Good practice in Relaying image plane

[Antonio Jose Pereira]

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Hi,

I'm willing to create a short infinite-conjugate path (with a pair of plane-convex lenses) after the primary image plane.
My concerns are essentially related to vignetting/aberrations in the 1x relayed image I'll be creating with this setup.

To prevent unforeseen surprises, I would welcome any hints/tips or clarifying docs regarding 'things to avoid' (such as minimum lens diameters and focal lengths). I'd like to make the effective 'delay' of the image plane as short as possible.

Thanks,
António Pereira

[John Oreopoulos]

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Use pairs of closely spaced achromatic doublets instead of single plano-convex lenses (4 lenses total) to avoid axial chromatic aberrations. You use more glass, but the losses aren't that bad. Imaging quality should be the top priority unless you're signal-limited.

Don't make the relay too short as you risk degrading the diffraction-limited image quality of the microscope output. In this regard, it's better to choose the focal length of the lens pairs to be similar to the focal length of the microscope tube lens focal length and position the lenses in a "4f" manner. That is to say, I've noticed better performance of image relays when the f/# or NA of the system is similar to that of the tube lens (which is dependent on the objective lens you're using).

If in doubt about what you've put together, test the PSF of the system with and without the relay inserted by collecting z-stacks of small fluorescent beads and compare (and be sure to compare at different wavelengths).

Cheers,

John Oreopoulos
Staff Scientist
Spectral Applied Research Inc.
A Division of Andor Technology
Richmond Hill, Ontario
Canada
www.spectral.ca

On 2014-05-22, at 10:47 AM, Antonio J Pereira wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> Post images on http://www.imgur.com and include the link in your posting.
> *****
>
> Hi,
>
> I'm willing to create a short infinite-conjugate path (with a pair of plane-convex lenses) after the primary image plane.
> My concerns are essentially related to vignetting/aberrations in the 1x relayed image I'll be creating with this setup.
>
> To prevent unforeseen surprises, I would welcome any hints/tips or clarifying docs regarding 'things to avoid' (such as minimum lens diameters and focal lengths). I'd like to make the effective 'delay' of the image plane as short as possible.
>
> Thanks,
> António Pereira

[Craig Brideau]

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Also, make sure to point the achromat pairs away from each other so they
are mirror images. This minimizes the aberrations. A basic eyepiece design
does this and gives decent correction.  Larger diameter and longer focal
length lenses will have less field curvature issues (generally speaking)
but you will be limited by the amount of space you have to work with. Good
anti-reflection coatings are also important to reduce back-reflections in
the system.

Craig Brideau


On Thu, May 22, 2014 at 9:53 AM, John Oreopoulos <
[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> Post images on http://www.imgur.com and include the link in your posting.
> *****
>
> Use pairs of closely spaced achromatic doublets instead of single
> plano-convex lenses (4 lenses total) to avoid axial chromatic aberrations.
> You use more glass, but the losses aren't that bad. Imaging quality should
> be the top priority unless you're signal-limited.
>
> Don't make the relay too short as you risk degrading the
> diffraction-limited image quality of the microscope output. In this regard,
> it's better to choose the focal length of the lens pairs to be similar to
> the focal length of the microscope tube lens focal length and position the
> lenses in a "4f" manner. That is to say, I've noticed better performance of
> image relays when the f/# or NA of the system is similar to that of the
> tube lens (which is dependent on the objective lens you're using).
>
> If in doubt about what you've put together, test the PSF of the system
> with and without the relay inserted by collecting z-stacks of small
> fluorescent beads and compare (and be sure to compare at different
> wavelengths).
>
> Cheers,
>
> John Oreopoulos
> Staff Scientist
> Spectral Applied Research Inc.
> A Division of Andor Technology
> Richmond Hill, Ontario
> Canada
> www.spectral.ca
>
> On 2014-05-22, at 10:47 AM, Antonio J Pereira wrote:
>
>
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > Post images on http://www.imgur.com and include the link in your
> posting.
> > *****
> >
> > Hi,
> >
> > I'm willing to create a short infinite-conjugate path (with a pair of
> plane-convex lenses) after the primary image plane.
> > My concerns are essentially related to vignetting/aberrations in the 1x
> relayed image I'll be creating with this setup.
> >
> > To prevent unforeseen surprises, I would welcome any hints/tips or
> clarifying docs regarding 'things to avoid' (such as minimum lens diameters
> and focal lengths). I'd like to make the effective 'delay' of the image
> plane as short as possible.
> >
> > Thanks,
> > António Pereira
>