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Exposure technique info please


wag

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This may not be the appropriate forum for the subject of exposure since I haven't seen it discussed here but I would appreciate being pointed in the right direction for info on manual techniques of proper exposure. I used to be a fully automatic, SLR shooter.

For example, I get considerable variation with landscape shots when I use the same shutter speed, say 8000, an ISO set at 320 and a 75mm lens wide open at 1.4 -

One shot will be washed out, the next seemingly well exposed on the same bright day, 3 minutes apart.

Should I be using a meter? Are aperture and shutter speed settings something one just learns with experience or is there a methodolgy I can study? I know focus skill comes

with patience and practice but I'm a little uncertain on how to approach shutter speed and aperture.

I'll worry about DOF next.

Thanks for any help or direction.

 

Brad Wagstaff

M8, 75 Lux. 50 Noctiluc, 50 Summitar

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Every basic book about photography covers this.

The most comprehensive and clear explanation about exposure and (in camera) exposure meters i ever read was in John Shaw's "Nature Photography Field Guide" ........ not an interesting book otherwise..... but the first 30 pages about exposure, aperture and shutterspeed are cristal clear written.

You have to keep in mind which meter the camera uses .... the M8 uses a center weighted type of exposure meter ....

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One shot will be washed out, the next seemingly well exposed on the same bright day, 3 minutes apart.

Should I be using a meter? Are aperture and shutter speed settings something one just learns with experience or is there a methodolgy I can study?

 

Yes you have a bit to learn. Any camera instruction manual explains this in at least rudimentary terms. The key to every in-camera meter is that they base the exposure on the subject being an average of middle gray. (18% gray.) That means that if your subject has a lot of bright area (or an extremely bright small area) the exposure may be too dark. If your subject has a lot of dark area the exposure will be too light.

 

All of the sophisticated developments in meters such as matrix metering are simply attempts by the camera to guess at what kind of subject you are shooting and what is the "best" way to expose for it. But they all fall victim to "subject failure." That is when the subject, or how you desire the image to look, doesn't match what the metering was designed for.

 

So when you use the metering in the camera, think about your subject and what part of it is being measured by the meter.

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I have come to the conclusion that the M8 is a manual exposure camera.

 

The metering is extremely center-weighted. Any other manufacturer would tout it as 'spot metering'. Sensitivity outside the center (see the manual for a meter diagram) is close to nil. This means that the outcome depends entirely on *where* you aim that center. If it happens to be at something with 'average', i.e. 18% reflectance, all is well. But if reflectance is less than 18%, you get underestimation of the light level, and consequently overexposure. If more, the result is overestimation and underexposure. Add to this the fact that the exposure range of the M8 is not much larger than that of Kodachrome, at least not on the overexposure side, and brainless auto exposure is a recipe for disaster. The M8 is a camera for thinking photographers.

 

So, meter a representative area of medium reflectance, re-compose and shoot. Exposure compensation would not be not an option even if there existed an outside control – it means simply that you take 1/2 metering and add 1/2 guesswork – the last half being the critical one. Auto exposure lock, via the pressure point – well, it is ticklish and also useless if you want a sequence of compensated shots. So manual it is.

 

I would get myself a small, reliable hand meter for incident light, at first just as a learning device. Correctly used it will give you a 100% true exposure. Compare that to what your inboard meter says. Later, that meter will be your lifesaver in lighting situations that a reflected-light meter simply cannot handle.

 

Exposure bracketing is relatively easy. You can bracket either with the aperture ring or with the shutter dial. The first finger on the shutter release, the second on the dial, watch the readout in the finder. And it doesn't cost you anything! Just delete what doesn't work. But before that, evaluate and remember the results.

 

The old man from the Age of Selenium Meters

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I have come to the conclusion that the M8 is a manual exposure camera.

 

The metering is extremely center-weighted. Any other manufacturer would tout it as 'spot metering'...... The M8 is a camera for thinking photographers...... So manual it is.....

 

Brad Wagstaff:

I get considerable variation with landscape shots when I use the same shutter speed, say 8000, an ISO set at 320 and a 75mm lens wide open at 1.4 -

One shot will be washed out, the next seemingly well exposed on the same bright day, 3 minutes apart.

 

Brad - I agree with a lot of Lars' observations but have come to an opposite conclusion. I have confidently manually metered for over 30 years, and even do so accurately and swiftly with my DSLR Nikon - by pre-selecting my chosen aperture and thumb wheel spinning the shutter selector. Ergonomically, the Nikons [and others] are fabulous for fast manual metering [though I obviously keep track of my progress by checking the histogram].

 

For usability in manual metering mode the M8 is the first camera to defeat me and I use it solely in Aperture Priority, with exposure compensation frequently at -1 stop [i hate blown highlights] and constant checking of the histogram. For me [a thumb wheel convert] the M8 shutter speed control is too imprecise offering only 1/2 stop variation, and it is in the wrong place [top of the camera] for efficient camera handling and picture framing whilst metering.

 

As Lars suggests, the metering could be better, and yes one has to think when using it, but in AP mode the histogram is our best friend so working the camera is pretty simple really. Why make life more complicated by choosing to use the camera in manual when it is built for automation with manual input?

 

Regarding the wildly differing exposures you described I have no idea what you were doing to get the discrepancies, or whether the camera is malfunctioning. My recommendation is to use the camera in AP mode, if you are unfamiliar with histogram technique some tutorial catch up is required. Good luck.

 

................Chris

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I think the biggest thing to remember when using the M8 is that, as many people have pointed out, the meter is strongly center weighted: you have the be very aware of what you're pointing it at to get good exposure. Overall I haven't found the auto metering to be a problem except in strongly high or low key scenes, which are easily compensated for. Coming from an M6 this was second nature, however I'm really enjoying the A mode on the M8. Dial in a bit of underexposure and check the histogram if you're in doubt.

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You know, it all depends what you're used to, and I find Lars is right...the M8 is heavily center-weighted.

 

Since I have the other cameras set to spot meter anyway, that's just fine with me :)

 

I have to admit, too, that sometimes I'll just stick that sucker on A. Not because of ergonimics, but because that little arrow thingy going up to 1/8000 is just not very useful (the way it in on a film m).

 

Since they have the room in the LED for shutter speeds, why o why didn't they just report the shutter speed instead (with the dot for even exposure in M, ok)....

 

Just personal, but I really like to know when I'm getting close to the hand-hold limit, and I just can't get a feel for it from the shutter wheel on the M8.

 

But I like the meter :)

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Since they have the room in the LED for shutter speeds, why o why didn't they just report the shutter speed instead (with the dot for even exposure in M, ok)....

 

If anybody reading this is in a position to do something about this, I feel the same as Jamie.

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If anybody reading this is in a position to do something about this, I feel the same as Jamie.

Me too! Now that gradually advancing age has shortened my arms so that my eyes can no longer focus on things in my hands, I have to put on my damn reading glasses to read the shutter speed dial. But I can read the neon figures in the vf without a problem.

 

Short Arm Pete.

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Jamie said: Since they have the room in the LED for shutter speeds, why o why didn't they just report the shutter speed instead (with the dot for even exposure in M, ok)....

 

Maybe Guy can add this to our wish list. This would be a very big improvement. I too, would like to know where I'm at with the shutter speed without having to move the camera away from my eye.

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I have a couple of thoughts. For anyone who really wants to get a thorough and solid background in exposure as it relates to tonality, etc., I have yet to see a better book than Ansel Adam's "The Negative". His series of three technical books are where my technical reading in photography began (when I was twelve). Once one understands some of the concepts that underly exposure in film photography, its not too hard to translate that knowledge for digital capture.

 

I'm quite happy with the M8's exposure meter but I never allow any camera to decide exposure for me. Even in AE mode, I monitor and tweak what it is doing. The histogram eliminated the spot meter for me (probably permanently). In fact, because of the histogram I no longer use external meters at all.

 

But, again, it really helps to have the foundation and "The Negative" provides that very well. The other two books in the series, in case some are interested, are called "The Camera" and the "Print".

 

Cheers,

 

Sean

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Me too! Now that gradually advancing age has shortened my arms so that my eyes can no longer focus on things in my hands, I have to put on my damn reading glasses to read the shutter speed dial. But I can read the neon figures in the vf without a problem.

 

Short Arm Pete.

 

Pete, I am now so presbyopic that I cannot focus even on the horizon. The solution is progressive specs. There is always one area of the lenses where you can see sharply at about 2m/6', and this is where your finder is. Lower down is the sweet spot for reading – that is where dials and rings are. Finding these spots is something you learn in a few minutes, and then it is instinctive. Just like riding a bike. Right now I am looking at the screen of my laptop, and at the horizon out of the window, without changing specs. And my M cameras fit in somewhere in the middle ...

 

The old man from the Age of Bifocals

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Sean, Adams formed his ideas in an age when large glass plate negatives were printed contact on papers in one contrast grade only, and exposure meters were extremely primitive or (mostly) non-existent. So some of Adams' ideas were quite peculiar, even from the point of view of the film handling techniques of my generation (you know, I was not tipped out of my cradle by the Great San Francisco Earthquake ...)

 

Even so, I would not dream of applying 1950's BW exposure techniques to the digital world. Negative and digital are radically different realities. This unfortunately is not the place to enlarge on that subject (no pun intended). But applying Adamite doctrines is not the way to go.

 

The old man from the Age Before Meters

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Lars, clearly a lot of the more technical parts of Adams' teachings are not applicable to digital, but his overall theory certainly is. He encouraged studying the capabilities at the limit of every single step in the process, and controlled experimentation to find it out, and then the proper combination of all steps to get the desired results. This is more common sense than anything else, and although the development process is very different, there is still the raw developer and the printer to deal with, and a lot of Adams' theory can be applied.

 

His theory was never about basic proficiency, although his books certainly cover the basics, but about full control of the entire process, and eliminating variables. As such, it is probably more applicable to professionals and advanced amateurs.

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If you start with Lars' premise that the M8 meter is so center-weighted as to be a spot meter, then use the camera as a spot meter before you take your exposure. Or, at least, before you take your final exposure.

 

The best guidance might be to go back and read some of the classic camera technique literature on the notorious Zone System originally mooted by Ansel Adams. Do a google search on that phrase and it will point you in right direction. You really should acquaint yourself with this literature if you want to consider yourself a serious photographer, anyway. There are various thoughts on this subject here in the Forum, too, if you want to search those.

 

The way I use the M8 in tricky exposure situations is to put the camera in aperture-preferred mode, pick the aperture I want to use, read the indicated shutter speed of the brightest highlight in the in-camera display, then off the darkest shadow, then shift the shutter speed wheel to a speed between the two that judgmentally approximates the balance I want, and shoot. If I have time, I will try to bracket (+2, -2 EV) just for insurance.

 

You can also chimp spots by using the thumb wheel to zoom in on a spot on a trial exposure, referring to the histogram info for that spot, move the spot rectangle to other spots and reading the histos for those, too.

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You know, it all depends what you're used to, and I find Lars is right...the M8 is heavily center-weighted.

 

Since I have the other cameras set to spot meter anyway, that's just fine with me :)

 

I have to admit, too, that sometimes I'll just stick that sucker on A. Not because of ergonimics, but because that little arrow thingy going up to 1/8000 is just not very useful (the way it in on a film m).

 

Since they have the room in the LED for shutter speeds, why o why didn't they just report the shutter speed instead (with the dot for even exposure in M, ok)....

 

Just personal, but I really like to know when I'm getting close to the hand-hold limit, and I just can't get a feel for it from the shutter wheel on the M8.

 

But I like the meter :)

 

I exactly have the same wish. PLease give us a manual mode with display of shutter speed.

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Brad--

As you see from all the different ideas above, metering is about learning how to do it. And that means understanding the basics (why does metering snow cause underexposure, for example?) and learning how to apply them to your particular technique.

 

Scott Geffert mentioned at one of the Leica/CDINY M8 seminars that with longer lenses the camera tends to meter more as a spot meter, and with wider lenses more as a center-weighted average meter.

 

In my experience, metering patterns shift with changes in focal length in all cameras without semi-transparent mirrors to meter a selective area. (And that depended on design as well--the Contarex's sensitivity outside the supposed metering area differed greatly between a 135 and a 35. Leica is the only company able to pull off a true 'spot' meter IMHO.)

 

So consider the M8 meter to be highly center-weighted, meter carefully (auto or manual), check the histogram, and re-shoot if necessary. You'll soon find a technique that works for you.

 

As for why you got different results from what should have been the same settings, I could only guess.

 

How repeatable is the 1/8000 sec setting? Certainly much more so than the 1/1000 sec setting on the cloth-shutter M's, but probably not as repeatable as the M8's 1/2000 sec setting.

 

The exposures are three minutes apart? Clouds can make a big difference over that period.

 

"Should I be using a meter?" Of course. And you need to know how to use it. I use the one in the M8.

 

At least two of the lenses you mention are super, but all three lenses are older designs and are not at their best wide open. A slight shift of angle between two shots can cause enough veiling flare to be noticeable, particularly wide open. I don't know the Summitar, but the Noctilux and Summilux really crispen up when you stop down just a little.

 

Don't misunderstand: They are far better wide open than anyone should hope, but they're fantastic stopped down a tad. Your style and mine differ of course, but to me those broad apertures are to be called up for specific purposes, like limiting depth-of-field, giving the image a dreamier look, or simply pulling things out of the dark. Again, practice is the only way.

 

And because the M8 asks me to think, I find I usually get better exposures from it than from my dSLR, whose matrix metering is always mis-figuring what I'm shooting.

 

--HC

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I get considerable variation with landscape shots when I use the same shutter speed, say 8000, an ISO set at 320 and a 75mm lens wide open at 1.4 -

One shot will be washed out, the next seemingly well exposed on the same bright day,

 

Is this a wind up?

Apologies...and welcome to the forum if it isnt...

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