ESP vs Spot Metering?

So I'm familiar with the basics of ESP vs Spot.   But I am more curious to know the nuances of spot metering (especially on the TG series).

Can you achieve identical results between the two by merely adjusting EV?  Or does spot metering do other hidden things under the hood?

- Does spot metering have different focus method (relative to ESP)?
- Will spot metering result in a different AWB calculation?
- Will spot metering affect contrast?

Also does  spot metering affect the black point?  When I change the EV, usually the blacks stay black.   But this doesn't make sense if I'm changing SS/ISO/A.  Shouldn't the blacks change to say a dark grey with more light?  I assume then that Olympus changes their contrast algorithm to compensate for what the sensor provides.  If this is the case, then do black points change for spot metering?

smithaa02 wrote:

So I'm familiar with the basics of ESP vs Spot. But I am more curious to know the nuances of spot metering (especially on the TG series).

Can you achieve identical results between the two by merely adjusting EV? Or does spot metering do other hidden things under the hood?

It depends on the scene lighting. ESP mode meters at the center of the scene and applies a slight bias towards the light value found there. But, it also evaluates the rest of scene and attempts to come up with a exposure to balance the brightest areas with the darkest ones. If the scene has perfectly flat lighting, the ESP and Spot metering values will be pretty close. It doesn't make any sense to use spot metering then change exposure to the evaluative value.

My problem with the TG series spot metering mode is it uses a fairly small area. I only use it when it makes sense. Wished a center weighted mode was offered.

Why would you think spot mode changes other parameters? It's just limits where light levels are measured.

- Does spot metering have different focus method (relative to ESP)?

No, the 2 functions are independent of each other.

- Will spot metering result in a different AWB calculation?

AWB attempts to determine the color temperature of the light source. It needs to evaluate the entire scene. But if metering causes clipping in any of the color channels, white balance calculations will probably be corrupted.

- Will spot metering affect contrast?

No

Also does spot metering affect the black point?

No, that's a function of the JPEG engine. It doesn't care how the scene was metered.

When I change the EV, usually the blacks stay black. But this doesn't make sense if I'm changing SS/ISO/A. Shouldn't the blacks change to say a dark grey with more light? I assume then that Olympus changes their contrast algorithm to compensate for what the sensor provides. If this is the case, then do black points change for spot metering?

If you use positive compensation, the blacks will move up in level. It's a global adjustment. But the JPEG engine will squeeze those darker values into a fairly small range of the tone curve. Again, the JPEG engine doesn't consider what metering method was used.

metering area to follow focus area location.

Not sure about your model. I actively change metering from center to spot, and have my Stylus 1 set so spot metering area location automatically follows wherever I move spot focus to.

In addition, because I shoot shutter mode so often, I find having AEL set up on a rocker/button a big help. I simply aim at a brighter/darker area, choke/open exposure, lock it, back down to my subject.

elliottnewcomb wrote:

metering area to follow focus area location.

Not sure about your model. I actively change metering from center to spot, and have my Stylus 1 set so spot metering area location automatically follows wherever I move spot focus to.

That's not a option with the TG series. When Face Priority a enabled, a slight exposure priority is assigned to the area(s) where faces are detected. However, the entire scene is still evaluated for exposure.

In addition, because I shoot shutter mode so often, I find having AEL set up on a rocker/button a big help. I simply aim at a brighter/darker area, choke/open exposure, lock it, back down to my subject.

There's no shutter priority mode (or manual exposure) on any TG. And, with a limited number of buttons, there's no seperate AEL option or the ability to reassign button functions.

Enders Shadow wrote:

elliottnewcomb wrote:

metering area to follow focus area location.

Not sure about your model. I actively change metering from center to spot, and have my Stylus 1 set so spot metering area location automatically follows wherever I move spot focus to.

That's not a option with the TG series. When Face Priority a enabled, a slight exposure priority is assigned to the area(s) where faces are detected. However, the entire scene is still evaluated for exposure.

In addition, because I shoot shutter mode so often, I find having AEL set up on a rocker/button a big help. I simply aim at a brighter/darker area, choke/open exposure, lock it, back down to my subject.

There's no shutter priority mode (or manual exposure) on any TG. And, with a limited number of buttons, there's no seperate AEL option or the ability to reassign button functions.

On my pocket zooms I also have no shutter priority (SH-50 and SH-1). I do have manual exposure, which permits me to change ISO, shutter speed and aperture, with the EV indicator telling me how far off I am from the correct exposure.

With spot-metering on stills it is very rare that I am so far out so I cannot correct in PP. I mostly use spot-metering for the moon.

For following a cruise ship out of the harbour on video, spot-metering causes the sky to brighten and darken as the ship goes with the shaded side towards me to the sunlit side towards me. Same thing happens with flying gannets moving in and out of the center spot when using spot-metering.

My understanding is that while the TG series does vary from my SH-series pocket zooms in the way lighting is metered, in my opinion ESP is still preferable for shot-to-shot consistency in still photos.

Henry