What would you recommend for higher power eyepieces beyond the standard 10x eyepieces found on scopes?
Thanks
Higher power eyepieces beyond 10x?
Re: Higher power eyepieces beyond 10x?
Generally, I would recommend avoiding such eyepieces. They are typically not super useful, unless you have an odd higher NA objective with a lower magnification.
Re: Higher power eyepieces beyond 10x?
I find 15X occulars work...12X..but I just do not use them. charlie g
Re: Higher power eyepieces beyond 10x?
It is recommended on Nikon's website for stereo microscopes when you want to increase magnification without losing DOF increase the eyepiece magnification. Increasing the magnification of the objective reduces the DOF.
However, keep in mind that increasing the magnification via the objective vs the eyepiece has the advantage of increasing resolution ( na). So there is a trade-off. You have to decide why you want to increase the magnification and choose how.
All of my Leitz compound scopes have a magnification changer located between the head and body of the scope. It allows me to increase magnification without changing the eyepieces from 1x 1.25x, 1.6x, and 2.0x.
That is an option.
However, keep in mind that increasing the magnification via the objective vs the eyepiece has the advantage of increasing resolution ( na). So there is a trade-off. You have to decide why you want to increase the magnification and choose how.
All of my Leitz compound scopes have a magnification changer located between the head and body of the scope. It allows me to increase magnification without changing the eyepieces from 1x 1.25x, 1.6x, and 2.0x.
That is an option.
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apochronaut
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Re: Higher power eyepieces beyond 10x?
Genarally, you are limited to 15X eyepieces except in rare instances, almost always in research applications, where eyepieces as high as 30X have been used for a specific reason.
12.5X used to be quite common , in order to maximize the magnification at 1250X of 1.25 N.A. objectives without entering into empty magnification. They are still made but uncommon now. There is one source I know of for 12.5X very W.F. very neutral diopter eyepieces. I use them on a specific infinity corrected stand.
15X have a technical possibility that doesn't really sink in until you use a version that takes advantage of it because not all 15X do. A 15X eyepiece can have an apparent field that is as much as 1.5X that of a 10X eyepiece when both have the same optical tube diameter. For this reason, a well engineered 15X can increase your magnification range, adding at least 4 more magnifications between 0 and 600X for most microscopes and 1 or 2 extra very low magnifications for some. Each extra magnification can have a wider field of view than the equivalent magnification when using a 10X eyepiece and the objective used will have IT'S working distance, not that of a more powerful higher N.A. objective, which is usually narrower.
The catch is that 15X work better the higher the N.A. The N.A. of any objective used with a 15X must be at least 1.5% of the objective's magnification for achromats and about 1.35-1.4 % for apochromats. The higher the better because objectives at marginal N.A.s in the range stated won't perform as well. In most microscopes this means that the cutoff magnification is 40X and with many cheaper 40X .65 objectives, you will see some resolution loss when used at 600X.
In order for that extra f.o.v. to be realized , the f.n. of the 15X eyepiece must be greater than 13.5. Many of them are 15 or more. The B&L U.W.F. are 20, so they present a field that if they were 10X eyepieces would be a 30 f.n.
A 15X eyepieces also has narrower eye relief than a 10X ftom the same design family. This is annoying to some and not all are the same. The ones I use are fine for me, hardly noticeable.
12.5X used to be quite common , in order to maximize the magnification at 1250X of 1.25 N.A. objectives without entering into empty magnification. They are still made but uncommon now. There is one source I know of for 12.5X very W.F. very neutral diopter eyepieces. I use them on a specific infinity corrected stand.
15X have a technical possibility that doesn't really sink in until you use a version that takes advantage of it because not all 15X do. A 15X eyepiece can have an apparent field that is as much as 1.5X that of a 10X eyepiece when both have the same optical tube diameter. For this reason, a well engineered 15X can increase your magnification range, adding at least 4 more magnifications between 0 and 600X for most microscopes and 1 or 2 extra very low magnifications for some. Each extra magnification can have a wider field of view than the equivalent magnification when using a 10X eyepiece and the objective used will have IT'S working distance, not that of a more powerful higher N.A. objective, which is usually narrower.
The catch is that 15X work better the higher the N.A. The N.A. of any objective used with a 15X must be at least 1.5% of the objective's magnification for achromats and about 1.35-1.4 % for apochromats. The higher the better because objectives at marginal N.A.s in the range stated won't perform as well. In most microscopes this means that the cutoff magnification is 40X and with many cheaper 40X .65 objectives, you will see some resolution loss when used at 600X.
In order for that extra f.o.v. to be realized , the f.n. of the 15X eyepiece must be greater than 13.5. Many of them are 15 or more. The B&L U.W.F. are 20, so they present a field that if they were 10X eyepieces would be a 30 f.n.
A 15X eyepieces also has narrower eye relief than a 10X ftom the same design family. This is annoying to some and not all are the same. The ones I use are fine for me, hardly noticeable.
Re: Higher power eyepieces beyond 10x?
Reminder: to match the required optical correction of your objectives eyepieces of the same brand and era are required, particularly if you are using a scope of 160 or 170 tube length.
For the infinity tube length scopes this requirement may be less strict.
I’m using (relative rare) Olympus WHK 12.5 eyepieces on one of my CH2 scopes with long barrel objectives of the same era/period, and appreciate the extended field of view.
For the infinity tube length scopes this requirement may be less strict.
I’m using (relative rare) Olympus WHK 12.5 eyepieces on one of my CH2 scopes with long barrel objectives of the same era/period, and appreciate the extended field of view.
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apochronaut
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Re: Higher power eyepieces beyond 10x?
Actually, no eyepiece match is less strict. All eyepieces are different due to the fact that they are needed as a valve in order to direct the flow of light in the most efficient manner required to produce as corrected an outflow as possible.If two eyepieces end up providing the same controls or lack of, it is either a complete accident, an engineer or two switched companies, or there were restrictions on available glass formulations, as was the case behind the iron curtain.
The eyepiece doesn't care whether the incoming light originated in a 160, 170 or infinity tube but over time eyepiece designs have been created to accomodate certain peculiarities associated with the necessities related to optical designs of their era. Those necessities were heavily mediated by the industrial environment of glassmaking and what could be accomplished in objective design, largely based on the glass available.
Eyepieces exist on a continuum from heavily correcting across nrutral to heavily compensating. As more and more objectives are being made that have more complete corrections and this is associated with the commercial advent of infinity correction and planar correction, eyepieces are being required to be more neutral on that continuum, so correcting or compensating eyepieces are more associated with older objective designs.
The eyepiece doesn't care whether the incoming light originated in a 160, 170 or infinity tube but over time eyepiece designs have been created to accomodate certain peculiarities associated with the necessities related to optical designs of their era. Those necessities were heavily mediated by the industrial environment of glassmaking and what could be accomplished in objective design, largely based on the glass available.
Eyepieces exist on a continuum from heavily correcting across nrutral to heavily compensating. As more and more objectives are being made that have more complete corrections and this is associated with the commercial advent of infinity correction and planar correction, eyepieces are being required to be more neutral on that continuum, so correcting or compensating eyepieces are more associated with older objective designs.