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  1. #61

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    It would be very nice if Peter could post his results.

    HowardDvorin

  2. #62
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    >Peter - Congrats! I am a mere mortal and don't get all this N-x talk, though, I do know AA's texts contain the whole explanation, however, in an effort to make this thread something mortals can follow, would you mind "101'ing" it? Like real brief,

    Zsas, while the negs look printable, it wont be until I actually print them that I will know for sure if I am subjectively happy. Objectively speaking unfortunately I am not able to offer a lot of advice for others to follow unless I perform some more testing to determine the exact location of the curve's shoulder - and even if I did that my results/advice would only apply to people also using a similar combination of film + developer + target gamma. So in summary Zsas, in non Zone System speak, in response to over exposing my film by 4 stops I reduced my normal development time by about 10% in order to ensure my white puffy clouds would retain their detail.


    **** DISLAIMER - I have not (yet) proven this dev time reduction was necessary ****


    >Forgive me for being devil’s advocate here, but if you are over exposing by 4 stops, isn't the rest of your post irrelevant, as you should concentrate on exposing correctly.

    Cliveh, the whole point of my post was to ensure success for a roll that I accidentally over exposed by 4 stops. OF COURSE I will also concentrate on not doing that again. That is a given. For the record here is how it happened. My hand held light meter (as would every other non ZS/modified light meter) gives readings to place the object I meter at Zone V whereas I wanted to place it at Zone III. That is a two stop difference. Instead of giving 2 stops LESS exposure than what the meter read, I gave 2 stops MORE exposure. I opened my aperture up two stops instead of closing it down two stops. I won't be making that mistake again in a hurry.


    >It may also be worth mentioning it is difficult to say how much "overexposure" was given. Based on what? And how did we meter the scene? Etc.

    Michael, I have calibarated my Exposure and film development process according to the "Elaborate and Precise" method described on p.217 of WBM 2e. I think it closely matches the methods described by AA in The Negative. Also Michael, below I address your comment about 2.1 probably not being where the shoulder lies.




    For those interested in my observations/results so far here are some more details:


    I actually had two rolls of film which I overexposed by four stops. The first roll of film (which up until now I haven't mentioned) I exposed and developed to N-1, and after inspecting the negs I realised my over-exposure error which prompted me to start this topic. A few of you suggested I run a test roll, well I decided that was a sufficient test roll as I made good notes of the meter readings at many zones in the image on that roll along with my exposure details. So last night before developing my second roll I measured the density of some Zone IX regions in that first roll (white puffy clouds) to be about 1.85 which turned out to be very close to my theoretical calculation of D_zone_IX_end = 1.74, in fact the reason it was a tad higher was because I accidentally over developed that 1st roll for a 7% longer period. So my theory was matching my practice. This then told me that I would indeed come close to 2.1 if I developed the 2nd roll as intended to N. As a quick aside, Michael suggested the value of 2.1 might not actually be the point my curve shoulders at owing to a different contrast index and developer etc (the HP5 datasheet shows a CI of 0.65 using ID-11), and he is correct, but it was what I used and only my own testing will ascertain the exact shoulder for my process.
    So while my presumption about the shoulder point is not water tight, it served as a guide to me to want to slightly reduce my dev time to lower the gamma of my curve to possibly avoid the should should I have otherwise run into it. Until I do further testing to exactly locate the shoulder and how it responds to reduced dev time, I won't actually know if my method had merit or not.
    So as I mentioned I proceeded to develop the 2nd roll to N-0.5 and this morning I measured a Zone VIII point on it to have a density of 1.74. this matches very close to my theoretical calc of where it should fall if I target a gamma of 0.45 (=N-0.5 in my process)
    0.45=(D_zone_VIII_mid - 0.3)/((4+6.5)x0.3)
    D_zone_VIII_mid = 1.72

    regards
    Peter

  3. #63
    zsas's Avatar
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    ^Thanks Peter for making this thread approachable to all! I look forward go seeing these puffy clouds you've saved
    Andy

  4. #64

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    I have tested HP5+ in Xtol and ABC Pyro. It is really an 180 ISO film in Xtol and 125 ISO in ABC Pyro to get the best out of it. Yes in ABC pyro it is almost 2 stops slower than it states. So 4 stops I dont think would do any harm, probably it will even look better than if it was rated as 400 ISO. ABC Pyro is grainy though, but how big prints do you want? Many love using Pyrocat HD, it builds a lot of contrast with stain and has finer grains. Maybe this is the right moment to try it? Test with some test rolls first. Maybe you will stick with Pyro forever.

  5. #65
    Thomas Bertilsson's Avatar
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    Quote Originally Posted by StigHagen View Post
    I have tested HP5+ in Xtol and ABC Pyro. It is really an 180 ISO film in Xtol and 125 ISO in ABC Pyro to get the best out of it. Yes in ABC pyro it is almost 2 stops slower than it states. So 4 stops I dont think would do any harm, probably it will even look better than if it was rated as 400 ISO. ABC Pyro is grainy though, but how big prints do you want? Many love using Pyrocat HD, it builds a lot of contrast with stain and has finer grains. Maybe this is the right moment to try it? Test with some test rolls first. Maybe you will stick with Pyro forever.
    With all due respect to your own findings about your chosen developers and Ilford HP5+, I must say that suggesting to change developer to fix an exposure mistake may not be ideal, because other factors come into play when you do. The OP already has one variable that is way out of bounds from his normal work flow; if you add another variable to the mix you're totally in the unknown.

    If you want to try a new developer, my suggestion is to do so when all other variables are under control.

    Also, many factors play into what you find as an Exposure Index for your chosen film. Metering technique, lighting conditions, light meter accuracy, film developer, film developing technique, lens contrast, lens shutter accuracy, water quality, bellows draw calculations, etc.
    Using HP5+ I find that I get the best results with full shadow detail at EI 400 in normal contrast lighting, using modern high contrast lenses, and replenished Xtol developer. More than a stop different from your 180, and we are both correct. I know those who use it at EI 800 as 'normal' too, and Dr5 reversal process has EI 1,000 as 'normal' for HP5+. Go figure.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  6. #66
    sun of sand's Avatar
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    everyone has heard that before
    most have ripped that tag off the cord long ago
    -whether or not they should have isn't the point

    I think the problem with that statement is that a 4 stop overexposure is not ideal, either ..and that is the reason for finding a developer+ which might possibly help
    i think most would agree that certain developers and certain ways of developing lose you speed while others give "full" speed
    It's pretty clear if you've overexposed and you're worried about it
    use a lower film speed developer etc and perhaps there is no reason to worry
    lemonaid from lemons
    obviously if his original film speed stems from a speed loss developer then another film speed loss developer won't do anything for him

    If you make potato salad and the salad isn't tasting right what do you do?
    just hope a day in the fridge will make it better
    just eat it anyway
    eat less? lol
    trash?
    or experiment
    you may make it worse
    you may remedy it
    if you already consider it "ruined" or "not good enough"
    what's to stop you?


    this guy should develop a snip of film- or another roll shot the same
    test it out
    if not to liking
    experiment

    he is experimenting by doing whatever he's doing in this thread
    but it falls short of true remedy
    and he's already "in the unknown"

    I'm suite sure you can lower film speed by 2 stops rather easily especially if your normal developer is a normal developer

    how about let it sit around for a few years? That might have lost it a stop in speed.
    develop it when your're 55
    probably right on!

  7. #67
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    sun of sand,

    Sure I've thought of switching to my WD2D+ instead of using my normal DD-X when I've used more exposure than planned, yep even tried it, especially when I was really green at printing. I was still looking for that elusive magic bullet. That never really fixed my problem.

    With a bit more experience I realized that chasing magic bullets to fix self inflicted injuries, is simply misguided.

    The materials available to us have reliable characteristics: given inputs, provide given outputs almost without fail. The negative materials I use (like HP5) have lots of latitude, they are very forgiving; as HP5's use at mass-market scale in single use cameras demonstrates.

    The real wildcards in my system (like for most people) are me, my understanding, and my craftsmanship; not my tools.

    In my experience, the big problem with jumping to "reset the film speed" or to "try a whole different curve" by switching to a different developer is that it messes with the whole film curve, not just the problem we want to fix.

    The first question that should be asked is "is there any benefit to changing my development?" With experience and practice under our belts we can actually answer that question.

    The OP actually provided all the info I needed to answer that question for myself in his first post. He actually had all the info he needed to decide for himself too, he did the math and the math said "you are fine in the normal process." The only piece of the puzzle that was apparently missing was that the OP had not tried this before.
    Mark Barendt, Ignacio, CO

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  8. #68
    Bill Burk's Avatar
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    Funny I didn't lead off my advice by telling that I once tested and rated TMY-2 at 64.

    I let some negatives sit four years undeveloped because they were so important.

    I finally developed and one print from the set is on my wall here and looks as good as anything else I've done at any other speed. (It was 4x5 in my case).

  9. #69
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    Quote Originally Posted by Bill Burk View Post
    Funny I didn't lead off my advice by telling that I once tested and rated TMY-2 at 64.

    I let some negatives sit four years undeveloped because they were so important.

    I finally developed and one print from the set is on my wall here and looks as good as anything else I've done at any other speed. (It was 4x5 in my case).
    So were you waiting for the latent image intensity to fall off a bit to save the highlights?
    Mark Barendt, Ignacio, CO

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  10. #70

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    Quote Originally Posted by PeterB View Post
    Thanks Bill. I'm curious as to why films are rated with so much latitude for over exposure but virtually none for under exposure ?

    regards
    Peter
    i am sure if you go to forums that deal in astro-photography they have information regarding gross UNDER exposure.
    some discussions here on apug have touched upon this sort of thing. what i have read ( here )
    it is done by steaming the film in a bath of hydrogen peroxide ( H2O2 ) either before or after exposure
    and then developed "normally"... ( whatever that means since my normal is different from ... yours for example )

    i have never done this so i can't say how useful it is, or the correct mechanics of it all ... and i don't know if anyone has "charted the curve"

    i hope you post the results of your over exposed film ... 7 pages is a long wait
    if my apug gallery looks empty you might check these places

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