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Natural Science Forum / Physics / Optics / March 2008Phaco for Nikon SE? 20x oculars?
A couple of questions-- Anyone knows if there is a cheap way to add a phaco condenser to a Nikon SE? What's the main drawback of using 20x oculars instead of higher magnification objectives? > What's the main drawback of using 20x oculars instead of higher > magnification objectives? 20X is much more expensive than 10X for equal optical quality. > > What's the main drawback of using 20x oculars instead of higher > > magnification objectives? > > 20X is much more expensive than 10X for equal optical quality. You also loose tons of field size. Now for the tough one, total mag will be beyond NA. At 1000 times the NA the image quality starts to fall apart. Think of a 100X Achromat, its NA is 1.25 so a thousand times is 1,250. Thats were the degradation starts and it gets worse from there. The core point is NA shows you the resolution of the objective, magnification is just an add on , its the least important number out there. A Nikon S series is hard to buy for since it uses short barrels. You might want to look at a good quality used instrument. Thanks, Kevin Cunningham SMS > You also loose tons of field size. Eh? Field size must be proportioned to magnification. In my kit of typical eyepieces are a 20X with 12mm field, and a 10X with 18mm. So the 20X is one-third wider for a given magnification. (20*12)/ (10*18) = 1.33. The 20X/12 beats even an ultra-wide 10X/22. > > You also loose tons of field size. > [quoted text clipped - 3 lines] > 18mm. So the 20X is one-third wider for a given magnification. (20*12)/ > (10*18) = 1.33. The 20X/12 beats even an ultra-wide 10X/22. Richard, field size (fn) is never given in mm. I think your math is a bit off. Kevin Cunningham SMS > > > You also loose tons of field size. > > [quoted text clipped - 9 lines] > Kevin Cunningham > SMS Hello Kevin, I read your remarks regarding field numbers with interest and surprise. Would you please refer to http://www.microscopyu.com/articles/formulas/formulasfieldofview.html and put the statement made there "The diameter of the field in an optical microscope is expressed by the field-of-view number, or simply the field number, which is the dia- meter of the view field in millimeters measured at the intermediate image plane." into perspective. Cheers GR. > Richard, field size (fn) is never given in mm. I think your math is a > bit off. My understanding is that the field number of an eyepiece is the diameter of the field in millimeters. Thus, for example, the common WF10X/18 eyepiece, with a field number of 18, has a circular field aperture of 18mm diameter at its image plane. This in turn, divided by the objective magnification, yields the object (specimen) field size, such as a 40X objective yielding an 18mm/40 = 0.45mm diameter field of view on the specimen. > > Richard, field size (fn) is never given in mm. I think your math is a > > bit off. [quoted text clipped - 5 lines] > yields the object (specimen) field size, such as a 40X objective yielding > an 18mm/40 = 0.45mm diameter field of view on the specimen. Thanks to all for your good comments. Field of view is a relative measurement, it works for a 2X as well as a 100X so it is not given in mm or inches, it is given as field size. The field size stays the same even as the total field changes due to changes in the objective mag. That is the good news, and there really isn't any bad news. Thank you again for your comments. Kevin Cunningham SMS > A Nikon S series is hard to buy for since it uses short > barrels. Does the Series S can mount only "short barrel" objectives? What if I use standard objectives? It does not seem that the objectives currently mounted on my SC are any shorter than standard objectives. How can I distinguish the standard from the short ones? In the 3rd Millenium, on Wed, 12 Mar 2008 23:12:03 +0100, "Pincopallino" <pincopallino@pincopallino.mil> submitted this: >> A Nikon S series is hard to buy for since it uses short >> barrels. [quoted text clipped - 3 lines] >on my SC are any shorter than standard objectives. How can I distinguish the >standard from the short ones? The SC (early 80s) was designed as a student microscope and the lenses were specially designed to be tightened on using the key ways near the thread so that the students didn't 'borrow' them. Standard RMS threaded Nikon CF lenses for the Labophot/Optiphot/ Alphaphot etc will work OK on the SC. The black 'S' series SKe, Model S, Lke, Skt, MS, etc and Apophot, Micropan form the 70s used short barrel lenses.  SignatureDave Ellis Fireblade cbr900rry > The SC (early 80s) was designed as a student microscope and the lenses > were specially designed to be tightened on using the key ways near the > thread so that the students didn't 'borrow' them. Standard RMS > threaded Nikon CF lenses for the Labophot/Optiphot/ Alphaphot etc will > work OK on the SC. Would you suggest to stick with Nikon lenses for the above mentioned microscopes or any good RMS threaded lens would be fine? A 100X from Nikon is probably way too expensive for my pockets. In the 3rd Millenium, on Thu, 13 Mar 2008 01:32:54 +0100, "Pincopallino" <pincopallino@pincopallino.mil> submitted this: >> The SC (early 80s) was designed as a student microscope and the lenses >> were specially designed to be tightened on using the key ways near the [quoted text clipped - 5 lines] >microscopes or any good RMS threaded lens would be fine? >A 100X from Nikon is probably way too expensive for my pockets. The original lenses work fine on the SC. SignatureDave Ellis Fireblade cbr900rry > In the 3rd Millenium, on Thu, 13 Mar 2008 01:32:54 +0100, > "Pincopallino" <pincopallino@pincopallino.mil> submitted this: [quoted text clipped - 10 lines] >> > The original lenses work fine on the SC. Sure, but I don't have a 100X. On Mar 12, 8:32 pm, "Pincopallino" <pincopall...@pincopallino.mil> wrote: > > The SC (early 80s) was designed as a student microscope and the lenses > > were specially designed to be tightened on using the key ways near the [quoted text clipped - 5 lines] > microscopes or any good RMS threaded lens would be fine? > A 100X from Nikon is probably way too expensive for my pockets. A modern 100X from Nikon is longer, doesn't use the same diameter thread and is infinity corrected so it just wouldn't work. There is nothing made world wide that uses 160mm correction. That standard is long gone (sigh). Kevin Cunningham SMS > On Mar 12, 8:32 pm, "Pincopallino" <pincopall...@pincopallino.mil> > wrote: [quoted text clipped - 12 lines] > nothing made world wide that uses 160mm correction. That standard is > long gone (sigh). Thus it has to be not simply RMS-threaded but also 160mm corrected? Only Nikon made that kind of lenses? > Thus it has to be not simply RMS-threaded but also 160mm corrected? 160mm is the standard finity tube length used by all manufacturers. http://micro.magnet.fsu.edu/primer/java/components/fixedtubelength/ > > Thus it has to be not simply RMS-threaded but also 160mm corrected? > > 160mm is the standard finity tube length used by all manufacturers. > > http://micro.magnet.fsu.edu/primer/java/components/fixedtubelength/ Actually not. Kevin Cunningham SMS >> 160mm is the standard finity tube length used by all manufacturers. >> >> http://micro.magnet.fsu.edu/primer/java/components/fixedtubelength/ > > Actually not. I don't mean to say that all finity tube lengths are necessarily 160mm, just most of them. If someone refers to a "standard", then that would be the one. > >> 160mm is the standard finity tube length used by all manufacturers. > [quoted text clipped - 5 lines] > just most of them. If someone refers to a "standard", then that would be > the one. There are profound differences between Olympus and Nikon, Leica and Carl Zeiss. They all work but you always have to stay inside the system. There is no similarity between 160mm DIN systems and any infinity corrected systems. Thanks, Kevin Cunningham SMS > There is no similarity between 160mm DIN systems and any > infinity corrected systems. Right, I don't think we have any disagreement here. I simply meant that a casual reference to a "standard" finity tube length would have to mean 160mm, although there are other finity tube lengths, as well as the variety of infinity systems. On Mar 13, 4:19 pm, "Pincopallino" <pincopall...@pincopallino.mil> wrote: > > On Mar 12, 8:32 pm, "Pincopallino" <pincopall...@pincopallino.mil> > > wrote: [quoted text clipped - 15 lines] > Thus it has to be not simply RMS-threaded but also 160mm corrected? Only > Nikon made that kind of lenses? At one point, before 1990, every one used the 160mm standard with the objectives having the RMS (Royal Microscopial Society) thread. When Nikon and Leica went to the infinity system they both chose to use their own thread so their designers had the freedom to try new stuff, not bound by a standard started in the 1880's and so it was very difficult to put an old objective on a new microscope. Zeiss and Olympus decided to stay with the well known older style, I wish they would have changed but they didn't ask me! Thanks, Kevin Cunningham SMS Olympus and Zeiss went to infinity optics but kept the RMS > On Mar 13, 4:19 pm, "Pincopallino" <pincopall...@pincopallino.mil> > wrote: [quoted text clipped - 24 lines] > At one point, before 1990, every one used the 160mm standard with the > objectives having the RMS (Royal Microscopial Society) thread. Thus, a RMS objective made before 1990, whatever the producer, is 160mm corrected. That seems to make it easier to find a 100x used lens for my SC. On Mar 14, 8:43 pm, "Pincopallino" <pincopall...@pincopallino.mil> wrote: > > On Mar 13, 4:19 pm, "Pincopallino" <pincopall...@pincopallino.mil> > > wrote: [quoted text clipped - 27 lines] > Thus, a RMS objective made before 1990, whatever the producer, is 160mm > corrected. That seems to make it easier to find a 100x used lens for my SC. (sigh) Not actually, objective produced by American Optical and Reichert were infinity corrected from 1962 on for AO and soon after for Reichert. Also SC optics were designed as short barrel objectives, the barrel length of the objective was much shorter than later 160mm objectives. If you replaced all the objectives and switched the eyepieces it should work reasonably well, however buying used objectives and eyepieces never works out as well as you would think. Think about a reasonably new microscope and sell yours to our collector friends. Thanks, Kevin Cunningham SMS > (sigh) Not actually, objective produced by American Optical and > Reichert were infinity corrected from 1962 on for AO and soon after > for Reichert. Also SC optics were designed as short barrel > objectives, the barrel length of the objective was much shorter than > later 160mm objectives. Are you sure this makes standard 160mm obj. not suitable for the SC? On Mar 16, 6:51 pm, "Pincopallino" <pincopall...@pincopallino.mil> wrote: > > (sigh) Not actually, objective produced by American Optical and > > Reichert were infinity corrected from 1962 on for AO and soon after [quoted text clipped - 3 lines] > > Are you sure this makes standard 160mm obj. not suitable for the SC? Its not the 160 mm part, its the physical length of the objective. Older Nikon and Olympus objectives were built to a length standard much shorter than the one specified by the DIN. If you mix the two you will, at some point, ram a modern objective through your slide, not recommended by management. I've seen this done by various....aaahhhh....not to smart individuals, to put it mildly. Then you have correction length problems, but don't worry, the biggest problem is, once again, ramming the DIN objective through your slide. The SC is a neat little 'scope but now its at the end of its rope. As a collectable it's really neat, as a user microscope it's got real problems. Thanks, Kevin Cunningham SMS > Its not the 160 mm part, its the physical length of the objective. > Older Nikon and Olympus objectives were built to a length standard > much shorter than the one specified by the DIN. If you mix the two > you will, at some point, ram a modern objective through your slide, Well... it's just a matter of being careful. I would not consider it a big problem as I'm the only user of the mic (and an occasional one). > Then you have correction length problems, That's may be the real problem if it affects significantly the quality of the image. > > Its not the 160 mm part, its the physical length of the objective. > > Older Nikon and Olympus objectives were built to a length standard [quoted text clipped - 8 lines] > That's may be the real problem if it affects significantly the quality of > the image. Well, were talking about a Nikon SC as the starting point so that isn't that hard to beat. However any DIN standard objective you get will be slightly degraded by the over or under correction of various factors. It just won't work well. Plus there are not a lot of trust worthy sellers of used 100X objectives out there. Thanks, Kevin Cunningham SMS > > > Its not the 160 mm part, its the physical length of the objective. > > > Older Nikon and Olympus objectives were built to a length standard [quoted text clipped - 19 lines] > Kevin Cunningham > SMS Kevin, This has been a long and very interesting thread. I apologize if I am asking a possibly repetitive question which is: If one considers a scope of a given make, designed wtih a tube length of 160 mm, would then not any objective designed to work with a tube length of 160mm work perfectly well, provided it is matched by its proper eyepiece? Thank you for clarifying this point. GR. > > > > Its not the 160 mm part, its the physical length of the objective. > > > > Older Nikon and Olympus objectives were built to a length standard [quoted text clipped - 35 lines] > > GR. Actually good point! There are a bunch of things that need to be corrected like primary color, lateral color, geometric distortion and the list goes on and on. Some makers correct these in the objective, like Nikon, and some correct in the eyepiece or a combination of both objective and eyepiece. This means that while some parts of the objective, like mag., will be OK, the objective will not look as good as it would on a microscope designed for it. This means tube length and eyepieces. Look, tube length is not supposed to vary but it does particularly if add something like fluorescence. Thanks! Kevin Cunningham SMS > If one considers a scope of a given make, designed wtih a tube length > of 160 mm, would then not any objective designed to work with a tube > length of 160mm work perfectly well, provided it is matched by > its proper eyepiece? You're asking if the tube is just a mechnical holder for a given length. The answer is yes. Furthermore, eyepiece correction is not typically a consideration either. >> > Its not the 160 mm part, its the physical length of the objective. >> > Older Nikon and Olympus objectives were built to a length standard [quoted text clipped - 15 lines] > factors. It just won't work well. Plus there are not a lot of trust > worthy sellers of used 100X objectives out there. I would not say that a "*Slightly* degraded" image makes a microscope not to "work well" especially if it's not intended for professional use. I guess it's a matter of "semantic nuances". Anyway I've contacted Nikon and they told me they probably can find optics for the SE series which, according to them, are optically identical, just a little longer. Will let you know. > Anyway I've contacted Nikon and they told me they probably can find optics > for the SE series which, according to them, are optically identical, just > a little longer. Will let you know. 160 euro for a new 100X oil for the SE series... if it's a good objective it's not that expensive but it's too much for the value of the whole microscope, i fear. > > > What's the main drawback of using 20x oculars instead of higher > > > magnification objectives? [quoted text clipped - 17 lines] > Kevin Cunningham > SMS What instruments would you suggest for a good quality used instrument? Thanks TMT |
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