What's the exposure latitude of Color Neg film?

[Alan Edward Klein]

I usually bracket my shots +1 and -1. I once shot Portra that way. What I noticed when I scanned it, that while all three could be reasonably adjusted to look right regarding contrast and general exposure, the colors were different between all three. Colors shift when you change exposure even a small amount. While you probably get away with landscape shots like that, it would NOT work if you needed to be true to the color of the subject like if you were shooting clothes, etc.
(corrected).

 

[RPC]

Adding a little overexposure causes absolutely no problems, in fact in can only help, yet such negativism in this thread towards it.

The colors may shift when scanning but I get no shift when printing optically with any negative film.

 

[DREW WILEY]

And what do you mean like "a little" extra exposure, and how much experience do you have optically printing Ektar, or assuming that all flavors of color neg films behave similarly? - that kind of generalization is a symptom of questionable results. "No shift"? I don't believe it. I personally have way better process control to fall for that statement.

 

[mshchem]

One note. If you bracket color negative film, and you have machine prints made, your prints may show no difference. It's amazing what a minilab computer assumes about what you are after. Auto, perfect, red eye free, pictures. Otherwise disposable cameras wouldn't stand a chance.

I usually shoot color using incident metering at box speed.

I'm guilty of slightly over developing black and white. Slightly, in XTOL.

C-41 RA Kodak Flexicolor chemistry and Kodak Portra are a match made in Heaven. Ektar is fun, but I absolutely love Portra 160 and 400.

 

[DREW WILEY]

Portra 160 is like the bunny hill of the ski slope. It's hard to crash. Ektar is like the face of the mountain. Way more contrast. Small changes have a greater effect.

 

[RPC]

And what do you mean like "a little" extra exposure, and how much experience do you have optically printing Ektar, or assuming that all flavors of color neg films behave similarly? - that kind of generalization is a symptom of questionable results. "No shift"? I don't believe it. I personally have way better process control to fall for that statement.

I routinely overexpose a stop. You just move the scene up the curves, where the curves are still parallel. There is no reason for any appreciable color shift, and I have never noticed any, even with Ektar in actual photos or gray scales.

 

[DREW WILEY]

I bet I could detect all kinds of unnecessary color errors in your prints. That's perfectly OK if you're happy with the results; but objectively, I know better, and it can make a significant difference in hue reproduction. Unfortunately, the web is a nearly useless vehicle for comparing fine color nuances.

 

[RPC]

I don't think Kodak is going to design a film that produces a lot of errors with one stop over.

A color shift with one stop overexposure indicates crossover. A printed gray scale would show this. That is what a gray scale tells you--if there is any color shift with changes in exposure/density. I print gray scales with Ektar that show no crossover. It would occur if the film was processed improperly. If you are experiencing a color shift with a one stop change, then I can only guess that your processing is off. If you can print a gray scale with no crossover then I can't see how you can get a color shift with one stop of overexposure.

 

[Photo Engineer]

If crossover is to take place with a particular color film, it is most likely to take place in areas of high density. Thus, overexposure by one stop would most likely show this fault. That is why I limit overexposure to much less, as I said above, 100 not 160 and 320 not 400. I would limit myself to that even if I know a film is capable of more.

I have made coatings myself that had some degree of crossover near Dmax. This is an inherent problem with all color films.

PE

 

[RPC]

The gray scales cover low to high densities, and I see no crossover in them at normal, one or even two stops over. If any is there, it is not significant.

 

[pentaxuser]

Looking for information here, Drew. Can you give us a list of films where any overexposure creates problems and a list of those films where there is some latitude and by how much i.e. 1/2 stop, 1 stop etc. It would be useful if we could see examples, assuming that scanning is capable of revealing the differences in correctly exposed and over exposed. Thanks

pentaxuser

 

[DREW WILEY]

I shoot and print Ektar all the time. I can't afford to bracket or guess or screw up - 8x10 is my primary format. I've done dozens of tests some of you have never even thought of. I have exceptionally precise custom additive colorheads. The fact is, in the real world, Ektar has just a little more range than some chrome films. Beyond that, you get into hue shifts. If it's a modest contrast scene, sure you can fudge the exposure a bit. But in full contrast, it's easy to go off a cliff. I shoot at high altitude a lot, and know from hard experience that Ektar needs just as much care in exposure as slide film. Yes, you can bend the rules, but I already know what happens when people do that - they often end up calling it an awful film or try to torture it back into shape in PS, unnecessarily, unsuccessfully. This is a film capable of rendering certain complex hues more accurately and cleanly than even chrome films, and I'm not speaking of just saturated colors, but subtle neutrals. There's more to it than just balancing a gray scale! But if you want to cut corners, fine. Just don't complain to me about all the cyan contamination in this or that color.

 

[DREW WILEY]

Hi, pentaxuser. Lists like you're requesting have been posted on other forums. The consensus among serious practitioners is to stick with box speed of 100 when shooting Ektar. Lower contrast films, esp Portra 160, seem to tolerate a bit of overexposure; exactly how much depends on contrast and color variables in the scene, but PE has already posted his custom. When 160VC was still made, I was comfortable with about half a stop overexposure if necessary, but don't know how closely it's successor, Portra 400, compares. Portra films are basically portrait films. Ektar is a different animal. Making scans and posting them on the web is utterly worthless for seriously comparing such things. Sometimes densitometer plots can tell the story over the web, but many people do not know how to read them properly. But the blue curve of Ektar shoulders off before the green or red, so overexposed highlights end up contaminated with cyan. There are issues in deep shadows too. Just changing the overall balance in PS won't correct this. It's far easier to correct at the actual time of the shot.

 

[pentaxuser]

Thanks for the reply. When you say lists have been posted on other forums I take it you mean other people's lists. The trouble with these lists is that most if jot all I have seen seem to suggest that +2 overexposure and -1 under make no discernible difference and in the examples I have seen and allowing for the difficulty of seeing in a scan on a screen what the viewer sees with his naked eye, this looks to be true.

Clearly your experience and the evidence you have gathered tells you otherwise so I had just wondered if this evidence was in a form that you could present.

pentaxuser

 

[DREW WILEY]

Serious color printers are more likely to speak face to face and look at actual prints rather than crawl over endless razor wire fences and minefields on the web. So much gets questioned on web chatter that is routine common knowledge among highly experienced printers. As usual, my evidence is real prints. Perhaps someday I'll open up a personal website again, but web surfers are one category of people, real print buyers a totally different category. That's why I stick to verbal communication on forums. Waste of my time otherwise. So, to make this brief, people can expose film in any manner they wish. But if optimal print quality is what you want, you need to stay within certain restricted parameters; and in my estimation oh how to do that, "latitude" equates to sloppiness. We all make exposure mistakes sometimes; but I at least try to do it right. And anyone who goes around claiming they can fix anything in PS afterwards begs the question. Why did they screw up to begin with? And why does their fix look so pathetic?

 

[wiltw]

A test of exposure latitude by petapixel with a scanned negative shows digital scanning is about the same as conventional C-prints in terms of exposure latitude which does not exhibit too much image degradation... -2EV to +5EV is pretty equivalent, but -3EV and +6EV shows too much bad effect in the final result (too muddy shadow areas at -3EV and too washed out color at +6EV, but still there area visible signs of muddiness at -1EV and washed out color at +5EV.

https://petapixel.com/2015/08/10/how-much-can-you-overexpose-negative-film-have-a-look/

 

[DREW WILEY]

What kind of crock test is that? ... As if all color neg films are the same. They aren't; nor are all printing papers the same. It's exactly those kinds of loosey goosey stereotypes that are the problem. None of the "test" parameters are even defined. You have to look at the film margin to see that it's Portra 400. The actual printing quality can't be conveyed on web examples. Just another half-baked "filler" article for lack of something serious.

 

[Sirius Glass]

Serious color printers are more likely to speak face to face and look at actual prints rather than crawl over endless razor wire fences and minefields on the web. So much gets questioned on web chatter that is routine common knowledge among highly experienced printers. As usual, my evidence is real prints. Perhaps someday I'll open up a personal website again, but web surfers are one category of people, real print buyers a totally different category. That's why I stick to verbal communication on forums. Waste of my time otherwise. So, to make this brief, people can expose film in any manner they wish. But if optimal print quality is what you want, you need to stay within certain restricted parameters; and in my estimation oh how to do that, "latitude" equates to sloppiness. We all make exposure mistakes sometimes; but I at least try to do it right. And anyone who goes around claiming they can fix anything in PS afterwards begs the question. Why did they screw up to begin with? And why does their fix look so pathetic?

I agree and as I said before the latitude of color negative film is so wide that one rarely needs to stray far from box speed to get shade detail.

 

[DREW WILEY]

In full sun shots, I often have to make supplementary unsharp contrast reduction masks to salvage shadow values with Ektar. I even had to do it sometimes with 160VC (vivid contrast), the predecessor of Portra 400. Subdued light and lower contrast films like Portra 160, doubt I'd need to, though I might make a contrast-increase mask instead. Either way, I'd start off with box speed. More often, I simply default to subject matter and lighting ratios that fit the film I'm carrying to begin with. But I'm not one of those 70's types who deliberately exploited or even induced flaws in old color neg films for art purposes. That was an interesting era, but films have changed, and my own launch into C41/RA4 was for sake of a worthy replacement to E6/Ciba. I have found it.

 

[wiltw]

What kind of crock test is that? ... As if all color neg films are the same. They aren't; nor are all printing papers the same. It's exactly those kinds of loosey goosey stereotypes that are the problem. None of the "test" parameters are even defined. You have to look at the film margin to see that it's Portra 400. The actual printing quality can't be conveyed on web examples. Just another half-baked "filler" article for lack of something serious.

It was ONE EXAMPLE, a generalization drawn from one film test! relax a bit. Nobody claimed that all color neg films were identical in performance with regard to latitude.

Here is a post that someone posted, which shows the result published in a magazine (Modern Photography)...and regardless of the 4 films tested, -2EV to +4EV seems to be a generalization that could be applied to three of four films (per the tests published)

https://www.photo.net/discuss/threa...odak-portra-400-and-160.5511897/#post-5709527

 

[DREW WILEY]

Thank you. A mixed bag of info, that's for sure, some of it good, some not. Anything that generalizes is not. I learn new things about certain films almost everytime I print something in the darkroom. Each image has its own challenges. Commercial-quality RA4 work is quite easy with traditional films reasonably exposed. Getting the most out of a contrasty high-performance film like Ektar takes more finesse. But it generally does what I need. They could improve it with respect to the annoying cyan tendencies. Yet it is a realistic replacement for chrome films in terms of convenient darkroom printing via RA4, perhaps the first such color neg film worthy of filling that niche, so worth the fuss that goes with it.

 

[pentaxuser]

I recall the Flyingcamera uses a lot of Ektar and his pictures look great. What I don't recall is whether he finds the exposure latitude to be small/non existent or even if he has needed to expose it in a plus or minus way.

His comments in this regard might be helpful

pentaxuser

 

[Eric Rose]

But there is no real need to over expose by one or two stops since the modern color negative film has such a wide latitude.

Sirius hit the nail on the head. It's useable latitude at rated ISO that counts.

 

[wiltw]

So, to make this brief, people can expose film in any manner they wish. But if optimal print quality is what you want, you need to stay within certain restricted parameters; and in my estimation oh how to do that, "latitude" equates to sloppiness. We all make exposure mistakes sometimes; but I at least try to do it right. And anyone who goes around claiming they can fix anything in PS afterwards begs the question. Why did they screw up to begin with? And why does their fix look so pathetic?

I agree fully. I deliberately underrated my color neg films when shooting weddings 2-3 decades ago on 645 format. Film with box rating of 160 would be rated by me as EI100, so that I would most likely avoid the issue of muddy color in the shadow areas due to underexposure, even when errors were made in exposure. I did try to do it right, all the time, nevertheless. But in the thick of the fray during weddings, we call can make mistakes, and no metering system is foolproof in its suggestions, ergo the EI to avoid the issue of muddy color in the shadow areas due to underexposure,

 

[DREW WILEY]

Many color neg films were designed to create a bit of mud, that is, expectations of "pleasing skin tones" at the expense of related hues. Ever notice how difficult it was on older films to differentiate subtle differences between yellows and oranges and tans? Stephen Shore built an entire body of work on pitting pumpkinish warm tones against cyan-inflected poison greens, using, I believe, Vericolor L. But Ektar isn't artificially warmed and the sensitivity spikes are relatively well separated. That's why you get cleaner hues in general but might sacrifice stereotypical expectations of soft unblemished skin tones. Earthtones tend to be very well differentiated. No homogenized pinkish tan deserts like Misrach or world turned pumpkin like Shore or Sternfield. If you want that effect don't buy Ektar. It's a new generation of films; and in my opinion the trio of Portra 160, Portra 400, and Ektar is the best suite of color neg films ever. They pretty much cover all the bases.