infinity objective magnification dependence on tube lens

[donroy81]

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Hello, I have a Nikon 100x infinity objective. It is supposed to magnify 100x with a  
200mm tube lens. I assume, with some optical equations ,that with a 25mm lens
the magnification should be 12.5x. Am I correct?

[Julio Vazquez]

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Hi Anjan,

according to one of the microscopy online tutorial sites I checked, the focal length of tube lens does not seem to change the overall magnification, only the distance at which the image is formed:

http://www.microscopyu.com/tutorials/java/infinityoptics/offaxisrays/



Julio
Fred Hutchinson Cancer Research Center
Seattle, WA


----- Original Message -----
From: "anjan roy" <[hidden email]>
To: [hidden email]
Sent: Saturday, April 20, 2013 9:42:44 AM
Subject: infinity objective magnification dependence on tube lens

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Hello, I have a Nikon 100x infinity objective. It is supposed to magnify 100x with a  
200mm tube lens. I assume, with some optical equations ,that with a 25mm lens
the magnification should be 12.5x. Am I correct?

[John Oreopoulos]

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Anjan,

I think your assessment is correct - the magnification equation still applies:

Magnification = focal length of tube lens / focal length of objective lens

However, I also expect you'll observe severe aberrations (chromatic and spherical) when not using the designed tube lens. In fact different wavelengths may have different magnifications with your proposed lens. And yes, as Julio indicates, the position of the image pane will be different - roughly 25 mm away from your new lens. If you're changing the tube lens inside the microscope (as opposed to building an open test setup on an optical bench), your image will not form outside the microscope body. If you want only 12.5X magnification, you're better off simply switching to a 10X objective lens.

John Oreopoulos


On 2013-04-20, at 1:20 PM, Vazquez Lopez, Julio wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi Anjan,
>
> according to one of the microscopy online tutorial sites I checked, the focal length of tube lens does not seem to change the overall magnification, only the distance at which the image is formed:
>
> http://www.microscopyu.com/tutorials/java/infinityoptics/offaxisrays/
>
>
>
> Julio
> Fred Hutchinson Cancer Research Center
> Seattle, WA
>
>
> ----- Original Message -----
> From: "anjan roy" <[hidden email]>
> To: [hidden email]
> Sent: Saturday, April 20, 2013 9:42:44 AM
> Subject: infinity objective magnification dependence on tube lens
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello, I have a Nikon 100x infinity objective. It is supposed to magnify 100x with a  
> 200mm tube lens. I assume, with some optical equations ,that with a 25mm lens
> the magnification should be 12.5x. Am I correct?

[Andreas Bruckbauer]

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I assume your 100x objective has high NA, then the trick with the different tube length gives you low magnification with high NA. This can be useful for bioluminescence.

Andreas


-----Original Message-----
From: John Oreopoulos <[hidden email]>
To: CONFOCALMICROSCOPY <[hidden email]>
Sent: Sat, 20 Apr 2013 18:37
Subject: Re: infinity objective magnification dependence on tube lens


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Anjan,

I think your assessment is correct - the magnification equation still applies:

Magnification = focal length of tube lens / focal length of objective lens

However, I also expect you'll observe severe aberrations (chromatic and
spherical) when not using the designed tube lens. In fact different wavelengths
may have different magnifications with your proposed lens. And yes, as Julio
indicates, the position of the image pane will be different - roughly 25 mm away
from your new lens. If you're changing the tube lens inside the microscope (as
opposed to building an open test setup on an optical bench), your image will not
form outside the microscope body. If you want only 12.5X magnification, you're
better off simply switching to a 10X objective lens.

John Oreopoulos


On 2013-04-20, at 1:20 PM, Vazquez Lopez, Julio wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi Anjan,
>
> according to one of the microscopy online tutorial sites I checked, the focal
length of tube lens does not seem to change the overall magnification, only the
distance at which the image is formed:

>
> http://www.microscopyu.com/tutorials/java/infinityoptics/offaxisrays/
>
>
>
> Julio
> Fred Hutchinson Cancer Research Center
> Seattle, WA
>
>
> ----- Original Message -----
> From: "anjan roy" <[hidden email]>
> To: [hidden email]
> Sent: Saturday, April 20, 2013 9:42:44 AM
> Subject: infinity objective magnification dependence on tube lens
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello, I have a Nikon 100x infinity objective. It is supposed to magnify 100x

with a  
> 200mm tube lens. I assume, with some optical equations ,that with a 25mm lens
> the magnification should be 12.5x. Am I correct?

 

[Christophe Lamy]

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To get high NA at low mag I would rather use 40x or 60x objectives that
will provide more brightness than a 100x.

Christophe

On 20.04.2013 19:40, Andreas Bruckbauer wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
>
> I assume your 100x objective has high NA, then the trick with the different tube length gives you low magnification with high NA. This can be useful for bioluminescence.
>
> Andreas
>
>
> -----Original Message-----
> From: John Oreopoulos <[hidden email]>
> To: CONFOCALMICROSCOPY <[hidden email]>
> Sent: Sat, 20 Apr 2013 18:37
> Subject: Re: infinity objective magnification dependence on tube lens
>
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Anjan,
>
> I think your assessment is correct - the magnification equation still applies:
>
> Magnification = focal length of tube lens / focal length of objective lens
>
> However, I also expect you'll observe severe aberrations (chromatic and
> spherical) when not using the designed tube lens. In fact different wavelengths
> may have different magnifications with your proposed lens. And yes, as Julio
> indicates, the position of the image pane will be different - roughly 25 mm away
> from your new lens. If you're changing the tube lens inside the microscope (as
> opposed to building an open test setup on an optical bench), your image will not
> form outside the microscope body. If you want only 12.5X magnification, you're
> better off simply switching to a 10X objective lens.
>
> John Oreopoulos
>
>
> On 2013-04-20, at 1:20 PM, Vazquez Lopez, Julio wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Hi Anjan,
>>
>> according to one of the microscopy online tutorial sites I checked, the focal
> length of tube lens does not seem to change the overall magnification, only the
> distance at which the image is formed:
>> http://www.microscopyu.com/tutorials/java/infinityoptics/offaxisrays/
>>
>>
>>
>> Julio
>> Fred Hutchinson Cancer Research Center
>> Seattle, WA
>>
>>
>> ----- Original Message -----
>> From: "anjan roy" <[hidden email]>
>> To: [hidden email]
>> Sent: Saturday, April 20, 2013 9:42:44 AM
>> Subject: infinity objective magnification dependence on tube lens
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Hello, I have a Nikon 100x infinity objective. It is supposed to magnify 100x
> with a
>> 200mm tube lens. I assume, with some optical equations ,that with a 25mm lens
>> the magnification should be 12.5x. Am I correct?
>