Flat field correction of objectives

[Nicholas Geisse]

Hey everybody,

I was wondering if there is a simple answer to this question. I am looking for data regarding the quality and/or efficacy of optical abberation corrections in various types of miroscope objectives. Particularly, I am interested in the linearity of the magnification from the central optical axis to the extremes of the field of view of objectives as well as flat field corrections. Obviously this will vary between different objective classes and wavelengths, but I can’t seem to find any hard data on magnification distortions across a field of view for any objectives.

Does anyone know of a good source for these types of data, or of an approved method of measuring these distortions, if any?

Thanks



nick

[Guy Cox]

This will vary from objective to objective.  I use a calibration slide (stage

micrometer) and measure the spacing at the edges and at the centre.

Do remember that in a confocal non-linearity of the scan is also a

possibility, so it’s best to check in widefield.  Also, the coupling lenses

for your camera may not be perfect, so if you get strange results check

them against an eyepiece micrometer.

 

For flatness (or otherwise) of field a very good sample is a coverslip

very lightly smoked over a match-flame.  Make a few scratches to give

some coarse detail for easy location of the focal plane.  Mount it on a

slide with a drop of oil.  Then check the focal shift between the centre

and the edge.  This sample is also very good for showing up chromatic

aberration.

 

You will probably be surprised by what you see when you do these

tests!

 

                                                                                     Guy

 

Optical Imaging Techniques in Cell Biology
by Guy Cox    CRC Press / Taylor & Francis
    http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Electron Microscope Unit, Madsen Building F09,
University of Sydney, NSW 2006 ______________________________________________
Phone [phone]     Fax [phone]
Mobile [phone]
______________________________________________
 

---

From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Nicholas Geisse
Sent: Tuesday, 2 December 2008 5:27 PM
To: [hidden email]
Subject: Flat field correction of objectives

 

Hey everybody,

I was wondering if there is a simple answer to this question. I am looking for data regarding the quality and/or efficacy of optical abberation corrections in various types of miroscope objectives. Particularly, I am interested in the linearity of the magnification from the central optical axis to the extremes of the field of view of objectives as well as flat field corrections. Obviously this will vary between different objective classes and wavelengths, but I can’t seem to find any hard data on magnification distortions across a field of view for any objectives.

Does anyone know of a good source for these types of data, or of an approved method of measuring these distortions, if any?

Thanks



nick

[Masoumi, Zahra (GE Healthcare)]

To do flat field correction of image please see the poster presented at the 11th Annual Conference of the Society for Biomolecular Screening, Geneva, Switzerland, Sep 11-15, 2005

 

Regards,

 

Zahra 

---

From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Guy Cox
Sent: Tuesday, December 02, 2008 1:49 AM
To: [hidden email]
Subject: Re: Flat field correction of objectives

This will vary from objective to objective.  I use a calibration slide (stage

micrometer) and measure the spacing at the edges and at the centre.

Do remember that in a confocal non-linearity of the scan is also a

possibility, so it’s best to check in widefield.  Also, the coupling lenses

for your camera may not be perfect, so if you get strange results check

them against an eyepiece micrometer.

 

For flatness (or otherwise) of field a very good sample is a coverslip

very lightly smoked over a match-flame.  Make a few scratches to give

some coarse detail for easy location of the focal plane.  Mount it on a

slide with a drop of oil.  Then check the focal shift between the centre

and the edge.  This sample is also very good for showing up chromatic

aberration.

 

You will probably be surprised by what you see when you do these

tests!

 

                                                                                     Guy

 

Optical Imaging Techniques in Cell Biology
by Guy Cox    CRC Press / Taylor & Francis
    http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Electron Microscope Unit, Madsen Building F09,
University of Sydney, NSW 2006 ______________________________________________
Phone [phone]     Fax [phone]
Mobile [phone]
______________________________________________
 

---

From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Nicholas Geisse
Sent: Tuesday, 2 December 2008 5:27 PM
To: [hidden email]
Subject: Flat field correction of objectives

 

Hey everybody,

I was wondering if there is a simple answer to this question. I am looking for data regarding the quality and/or efficacy of optical abberation corrections in various types of miroscope objectives. Particularly, I am interested in the linearity of the magnification from the central optical axis to the extremes of the field of view of objectives as well as flat field corrections. Obviously this will vary between different objective classes and wavelengths, but I can’t seem to find any hard data on magnification distortions across a field of view for any objectives.

Does anyone know of a good source for these types of data, or of an approved method of measuring these distortions, if any?

Thanks



nick