Chapter 7 Tips on Photographing52PhotographingBasics of DS-L3(2) Setting the field diaphragmAdjust the field diaphragm so that it circumscribes the viewfield. The field diaphragm has a significant impact on contrast,especially for fluorescent specimens against dark backgrounds.Note: For how to adjust the field diaphragm, refer to the manual of your microscope.(3) Setting the aperture diaphragmAdjust the aperture diaphragm in the following way according to the lighting.For diascopic illuminationGenerally, the numeric value of the condenser aperture diaphragm should be adjusted to approximately 70% to 80% of thenumerical aperture (NA) of the objective.For episcopic illuminationGenerally, the aperture diaphragm should be adjusted to approximately 70% to 80% of the size of the pupil of the objectivethat can be seen by removing the eyepiece and looking into the eyepiece tube.Adjustment of aperture diaphragm• For details of the aperture diaphragm adjustment, refer to the manual of your microscope.• For photographed images that have greater depth of focus, close down the aperture diaphragm. Note that closingdown the aperture may limit the performance of the objective.What is depth of focus?“Depth of focus” refers to the in-focus range along the direction vertical to the specimen surface. Although reducingthe aperture diaphragm extends the depth of focus, doing so will also reduce resolution. Adjust the aperturediaphragm in accordance with your needs.(4) Adjusting the focus on the subjectAdjust the focus of the microscope so that the image can be clearly seen on the monitor.Adjusting the focus on a dark subject• If the subject is dark making the exposure time long and the focusing difficult, we recommend that you use the[DF/FL] scene mode.• For how you operate the [DF/FL] scene mode, refer to “8.2.5 Photographing Procedure Using DF/FL SceneMode”.
