JPEG

Macro Photography is all about capturing small subjects, or small parts of subjects, at high magnifications. 1:2, 1:1 (life size), 2:1 are some of the magnifications you will come across in the macro photography world. Life size or 1:1 magnification means that the subject you are going to photograph would appear on the sensor at its actual size. And a 2:1 magnification is when the subject appears twice its actual size. If it appears half its actual size, it is called a 1:2 magnification ratio and so on. In this post I would like to share some techniques to be followed before post processing macro photographs. Two things you should do before post processing macro photographs 1) Shoot in Raw Try to shoot in RAW if your camera offers RAW file format. It has lots of advantages over JPEG format which I am going to explain now. When CMOS sensor is exposed, the imaging sensor records the amount of light that hit each pixel. This is corresponds to a voltage level. Now, it changes the analog signal to a digital signal. Digital Camera records 12 or 14 bits of data depending on the circuitry. These 12 bits and 14 bits data records different brightness levels. That is, in 12 bits of data, each pixel can handle 4,096 brightness levels, and, 14 bits of data can record 16,384 brightness levels. To put it simple, a 14 bit RAW file carries more information than a 12 bit RAW file. Saving the JPG File When you use JPEG file format for capturing, here's what happens:- Image sensors are liner devices. So if twice the amount of light hits a pixel, then it will generate twice the voltage. Since brightness values are rendered logarithmic, an un-processed image appears very dark. To solve this, tone curve is applied to the data to recreate a natural looking scene. When you take photos in JPEG format, the camera process the files before you preview them in the LCD. But camera does nothing to a RAW file. So RAW files are not sharpened, or applied any contrast by the camera. So they look soft and flat. Camera applies unsharp masking (USM) to the JPEG images so that they will look good. What USM actually does is it finds the edges between light and dark regions in an image and increases the contrast. This process generates halos around these edges. If sharpening is set too high, these halos will be visible in a final print, which is bad. If they are set too low, then sharpening may be insufficient resulting in soft images. Digital cameras usually have between 1 -3 different sharpening settings that a user can choose. There will be two or three setting levels for color saturation in some cameras. So the saturation level in your photographs will vary according to them. When we press the shutter, it will capture the image in 12 or 14 bit mode. Then, it is converted into a 8 bit mode. Otherwise, each pixel records 256 brightness levels instead of 16,384 brightness levels. Compression is the final setting for a JPEG file. Generally, it is considered as a lossy format -- It will reduce the size of an image and so some data will be lost. We can minimize the data loss if compression is set to a low level(2:1). Most cameras offer at least two or three compression levels. Why you should shoot RAW? The main advantage of shooting raw is that if one has a 16 bit image, it is very easy to process the image. This is opposed to a JPEG file's 8 bit space with just 256 brightness levels available. So there will not be any flexibility in processing the image. It is very important when editing an image, particularly if you are trying to open the shadows or alter the brightness in a standard way. You can find out the difference when you try to process the both JPEG and RAW images (see the comparison below) It’s very difficult to post process the image when it is captured in JPEG file format. You will find more grain when you add a little sharpness, and it looks blunt when no sharpness is added. So I always prefer shooting RAW not only for macro photography, but also for any kind of commercial shootings; because, it will be useful to print in large size format without compromising the loss of image quality. 2) Set a Low Level Contrast and Color Saturation in your Camera My suggestion is to set the contrast and saturation to a low level in your camera (Please refer your camera's manual for this). I will explain the reason in detail. Color saturation is the strength of colors in a photograph. It specifies the amount of gray in proportion to the hue. For example, a picture with poor color saturation will look washed out or faded. When a color's saturation level is reduced to zero, it becomes a shade of gray or monochrome. So, you will not see gray if the saturation is high. If it’s overused, photographs become unrealistic. So it is better to adjust the saturation during post production. Contrast in photography is the difference between the darkest and the lightest regions. It can be either high contrast, which is the extreme difference between dark and light regions, or low contrast where the difference is less. If contrast is increased, it will make shadows darker and highlights brighter. Improper contrast adjustment may result in loss of details. Improper contrast adjustment may cause loss of details. So, the right choice of contrast can be applied during post processing the images. So, saturation and contrast are always kept in low-level in your camera. Details on the image will be lost because of deep shadows and spooky colors. I always prefer the 'faithful' picture style in my camera for macro photography. So, editing the image becomes very easy and flexible. If you let your camera do this job, you cannot control the level of adjustments it makes. Recommended Softwaresfor Macro photography Below are some image editing softwares I recommend. Quick post processing software: Lightroom 4 or above. For any kind of advanced post processing Adobe Photoshop CS4 or above Photoshop Elements. Focus stacking Software Helicon focus(highly Recommended) Adobe Photoshop CS5 or above. Zerene Stacker I hope you will find these tips useful. I would suggest you to follow this before post processing any photograph. Read my Post production workflow: Step by step photoshop tutorial on post processing a macro photograph Other posts on Macro Photorgaphy 10 tips to shoot macro droplets on flowers Introduction to macro photography with some examples