"Double" psf's

[Pedro Almada]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear listers,

This is not strictly a confocal question since it's about a widefield
system, but I think it's quite suited to the readers of this list.

Our users of a DeltaVision system (an Olympus IX71) were complaining of
"blurry" images. After checking that their parameters were normal we made a
stack of 0.17 um beads and observed that the PSF was very wrong: we could
see two spots instead of one! It's not the DIC slider (the obvious culprit)
and it's independent of what dichroic or emission filters we use. The
problem is present in all objectives but gets worse with magnification.
With the 40x we just see elongated spots but with the 100x we clearly see
two spots. This was not there before.

You can observe all of this by yourselves in the files available on this
folder. I've included stacks and comparison shots of PSF's acquired in
December.
https://www.dropbox.com/sh/i770v4a0a4owrb8/p_qBYW4E-2

Do anyone have a clue on what could be causing this?

Preemptive thanks for your input,
Best regards,
Pedro Almada

[Pedro Almada]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

One important detail I forgot to mention: this happens with both camera and
eyepiece!


On 2 April 2013 18:53, Pedro Almada <[hidden email]> wrote:

> Dear listers,
>
> This is not strictly a confocal question since it's about a widefield
> system, but I think it's quite suited to the readers of this list.
>
> Our users of a DeltaVision system (an Olympus IX71) were complaining of
> "blurry" images. After checking that their parameters were normal we made a
> stack of 0.17 um beads and observed that the PSF was very wrong: we could
> see two spots instead of one! It's not the DIC slider (the obvious culprit)
> and it's independent of what dichroic or emission filters we use. The
> problem is present in all objectives but gets worse with magnification.
> With the 40x we just see elongated spots but with the 100x we clearly see
> two spots. This was not there before.
>
> You can observe all of this by yourselves in the files available on this
> folder. I've included stacks and comparison shots of PSF's acquired in
> December.
> https://www.dropbox.com/sh/i770v4a0a4owrb8/p_qBYW4E-2
>
> Do anyone have a clue on what could be causing this?
>
> Preemptive thanks for your input,
> Best regards,
> Pedro Almada
>

[Pedro Almada]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear Listers, especially to all those who contacted me off-list with
suggestions,

After much headscratching and some visits from Olympus and Image Solutions,
we've finally pinpointed the problem. It seems the fan of the camera was
introducing a vibration that was not detectable until we could upgrade the
software to be able to expose for under 35ms. With 1ms exposures, we saw
that the double beads were actually single beads vibrating at a fairly
consistent direction and distance, which averaged to a "double" psf on both
the eyepiece and camera!

After further headstratching and turning everything off step by step we saw
it was the fan of the camera (!) that was introducing the vibrations! It
should be a matter of replacing that now.

Anyway, I'd like to thank all those who offered help and I hope this story
will actually be of use to someone in the future.

Thank you,
Pedro Almada


On 2 April 2013 18:53, Pedro Almada <[hidden email]> wrote:

> Dear listers,
>
> This is not strictly a confocal question since it's about a widefield
> system, but I think it's quite suited to the readers of this list.
>
> Our users of a DeltaVision system (an Olympus IX71) were complaining of
> "blurry" images. After checking that their parameters were normal we made a
> stack of 0.17 um beads and observed that the PSF was very wrong: we could
> see two spots instead of one! It's not the DIC slider (the obvious culprit)
> and it's independent of what dichroic or emission filters we use. The
> problem is present in all objectives but gets worse with magnification.
> With the 40x we just see elongated spots but with the 100x we clearly see
> two spots. This was not there before.
>
> You can observe all of this by yourselves in the files available on this
> folder. I've included stacks and comparison shots of PSF's acquired in
> December.
> https://www.dropbox.com/sh/i770v4a0a4owrb8/p_qBYW4E-2
>
> Do anyone have a clue on what could be causing this?
>
> Preemptive thanks for your input,
> Best regards,
> Pedro Almada
>

[Chris Tully]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

This is a very LATE reply, but I would suggest that you consider
upgrading to a camera with no fan.  Or, if you don't mind voiding the
warranty strip the case off the camera and use an external (not
mechanically coupled to the camera) fan to cool it.

The bottom line is that fan will almost always start to vibrate at some
point!

Chris Tully
Image Analysis Expert
www.ImageIncyte.com
[hidden email]
[hidden email]

On 4/24/2013 12:39 PM, Pedro Almada wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear Listers, especially to all those who contacted me off-list with
> suggestions,
>
> After much headscratching and some visits from Olympus and Image Solutions,
> we've finally pinpointed the problem. It seems the fan of the camera was
> introducing a vibration that was not detectable until we could upgrade the
> software to be able to expose for under 35ms. With 1ms exposures, we saw
> that the double beads were actually single beads vibrating at a fairly
> consistent direction and distance, which averaged to a "double" psf on both
> the eyepiece and camera!
>
> After further headstratching and turning everything off step by step we saw
> it was the fan of the camera (!) that was introducing the vibrations! It
> should be a matter of replacing that now.
>
> Anyway, I'd like to thank all those who offered help and I hope this story
> will actually be of use to someone in the future.
>
> Thank you,
> Pedro Almada
>
>
> On 2 April 2013 18:53, Pedro Almada <[hidden email]> wrote:
>
>> Dear listers,
>>
>> This is not strictly a confocal question since it's about a widefield
>> system, but I think it's quite suited to the readers of this list.
>>
>> Our users of a DeltaVision system (an Olympus IX71) were complaining of
>> "blurry" images. After checking that their parameters were normal we made a
>> stack of 0.17 um beads and observed that the PSF was very wrong: we could
>> see two spots instead of one! It's not the DIC slider (the obvious culprit)
>> and it's independent of what dichroic or emission filters we use. The
>> problem is present in all objectives but gets worse with magnification.
>> With the 40x we just see elongated spots but with the 100x we clearly see
>> two spots. This was not there before.
>>
>> You can observe all of this by yourselves in the files available on this
>> folder. I've included stacks and comparison shots of PSF's acquired in
>> December.
>> https://www.dropbox.com/sh/i770v4a0a4owrb8/p_qBYW4E-2
>>
>> Do anyone have a clue on what could be causing this?
>>
>> Preemptive thanks for your input,
>> Best regards,
>> Pedro Almada
>>

[Craig Brideau]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

The Hamamatsu 7422 PMT series can be purchased with an integral heat sink
and fan.  The controller lets you 'pause' the fan for short periods when
vibration would be an issue, allowing you to take a few scans before it has
to kick back in.  I wonder if there is anything like this for cameras?
 Otherwise water cooling might work; lets you move the fan away from the
camera.

Craig


On Thu, Aug 1, 2013 at 8:02 AM, Chris Tully <[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/**wa?A0=confocalmicroscopy<http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy>
> *****
>
> This is a very LATE reply, but I would suggest that you consider upgrading
> to a camera with no fan.  Or, if you don't mind voiding the warranty strip
> the case off the camera and use an external (not mechanically coupled to
> the camera) fan to cool it.
>
> The bottom line is that fan will almost always start to vibrate at some
> point!
>
> Chris Tully
> Image Analysis Expert
> www.ImageIncyte.com
> [hidden email]
> [hidden email]
>
>
> On 4/24/2013 12:39 PM, Pedro Almada wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/**wa?A0=confocalmicroscopy<http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy>
>> *****
>>
>> Dear Listers, especially to all those who contacted me off-list with
>> suggestions,
>>
>> After much headscratching and some visits from Olympus and Image
>> Solutions,
>> we've finally pinpointed the problem. It seems the fan of the camera was
>> introducing a vibration that was not detectable until we could upgrade the
>> software to be able to expose for under 35ms. With 1ms exposures, we saw
>> that the double beads were actually single beads vibrating at a fairly
>> consistent direction and distance, which averaged to a "double" psf on
>> both
>> the eyepiece and camera!
>>
>> After further headstratching and turning everything off step by step we
>> saw
>> it was the fan of the camera (!) that was introducing the vibrations! It
>> should be a matter of replacing that now.
>>
>> Anyway, I'd like to thank all those who offered help and I hope this story
>> will actually be of use to someone in the future.
>>
>> Thank you,
>> Pedro Almada
>>
>>
>> On 2 April 2013 18:53, Pedro Almada <[hidden email]> wrote:
>>
>>  Dear listers,
>>>
>>> This is not strictly a confocal question since it's about a widefield
>>> system, but I think it's quite suited to the readers of this list.
>>>
>>> Our users of a DeltaVision system (an Olympus IX71) were complaining of
>>> "blurry" images. After checking that their parameters were normal we
>>> made a
>>> stack of 0.17 um beads and observed that the PSF was very wrong: we could
>>> see two spots instead of one! It's not the DIC slider (the obvious
>>> culprit)
>>> and it's independent of what dichroic or emission filters we use. The
>>> problem is present in all objectives but gets worse with magnification.
>>> With the 40x we just see elongated spots but with the 100x we clearly see
>>> two spots. This was not there before.
>>>
>>> You can observe all of this by yourselves in the files available on this
>>> folder. I've included stacks and comparison shots of PSF's acquired in
>>> December.
>>> https://www.dropbox.com/sh/**i770v4a0a4owrb8/p_qBYW4E-2<https://www.dropbox.com/sh/i770v4a0a4owrb8/p_qBYW4E-2>
>>>
>>> Do anyone have a clue on what could be causing this?
>>>
>>> Preemptive thanks for your input,
>>> Best regards,
>>> Pedro Almada
>>>
>>>