Do You Center The Meter?

[smoke665]

There was a comment in another thread that led me to do a little experimenting with my camera. I discovered that when using camera spot meter, if I center the meter, I'm still about 1 to 1-1/2 stops short of a full exposure when viewing the histogram.

Do others experience this? Do you compensate by overexposing according to the meter, or do you adjust it post? Theory behind your choice?

 

[The_Traveler]

Everything depends on the nature of the 'spot' you are metering. Use exposure compensation to adjust the exposure to put that spot where you want on the histogram.

 

[smoke665]

Everything depends on the nature of the 'spot' you are metering. Use exposure compensation to adjust the exposure to put that spot where you want on the histogram.

I agree, but the other thread that started me checking, has me wondering now if the camera manufacturers are adjusting the meter readings to a properly exposed JPEG and not a full sensor.

 

[fmw]

The Traveler has it right. Meters are designed to render a 15% gray subject at proper exposure. Spot meters are normally used to measure dynamic range by comparing readings between shadow and highlight. If you put the spot on a shadow, the meter will recommend an overexposure. If you have enough experience to recognize what would be a 15% gray area in your subject, then placing the spot there will expose that area and probably the entire subject correctly.

In other words using a spot meter requires practice. Spend some time comparing various results with the spot meter to the matrix meter. In time, it will all come together.

 

[smoke665]

a 15% gray subject at proper exposure

True, but is that a proper exposure for a JPEG per the camera manufacturer internal software - meaning it's hedging on a full ETTR?

 

[KmH]

The file type does not matter.

Plus, being a mass produced product, each camera's meter will perform a little differently based on how accurately the meter was calibrated on the assembly line.

Note too that Nikon DSLR cameras have color -aware metering.

 

[Gary A.]

Meters, all meters will calibrate to a medium gray, a gray card, (12%-18% gray). (Internal software adjustments notwithstanding.)

If you sample a black wall, center the needle, the wall will come out medium gray. If you sample a white wall, center the needle, the wall will come out gray. If you sample wall that is similar in density to a gray card, your wall will be perfectly captured.

Using Spot, you need to understand how the meter reads. If you Spot a white person's skin, you have to open up a stop to a stop and a half to compensate for medium gray, (as white skin is lighter than medium gray), and to attain a 'proper exposure'. If metering off a person of color's skin, you have to underexposure to attain a proper exposure.

When using Spot, you really have to look hard at what is in the 'spot' then adjust accordingly, using medium gray as a reference, (either overexpose for a subject lighter than medium gray or underexpose for a subject darker than medium gray).

Spot is great for landscapes and architecture and studio work when you have time to sample different areas and find a happy exposure that doesn't clip highlights or shadows (if that is what you desire). Spot is great in a fluid/changing environment when the subject is vitally important and the other elements in the image are secondary (photojournalism).

When I use Spot, (some 90% of the time), usually I'm in a fluid environment action situation. If I am waiting for the subject I'll meter off a known substance, like grass and close it down a stop or two, a street lamp, road top, et cetera and adjust accordingly, then when the subject arrives I'm in the ballpark ... and I can shoot confidently with my original setup exposure or if I have time I can sample the subject and tweak the settings to fine tune the exposure. If the subject is a person, I'll look for something medium gray on the subject and compare that reading to reading a skin tone plus a over/under adjustment for skin coloration.

My techniques can be used with any metering mode, but with Spot you know exactly the zone/density of the sampling.

Meters are guides and are not to be taken literally.

 

[KmH]

Meters are guides and are not to be taken literally.

Yep.

And is why many photographers use a hand held meter so they can not only meter reflected light but also incident light and strobed light (flash).

 

[Gary A.]

Everything depends on the nature of the 'spot' you are metering. Use exposure compensation to adjust the exposure to put that spot where you want on the histogram.

I agree, but the other thread that started me checking, has me wondering now if the camera manufacturers are adjusting the meter readings to a properly exposed JPEG and not a full sensor.

" ... not a full sensor ..."?
I could be wrong, but if I recall correctly, there may be a slight exposure difference between RAW and JPEG.

 

[Gary A.]

Meters are guides and are not to be taken literally.

Yep.

And is why many photographers use a hand held meter so they can not only meter reflected light but also incident light and strobed light (flash).

Lately, with my EVF cameras, I've been getting lazy and adjusting the setting per the EVF.

 

[Braineack]

I discovered that when using camera spot meter, if I center the meter, I'm still about 1 to 1-1/2 stops short of a full exposure when viewing the histogram.

the spot meter, as described, meters a small area...
the histogram, displays the content of the entire capture...

how are you using a histogram to tell you you're under exposed?

if you spot meter on the only light source in a scene, i'd expect a HEAVY left-weighted histrogram -- doesn't mean you're underexposed, just that there's a lot of black in the capture, since you exposure for the light.

 

[fmw]

a 15% gray subject at proper exposure

True, but is that a proper exposure for a JPEG per the camera manufacturer internal software - meaning it's hedging on a full ETTR?

It isn't hard find out.

 

[smoke665]

Meters, all meters will calibrate to a medium gray, a gray card, (18%-22% gray). (Internal software adjustments notwithstanding.)

You'd think but I'm beginning to wonder. Centering the meter gives a useable exposure for both JPEG and Raw, it just seems like it consistently stops short of a full sensor exposure.

 

[table1349]

Most DSLRs have meters calibrated t0 approximately 12% gray. That is the reason for more and more gray test media being made of 12% gray material. The differences between 12% and 18% are not much.

 

[Braineack]

You'd think but I'm beginning to wonder. Centering the meter gives a useable exposure for both JPEG and Raw, it just seems like it consistently stops short of a full sensor exposure.

but where are you aiming the center spot at? that matters -- you're only exposing to that spot...