Matrix vs CW vs Spot metering

[greg_barnett]

Hi there,

I just got back from a trip to Hawaii where I was taking pics with my

Fm3a. I was shooting slide film but was disappointed with the results

although I love using this camera. The majority of what I was

shooting is over exposed.

 

Now I expect a lot of this is my metering technique with using that

cameras CW meter. In the past I have used my F4's spot meter and got

ok results. But I find it harding picking out the midtone with the CW

meter. Not to mention I often hesitate as to what actually is a mid

tone or slightly either side.

 

But a friend and pro photographer suggested I take advantage of my

F4's matrix meter instead and see how I go with that rather than use

the FM3a. The part I am confused about is this. With the spot meter I

am used to finding a mid tone and metering that in my scene or

metering another tone in the scene and adjusting accordingy. I'm

certainly no wiz at this but I get the basic idea of it. But with the

matrix meter am I expected to do the same sort of compensation or am

I basically pointing and shooting?

 

Hoping someone can give me some pointers on this area.

 

Many thanks!

 

Greg.

[saikat.pathak]

Read John Shaw's "Nature Photography Field Guide" to clear your confusion. Using spotmeter, you decide which tonality to use for which part of the image in a more controlled manner imho. Whether the selected part needs to necessarily be placed at midtone, depends on the tonality of that part. You don't "have to" fined a mid toned subject everytime. Take multiple spot readings from the same scene and arrive at the exposure which best suits the dynamic range of the film being used. Or take a single spot reading of the main subject and decide on which tonality level you need to put it in to match its actual tonality.

 

If all these sound too confusing, read the above book which does an excellent job in explaining this. There are multiple web resources on spotmetering and also on this site. Do some search.

[photo5]

I've shot slide film since 1983. In 1987 I took a trip to Carmel, California and the many of the slides I shot with my Nikon FE2 were overexposed. I usually expose ISO 100 slide film at 125, and remember I used to shoot Kodachrome 64 at 80, and Kodachrome 25 at 40. I like more saturation. Of course, with negative film it is the opposite. I shoot Fuji NPH 400 at 250, and Fuji NPS 160 at 100.

 

I always use Matrix metering in my F100 unless I'm shooting with a manual focus lens which won't work with Matrix. I find the center weighted metering on my F3 to be just as good as the 10 segment Matrix metering in most cases. Sometimes I feel as if I have more control with center weighted too. Spot is something I don't use too often but I can think of times I should try to use it more often.

 

Dave

 

Dave

[david_h._hartman]

Greg,<br>

<br>

I traditionally used CW with slides and a hand held spotmeter

with B&W. Ive always found CW very good for shooting

slides. I learned the zone system and use a simplified version

roll film cameras. This helps me a lot when using CW even though

I'm not shooting a zone system with slides. Color print is very

forgiving if you use a realistic ISO speed. I use an EI of 0.5x

ISO. This is because the dynamic range of most subjects I shoot

exceeds the ISO test perimeters.<br>

<br>

Matrix vs CW vs Spot metering? This is all about knowing your

camera, its metering systems and using it to the best advantage. I

use or used CW with my Nikkormat FTn, F2(s), F2As(s), FE2(s), F4

and F5. The early cameras had Cds meters and they react slowly in

low light and remember bright light which can cause under

exposure. The Cds meters seem to be calibrated a little

differently, camera to camera. <br>

<br>

I have absolutely no complaints about the SBC (silicone blue cell)

meters and center-weighted metering with the F2As through F5

excepting the F4 for macro with slow setups, slower than f/5.6. I

often use matrix with my D2H, that or hand held meters.<br>

<br>

I do not care to switch metering type in the camera. Its

much easier for me to use a hand held spot or incident light

meter. I also skip the problem of thinking Im shooting CW

or Matrix and finding I was shooting something else, worst of all

spot. This last item is a matter of simplifying to avoid errors.<br>

<br>

Best,<br>

<br>

Dave Hartman.

[robert_k1]

For shooting chromes with static subjects, I use spot metering almost exclusively (as taught by John Shaw and others). It is the only way I know to capture the highlight details in chromes. A Fujicolor lab manager once told me that he was amazed by how my chromes are exposed correctly, and how the other customers' end up with blown highlights. Not sure if he was stating the fact, or just trying to pacify me.

 

There are two situations that I have to switch from spot metering to matrix or CW. One is when I don't have time to spot meter on a moving subject. The other is when the light is too low for the spot meter to be active.

[greg_barnett]

Thanks everyone, this is some really helpful info. I've actually been going through John Shaw's Close Ups in Nature for some tips. The thing I find interesting. In that he seems to be using an F3 with CW metering and anywhere he talks about metering it seems to be based on pointing the CW area at an area that is all of the one tonality and working from there. He doesn't state this as such but all the example images fall into this category.

 

But from the responses here I got the impression that you are pointing the CW area but what you point at may not necessarily be uniform in tonality. Is that where you then use the zone system Dave H. ?

 

Dave Lee, interesting your comment about how you set your film speed to 125 etc. I compared my metering of my FM3a to my F4 and it seems the Fm3a is about half a stop different, so perhaps just some calibration will go along for me solving my over exposure issue.

 

All sounds like some good opportunities for some tests.

 

Many thanks again folks.

Really appreciate it.

 

Greg.

[cepie]

I don't think a CW should be used like a big spot meter. This might explain your overexposures.

 

A spot meter measures a small area in the center of your frame. You can either point it on some mid tone object and lock it or use some 'zone' approach and place a light object on VII.

 

A CW meter does what it says: it meters the _whole_ frame, right to the corners. A rather big chunk of the center area is typically slightly more important (60%) than the edges of the frame (40%). It still measures and averages the whole frame. Unless you are able to fill the whole frame with your mid tone object this is not going to work. Just point your CW meter somewhere where there are light and dark objects; they will even themselves out. For landscape just point the meter at the horizon (I normally place the horizon about 2/3 up) and use this value. Of course, you have to compensate if there isn't light and dark in equal proportions (e.g. snow, or in the woods, indoors).

 

The F3 is a different beast because the meter has almost spot characteristics, same with a Leica M6 for example.

 

Select a nice object, e.g. a view to a landscape. Get a reading with your F4 matrix (don't compensate, don't lock, just point it to exactly the view you want on the picture). See where you have to point your FM3a to get the same reading.

[greg_barnett]

Hi again,

 

I was just going through all my pics again from my Hawaii trip where so many of the shots are overexposed and something occured to me...

 

I was using my 20mm f2.8 AF, 50mm f1.4 AI, and 180 f2.8 AF.

 

Occasionaly I used the 180 on a 52.5mm ext tube. Looking through the pics, the ones that are by far exposed the best are the ones that were taken with the 180mm and the ext tube. I'm just thinking with regards to the tube taking away a stop, could this indicate something I am doing wrong in my technique to get most shots wrong except the ones on the tube?

 

Just a thought.

 

Thanks again.

Greg.

[steve_ql]

Every camera works differently. I would prefer to experiment with

shots to understand a camera meter before a trip.

 

On the three F100 samples I've worked with, the Matrix meter

tended to underexpose in order to preserve highlight detail

on slide film (i.e. high contrast range shots including sky

resulted in

properly exposed sky and loss of shadow detail).

With the limited contrast range you can capture on

a transparency, if you meter for the midtones, you'll still

get slides showing blown highlights since they fall outside

the range that can be captured on slide film.

One thing you can do is select your shots

to include scenes of limited contrast range which can all fall

within what's capturable on slide film.