A ring has two size markings in millimeter such as 28mm-37mm, 49mm-52mm, 77mm-72mm and so on. The first number is the size of the thread that is closer to the camera lens (i.e. , the male thread), while the second is the size of the thread of the farther end (i.e. , the female thread). Therefore, a step-up ring with marking 43mm-49mm means the male and female thread sizes are 43mm and 49mm, respectively.
Some forms of ordination analysis, classical or canonical, are widely used by palaeolimnologists. as tools in the handling, summarisation, and interpretation of palaeolimnological data, either modern assemblages or. core fossil assemblages.
Task analysis is also studied in relation to group support systems (GSS). This type of analysis does not focus on the study of all tasks, but on those tasks typically encountered in organizational decision-making groups.