically the same shots with both Films. THe TX shots looked great. THe Provia

shots weren't usable as there was a lot of shadow in frame as well as full sun Blue

Sky....the Shadows were completely lost (I needed them :)

 

Negative and Postive Films both have their 'negatives and positives'.....you just have to

figure out why you want them.

 

jmp

Given the near-death of color chrome in 5x7 I suspect many of us are being pushed to CN as an alternative. ON the other hand, for both digital scanning and printing there may be other advantages to the CN since a modest overexposure will protect the shadows without risking the highlights... thus better ensuring a usable image especially under the difficult lighting conditions many field photographers face. And isn't CN film processing a bit easier to deal with as well?

 

I used to use CN for much of my 35mm sports and team photography since a saleable print was the final objective. Digital cameras are now eliminating that need but in larger format work CN may yet be the savior. I haven't yet tried to do any CN scans but suspect it isn't too challenging.

A belated comment: Leonard wrote: "Transparencies became the dominant medium because of the needs of commercial users of photography. It was much easier to submit a tranparency, and that became the accepted method"

 

Actually from my experience as a client during the 60's through the 90's, clients and publishers demanded transparencies. Transparencies gave you beautiful, crisp separations and popped off the coated-sheet publication page. Prints (from color negative) were dull and lifeless and totally unacceptable, and you had to use them only if there was retouching to be done (ugh!) In fact, when dealing with some of America's leading photographers, negative never came up. And we shot the thing all over again, rather that do any retouching and then make separations from "reflected art," (i.e. prints).

 

We were very much wrapped up in the ability of certain houses to produce the top separations -- and many times, you had your separations done by a specialist separation house, and not your printer!

 

And of course, in the 60's and earlier, National Geographic was the guiding example of publication color -- and of course that was mainly 35mm Kodachrome, shot by great photographers like Thomas J. Abercrombie.

 

Just some insight about how some things came to be...

 

Henry T Stanley

More on why transparency film was the "default" film over color negative...

 

In case you were wondering why we didn't just scan the color negative during this period, well that just didn't come up...I don't think printers could do that. You see, separations weren't made from scans, the transparency was shot by the printer/separations specialist using giant horizontal cameras, and for each color separation, a different color filter was used to create the "red-yellow-blue-black" plate films we knew as "separations." These film separations had also broken the image up into dots (screens) of red - yellow-blue on each respective separation, so all of that was done in the separation camera. No scanning involved. (Newspapers had coarse screens, coated-stock pubs had fine screens).

 

You could see and to some extent, proof, what you were going to get by viewing a "chromolin" made up of color films sandwiched and registered.)

 

The same big separation cameras could shoot separations from "reflected art" (color prints, etc.), but as mentioned, these were not very acceptable.

 

Much was different, and much was in the hands of the printer, and designers and project managers spent a LOT of time at the printers before the job was ready to run. And you never really knew what you were going to get on the page until the presses started up, and then you and the senior pressman could tweak things here and there to get it right.

 

We've come a long way.

 

-- Henry

Fred, you might want to give this article (http://www.dannyburk.com/drum_scanning_color_negative_film.htm)by Danny Burk a read. He is an excellent professional photographer with substantial experience using both slide and negative film. He convinced me to give negative film a try and in high contrast situations I pull out the negative film. It has worked well for me both in medium and large format. As far as scanning, Danny uses his own drum scanner. I use a Nikon Coolscan 9000 for medium format scans and an Epson 4990 for my 4 X 5 stuff and both do an excellent job with negative film.