In the pictures there is a measurement bar in microns. A micron is 1000th of a millimeter. Does this help? In the top left picture of the radula, the bar is 200 microns - that is about the width of three of the middle teeth, so the width of three of the middle teeth would be 0.2 millimeters. On the bottom left image of the hooks, the width is 1 millimeter, so the total length of that hook would be about 1.5 millimeters.
A little after I enlarged the photos to read them but I am afraid I don't get the spacial feel for how many times reality I am looking at when somthing is stated that way. If the bar in the key is 200 x .001 or .2 mm I can look at a tape and guestimate 1/5 th of a mm but that does not help me visuallize the magnification level - just did not do bio in college (night classes meant astromomy even though I wanted to take biology) and have not even toyed with a microscope since I was a kid.
In the first photo of the radula, it says 1600x magnified, but that is not taking into account the size of the image that you are viewing. If you enlarge the photos, then you are magnifying it even further. Are you confused yet?
It does help a lot with spacial imagery to know the magnification. I can't tell the actual size of what I am looking at but I can get prospective. If you magnify your thumb 1600 X's you can see finer details so it is the amount of detail with relation to normal viewing that knowing the magnification level helps intuitively understand.
Hey, I still prefer an analog clock because I can see how late I am because it displays a picture of an hour's worth of time and the relationship of the current time and when I was supposed to be somewhere.
Yeah... don't breathe, don't sneeze (almost as difficult for me as not breathing for most people ), don't drop it onto the sticky surface upside down, don't squeeze too hard otherwise you get tweezer-marks, don't let your hands shake... actually it's a wonder I got any of these pics at all.
Here are some more. These are tentacle clubs of paralarval onychoteuthids. Sorry that some have mags on them and some don't - I usually don't include them in the legend because journals don't want them, due to image resizing changing the mag. Scale bars are much preferred even if they make visualization a little harder for some.
1 - a normal adult arm sucker in Onychoteuthis
2 - a tentacular sucker in the middle of developing into a hook, in paralarval Onychoteuthis
3 - the 'back' (interior/aboral side) of an exposed paralarval tentacular sucker ring - the smooth rounded part in the foreground would normally be set into the sucker musculature
4 - a tentacular sucker in the middle of developing into a hook, in paralarval Onykia