Friday, April 13, 2018

Getting accurate exposures with the Sony A7M3

1/1600 sec. at f7.1 and 100 ISO - Easter Sunday sky
Coming from the A700, A77 and A7, I've noticed loads of improvements in the Sony mirrorless segment since October 2011 and December 2013 with this newest camera, the A7M3.

Today I want to touch on three points regarding picture quality. One is especially important if you want to shoot JPEGs. There have been improvements in the white balance menu and settings.
I nearly always have my white balance set to "Automatic" (AWB) because when shooting RAW you usually change the colors a bit while post-processing anyway. And yet Sony realized that shooting inside as much as you would with such a high-ISO monster, you might want to tell the camera's computer exactly what kind of automatic output you prefer. So they have come up with a way to prioritize the tone when shooting under certain lighting conditions. You can have the traditional AWB working; you can prioritize the ambient lighting (creating a warmer color cast); or you can set it to "white", resulting in a cooler tone. I think this is a great tool!

1/30 sec at f6.3 and 4000 ISO - the Freiburger Münster
Furthermore, there are 16 different white balance pre-sets, all of which you can tweak to your heart's content - more red, more green, blue or yellow. When shooting JPEGs, set your white balance to the room's light temperature by pointing the camera at a white piece of paper that is lit with the same ambient lighting as your motif. While your camera is set to the "Custom Setup" function (the last one in the WB menu), take a shot with the center circle pointed at the white paper. Then assign that specific WB to one of the three custom WB settings and you are good to go - until you move into another room or someone turns off the lights and decides candlelight is more romantic!

1/30 sec. at f4 and 1250 ISO - Brass workshop
Second, there are two settings that help you nail the right exposure on the motif in your picture. The first one detects the brightness on faces in your shot when your metering mode is set to "Multi-segment", which is the setting you'll normally want to use. That setting together with the spot metering coordination seem to be very helpful tools when shooting events with tricky lighting situations (bright lights in the picture, backlighting, etc.).

Spot metering is the way digital photographers measure the amount of light needed for a perfect exposure on the chosen motif. No longer do we have to run up to the model or mountain top and hold up a lighting meter to get a good reading of the exposure! This camera can pick a spot and determine how much light is needed for a normal exposure. With the new A7M3 you can coordinate the spot metering point with the focus area even when it is not in the middle of the focus area.

Below is an example of a situation in which I wish I had still been shooting either with both RAW + JPEG or in the spot-metering mode. My cards were filling up, though, and I was taking fast sequences of shots of these birds, so I switched to JPEG only. Unfortunately, the beautiful dark feathers of this hawk were no match for the bright background, which the camera also figured into the "Multi-segment" metering equation.

1/3200 sec. at f4 and 100 ISO
As with the A7, I've had situations where the A7M3 took an absolutely wrong reading of the light and overexposed the scene by a whole stop or two. I never had that with the earlier cameras. However, the electronic viewfinder lets you know immediately that the exposure is wrong. My experience shows that this usually happens after you have just turned on the camera and want to take a picture right away.

So you can set both the exposure and focus areas for the shot you are about to take. Speaking of the focus area, you can set the camera to prioritize focusing on faces when in the wide or zone focus area settings. That's often a good idea when you are shooting people in landscapes, but look what happens when you aren't!

Both photos were taken at 1/640 sec., f5 and 400 ISO - Sea lion feeding time at the Wilhelma
Here is, of course, what I really wanted to focus on:


Finally, for those of you who don't want to guess which exposure might be best in the end, you can set the drive to "Bracket". Now this is nothing new except that Sony has now expanded your bracketing capabilities from three or five images to nine! Together with the 14-bit uncompressed RAW files, this ability to capture a nine-image series of varying exposures will enable you to put together some incredible landscapes! On the other hand, I have seen few situations where I've needed the bracketing. A RAW file is so flexible that you can usually brighten the shadows and tame the highlights to have as good a result as a three-shot, four-stop bracket could give you.

1/500 sec. at f8 and 320 ISO - Vineyards in Rotenberg










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