To trust built-in metering or to use external pro-exponomete

[Margus]

Wondering how much practical output there is for professional light meter (exponometer) compared with camera's built in light-meter?

I'm mostly shooting on MF slide-film, so good precision is expected.

Todays pro-lightmeters are so small so no problem to take with on the road, but very expensive pieces indeed - worth the price or not?

Margus

[AliBaba]

The build in exposure meter measures reflected light (the amount of reflected light depends on the colors of the motive). With an external exposure meter you are able to measure incomming light (which is the "correct" thing to meassure, and doesn't depend on the colors) and you don't have to compensate for dark/light motives.
If you meassure light with your camera and use a greycard (or experience) then it will give pretty much the same result as using an external exposure meter. You can also use the spotmeter to make a virtual histogram which gives you more information then histograms on a DSLR.
Personally I prefer to use a spotmeter instead of an external exposure meter.

[vagabond]

You can certainly trust a built-in meter, it all depends on your technique but; since bracketing exposure with MF isn't cheap and you are going to be shooting slide film, a hand-held spot meter will be the best option even if your camera already has a meter.

[This message has been edited by vagabond (edited 28 October 2004).]

[John Roberts]

Hi again, Margus

If you say you need a meter for use on the road then I'd go for incident reading meter every time, although that usually means the ordinary reflected light type of meter with the appropriate adaptor. I would consider a spotmeter a heavy and expensive luxury for use on the road. Having said that, of course, if you have a spot-metering option in your Medium Format (some Hasselblads, including the H1 and the 645 Contax I believe have them built in) then use that by all means.

Since you say that you will be using slide film then myself I would definitely go for incident rather than reflected metering, the thing is with slide you only get the one chance, it just doesn't have the latitude of negative film and metering errors cannot be compensated for at the printing stage. Incidentally, err on the side of under exposure with slide film, once the highlights are burnt out then there's nothing left in them to work on, whereas there's some chance of of detail lurking in the shadows if you do under expose.

As AliBaba says the incident meter shows how much light there is on the subject: set the exposure to this reading and both a black skinned and a white skinned person will be correctly exposed. On the other hand, were you to take a reflected light reading of the skin of a black and then of a white person then you would get two different readings, and if you were to take a picture of each with the readings obtained then on slide film you would end up with substantially the same skin tone for both subjects. Obviously, that would be just plain wrong, you will want a black man to look black and a white man to look white.

I would add that, for instance, if you are indeed taking the picture of a person, then hold the meter on the side nearest to the camera of the subject with the meter pointing halfway between the camera and the main source of light.

Another situation where incident metering is more appropriate is when you take a picture of somebody with their back to the sun, i.e. with their face in the shadow. If you take a reflected reading of the scene then you will get a reading that will be far too high because you are pointing the meter partly towards the sun, and if you set the camera to this reading then the subject's face will be underexposed. If on the other hand you took an incident reading with, as I said, the meter pointing halfway between the position of the camera and the main source of light (i.e. the sky in this case-not the sun, since the face of the subject is now in the shadow) then you should end up with the correct exposure.

As I said to you in another thread I'm a wedding photographer, I have both a Minolta Flashmeter V costing £600 to £700 (around 1000 Euros) (well it did when I got it) and the far cheaper Sekonic F328(?) which cost £60 (100Euros) at a guess. They both have an incident reading adaptor. The fact is, I hardly ever use the Minolta, I've got to know the Sekonic, side by side they give me practically the same reading anyway. So if money is an issue then I'd definitely go for a modestly priced meter and get to know it.

Best wishes,

John

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Johnefyn

[This message has been edited by John Roberts (edited 06 November 2004).]

[John Roberts]

Margus,
PS
I've just read AliBaba's reply again and would just like to add that if I don't have a Gray Card then taking a reading off the palm of my hand gives a good approximation.

J.

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Johnefyn

[Margus]

Thanks for your good answers!

I have only centre-weightened meter in my MF camera, and the meter itself is quite bulky i think (it's a russian prisma with built in metering).

So i'd rather consider external metering. So far i'd used my digital as reference camera - metered with it, checked the picture and then shooted with MF if the conditions seemed right from that tiny LCD monitor of crappy digital.

Yes, the money is issue for me. So maybe to get cheaper meter and get to know it.

With the Sun, Margus

[John Roberts]

Crappy digital, eh? Heh-I can do business with this man!

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Johnefyn

[Margus]

John,

sorry, i mean that to circa 1,5 inch diameter LCD displaly that doesn't give much detailed overview (i.e. if eyepupils are over or underexposured)

Margus

[John Roberts]

Margus,
No, what I meant was that I absolutely agree with your views on digital. I meant it as a compliment!
I'm still very cynical as to its picture quality, though I have to admit that it beats film hands down for convenience.
Cheers
John
PS liked yor shot of the approaching bike in the other thread a lot.

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Johnefyn

[Margus]

OK. Took your advice - got the Pentax Spotmeter V. The results are getting better than ever i think - i can even measure the contrast differences on the whole picture with that precise 1 degree measuring system and select the precise exposure and aperture. I now ca perform highlight or shadow readings, halftones on b&w etc that i couldn't do ever before - i've found a wonderful world of measuring the light
Probably the best thing is now i can measure the infrared light quite precisely (had previously serious problems with it).

Cheers, Margus

[This message has been edited by Margus (edited 24 November 2004).]

[A.B.]

A separate incident meter would be my first choice too and will be the most used meter; however I think that in several situations a spot meter is just as important so I would get a meter that has both as most in camera spot meters are too wide angled.
One example where a spot meter becomes indispensable is when photographing big interior halls like inside a cathedral or mosque. Usually the light intensity differs dramatically from one area to the other, often within just a few meters. This is because some areas are hit with direct sunlight from windows and others only get reflected light and the difference in light intensity is too much for slides and often too much for print too. You have to compromise and select the area you want to show details in and meter and compose accordingly.
Having an incident meter in this situation will have little benefit, since most likely you won’t be able to take a reading from the place you want to expose correctly (the ceiling?) and you’ll probably be standing in an area with completely different light intensity so you can’t take a reading there. Only a spot meter would do the trick.
Along the same lines, in long open ended corridors the light intensity drop from the open end downwards is usually dramatic and again hard to meter. A spot meter will let you expose for a certain arch that you focused on and composed your picture around.


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A.B.

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[Margus]

A.B.,

you're right about that.

One of the best advantages i find on spotmeter is the option to be adaptive for film capabilities. For slide film the maximum contrast differential is 5 EV stops, for negative 7 EVs. There's no way you'd know it with simple reflective light meter in a bit more difficult conditions to choose the proper exposure time. And with separate spotmeter you may always sum the reading results over the picture to reproduce the simple reflected light meter even more precisely for your needs (you may choose your own custom summing spots). I shoot fully manual medium and large format and search for the higher image quality, thus no hurry anyway to get all done with one button push as dominant digitals and 35mm do.

Margus