Lattitude of Portra 400 film

Discussion in 'Color: Film, Paper, and Chemistry' started by mingaun, May 12, 2011.

  1. mingaun

    mingaun Member

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    Hello,

    I need to ask a beginner question. I understand from the internet that the new Portra 400 has a great lattitude but i am wondering how this advantage is put into practice.

    Does that mean for one roll of film i can take shots at different iso and once finish i just drop it in the lab and ask them to develop normally without any push processing.

    Will there be any risk of under or over exposure depending on the skill of the lab, or can all lab handle this well.

    I personally will try to take them all at box speed but just occasionally might need to increase the iso.

    Please advise
     
  2. Athiril

    Athiril Subscriber

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    You can vary your exposure without (edit: typo) process adjustment when you simply have no choice otherwise except to not take a photo. Underexposing on Portra 400 is -much- better with a push rather than just relying on latitude alone.

    You probably wan't be able to overexpose the film severely enough to ruin your pictures, unless you actually try quite hard.


    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.

    [​IMG]
    OCAU Melb Photowalk Week 2 #11 by athiril, on Flickr
     
    Last edited by a moderator: May 12, 2011
  3. Dr.Pain-MD

    Dr.Pain-MD Member

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  4. markbarendt

    markbarendt Subscriber

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    Ok here's a real life example, not Portra but C-41 negative film. (They all have great latitude BTW)

    This summer my family is heading to Hawaii to vacation with the inlaws and I don't have an underwater/waterproof 35mm camera.

    My solution is simply to get ten or so disposables. http://www.ecamerafilms.com/category_s/36.htm

    There aren't any exposure adjustments on disposables, except for flash, you just point and shoot and let the lab deal with what ever lands on the film.

    The C-41 films, even without a flash, in these disposables have enough latitude to do a reasonable job in most any situation from sunrise to sunset. Add the flash and there is almost no limit on the lighting you can shoot in and get reasonable results.

    These cameras use the film's latitude instead of exposure controls.

    You can do the same thing with your camera, dial in 1/100 @ f/11 on a wide angle lens put in some Portra 400 and go shoot. Send the roll off to the lab and you will probably be pleasantly surprised.

    Understanding that you can miss perfect exposure by a few stops is very freeing.

    For example, lets say you want to shoot a portrait in full sun at f/2 on Portra 400. Your camera might not have the 1/25,000th shutter speed you might to get a "normal" exposure, so what, shoot at the fastest you got and let the latitude do the rest. 1/4000th will probably get you a very workable result.

    What you need to do to really see what your Portra will do is shoot some with intentionally bad settings and see where your limits are.
     
  5. mingaun

    mingaun Member

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    Wow thats all great news.

    I still cant quite figure this out. These mini labs will process based on the time for ASA 400, so if i shot at ASA 1600, without any special processing why is it that the picture will not be badly underexpose? What is compensating for all these? Apologise if this sounds really dumb.
     
  6. markbarendt

    markbarendt Subscriber

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    This is not a free lunch.

    It will be underexposed. You give away 2-stops of shadow detail when you expose an ISO 400 film at an EI of 1600.

    Is what's left workable? Your call.

    The only way you'll know is trying it.

    Most C-41 film's are much more tolerant of overexposure rather than under.
     
  7. markbarendt

    markbarendt Subscriber

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    The film can catch a wider range of brightness than the paper can print.

    So on film you might catch 12-stops of detail but the paper can only use/print 6 or 7 of them, which 6 or 7 is up to you and the lab.
     
  8. mingaun

    mingaun Member

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    Ok that sounds more logical. This was the site that confused me http://www.rebophotography.com/blog/links/1116
    At the end of his review he had a few shots taken at ASA 800 and develop normally, the picture looks pretty good to me especially the portraits ... dont seem like underexposing at all.
     
  9. timparkin

    timparkin Member

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    -4 +6

    Here's a shot taken on an olympus OM1 with each exposure separated by a whole stop..

    [​IMG]

    The far right exposure is -4 stops and the far left exposure is +6 stops.. Drum scanned on a Howtek 4500 with Aztek DPL..

    The scene is from 16LV (ev@100) next to the sun to 7LV in the shadowed trees. Clouds are around 11LV which the exposure was taken for. foreground is about 9LV

    Given that the next to the sun bit doesn't blow out and it's at +5EV already, then we get +11 EV at least ... the shadows go down to about -5 EV but you are losing a lot of detail by then. I would say -3 EV is where you should be placing useful shadows and useful highlights probably go up to +8 or 9 EV but you'll still be getting texture up to +11 EV and colour all the way up to +15 EV ..

    I didn't believe it until I took the pictures for myself.

    Here's a sunrise for you taken by a colleague.. The trees were a silhouette from where we were and the sun isn't blown out in the final picture..

    http://www.flickr.com/photos/davtee/5615975224/

    Tim
     
  10. CGW

    CGW Member

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    "Nothing has been done to them other than some (not all) have a very slight curves adjustment, and then they are all resized for the web."

    Though I'm looking forward to trying the new Portra 400, this statement tempers my expectations a bit since the shots he published have been processed to an undisclosed degree. How does he quantify "very slight"? No science there.
     
  11. Tim Gray

    Tim Gray Member

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    In my tests, the new Portra has great latitude, but not that much different from the previous Portras. The underexposed shots most definitely have less detail in the shadows and grain goes up. Remember, anything that is scanned can always have it's contrast affected.

    In the right scenario, you might get away with 1-2 stops of underexposure, but it will probably look better with proper exposure. It will probably also look better if you get underexposed shots push developed.

    It's a wonderful film, but there's a lot of hype about it in my opinion. I really do like it a lot, and it does have great grain, but in terms of this 'magic ISO' crap that you read about it, I'm convinced that it's about the same as the previous Portra 400NC. And I never heard one person say this stuff about that film.

    Here's the link to my personal test. The test goes from 4 stops underexposed to 6 stops overexposed. Not the most scientific, but the charts were lit by window light, the dark room was several stops down according to an incident meter. So keep in mind that the scenes don't have the largest brightness range you'll ever encounter. On the other hand, the charts do cover a lot of what's in a normally lit scene. Unfortunately, the Kodak chart had some glare on it, but the Color Checker should be a reliable reference. I also ran some tests in tungsten light set to 3200K, with and without a partial corrective filter on the lens.

    http://www.flickr.com/photos/tgray1/sets/72157625883846979/
     
  12. mingaun

    mingaun Member

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    :eek:Incredible!! You could have miss exposure by so many shots and the image is still usable. Thank you so much for your shots, sure helps. Hopefully this will not make me go slack in terms of exposure.
     
  13. mingaun

    mingaun Member

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    Sorry. My answer was in response to the post made by Tim Parkin.

    Tim Gray thanks for the tests that you made. To me its obvious you could miss by two stops and still pretty good.
     
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  15. markbarendt

    markbarendt Subscriber

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    The wild cards we haven't touched on are the quality/competence and tools the lab uses and your relationship with the lab.
     
  16. mingaun

    mingaun Member

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    Mark, how much do the labs differ? I come from a digital background and pretty innocent in this. I expect them all to follow certain chemicals and time. Even in a good lab can a personnel actually make specific changes as he sees my film being developed?
     
  17. markbarendt

    markbarendt Subscriber

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    At most any lab normal film processing will be fine, there are bad apples but the process is standard so quality is pretty good across the board.

    After the film is developed it is a whole different world and results can vary wildly.
     
  18. mingaun

    mingaun Member

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    Thanks Mark and thank you all for your contribution. My question has been answered and now at least things are much clearer. Still amaze somewhat at the exposure lattitude of film.
     
  19. markbarendt

    markbarendt Subscriber

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    The background, door and the like, in Tim Gray's example is very revealing of the shadow losses.

    Now just go burn through 10 rolls and see what works for you.
     
  20. timparkin

    timparkin Member

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    Agreed - it's the grain that's different from what I can see so you probably get an extra stop or two usable because of this..

    Tim
     
  21. film_man

    film_man Member

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    I disagree. I have used 400NC and it would get quite blocky once it went -1 stop. On the other hand, I have a nice set of prints that were shot at 1600 stops and I also have a roll at 3200 (but pushed one stop) and the detail is very good. In fact, I have prints from a roll that I started at 400 and ended up at 1600 as the light went in the evening and I can't say there is any issue in the quality of the image. However I will say that perhaps in real life situations as you end up using it at 1600 you have to because the light is too low and the scene, contrastier lighting (which is generally what happens at night) and shutter speeds will compromise the image more than any loss of detail due to the underexposure.

    Also, I am speaking about my experience with 120 film. I would expect the grain and blockiness of shadows to show more with 135. So I'd say that the hype is real, at least for 120.
     
  22. Tim Gray

    Tim Gray Member

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    I'm basing my statements on my experiences with Porta 400NC-3, 400VC-3, and the new 400. The -3 versions of these films were better than the -2 versions, of which I shot a little. I never shot the original 400NC or 400VC. Those comparing Portra 400 to the original 400NC/VC probably do see much larger improvements than I did, because most of my experience has been with the -2 and -3 versions.

    While none of the tests are super scientific because I couldn't control the weather and my days off, they do provide some references between the 3 films (and 160NC, 160VC, and Ektar) which I haven't seen any where else on the web. The most controlled of the shots in terms of lighting are the first 3 indoor tests under tungsten lighting. The three 400 films look much more similar to my eye than different. Again, I think the new Portra 400 is fantastic and does represent an improvement over the previous two versions.

    All of them can be seen here:
    http://www.flickr.com/photos/tgray1/collections/72157623656649261/
     
  23. puptent

    puptent Member

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    If you do your own tests, I'd suggest that you let your lab know that the rolls are test film. Sometimes the lab is trying to make every neg into a good print for their customers who don't have command of the medium. If you're doing test rolls, you would like everything neutral. Also, avoid the box store outlets, perhaps a potrait studio near you, or camera store, has lab services available. Or even mail order, like Lattin Labs in Iowa.
     
  24. Athiril

    Athiril Subscriber

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    Portra 400 is a free lunch.

    You're not giving up shadow detail. Perhaps it has grain that doesn't get developed at the standard time. But here even the deepest shadow was still revealed at 1600.

    [​IMG]
    OCAU Melb Photowalk Week 2 #6 by athiril, on Flickr
     
  25. OzJohn

    OzJohn Member

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    Much of what has gone before in this thread is to a great extent true of most colour neg films but particularly those faster than 100 ISO. The extraordinary latitude of these films is IMO the outstanding difference between them and digital capture. Although I use them fairly infrequently these days, it will be a sad day if they eventually become unavailable as seems increasingly likely.
    OzJohn
     
  26. markbarendt

    markbarendt Subscriber

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    I'm not saying acceptable results can't be had but there are a lot of variables that affect that judgement. Metering technique, print size, personal taste...

    What I have suggested at various points in this thread, including in the post you are replying to, is that it would be good to test the film for ones-self and to judge for ones-self.

    What I will say now, is that wishful thinking can't change the laws of physics or the film curve.

    Portra is very flexible but reducing exposure by two stops means every zone will "fall" two stops further down the film curve.

    Two stops fall off the toe, never to be seen again.

    Two stops of good detail slide onto the toe and get muddier, grainier, and harder to use.

    The mid-tones move two stops closer to the toe, blah, blah, blah....

    There are consequences to reducing exposure.