![]() The dots are short-lived, visible for about one second or less, and traveling short distances along seemingly random, undulating paths. The blue field entoptic phenomenon is an entoptic phenomenon characterized by the appearance of tiny bright dots (nicknamed blue-sky sprites) moving quickly along undulating pathways in the visual field, especially when looking into bright blue light such as the sky. Note the size of the bright dots in relation to the hand. of the optical system.Simulation of the blue field entoptic phenomenon. You cannot do the same thing by adding eyepieces because you are not changing the N.A. objectives but they are often 50.00 or less + a pair of compens eyepieces and voila, you just upgraded your microscope. Most of these will need short extensions ,in order to get them parfocal with D.I.N. Additionally, however Lomo water immersion objectives, offer advantages, as well as some of the older apochromats from Bausch & Lomb, Zeiss, Reichert, even Lomo. of your system, close to or above 1.0 in bright field, in order to get the details visible, that's why they invented oil immersion. The other, if you need to stay with bright field and if your microscope is a 160mm type, is to keep your eyes open for cheaper 160mm objectives that offer better resolution than standard average grade achromats. There is a lot on this forum about those 3 techniques. Phase contrast is likely expensive for your scope, if you have to buy new but adapting oblique illumination, UGF or dark field are not expensive and a lot of it can be done with some elbow grease. This gives you much more detail, than simply adding magnification. One is to add some contrast enhancing techniques to your arsenal. What you are using for a microscope? I'm guessing you are trying to get a more resolved view of the internal structures? In order to do this, there are two options and it is best if you can fuse the two. It's kind of like an objective, with a supercharger on it. and with it's apo correction easily exceeds the performance of most well corrected achromats, I have used. Firstly, the objective is an exceptional 40 X objective, when oiled but when used dry it probably works at around. I had never thought to use it dry because my experience with other oil objectives used dry has been less than encouraging. I was recently surprised too, by how good a 40X 1.0 N.A. 85 dry objective can be almost breathtaking. 85 objective, you theoretically could jump to 800X with aquality 20X eyepieces and get something other than an image through a London fog, in front of your eyes. 40X objectives, to go along with them( do they even make them)? If you put in a 40X. Unfortunately, the companies that provide them in their kits, do not provide high N.A. The other reason for using high magnification eyepieces, is that it is easier than messing with oil. ![]() ![]() In the modern world, with the widespread adoption of multiple nosepieces( most are fairly precise, although my experience with some cheap oriental stuff says, otherwise), this is not as necessary. You could even get away with a 25X coupled to the 10X objective. ![]() objective and the image would be quite good. A quick idea of a magnified view could be gained by slipping in a 20X eyepiece over a 10X. So, the best method for quality observation was through a simple tube with one objective, manually replaced by the next when needed but that can be cumbersome and with enough changes, dangerous, because an objective will eventually be dropped. Older multiple nosepieces were imprecise. Binocular heads do not provide quite as bright an image as a monocular and on a microscope sitting in a lab surrounded by microscopists smoking their brains out it will be worse. It took a long time for the binocular head to be accepted by professionals( 1920's) and a relatively shorter time for the multiple nosepiece to be widely accepted( 1920). Microscopes, originally had one objective as well as one eyepiece. Add to this, the fact that the maximum magnification and resolution of any optical system has a limit ( drop the decimal and add one zero to the N.A.) and the use of high power eyepieces becomes a de facto no no.Īt one time they made some sense. Entoptic affects, floaters, dust,optical defects, even crap in the condenser, which otherwise are not obvious can become extremely annoying. The darkened background that high magnification eyepieces gives, allows for a number of optical artifacts to show up in higher contrast, and be noticeable enough to interfere with the experience. It is unfortunate that these companies continue to woo unsuspecting customers with their little "power" trip. JimT wrote:25x eyepieces will give very inferior images. ![]()
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