Spot metering reversal/E6 films (Velvia, Provia, etc) films for twilight cityscapes

[dave_whatever]

The thing is, making a zone system placement of important tones in the scene IS the only reliable (aka "precise") way to meter transparency film. You don't really want an accurate metering methodology, you want precise metering methodology, because then that's easy to adjust to give you bang-on results.

If you can spot meter individual parts of a scene and you know what the latitude of the film is, then averaging isn't doing anything for you - you already know all you need to come up with the right exposure every time, short of human error or lapses in judgement.

Basically, someone should be able to ask you where you would place various typical elements of the sorts of scenes you shoot in terms of zones/EVs, and you should be able to tell them - because you need to answer that same question to yourself every time you pick up the meter. If you can't answer it, then this is your problem. The solution to that is just a bit of decision making based on past (and possibly future) results. That's the critical step.

If you're already making those decisions and you're consistently under or over exposing then that's easy enough to correct too.

[spotless_camera]

The thing is, making a zone system placement of important tones in the scene IS the only reliable (aka "precise") way to meter transparency film. You don't really want an accurate metering methodology, you want precise metering methodology, because then that's easy to adjust to give you bang-on results.

If you can spot meter individual parts of a scene and you know what the latitude of the film is, then averaging isn't doing anything for you - you already know all you need to come up with the right exposure every time, short of human error or lapses in judgement.

Basically, someone should be able to ask you where you would place various typical elements of the sorts of scenes you shoot in terms of zones/EVs, and you should be able to tell them - because you need to answer that same question to yourself every time you pick up the meter. If you can't answer it, then this is your problem. The solution to that is just a bit of decision making based on past (and possibly future) results. That's the critical step.

If you're already making those decisions and you're consistently under or over exposing then that's easy enough to correct too.

Sure. The difficulty is (as I noted before) judging whether something that looks "about +1 EV" should be at, for example, +0.7 EV, +1 EV, or +1.3 EV. Can you consistently get that right?

Averaging (as I described it in my previous post) is about saying "I think that bright spot should be at about +2 EV, and that dark shadow over there looks like it could be -2 EV." Of course in practice the bright spot may be better placed at +1.5 EV... but by averaging the two, your exposure error is cut in half.

The next step then is to just do some tests with color charts and figure out how exactly things look at every possible placement. And then in the field it's much easier to say, "That pavement goes at -1.7, the white lines over there at +1, the red roof at +0.7"

If we assume a range of -2EV to +2 EV, and a step size of 0.3 EV, that is only 12 possible "zones". I may get the tests scanned, and make up an "E6 zone menu," so choosing a placement becomes as easy as pointing at a picture... like ordering Asian food off a picture menu. I'll have that Pad Thai at +0.7 EV, please!

[dave_whatever]

Sure. The difficulty is (as I noted before) judging whether something that looks "about +1 EV" should be at, for example, +0.7 EV, +1 EV, or +1.3 EV. Can you consistently get that right?

Can you show us some of your images are are a disaster because you got the metering 1/3rd of a stop out?

If I was worrying about the difference between +0.7 EV, +1 EV, or +1.3 EV then I'd just call it +1, then if after doing that for a long time you're convinced that you're systematically miss-estimating certain values to the tune of 1/3rd of a stop, and all other variables are absolutely nailed down (see below), and it's causing a problem then I'd say fair enough, but if this is a purely theoretical problem rather than an actual problem then I don't think there's much to be gained.

Most of the time, even on Velvia, 1/3rd of a stop is neither here nor there except if you're right at the upper limit of the highlights and certainly well within the scope of scanning and post-processing. Pragmatically there's only so much you can do. Bear in mind also that most leaf shutters are probably operating at +/- 30% to begin with. Most grad filters don't come in 1/3rd stops either, then throw in reciprocity correction estimates, how closely to 1/3rd of a stop you can move the aperture lever on your lens, age and storage of the film, variations between light meters, variations between repeated meter readings of the same subject, light falloff of shifted wide angle lenses etc etc. You'll end up chasing some ideal which is neither practical, possible, nor has any tangible benefit in most cases.

[bdkphoto]

Are you saying I am wrong about cine lenses being calibrated in T-stops because exposure accuracy is critical when shooting moving pictures on a big set?

https://fstoppers.com/education/why-...-f-stop-158541

Yes cine film is high latitude color negative stock, but on set you still try to get everything right to <1/3 EV accuracy, because it saves time and money. The high latitude of the film stock is there (in addition to the reasons you listed) as a "safety net" to catch you if you screw up, to save you from a (horribly expensive) reshoot. (all that notwithstanding, some commercials were/are shot on reversal/E6 film to get punchier colors -- I believe Velvia was a popular choice back in the day)

I understand you have a lot of experience and I certainly appreciate your contributions. But while your "estimate and bracket" approach may be very useful shooting buildings in NYC (where you know what the light will be, because you have been shooting in the city for years, and where you can get any film you like whenever you want) that is not necessarily a viable approach for me in a very different situation.

Darr's thoughts in post # 34 are spot on.

T stops are not relevant to this discussion -

The fundamental problem with your initial question is that there is no perfect exposure - especially working in transitional light - just a range of options where minor/major exposure changes will yield a range of choices.
My technique works everywhere- bracketing is how professionals work to insure you have perfection - whatever that means for you.
Husbanding film is a terrible idea
Your digital camera will give you all the information you need to determine your base exposure. Need more latitude shoot color neg. 4x5 too expensive, shoot a different format. Need perfection shoot digital.

[spotless_camera]

Can you show us some of your images are are a disaster because you got the metering 1/3rd of a stop out?

If I was worrying about the difference between +0.7 EV, +1 EV, or +1.3 EV then I'd just call it +1, then if after doing that for a long time you're convinced that you're systematically miss-estimating certain values to the tune of 1/3rd of a stop, and all other variables are absolutely nailed down (see below), and it's causing a problem then I'd say fair enough, but if this is a purely theoretical problem rather than an actual problem then I don't think there's much to be gained.

Oh they're not a disaster because the metering is off by 1/3 stop, it's just causing me to miss shots (and waste film) because I have to bracket to get it just right. With a 30 second - 2 minute exposure time the light can change significantly from shot to shot. That means the "right" light (for whatever definition) may happen during the "wrong" bracketing exposure.

Since you mentioned: yes I do have a device to measure my shutter timings, and I keep a correction table at hand when I am relying on the shutter. (I'm usually not, as mechanical shutters can't handle 30 second exposures.) I shoot films (Provia and Velvia 100) where reciprocity is not an issue at these exposure times and yes, I do have the reciprocity tables at hand just in case.

Grad filters aren't much use for urban/architecture work unless you like your skyscrapers dark on the top and bright at the bottom.

My light meters all agree, except for the cheap one, which goes to show it's not a good idea to pinch pennies when buying light meters.

For precision exposure changes I find it more useful to change the exposure time than the aperture. It's easier to time a few more seconds than it is to precisely nudge the aperture lever.

[spotless_camera]

Darr's thoughts in post # 34 are spot on.

T stops are not relevant to this discussion -

T-stops were relevant because we were discussing using digital cameras as light meters. If you are using a nice zoom on that DSLR then the light losses inside the lens may be substantial, throwing off the results.

The fundamental problem with your initial question is that there is no perfect exposure - especially working in transitional light - just a range of options where minor/major exposure changes will yield a range of choices.

Of course there's a perfect exposure.. the perfect exposure is the one that gets me the look I want to have!

[dave_whatever]

Oh they're not a disaster because the metering is off by 1/3 stop, it's just causing me to miss shots (and waste film) because I have to bracket to get it just right. With a 30 second - 2 minute exposure time the light can change significantly from shot to shot. That means the "right" light (for whatever definition) may happen during the "wrong" bracketing exposure.

In this case, don't bracket. Just shoot one. If all your shutters are fine, and all your meters are perfect, and you're within, say, half a stop of the theoretical ideal (sounds like you are if one of your brackets is right) then you're done right? Hard for me to imagine what problem's being 1/3rd of a stop off is without seeing any examples TBH.

[bdkphoto]

T-stops were relevant because we were discussing using digital cameras as light meters. If you are using a nice zoom on that DSLR then the light losses inside the lens may be substantial, throwing off the results.



Of course there's a perfect exposure.. the perfect exposure is the one that gets me the look I want to have!

You spend too much time believing internet twaddle. The only thing you are doing here is showing your ignorance. Your questions have been answered here by people who have far more experience and success than you. Its time for you to stop trolling.

[Eric James]

I’m beginning to believe our OP is Making Imaginary Kodakachrome Exposures, but Frankly I may be wrong.

[phdgent]

T-stop and F-stop are interchangeable for purposes of metering and calculation, so no light meter reads in T-stops. If the lens is marked T-2.8 then that means a light meter reading of F/2.8 is correct. The lens being marked as T-2.8 just means you will get precisely correct exposure if the meter says F/2.8, and you do not need to add exposure to compensate for light losses in the lens.

I don't know why the other lenses were marked as F-stops and I don't know whether their values were derived from optical calculation (the ratio of effective aperture size to focal length) or based on measurements of light travelling through the lens (T-stop).

I never touched VNF... sounds like interesting stuff if it could cope with mercury vapor lighting though!

No VNF couldn't handle mercury vapour light as such, but it was forgiving and by this rather easy to colour control filtering in the sense that one could never filter at the (deca-) Mired precise as these lamps changed colour by age, duration of under power, environmental temperature and imagine a production hall lit by a few dozen of these, and the colour meter (Gossen) sometimes seemed to have a hard time to measure this too...

BTW, I do realise that this little conversation is deviating from the initial topic, apologise me for chatting to much...