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mim_ramm_vts [2018/03/22 14:08]
jon [Infinity Space Limitations]
mim_ramm_vts [2018/07/24 10:34] (current)
jon [Tube Lens Performance]
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 ==== Tube Lens Performance ==== ==== Tube Lens Performance ====
  
-For best imaging performance we recommend the ''​C60_Tube_B''​ which uses a Nikon 200 mm focal length multi-element tube lens.  In general longer focal length lenses will have better performance. ​ By using multi-element lenses ''​C60_TUBE_180D'',​ ''​C60_TUBE_140D'',​ ''​C60_TUBE_125D'',​ and ''​C60_TUBE_100D''​ usually are satisfactory for imaging. ​ Likewise ''​C60_TUBE_250'',​ ''​C60_TUBE_300'',​ and ''​C60_TUBE_400''​ are usually satisfactory even though they only contain a single element. ​ ''​C60_TUBE_100'' ​is not recommended for imaging applications,​ and ''​C60_TUBE_160''​ is marginal for imaging applications.+Spherical aberrations are usually the main determinant of tube lens performance. ​ This quantifies the degree to which all parallel rays are focused to the same point axially. ​ Chromatic aberrations are also important for applications where more than one wavelength is used (e.g. fluorescent samples with both GFP and mCherry labels). 
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 +All ASI's tube lenses are intended for use with infinity-corrected objectives. ​ Nikon and Olympus objectives (and tube lenses) include all corrections internally and can be safely mixed and matched for convenience,​ to adjust the magnification,​ etc.  Leica and Zeiss objectives and tube lenses split the chromatic correction between the objective and tube lens in a proprietary way and cannot be mixed without some performance degradation. 
 + 
 +For best imaging performance we recommend the ''​C60_Tube_B''​ which uses a Nikon 200 mm focal length multi-element tube lens.  In general longer focal length lenses will have better performance. ​ By using multi-element lenses ''​C60_TUBE_180D'',​ ''​C60_TUBE_140D'',​ ''​C60_TUBE_125D'',​ and ''​C60_TUBE_100D''​ usually are satisfactory for imaging. ​ Likewise ''​C60_TUBE_250'',​ ''​C60_TUBE_300'',​ and ''​C60_TUBE_400''​ are usually satisfactory ​for imaging ​even though they only contain a single element. ​ ''​C60_TUBE_100'' ​and ''​C60_TUBE_70''​ are not recommended for imaging applications,​ and ''​C60_TUBE_160''​ is marginal for imaging applications. 
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 + 
 +==== Example Images ====
  
 Imaging performance of the tube lens will depend upon the suitable combination of lens and objective, the field of view in the image, and the focal length of the tube lens.  In general, longer focal length lenses will have better performance across the field of view.  To illustrate this, we show some sample images taken with a variety of tube-lenses using a high quality objectives. ​ All of the images are of a fixed stained bone marrow smear, which provides a nice uniform large area color sample with large spatial dynamic range. ​ The images show a reference circle corresponding to a 25mm field number (FN) for the objective. ​ Magnified sections of the image in the center of the field and near the objective design FN are shown as well.  Images were taken using a Sony NEX-3 camera with 23.4 mm x 15.6 mm sensor with 5.1µ pixels. ​ For a more complete set of test images, see the Tube Lens Performance document. Imaging performance of the tube lens will depend upon the suitable combination of lens and objective, the field of view in the image, and the focal length of the tube lens.  In general, longer focal length lenses will have better performance across the field of view.  To illustrate this, we show some sample images taken with a variety of tube-lenses using a high quality objectives. ​ All of the images are of a fixed stained bone marrow smear, which provides a nice uniform large area color sample with large spatial dynamic range. ​ The images show a reference circle corresponding to a 25mm field number (FN) for the objective. ​ Magnified sections of the image in the center of the field and near the objective design FN are shown as well.  Images were taken using a Sony NEX-3 camera with 23.4 mm x 15.6 mm sensor with 5.1µ pixels. ​ For a more complete set of test images, see the Tube Lens Performance document.
mim_ramm_vts.txt · Last modified: 2018/07/24 10:34 by jon