i wanted to post this in the plant sourcing area, but i cant seem to post there...hope this is ok to post. what i want are some slides that i can use to measure small things (like spores and pollen, up to seeds). When i search for "stage micrometers" all i can find is $150+ slides! is this normal? are there any alternatives? all i need is a simple glass slides with etched measurements....i dont get why so expensive. any help would be GREATLY appreciated!!!!
Hi, stage micrometers are very expensive, but unless you are doing scientific work requiring a very high degree of accuracy + precision you probably do not need one. To make measurements with the microscope, you do need (and may already have ) an eyepiece graticule (=reticule = reticle) - a scale built into the eyepiece. If you do not have one they are relatively cheap. One potential source is someone selling an eyepiece on EBay - they often contain a graticule - check the listing. Having got the graticule (which will normally have a scale of 0 - 100), you need to calibrate it against a known length. Ideally this would be a "stage micrometer", but at low magnifications, using the x4 objective and using the x 10 objective you can use a normal millimetre ruler. You will probably find that using the x4 objective, 25 graticule units corresponds (more or less) to 1 millimetre. In this case each graticule unit = 40 micrometres. Similarly, you will probably find that using the x10 objective, 100 graticule units corresponds (more or less) to 1 millimetre. In this case each graticule unit = 10 micrometres. In each case, the relationship may not be exact because of small differences in the optical system of your microscope - this is why you need the stage micrometer for exact work. You cannot calibrate the higher power objectives directly in the way I suggest with a ruler, but the calibration follows the magnification so: x40 objective 1 graticule unit ~2.5 micrometres x100 objective 1 graticule unit ~ 1 micrometre You might like to read the following article: http://www.microscopy-uk.org.uk/mag...microscopy-uk.org.uk/mag/artdec99/cwnano.html You only need to calibrate your microscope once, therefore another option would be to see if you can borrow a stage micrometer from a university, college etc or bring your mike into the college and calibrate it there. Good Luck BrianO
excellent thanks a lot! i need pretty exact measure as it is for plant and fungus identification and study. guess there is no cheap way to do it...at least i know they are expensive and i dont find out after they were cheap. thanks again.
