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  1. #21

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    I will continue to be a slave to a light meter.
    Dave

    "She's always out making pictures, She's always out making scenes.
    She's always out the window, When it comes to making Dreams.

    It's all mixed up, It's all mixed up, It's all mixed up."

    From It's All Mixed Up by The Cars

  2. #22

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    Quote Originally Posted by markbarendt View Post
    I try to preset for each situation too. It is very valuable. In fact I started a thread about it today http://www.apug.org/forums/forum48/1...nting-bit.html

    So i have a question, what ISO?

    It's an honest question, not flippant. It takes all three.

    Time and aperture are used to make creative choices, time controls blur, aperture controls DOF.

    ISO finishes the equation to get proper exposure.

    Im trying to figure out why.
    Although I can't reply for cliveh, when I think that the scene looks like it's 1/125 @ f/8 I think of ISO100. And then if I do not use ISO100 I would have to convert or if I don't want to use f/8 or 1/125 I would have to convert too. When I came up to a scene I tend to think it's 1/125 @ f/8 rather than EV13. I would have to use the method described by the OP to convert it to an EV value for ISO100. Taking the above example it's 1/125=7 + f/8=6 so it's EV13 at ISO100. If I am using ISO400 then it's 13+2=EV15. Then If I decide to say use f/11 and that's 7. 15-7=8 and that's 1/250.

  3. #23

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    I try to think in EV. It's not too hard to guess an EV for a particular ISO based on stops down from sunny/16.

    Low light is hard, but I guess that's just a matter of experience. That I would approach by having a guess at it at EV100 (which is the same thing as LV, an absolute measure of amount of light) based on previous experiences and converting to EV at whatever ISO. That's a factor like EV400 = EV100 + 2).

    The biggest thing for me was working out how to do the calculation from EV to actual exposure quickly. It's easy enough.
    Start with 2, then add the number of aperture stops past f/2 you want(ie. f/16 is +6EV compared to f/2. You just have to memorise these, but there are only 6 maybe 7 values). Then whatever is left is the shutter speed in the closest power of two. (ie. 1sec = 1/2^0, so +0EV, 1/60 =~ 1/2^6, so +6EV). Powers of two are pretty easy.

    So to get EV100 = 15, (sunny 16), you go 2 + 6 (for f/16) + 7 (1/125sec).

    If you are shooting a scene at ISO1600 that is say -3EV from sunny 16 you say, sunny 16 is EV1600=19 (EV100+4). So I want 16. Which is 2+6 (f/16)+8(1/250s)

    Easy. You can do the shutter speed and aperature around the other way if you want to say pick a particular speed for whatever reason. Say you want to open up as wide as you can using the last example and 1/1000 is the fastest shutter speed you have. 16 = 2+10(1/1000s)+4 (f/8).

    The other thing that really helped getting my head around this is simply realising that an EV value is actually around the wrong way from what it sounds. It's called exposure value, and is referring to how much exposure you give the film, but it is actually less exposure the bigger the number. I try to think of it as 'degree of attenuation'. It's sort of seems to be measuring the amount of light, but this becomes nonsense when you start talking about EV100 vs EV400. It's not amount of light. It's amount of attenuation that light gets before it hits the film. An EV number always means exactly the same shutter speed/aperature irrespective of the ISO value it's for. So once you know what those are, or can get there quickly, the thought process gets much faster.

    This is probably quite basic, but it's really helping me to get quicker at doing this without a meter. It doesn't take me long now from guessing the light to actually setting up the camera to take the shot. As for guessing the light correctly or making sure the photo was worth taking in the first place, still working on that
    Last edited by octofish; 10-14-2012 at 11:02 PM. Click to view previous post history.

  4. #24
    Steve Smith's Avatar
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    Quote Originally Posted by Diapositivo View Post
    For ISO 400, 1/125@f/16 the light meter indicates EV17. The same exposure values at ISO 100 would be rendered as EV15.
    EV 15 is 1/125 @ f16 regardless of ISO. EV is purely a factor of shutter speed and aperture, light level or ISO does not affect it.


    Steve.
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  5. #25
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    I am in the camp of "Whatever works".

    Awareness of the light is not tied to the use or non-use of a light meter, but resides in the eye of the beholder. For me, this awareness has come about by seeing, exposing a sheet of film to that light, and then transferring the light to paper. I find a meter handy for the second step, not so directly important for the first or last steps.

    Vaughn
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  6. #26

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    its much easier to take the little paper that came with the film
    or look in the film box ... see if it it is cloudy, partly cloudy
    sunny, or whatever and do what the box says ...
    i am always amazed at how complicated people make things ...

    but then again YMMV

  7. #27
    David Lyga's Avatar
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    First, don't accuse me of being something I am not. I am NOT a CPA because, unlike for lawyers, passing the Exam in not sufficient. You have to work for a CPA for two years. I have not! (Who wants someone that is 62 even if he feels that he will live for another 40 years?)

    Now, all of you have provided sensible input. I will admit that having a light meter present is one of the most comfortable things on earth to have. To add to this, Diapositivo stresses that the eye is adaptable and I certainly agree. In fact, my point was to challenge that (in ths case) 'negative adaptablility' with reason and experience. Many of you say or infer that low light, especially, is 'hard' to determine. This is entirely true and a valid assessment.

    My 'system' is, in fact, the extant EV system simply expressed my way. Long ago I memorized the simple numerical equivalences of aperture and shutter speeds. Thus, it becomes easier for me to think of 1/500 as simply '9' and an aperture of f8 as '6' rather than with employing the more cumbersome standard way. In fact, my cameras and lenses are marked that way with neat stickers. If I know that a scene demands '11' for exposure, judging by the film used and the light available, I can provide a multitude of exposures varying the shutter and aperture, so long as the total is '11'. That, I feel, is easier than reading an instruction sheet that limits to discrete examples (ie, f5.6 with 1/60). This is all based upon the brain challenging the 'adaptability' of the eye. Of course most of you will assess an ISO 100 film to be a sunny rule '15'. My assessment at '14' is simply my way of imparting more shadow detail onto the film at the tiny expense of SLIGHTLY reducing highlight separation.

    This is different than using a meter, of course, but even while using a meter we can utilize the EV system. I love this system because it reduces the dilemma of proper exposure to a simple whole number (or, possibly, if you are fussy, a whole number with at fraction, like 10 1/2).

    Chan Tran wrote: "The second part you assign a light value to a condition for example full sun EV15 etc.. This part replaces the meter but one can elect to use this or not. One can use a meter to get the EV reading off the meter. However, I am like Cliveh that when I look at the scene I tend to intutively thought of an exposure in term or shutter speed and aperture combination rather than an ev number. And thus may need to those back to EV number mentally if I need to."

    Yes, Chan Tran, assigning a light value to a light CONDITION is what my post is all about. Most of us already know that the EV system exists. Hassleblad used to use just that system and so did, I think, Rollei. What I am driving at here is in attaining the ability to discern light value DESPITE the fact that (Diapositivo) the "eye is adaptable". Surmounting this obstacle becomes, I stress, a real mental achievement, even though with readily available light meters the 'value' of this achievement is (properly) challenged on this thread. To derive this achievement (I am still learning) you have to employ insight, pragmatism, and also, sometimes a practical judgment of the surroundings.

    This vociferous challenging of the value of this 'achievement' is understandable in the same way that an escalator is deemed an 'improvement' (where in many aspects it is NOT, with regards to human health). I am forcing all of you to dissect the real meaning and impetus of 'improvement' here and I think that that is a worthwhile 'cause'. In essence, what I say is that there is a certain comfort in knowing light and not being wholly and persistently dependant upon being told what it is. And whether or not we actually attain the ability to 'learn light' to the extent necessary to give us confidence, we still learn a lot. I am NOT saying that you must abandone meters and do what I say to do. I don't, for sure. But I do take time with film to challenge myself and to simply see how correct I have been. It is actually fun to do.

    Even then, light meters do not KNOW what they are being pointed at: in the SAME light a black cat in a dark surrounding should, theoretically, demand the SAME exposure as a white cat in a light surrounding. After all, the (incident) light is the same in both cases. The reflective meter will state the relative exposures quite differently because that meter is so 'stupid' that it will think that anything that it is pointed to is 'medium grey'. We are supposed to know that we must correct that faulty reading, so the mental effort is not eliminatied with meters either.

    And before anyone dares infer that I am not stupid I wish to remind all, again, that I cannot even do a damn crossword puzzle! - David Lyga
    Last edited by David Lyga; 10-15-2012 at 08:14 AM. Click to view previous post history.

  8. #28

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    I like EV... especially when the shutter is marked in EV.

    I also like elipsises (gosh, I hope that is the proper plural of "elipsis")... but I prefer mine with three dots, not four or five.

  9. #29

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    Quote Originally Posted by David Lyga View Post
    Doing crossword puzzles is an impossible task for me. I simply cannot solve puzzles. Getting nearly straight A grades in the accounting curriculum and passing the CPA Exam were easier. Figure out that craziness.

    But figuring 'light' intensity, despite the changing luminary parameters, can also be a formidable task. When is shade, shade? Easier said than done but the key here is making 'shade' mean something very personal to you and not ever deviating from that perception.

    Slowly learning how to harness this complex subject can, at least, be made easier by forgetting 'f stops' for a while. In fact, why are there such things as f stops at all for other than theoretical verification of that all important concept of the focal distance (to film plane, at infinity) divided by lens opening diameter ? Hollywood long ago entered the real world with their sensible 't stops' zeroing in on the ACTUAL light transmission. Much more rational. (Do I sound like the pragmatism of David Vestal yet?)

    There is a certain freedom with taking an extension of your eye, a mechanical camera with adjustments available, and 'knowing' how to expose a certain film. I am still learning after decades of frustration but I am certainly better at it. It is intellectually revealing how right or wrong one can be and this exploration is perfect ammunition to circumvent, even diffuse, an overconfident ego. But there are certainly hurdles here: for example, shade at noon is not necessarily shade at noon merely a block away. Much depends upon the amount of sky allowed to illuminate the scene and whether clouds intervene. Then again, twilight is not an objective measure either: When is the sun low enough? Are buildings or mountains adding to the 'light value' confusion? But there is a kind of beginning benchmark with open, noon sunlight hitting an open space. But even here one has to look just how low that sun is in the dead of winter conflated with how high one's latitude is on planet earth.

    I offer some tips that have helped me in this endeavor. First, translate 'f stops' to the less cumbersome light value system: f2 is '2', f2.8 is '3'....f16 is '8', f22 is '9. Then do the same for the time part: 1 sec is '0', 1/2 sec is '1'....1/30th sec is '5'.....1/250th sec is '8'....1/1000th sec is '10'. (You fill in the grammatical ellipses.)

    Thus, we have a convenient, transferable way to express exposure at least, even if we have still not mastered light itself. To add to this convenience, rate film the same way. Consider a 400 ISO film. For me, I rate negative film about 2/3 stop less than the manufacturer says to. I would, thus, rate HP5+ or Tri-X at EI 250. Translated into light values this becomes (combined light value) LV 16. (NOT downgrading this speed from 400, this LV would be 17 if the manufacturer's recommendation were to be followed.) Similarly, I rate Pan F+ at EI 16. My 'rating' expressed in LVs is 12. What does all this mean?

    Simply, this 'rating' is the amount of exposure given to a brilliant, sun lit, noontime, 'no holds barred' scene that is the epitome of what nature can provide in terms of light intensity. That is my outdoor benchmark. In other words I would expose HP5+ at 'LV 16'. This is the combination of aperture and shutter speed that I would use. For example, that would translate into f22 plus 1/125th sec, or f11 plus 1/500th sec. Both, conveniently and easily, add up to the '16' you want. In the former it would be 9 + 7, in the latter it would be 7 + 9. This is why I convert both apertures and shutter speeds into these easy numbers.

    That's for brilliant sunlight. For other values: My exposure chart column is stated as follows for outdoor lighting: SUN SHD TWL DIM with each category giving four more stops (or, more correctly, steps) exposure than the preceding. This means that HP5+ starts at '16' for sun and proceeds to '12' for shade, then '8' for twilight, then '4' for dim daylight. So for MY interpenetration of 'shade' I would expose HP5+ at, say, 1/60th sec and f8, or '6' + '6' to get the wanted '12' LV. For MY interpretation of dim daylight I would expose HP5+ at, say, 1 sec and f4, or '0' + '4' to get the wanted '4'. You can see that it becomes extremely easy to change the aperture and shutter speeds to accommodate the exposure as all you have to do is add up to the proper combined LV.

    The work comes with mentally anchoring the amount of light that 'sun' 'shade', 'twilight', 'dim' are supposed to represent in order to get proper exposure. For example, if the negative is too dense, you judged the light as too intense. 'Shade' does not necessarily have to be a shaded situation. It can be a level of overcast that equates with the level of proper shade. Likewise, 'TWL' does not have to be actual twilight; it can be a dark alleyway whose light intensity equates with the proper level of actual twilight. This is what really 'teaches' light, folks: refusing, on occasion, to bring your 'crutch' light meter with you. It is an exercise that forces you to come to grips with the reality of actual light intensity and correctly nullifies subjective interpretations that have little to do with this actual measure, such as assuming that shade is always of nearly the same intensity, or that twilight is 'when cars turn on their lights'. It forces you to really 'see' light in objective terms and removes the 'romantic' aspects of light interpretation that can easily get in the way.

    The other side of my exposure chart is for 'tungsten light'. This side is a bit more complex, as the sensitivity of chromogenic (color or B+W) films are markedly more sensitive to the lower Kelvin (say 2800 K) than are traditional black and white films. (I assume NO filtration in all my examples). (For convenience, and usual accuracy, consider fluorescent to be the tungsten equivalent.) My side of the chart for tungsten is as follows: HIGH MED LOW DIM Each category requires two stops more exposure than the previous. For example, again using HP5+, a traditional B+W film, my rating for tungsten starts with '7' for HIGH, then '5' for MED, then '3' for LOW, then '1' for DIM. Here, importantly to understand, is that the SAME intensity exists for daylight's "DIM" and for tungsten's "DIM": the considerable difference in exposure (daylight dim = 4 while tungsten dim = only 1) is because traditional B+W film is very slow when exposed to tungsten light. The ACTUAL intensity of both 'dims' is the same. With chromogenic films this interpretation is more in line with human perceived value. With, say either a ISO 400 chromogenic B+W film or an ISO 400 color film, the tungsten chart is: '10' for HIGH, '8' for MED, '6' for LOW, '4' for DIM. Again, this assumes no 'proper' blue filtration for the chromogenic films. You can easily correct this 'lack' in the darkroom's enlarger. If you were to use the blue filtration (I think the 80A filter?) your numbers would be in line with those for traditional B+W films. Few realize just how much of a bonanza this is for available light black and white photography: an increase of three stops for using the chromogenic films without filtration.

    With outdoor lighting the films' sensitivity is the same. - David Lyga
    I can't afford to waste film, (you might wish to price 4x5 and 8x10 sheet film) and I won't waste the energy it takes to think through, set up, expose, and develop a photograph only to find it's improperly exposed. So I use an exposure meter - carefully and thoughtfully - whenever possible. Including 35mm, I lose a tiny fraction of 1% of my exposures to error.

    I don't hunt game by firing blindly into the woods, either.
    Last edited by E. von Hoegh; 10-15-2012 at 11:23 AM. Click to view previous post history. Reason: Clarity.

  10. #30

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    Quote Originally Posted by BrianShaw View Post
    I like EV... especially when the shutter is marked in EV.

    I also like elipsises (gosh, I hope that is the proper plural of "elipsis")... but I prefer mine with three dots, not four or five.
    Singular - Ellipsis.

    Plural - Ellipses.


    ...

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