Lattitude of Portra 400 film

I don't know technically how Portra 400 is so tolerant of underexposure, but it is. I've shot it at 400, 800 and 1600 on the same roll, developed as normal and 400/800 look the same, 1600 just a touch darker. All shot completely usable.

I can only assume it's because it's based on a motion picture film, where you *have* to shoot at a certain shutter speed and can only rely on ND filters or aperture for exposure (and you likely can't use aperture, as that would change how the shot looked). That means motion picture films simply would not be practical if they didn't have latitude. That's just what I think though, I'm not an expert, and could easily be making this up.

mugent said:

I don't know technically how Portra 400 is so tolerant of underexposure, but it is. I've shot it at 400, 800 and 1600 on the same roll, developed as normal and 400/800 look the same, 1600 just a touch darker. All shot completely usable.

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Most C-41 type films are very tolerant. This is true of B&W negs too BTW, especially films like T-Max and Delta in their 400 & 3200 versions.

The tolerance/latitude of negative film is rooted in the fact that the film can catch a much wider brightness range than the paper can print.

The reason the prints from your 400/800 shots look the same is that the film had an extra stop of detail available "below the normal printing range" that the lab used to your advantage.

The reason the 1600 print looked darker is that you were starting to bump that lower limit. You could "brighten" the print from the "1600" neg but the blacks in a "straight print" wouldn't be as strong. Without strong blacks, prints start to lose their snap and look muddy or washed out.

Shooting at 3200 compounds the issue.

This doesn't mean you can't get good prints from negs that get less exposure!

It does mean that the process you/your lab uses to get a good print from an EI3200 shot isn't the same as what it would be for an EI400 shot.

It does mean that a bit of experimentation, as you have done, to find your own limits is worthwhile.

mugent said:

I can only assume it's because it's based on a motion picture film, where you *have* to shoot at a certain shutter speed and can only rely on ND filters or aperture for exposure (and you likely can't use aperture, as that would change how the shot looked). That means motion picture films simply would not be practical if they didn't have latitude. That's just what I think though, I'm not an expert, and could easily be making this up.

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There is another whole set of controls that movie makers use during a shoot, artificial controls.

Lights, camera, action.

Movie makers (like most pros) will go to great lengths to get the lighting just right for the shot so that they don't have to fix it in post; that is the norm, not the exception. "Post" is an expensive 4-letter word, there's no point to going there, unless there is no other choice.

Most amateurs I know aren't so keen on scrims, reflectors, strobes and the like.

markbarendt it doesn't how matter you look at it, Portra 400 is faster than any other 400 speed colour film, so it already has a leg up.

It has more deep shadow detail than 400H does @ 200, when the Portra is @ 1600. The vents under the step at the very top right in the blackest part, it all has contrast there if you wanted to bring that, and that is a -long- way down. This shot is incident metered at 1600. There is a huge contrast difference there to under the step.

400H has on several occassions dropped shadow detail straight to black no contrast on black hair on a model - in the same lighting with incident @ 400. That's probably 3 stops below mid tones (the hair) in reflectivity brightness at most, and the detail is dropped. The example above is much greater than 3 stops from mid tones to detail that is not dropped.

You're making several assumptions about how far down the film extends and that the cut off point is the same in push processing as it is standard. Then you also need to take into account the dynamic range below midtones or incident (midtones to deepest shadow wanted in reflectivity) you need or want, which can be quite often, small anyway.



Majority of stuff is shot intended for post, rather than getting what they want in camera/lighting. And that statement you made is a bad generalisation about the film industry, it's more often than not - bedlam. Many great scenes from films were fixed in post. Like in The Shining - the snow scenes were originally yellow as captured on film. Many great things have been captured for cinema in a run and gun and impromptu as an after thought or on set creative spark shooting in equipment and light/etc restrictions/limitations and seeing what came back.




Logically if you can retain a ridiculous amount of highlights, then I would compare film speeds based on how many stops below mid tones a film can capture before there is no contrast left available (ie: I can retain nearly anything on one end, but not the other I would count towards the other).

Given this methodology I would count Portra 400 several stops faster than 400H.

Athiril said:

markbarendt it doesn't how matter you look at it, Portra 400 is faster than any other 400 speed colour film

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That may be so but exposure changes still work the same way. Reduce exposure by 1-stop and 1-stop of detail is lost on film, that's pure physics.

Whether there is still enough detail left or not is a separate question.

I'm not suggesting that your results are wrong, just that your expectations might be different than mine.

Athiril said:

You're making several assumptions about how far down the film extends and that the cut off point is the same in push processing as it is standard.

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No assumptions.

The OP specifically asked about normal processing.

With normal processing a given amount of exposure will provide a given response from the film.

Athiril said:

Majority of stuff is shot intended for post, rather than getting what they want in camera/lighting. And that statement you bad is a bad generalisation about the film industry, it's more often than not - bedlam. Many great scenes from films were fixed in post. Like in The Shining - the snow scenes were originally yellow as captured on film. Many great things have been captured for cinema in a run and gun and impromptu as an after thought or on set creative spark shooting in equipment and light/etc restrictions/limitations and seeing what came back.

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I don't know a single self respecting pro that doesn't plan their lighting whenever they can, even if that's just simply scheduling the beach portrait for morning or evening rather than mid-day.

Studio work is always planned lighting.

I do agree that they will take what they can get when there isn't another choice but so what. I'll take it too but it is a lot easier to get it right in camera.

If the camera work and lighting is right the people doing the post will be happier.

Athiril said:

Given this methodology I would count Portra 400 several stops faster than 400H.

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I just want to point out that I was comparing to the previous generation of Portra, not Fuji 400H. And I think the above quote is the first mention of 400H in this thread.

If I remember correctly, almost everyone who claims the new Portra is stops faster and amazingly flexible compared to 'other' 400 speed films is comparing to 400H, not the previous Portras. And that includes most of the wedding photographers on blogs. It could very well be the fact that Portra 400 is faster than 400H. I would probably assume that this was true for the previous Portra. Heck, most of those wedding guys say to expose 400H at EI 200 anyway. Never really heard that recommendation for 400NC - it was always 400 or maybe 320.

All of my statements were made in reference to the previous Portra 400s.

That's not pure physics, it's pure speculation. It's making the assumption the last stop of dynamic range is falling neatly right at the cut off point. Portra 400 captures a long range below midtones. You would need a very high contrast scene from mid tones to shadows to do that. There's no detail in the scene @ 1600 I shot that was lost., and that is high contrast if you include the deepest shadows under the step, without that (like any more normal scene) the dynamic range below mid tones is quite short.

Athiril,

No guessing, conjecture, or speculation. Simple math/physics.

If Portra has "x" stops below mid-tone available when shot at EI 400 and we expose it at EI800 instead then at that exposure the same mid-tone is 1-stop closer to the toe and it has x-1 stops below mid-tone available, 1-stop of shadow detail below mid-tone is never caught. At 1600, x-2, etcetera...

Separate from that math issue is the "does losing a stop or two matter?" question.

Do we lose anything of consequence in the print? In your example, no. That is Cool! Heck there might even be more detail on the neg that you didn't even use.

It is normal not to print everything on the neg.

Not to hijack the thread but these are some good results for a 5 stop difference...People just don't get the advantages of film and when I say that too people regarding you sample image they go, really? Yes really..Thanks for post.

Athiril said:

The below shot is exposed for the shade (incident metered in the shade) there is 5 stops of different in the direct sun and shade in this particular scene (via incident metering in both), I did this to get good mid tones in the shade, yet I have simultaneously good mid tones in both, though the image is of lower contrast as a consequence of this exposure. But when your subject is mixed over hard sun light and shade with a huge contrast difference, that is a benefit.

OCAU Melb Photowalk Week 2 #11 by athiril, on Flickr

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OK, so what's the verdict? I shot a roll of Portra 400 at ISO 800. Do I develop 3.5 min at 102F like usual, or change the time and/or temp?

Should be 3min 15sec, and 3min 45sec iirc for +1 stop push. It's better pushed as opposed to simply underexposed, but at only 1 stop, it's not important at all imho.

Athiril said:

Should be 3min 15sec, and 3min 45sec iirc for +1 stop push. It's better pushed as opposed to simply underexposed, but at only 1 stop, it's not important at all imho.

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+1

Interesting thread to the extent that I see it affecting my photography, especially with reference to shooting meter-less cameras and more color film. For a long time I preferred not shooting a 35 camera without an incorporated working meter, and using a handheld, as it was just to slow for me in certain circumstances of changing light and catching a subject (usually street) at a certain moment in time. I was just to aware of trying to always nail the exposure. With what I read here I feel that I can meter once, take an average and just work the aperture ( if need be) without worrying about lining up a meter needle. It's kind of a freeing thought and will bring new life to my drawer of bodies with bad meters.

waynecrider said:

Interesting thread to the extent that I see it affecting my photography, especially with reference to shooting meter-less cameras and more color film. For a long time I preferred not shooting a 35 camera without an incorporated working meter, and using a handheld, as it was just to slow for me in certain circumstances of changing light and catching a subject (usually street) at a certain moment in time. I was just to aware of trying to always nail the exposure. With what I read here I feel that I can meter once, take an average and just work the aperture ( if need be) without worrying about lining up a meter needle. It's kind of a freeing thought and will bring new life to my drawer of bodies with bad meters.

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I "set and forget" a fair bit for street shooting where I just want to spin focus and shoot.

Typically when I walk into a situation like that I'll meter once to place faces in the darker settings (like open shade at a mid-day street fair) in zone v (EI 800) or even zone iv (EI 1600), instead of the normal zone vi (EI 400). Basically I'm picking a workable setting for the shadows, from there I know I can get workable faces with reasonable detail around them in a 5-stop range with Portra (and Superia 400 and Delta 400 and other negative film's).

Coincidentally that is close to what a Holga or disposable is designed to give you with 400 speed film. ~f/11 @ 1/100

Shooting later in the day with a Holga you may want to push-process the film 1, in the evening 2, at night 3.

In your meter-less 35mm camera you can just open up more.