Portra 160/400/800 emulsions

[chassis]

Are all three of these emulsions the same technology / vintage?
Aside from speed, of course. And do they differ between formats e.g. 135/120/sheet film?

My guess is they are not the same technologies, particularly Portra 800. I have shot each speed in a few formats/sizes and to me they are not quite the same thing, setting speed aside.

800 seems more contrasty and the grain seems to have a different texture than 400. 400 and 160 seem to have moderate contrast and grain somewhat similar to one another, with 160 being finer/smaller.

Maybe I'm imagining it, but wondering if PE or others could comment.

All have been exposed at box speed and processed normally in C-41. My experience has been in a mix of lighting from daylight to tungsten to strobe. No controlled experiments, just every day shooting.

 

[Richard Man]

The 160 and 400 were redesigned a few years ago, eliminating the VC and NC versions. I read that no such redesign was done for Portra 800, so it would be "older" technology.

 

[Mr Bill]

I couldn't say, it's been 6 or 8 years since I was heavily involved with color neg films.

But if I wanted to know (without doing the testing), I'd start with the Kodak data sheets. I'm guessing that you may not be too familiar with them? They currently have separate data sheets for each of these films, all dated in 2016. You can judge a film's contrast from the "characteristic curve." The steepness of the lines IS contrast, albeit for a neutral color only. (The horizontal axis is exposure, expressed as a log; this means that every change of 0.30, left or right, is equivalent to a one f-stop exposure change.) If you print the graphs you can overlay them on a light table or your computer screen, etc.

The data sheets also give a grain index at several enlargement sizes, so you could compare based on that.

Lastly, regarding the technologies, these are sort of listed near the beginning; if you have the patience you can compare these on a line by line basis. At first glance, it looks like Portra 800 is more different than the two slower films.

 

[Mr Bill]

My experience has been in a mix of lighting from daylight to tungsten to strobe.

Something worth pointing out, in case you're not aware (forgive me if you are), is that these films include both hi-speed (larger grain) and lo-speed layers for each color. Meaning that if a particular layer is underexposed, it will appear grainier - most of the exposure is in the hi-speed part.

Now, everything is fine for daylight and strobe, since that's roughly the design color balance for these films. But... you said you also shot under tungsten light, still using box speed(?). This is a problem - tungsten is weak on blue light, down a couple of stops relative to reddish light when compared to "daylight." If you set exposure according to your meter, the blue-sensitive layer of the film is essentially underexposed by near two f-stops, and... the hi-speed grainy part of that layer is gonna predominate in the darker parts of the print. The only cure, you gotta get more exposure in the blue-sensitive layer. In fact, I wonder if this is what you're seeing in your 800 speed film - probably this is the one you're using with tungsten light, right?

 

[chassis]

Thanks Mr. Bill. I forgot about the datasheets and characteristic curves. By eyeballing the curves, the films are different but it doesn't seem drastically so. I am aware of the tungsten lighting situation. I did a shoot a few days ago with several types of lighting and used one film type throughout. Postprocessing was a challenge.

 

[Les Sarile]

No doubt everyone's tolerance for the apparent grain varies greatly and there are many factors to consider when evaluating them not the least of which is how you are extracting the image from the film and what your final use is. I've used all three and found grain to be of no consequence and certainly can massage in post very easily if I wanted to.

Color and contrast are certainly even more personal in nature and due to their ultra wide latitude - particularly in the over exposure side, I believe they have to have low contrast and saturation in order to achieve this. This of course makes it very easy to alter color and contrast in post.

 

[chassis]

Thanks Les, makes sense.