Lens: Nikon BD Plan 5x/0.10 210/0
Vintage: 1990's?
Lens Mount: M26 x 0.75mm
Needed Adapters: This lens has a larger mounting thread than traditional microscope objectives -
26 mm. There are adapters available on eBay that will adapt the M26 to a 52mm male filter thread. I
use the inside threads of a 55 - 52 mm step-down ring as a male-to-male adapter. Then you can fit
that onto a 52mm reversing ring specific to your camera.
26 mm. There are adapters available on eBay that will adapt the M26 to a 52mm male filter thread. I
use the inside threads of a 55 - 52 mm step-down ring as a male-to-male adapter. Then you can fit
that onto a 52mm reversing ring specific to your camera.
Preferred Mounting: Normal.
Filter Thread: None.
Controls: This lens has no controls.
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Corner Sharpness vs Aperture:
Corner sharpness is only so-so for this lens.
Below 5:1 magnification, I would call it pretty bad.
Above 5:1 magnification, it's OK.
Corner sharpness is only so-so for this lens.
Below 5:1 magnification, I would call it pretty bad.
Above 5:1 magnification, it's OK.
Sharpness and Resolution vs Magnification:
This lens shows good sharpness and resolution
across its usable magnification range of 4x - 6x.
Compared to lens that have a similar
magnification range, it is good, but not great.
Good 20 mm (Canon, Olympus) and 25 mm
(Leica) bellows lenses will outperform this lens,
mainly related to the larger apertures these
lenses have.
This lens has a numerical aperture of 0.10. That
corresponds to a working f/number of f/5 and
traditional f/number of about f/4.2. The
competitors work in the f/2.8 to f/3.5 range,
allowing for more resolution.
This lens shows good sharpness and resolution
across its usable magnification range of 4x - 6x.
Compared to lens that have a similar
magnification range, it is good, but not great.
Good 20 mm (Canon, Olympus) and 25 mm
(Leica) bellows lenses will outperform this lens,
mainly related to the larger apertures these
lenses have.
This lens has a numerical aperture of 0.10. That
corresponds to a working f/number of f/5 and
traditional f/number of about f/4.2. The
competitors work in the f/2.8 to f/3.5 range,
allowing for more resolution.
Street Price: ~$75 - $150 in good used condition.
Chromatic Aberration: This lens show minimal color fringing in the center
(about 0.20 - 0.30 pixel) and fairly severe on the periphery (4-10 pixels).
Anything below 1.0 pixel is good.
(about 0.20 - 0.30 pixel) and fairly severe on the periphery (4-10 pixels).
Anything below 1.0 pixel is good.
Image Contrast: Image contrast is good across the magnification range,
typical for microscope objectives.
typical for microscope objectives.
Flare: No significant flare is evident during lens testing, although the gaps on
the inside of the lens do need to be plugged as stated above.
the inside of the lens do need to be plugged as stated above.
Conclusion:
This is an easy to find and relatively inexpensive microscope objective that is fairly easy to adapt to
the bellows although the end cap needs to be removed and internal lighting baffles need to be
plugged.
It has good, but not great sharpness and resolution owing to its relatively small numerical aperture
and can be outperformed by many good 20 mm and 25 mm bellows lenses. The main advantage
that it does have over these other lenses is good working distance for the magnification.
The other limitation of this lens is that it doesn't have particularly sharp corners until you get above
a magnification of about 5:1. There is also fairly severe chromatic aberration on the periphery and
some mild distortion present. These factors are much more obvious during testing and are not as
prominent in real world imaging.
This is an easy to find and relatively inexpensive microscope objective that is fairly easy to adapt to
the bellows although the end cap needs to be removed and internal lighting baffles need to be
plugged.
It has good, but not great sharpness and resolution owing to its relatively small numerical aperture
and can be outperformed by many good 20 mm and 25 mm bellows lenses. The main advantage
that it does have over these other lenses is good working distance for the magnification.
The other limitation of this lens is that it doesn't have particularly sharp corners until you get above
a magnification of about 5:1. There is also fairly severe chromatic aberration on the periphery and
some mild distortion present. These factors are much more obvious during testing and are not as
prominent in real world imaging.
Basic Function: Requires extension tubes or bellows to focus.
Appearance:
Aperture: fixed aperture.
Image Samples:
About 4:1 magnification, focus stack of 29 images, resized:
About 4:1 magnification, 1 to 1 crop of a source
image from above:
Good pixel level detail. The corners are clearly not
sharp in the above image.
image from above:
Good pixel level detail. The corners are clearly not
sharp in the above image.
About 6:1, focus stack of 28 images, resized:
About 6:1 magnification, 1 to 1 crop of a single
source image from above:
Good detail for the magnification. The corner
sharpness on the above image is considerably better
than at 4:1.
source image from above:
Good detail for the magnification. The corner
sharpness on the above image is considerably better
than at 4:1.
Distortion: There is slight distortion with this lens that I can see through the
viewfinder, worst at lower magnification.
viewfinder, worst at lower magnification.
Things you need to modify before using:
BD stands for brightfield/darkfield. The end cap and lens is
designed to allow darkfield lighting. The lighting actually
comes down the inside of the objective around the actual
lens assembly. The end cap should be removed (will allow for
more working distance). You will also need to plug up the
gaps surrounding the lens assembly to prevent unwanted
flare. I plugged the gap with some black cord.
BD stands for brightfield/darkfield. The end cap and lens is
designed to allow darkfield lighting. The lighting actually
comes down the inside of the objective around the actual
lens assembly. The end cap should be removed (will allow for
more working distance). You will also need to plug up the
gaps surrounding the lens assembly to prevent unwanted
flare. I plugged the gap with some black cord.
Performance: Sharpness vs Magnification:
This is a new graph that I recently constructed. I
have 4 lines that represent levels of performance
from outstanding (top) to fair (bottom). This
shows where this lens fit into the hierarchy that I
have created.
The Nikon BD Plan 5/0.1 shows sharpness
performance that varies from very good to good
across the magnification range of 3.8:1 to 6.3:1.
This is a new graph that I recently constructed. I
have 4 lines that represent levels of performance
from outstanding (top) to fair (bottom). This
shows where this lens fit into the hierarchy that I
have created.
The Nikon BD Plan 5/0.1 shows sharpness
performance that varies from very good to good
across the magnification range of 3.8:1 to 6.3:1.
Performance: Resolution vs Magnification:
This is a new graph that I recently constructed. I
have 4 lines that represent levels of performance
from outstanding (top) to fair (bottom). This
shows where this lens fit into the hierarchy that I
have created.
The Nikon BD Plan 5/0.1 shows resolution
performance that varies from good to fair across
the magnification range of 3.8:1 to 6.3:1. This
slight drop compared to the sharpness is likely
related to the fixed aperture of about f/4.2 -
relatively small for the magnification.
This is a new graph that I recently constructed. I
have 4 lines that represent levels of performance
from outstanding (top) to fair (bottom). This
shows where this lens fit into the hierarchy that I
have created.
The Nikon BD Plan 5/0.1 shows resolution
performance that varies from good to fair across
the magnification range of 3.8:1 to 6.3:1. This
slight drop compared to the sharpness is likely
related to the fixed aperture of about f/4.2 -
relatively small for the magnification.
