Questions About Color Transparency Films

[Peter York]

Hi all,

After several years working in B&W I recently began shooting in color, and I have a few questions about exposing color transparency films. I have read previous posts on these films and I am quite comfortable with the basics - limited latitude, spot metering and exposing for highlights, testing for ASA placement, using graduated ND filters, etc. - but I would like to "master" these films, and I have some questions that I was hoping you could help me answer.

1. Many express a preference for one transparency film over another because of its color palette. Is there any resource to obtain more detailed, objective information about the color gamut of particular films?

2. Many express a preference for Velvia 50 due to its saturation, and perhaps even its high contrast. Is saturation here used in a technical sense? In my experience, Velvia 50 is hit and miss, even when accounting for its latitude. Too many times I have "nuked" the subject with Velvia, ending up with a candy color rendition. On the other hand, I have been astonished with this film's rendition of other subjects and certain colors - I am thinking of the deep purples, burgundies and pinks you get out of a sunset in the Southwest, as well as yellows. All of these renditions are artificial, yet I would like to understand why this film and others work so well with certain subjects and so poorly with others. I guess what I am getting at is how have you have come to visualize the films' capabilities and appropriateness for certain subjects?

3. If the SBR allows it, do you over or under-expose a scene to darken or lighten colors according to your visualization?

4. Finally, for a scanning workflow, and again provided the SBR allows it, do you overexpose to aid the scanning process?

Any/all comments are welcome. Thank you!

Peter

[Drew Wiley]

You'd be better off forgetting about "latitude" with trans films and learning the
inherent range of specific ones. Fuji does you a big favor by offering three distinct
categories. Velvia has the highest saturation but also the highest contrast, therefore
the shortest exposure range. Provia 100 is in the middle, and then Astia 100F is at
the other end, with the least saturation and contrast, but a slightly wider exposure
range. You have to pick the film which suits the contrast range of your subjects, or
more wisely, carry more than one film. If you want to learn with just one, you could
start in the middle, with Provia or its Kodak counterpart E100G. It also depends on
how you intend to make prints. Some digital workers like Astia because it has the
most range and neutrality, and they can always boost the contrast and saturation in
Photoshop afterwards. But if it isn't on the film in the first place, you don't get
anything. There are different exposure techniques too. I always read the midtones
then the highlights and shadows too with a spotmeter. It takes experience. You also
have to decide what you're willing to sacrifice if the exposure range is too great -
do you let the shadows go black or let the highlights wash out in order to protect
your main colors? After awhile we simply and subconsciously choose subjects and
lighting conditions which fit the film itself, and this all becomes quite spontaneous.

[Mark Barendt]

If I may ask why aren't you considering negatives?

Exposing, developing, and printing C-41 is very much like B&W. Trannies on the other hand require thinking very differently.

[Nathan Potter]

Drew expresses pretty much my sentiments. I carry Velvia 50 and Astia 100 rather than the middle range Provia. I just find some added flexibility using the two extremes. Velvia 50 I tend to use for narrower SBR (often cloudy conditions) while the Astia for larger SBR and sunny conditions. But it's hard to generalize. It is essential to generate a sensitometric curve for both to get a feel for their exposure performance. The color gamut (if that's the right word) is difficult to quantify. Running color patches shows substantially higher color saturation with the Velvia 50 of course. I have run (3 months ago) a sensitometry curve for both the Velvia and Astia exposed at rated ASA and will say the following.

1. Zone V, 18% grey card fell at chrome density 0.96
2. Zone V, 18% grey card fell at chrome density 0.93
3. The contrast index at Zone V was about identical
4. The Velvia shows no shoulder becoming a straight line and intercepting log D 2.9 at EV 7.0
5. The Astia show a substantial shoulder becoming level at logD 2.7 at EV 7.0

Maybe to guide you more precisely I can type in table from recent data that you can then plot. Subject Brightness/logD format below

Astia 100: 0.08/15; 0,14/15; 0.26/13; 0.5/12; 0.85/11; 1.37/10; 2.0/9; 2.55/8; 2.7/7

Velvia 50: 0.08/15; 0.08/14; 0.13/13; 0.27/12; 0.58/11; 1.04/10; 1.57/9; 2.25/8; 2.90/7

Note that I did not develop these films - they went to Praus Productions, but differ little from my previous runs.

Nate Potter, Austin TX.

[Peter York]

Thanks Drew and Nathan. I'm not sure if color gamut is the appropriate word either, but it seems to me like there should be a more objective way to describe a films "color palette"

Mark, I also carry Fuji 160s and shoot color negative if the SBR is too high. I'm working with transparency to hone my skills, obtain feedback on a lightbox, and experiment with what is out there.

I have no problems determining a film's range and calculating exposure to ensure that highlights are not blown, and if possible, shadow detail is preserved (though I am struggling with slow shutter speeds right now). As a convert from B&W, what I struggle with is color, specifically visualizing how a particular film will render the colors of a scene, and how I might adjust exposure (and filtration and other variables I probably haven't considered yet) to affect that color.

For example, you have a subject whose SBR is only 2.5 stops. Any transparency film will capture this scene. Furthermore, you can place this scene on the toe, shoulder or middle of the film's characteristic curve. What determines which film and what exposure you choose?

[Eric Leppanen]

For example, you have a subject whose SBR is only 2.5 stops. Any transparency film will capture this scene. Furthermore, you can place this scene on the toe, shoulder or middle of the film's characteristic curve. What determines which film and what exposure you choose?

What is your goal? Color accuracy? If so, meter on an 18% gray scale target and use a relatively color accurate film such as Astia. Maximum tonal separation? Pick the film with the steepest characteristic curve that still fits the SBR. Specific subjective rendition of a few key colors? Pick the film that, per your taste, best renders those colors.

These various criteria often result in entirely different film selection. It all comes down to what your creative goals are.

For the example you give (2.5 stop SBR), for landscape subjects I would go for maximum color saturation and tonal separation (arguably the color equivalent of pushing B&W film), and choose between Velvia 50, Velvia 100 and E100VS (all high contrast, high saturation films). Which one I pick depends on which I feel will best render the key colors in the composition. Velvia 50 has a warm cast and has strong greens. E100VS separates red and orange elements well, and has strong yellows. Velvia 100 has a more neutral cast than Velvia 50, has a bit more contrast, and holds its colors better when pushed (theoretically Velvia 50 and E100VS are not pushable, although in reality folks push these films fairly frequently). I would then meter so that the highlight and visible shadow areas both fall within the toe and shoulder of the curve.

Not everyone appreciates colors the same way, and there are differences in opinion as to how certain films render certain colors, particularly when using real world targets (with different lighting conditions and color temperatures) and not color charts. This is why there are few rigorous "objective" analyses of how certain films render colors. What I started color shooting, I shot a 35mm roll of each candidate film and shot a variety of subjects representative of my shooting style, so I could form my own opinions about the various films (although, to be honest, these opinions evolved, sometimes quite significantly, as I gained field experience).

[Mark Barendt]

As a convert from B&W, what I struggle with is color, specifically visualizing how a particular film will render the colors of a scene, and how I might adjust exposure (and filtration and other variables I probably haven't considered yet) to affect that color.

With color (E-6 or C-41) there are essentially three SBRs and three exposures and they are rarely the same. If one color is underexposed it can add grain and color casts.

With E-6 you need to nail the filtration or you will have a color cast.

Most of my filtering for C-41 is simply polarizing or major color corrections, daylight vs. tungsten. Most corrections are dealt with using filtration at printing.

What makes this possible and easy is the latitude of C-41. A little extra exposure can get the offending color off the toe without blowing the highlights on the others.

For example, you have a subject whose SBR is only 2.5 stops. Any transparency film will capture this scene. Furthermore, you can place this scene on the toe, shoulder or middle of the film's characteristic curve. What determines which film and what exposure you choose?

I actually use Portra 400NC for virtually all my color work now.

I place the shadows or mid tones. I pick placement for effect, as you describe. C-41 just has a lot more room to do it with.

I've just started my own C-41 processing so I'm anxious to try expansion and contraction development.

[adonis_abril]

I've worked quite a bit with Velvia 50 and 100 (not F) on medium format and Large format. Yes, lattitude..very narrow - graduated neutral density filters are a necessity - I usually use 3-4 stop GND. Velvia 50 tends to go crazy on the greens while the 100 version does on reds...Sunrise/sunsets are amazing on both films, at least to my eyes...but magenta cast on the 50 is very apparent.

Also consider an alternative technique to Graduated neutral Density filters..take a dark card or similar and mask out the highlights during exposure...works well with landscapes when your aperture is f/22 or higher - hence longer exposures..


Velvia 50 (cropped), Tachihara 4x5, Super Angulon 90mm f8, Polarizer



Velvia 100, Wista SP Metal, Super Angulon 75mm, 3 Stop GND

**These are scanned on an Epson 4870 Flatbed..so the dynamic range may not necessarily depict what's on film...I am soon to recieve a Colorgetter Plus, however, and will update the scans