Sunday, April 1, 2012

Light Metering With The HS20 Pt 1 .. general scenes

I've fielded a number of queries recently in regard to my advising not to use The Multi metering setting when taking a photo with the HS20.
I found early on in my use of the HS20 that the results from using "Multi (pattern) metering aren't particularly accurate. Its also one of the main reasons (but by no means the only one) for so many incorrectly exposed images when people use it in Auto or EXR Auto modes.
Essentially multi metering should provide the best of both worlds for tricky lighting conditions to give the most balanced light/shadow. Unfortunately this isn't the case, and I wish it wasn't as it would help immensely with some of the shooting conditions I find my self confronted with.
We have been most fortunate lately to have had some very nice clear Autumn weather. Big blue skies, lots of light and contrast. So while sitting in the truck contemplating nothing in particular ( I get to do a lot of that in my job), I noticed this scene and thought you might like to see the results.




I set the camera as follows:
Image Format 3:2
EXR HR @ 16mp
0.00Ev to start, and let the camera do everything else as far as shutter speed & f-Stop is concerned.
DR100% and ISO 100.
White Balance - Auto.
The part of the scene I choose for the first test series is the sign seen at left in the above image.There is a lot of differing light variables both with the sign and its surrounds.
Point of focus is the yellow chicken.
-0.33 spot metered




-0.33ev multi metered


-0.33 Averaged metered
At first glance there doesn't appear to be much in it at this point and all these images would be useful prints. There are however a few clues and when you look closely they are evident although very subtle. Checking the Histograms in Lightroom agreed with the in camera histogram s well. Correct metering is the "Averaged" setting. In the averaged image the background behind the chicken is more accurate in color, there's less highlight blowout on the white part of the sign, and the blue baling cord isn't showing as much blown highlights as the top two images.


Tip: For those new to the HS20 when you review your images in camera, press and hold the AF C-S-M button on the left of the camera body, this brings up the Histogram and other associated info for the image. One very important component of this is the highlight indicator. If a region of the image is overexposed this portion of the image will blink on and off to highlight the problem area. This is the best way of telling if your exposures are good. I use this process all the time when needing instant feedback from the images.
Now back to the above images, all the images when reviewed in camera showed over exposure of the white part of the sign, the "Averaged" image showing a small amount  compared to the two other modes.
So how would it look at -0.67EV?


-0.67ev multi metered
0.67ev spot metered
-0.67ev averaged metered
Again its close and again the "Averaged" is the closest to being correct. In camera review showed slight over exposure on the white sign but nothing else. The spot setting was considerably off and the Multi image was very close to the Averaged but showed more blown highlight in the white sign and the bars of the gate still show slightly blown as well. For this test apart from the one spot metered image they are all very close and handled the scene fairly well.
You will have heard me say that when using Spot metering you need to use + EV and that when using average  metering use -Ev. The images above give a fairly good indication of why I've said this in the past.
Note too that I have not processed this images they are exactly as they were shot straight from the camera.
In Part 2 we will examine a scene that has more concentrated highlight areas and see how the camera performs. 


Light Metering with the HS20 .. Pt 2

3 comments:

  1. Very interesting take on metering. I will take a look myself and compare the differences. Thanks for the post.

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  2. Hi Santo

    Yes I found it interesting too, especially when shooting in EXR Auto mode. The exposures were all over the place. I have a suspicion that the camera selects multi metering for most situations as its trying to cover the whole range. Sometimes its better to rethink how the shot should be taken and select accordingly.

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