Getting more from you sensor
There is some discussion about getting it right in camera or post processing. If you have read my previous posts, some have been about taking the shot and some have been about post processing. Today I am going to start the discussion with jpegs. Olympus (and the latest Panasonics) make some excellent jpegs in the right conditions. There are also many comments about a new sensory while many photos do not even use the potential the sensor we not have has. This is about getting more from your sensor for those who care. I am trying not to be too technical, but the reasons for doing things are technical by nature. This is not meant to be everything as there is a lot on information about ISOs, color setting, art filters, etc. This is meant to touch on some basics I do not often see discussed or see people comment why did you...
Jepgs:
Jegs are 8 bit. You will want to set the color space to sRGB for jpeg shooting which is the 8 bit color space. This means you have levels of each color. A lot of people shoot at the native ISO of 200. Many photos do not use the whole dynamic range this allows. If you look at the histogram, you will often see it does not reach the dark or light areas of the histogram. By compressing the dynamic range you have less contrast. Also as there is less color information as instead of 256 levels of each color you may only be using 150. This is first step towards getting more from your sensor to make better jpegs. When you have a limited histogram, change to Low for ISO. The 100 or 69 ISO change the curve of the colors and luminosity. Instead of the S Curve that keeps more highlights and shadows, you have a more straight line. This means the highlight are bright, the shadows darker and there are more colors. Since each RGB channel has more levels color, when they are combined to make colors, you have more colors. While the jpeg engine does fairly well at preventing banding, having the more colors to work with smooths the whole image out and does far better at preventing banding. This also helps with RAW as the stretched range gives you more information to work with in post processing.
There are other in camera settings for jpegs. One which really make a difference is the shadows and highlights. Many people if they use this use it to raise shadows or lower highlights. However, if you look at the histogram and it is flat or rounded in the middle and tapered off at the ends, you may want to use the highlights shadows adjustment to make a more dramatic image. You can increase the highlights and lower the shadows. This gives the whole image a more dramatic look.
Most of the color settings, contrast, sharpness, and saturation are already pretty well explained and are about making the shot yours, rather that some programmers who wrote a program for the camera. One thing I would like to point out that is excess saturation and eliminate detail. Many of these adjustments are about eliminating detail and lowering dynamic range (to make a more dramatic photo). If you are not doing doing forensic photography, you do not want the most detail as this creates a flat boring photo. The reason I mention saturation as it often removes texture from a subject. I find this seems to happen fairly quickly in the reds in Olympus cameras. Sometimes lowering the saturation and increasing the sharpness and/or contrast in vivid still gives bright colors and maintains some detail in flower petals, dresses, etc. Since most jpegs are meant to be shared via online displays and the number one way of viewing photos is on a cell phone the sharpness does not show the artifacts it would in prints or on 4K TVs.
Another setting for jpegs many people do not use it filter bracketing. Shooting with filter bracketing, you have a variety of looks and can chose the one that matches the photo. You do not have to change for every shot, you just shoot and chose later. When doing this, it helps to turn off the filters you do not use and chose just a few looks you like. Although if you are new to this, you may want to take some shots bracketing with many filters to see what the looks are.
Often some people think post processing is better. While I do post process every photo I do because they will either be printed or seen on a 50 to 80" 4K TV as a slide show, for many people it is not required. If your photo will be looked at for a couple seconds by everyone who sees it on social media, it makes a lot of sense to shoot and post jpegs. By using your camera settings, you can still make your jpegs stand out from most of what you see.
RAW:
RAW is somewhat easier. First shoot RAW in Adobe RGB so you have all the info that comes from the sensor. Especially if you transfer TIFFs from one program to another. It appears to me that the full info is in the RAW either way. However some programs see the sRGB and limit the colors when you save or export the file. If you shot in sRGB, I am not sure just when the program changes it from the full RAW to 8 bit. I can see the results in the output file are different than what I see on the screen editing. So I tend to think it is later in the process. Most programs (I have not used all) you can set up the export to sRGB and still your project will have all the color information when you come back it if you save it as tiff or PSD (which seem to be the same size). If you do not export, but save a jpeg (which makes a bigger file as it retains the exif usually) it will be in the color space you used and the device displaying it will be sRGB which will not be a good look. Just so I do not forget when I want to keep the exif for some sites, I made a save jpeg action which does the SRGB version. This way I can export for facebook and instagram and save for the sites that display the exif.
Now for maximizing your sensor. A lot has been written about ETTR. For processing RAW, you want the most information from the camera possible. Getting it right in camera is great for jpegs (and necessary). However to post process that is not the goal. The RAW with no adjustments will look flat and less sharp than more SOOC jpegs. The more information you have to work with the more you can do in post. Different cameras have different bit depths of color. Often it is 12 to 14 bit with m43 cameras. Back has a zero level. White is the maximun level (4096 for 12 bit, 16,384 for 14 bit). This of course far exceeds the dynamic range of the sensor. However using Adobe RGB 16 bit color space allows for using all the colors and keeping all the info when processing that may push the colors or add colors to the original image. Just because it is easy, I am going to use 12 bit color in my explanation. If part of the image is in the lower quarter of the histogram, then it is using 3 bits. This is 3 bits of Red, Green, Blue. Which is 8 levels of each RGB channel. For the 3 colors (RGB) combined to make the other colors you have 512 available colors. White is white, so I will ignore it. Now lets look at something in the top quarter of an image. This would be 9 bits for each RGB channel. This is 512 levels of each RGB channel. When the channels combine to make the actual colors, this gives 134,217,728 colors. When you raise the shadows or a dark photo in post, you are still limited to the 512 colors that were recorded. You can see this very easily in any photo you process the shadows have less color when raised. ETTR (exposing to the right) even to add 1 bit of color depth to each channel gives 8 times the number of colors. To get the most info from your sensor it helps to do ETTR shooting. The point that needs to be added here is I do not use auto ISO because raising the ISO creates other issues. By using ETTR, and a longer shutter or bigger aperture, we also allow more light to enter the sensor. This improves the signal to noise ratio. Another way of saying this is "it lowers noise." ETTR can be done with histogram or the highlight shadow warning. I actually find for myself, the highlight shadow warning works better.
The next topic to discuss about maximizing you sensor is dynamic range. While Robin Wong did a nice video on how far you can underexpose or overexpose, I find 2 stops to be a conservatively useful amount. This means if the dynamic range is beyond the sensor the histogram, I set recover 2 stops of highlights and shadows if I center compensation the image. Depending on what percentage of the shot is highlights and what percentage is shadows this may look as bad in SOOC as ETTR does. I do not care, because I am shooting the best results after processing. A really useful place to know this is portraits outside. The highlights and shadows can do this sometimes. The highlights and shadows have set curves. By using graduated filters to the side of the image so there is no graduation, you can use the range mask to tune it more precisely. I make a +2 and -2 graduated filter and then use the range mask so one applies to shadows and one to highlight. Effectively getting all the data the camera can capture in a single shot. If you use Photoshop, in Lightroom make a +2 exposure and a -2 exposure and The Edit In>Open as Layers in Photoshop. Now you can use the blend if instead of the range mask. The range mask has 2 sliders. The Blend IF, you has 2 additional adjustments to smooth the edges of the effect so you can fine tune the transition
In bright light (weddings early afternoon, etc) spot meter the face and dial in minus 2 exposure compensation. This will get most highlight possible while keeping the face good. You can then increase the exposure plus 2 in post with a graduated filter to side of the photo does it globally, but the range mask works to prevent it from being applied to the highlights. Then pull the exposure minus 2 with another graduated filter to side of the photo and a range mask to only apply to the highlights. You may need to do a brush on graduated filters to fine tune it. But usually that is not needed. Besides the sky, it also brings back details in white dresses, etc. Both of these uses utilize the full dynamic range of the sensor.
Many situations do not require the full dynamic range of the range. In these situations and good light using Low ISO really helps photos. This is not to recover black and whites as it uses a different tone curve straight from the sensor. However, when the you do not need to recover highlights and shadows, the different tone curve does some nice things. It does open the aperture or give a longer shutter speed improving the signal to noise ratio. It also does less to the data from the sensor. At the normal ISOs the sensor data is flattened to get all of the dynamic range into the image. At ISO 100 or 64, the data is not flattened. This gives more contrast. Also because it is not flattened the image has more levels of each color. I just mention this here in case someone skipped the jpeg section. If you are shooting at ISO 200, you might want to try low ISO to see the look. While it is really helpful for jpeg shooters, it does add something for people who post process although usually not as dramatic, the difference is there.