FV1000 : HV vs gain

[Oky]

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http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Hello listers,

I am wondering the difference between HV and gain in the operational
software of FV1000. Please educate me. Thanks very much in advance.

Ohkyung

[James Beals]

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Hello Ohkyung,
The HV is the current supplied to the PMT.
The Gain is the amplification of the signal from the PMT.
hope this helps.
best
James Beals
[hidden email]
734.936-2051

205 Zina Pitcher Place
2038 MBNI
Molecular and Behavioral Neuroscience Institute
University of Michigan
Ann Arbor, Mi
48109





On Sep 3, 2008, at 11:28 AM, Ohkyung Kwon wrote:

> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> Hello listers,
>
> I am wondering the difference between HV and gain in the  
> operational software of FV1000. Please educate me. Thanks very much  
> in advance.
>
> Ohkyung

[Mario-2]

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Ohkyung, James,

I admittedly have never used an FV1000, but I am surprised that the
HV refers to current rather than PMT operating voltage (which drives
the current). Current generated in a PMT is exponentially sensitive
to the voltage applied and each tube will have an optimal voltage
(usually several hundred) that gives a linear current output over a
range of light intensities. Gain, on the other other hand, would be
normally pertinent to amplification of the PMT current output to
something suitable for the A/D converters that digitize the signal.

A clarification would helpful. Thanks,

Mario

>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>Hello Ohkyung,
>The HV is the current supplied to the PMT.
>The Gain is the amplification of the signal from the PMT.
>hope this helps.
>best
>James Beals
>[hidden email]
>734.936-2051
>
>205 Zina Pitcher Place
>2038 MBNI
>Molecular and Behavioral Neuroscience Institute
>University of Michigan
>Ann Arbor, Mi
>48109
>
>
>
>
>
>On Sep 3, 2008, at 11:28 AM, Ohkyung Kwon wrote:
>
>>Search the CONFOCAL archive at
>>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>>
>>Hello listers,
>>
>>I am wondering the difference between HV and gain in the
>>operational software of FV1000. Please educate me. Thanks very much
>>in advance.
>>
>>Ohkyung

--
________________________________________________________________________________
Mario M. Moronne, Ph.D.

[hidden email]
[hidden email]
[hidden email]

[Barry O'Brien]

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

On the FV1000 the gain is applied after the A/D conversion. This becoms
evident if the histogram is studied closely on images collected at gain
settings higher than 1.0.  We confirmed this through dialogue with the
local consultant and the manufacturer.
I understand that other makes have a gain stage prior to this step, as
Mario suggests.

Regards,

Barry


At 05:16 a.m. 4/09/2008, you wrote:

>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>Ohkyung, James,
>
>I admittedly have never used an FV1000, but I am surprised that the HV
>refers to current rather than PMT operating voltage (which drives the
>current). Current generated in a PMT is exponentially sensitive to the
>voltage applied and each tube will have an optimal voltage (usually
>several hundred) that gives a linear current output over a range of light
>intensities. Gain, on the other other hand, would be normally pertinent to
>amplification of the PMT current output to something suitable for the A/D
>converters that digitize the signal.
>
>A clarification would helpful. Thanks,
>
>Mario
>
>>Search the CONFOCAL archive at
>>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>>
>>Hello Ohkyung,
>>The HV is the current supplied to the PMT.
>>The Gain is the amplification of the signal from the PMT.
>>hope this helps.
>>best
>>James Beals
>>[hidden email]
>>734.936-2051
>>
>>205 Zina Pitcher Place
>>2038 MBNI
>>Molecular and Behavioral Neuroscience Institute
>>University of Michigan
>>Ann Arbor, Mi
>>48109
>>
>>
>>
>>
>>
>>On Sep 3, 2008, at 11:28 AM, Ohkyung Kwon wrote:
>>
>>>Search the CONFOCAL archive at
>>>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>>>
>>>Hello listers,
>>>
>>>I am wondering the difference between HV and gain in the operational
>>>software of FV1000. Please educate me. Thanks very much in advance.
>>>
>>>Ohkyung
>
>
>--
>________________________________________________________________________________
>Mario M. Moronne, Ph.D.
>
>[hidden email]
>[hidden email]
>[hidden email]

Dr Barry O'Brien
Dept of Biological Sciences,
University of Waikato
Private Bag 3105
HAMILTON
New Zealand

Fax [phone]
Phone [phone]

[Stephen Cody]

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

G'day Ohkyung,

I'm only new to the FV1000, so if others disagree please correct me.

HV refers to High Voltage and is the number of volts applied to the PMT.
To add to your confusion this is sometimes also called "Gain" or "PMT
Gain" by other manufacturers.

As you and others have pointed out the FV1000 also has a "Gain"
function, and this is an amplification of the PMT signal as previously
pointed out.

Generally speaking I think it is preferable to have this amplification
gain switched off (ie. set to 1), and use only the HV to increase
signal. I presume as the Amp. Gain feature is offered by Olympus, there
must be situations where if the signal strength is low, and if
increasing the HV further results in more noise (Lower signal/noise
ratio (S/N) ), then using some Amplifier gain and a little less PMT HV
may produce a better S/N ratio (ie. a less noisy image). I have not yet
found that set of circumstances. Can anyone comment in what set of
circumstances the Amp. Gain becomes useful?

Cheers
Steve  

Stephen H. Cody
Microscopy Manager
Central Resource for Advanced Microscopy
Ludwig Institute for Cancer Research
PO Box 2008 Royal Melbourne Hospital
Victoria,      3050
Australia
Tel: [phone]    Fax: [phone]
email: [hidden email]
www.ludwig.edu.au/labs/confocal.html
www.ludwig.edu.au/confocal

Tip: Learn how to receive reminders about you microscope booking:
www.ludwig.edu.au/confocal/Local/Booking_Hint.htm  

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On
Behalf Of Barry O'Brien
Sent: Thursday, 4 September 2008 8:07 AM
To: [hidden email]
Subject: Re: FV1000 : HV vs gain

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

On the FV1000 the gain is applied after the A/D conversion. This becoms
evident if the histogram is studied closely on images collected at gain
settings higher than 1.0.  We confirmed this through dialogue with the
local consultant and the manufacturer.
I understand that other makes have a gain stage prior to this step, as
Mario suggests.

Regards,

Barry


At 05:16 a.m. 4/09/2008, you wrote:

>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>Ohkyung, James,
>
>I admittedly have never used an FV1000, but I am surprised that the HV
>refers to current rather than PMT operating voltage (which drives the
>current). Current generated in a PMT is exponentially sensitive to the
>voltage applied and each tube will have an optimal voltage (usually
>several hundred) that gives a linear current output over a range of

light
>intensities. Gain, on the other other hand, would be normally pertinent
to
>amplification of the PMT current output to something suitable for the
A/D

>converters that digitize the signal.
>
>A clarification would helpful. Thanks,
>
>Mario
>
>>Search the CONFOCAL archive at
>>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>>
>>Hello Ohkyung,
>>The HV is the current supplied to the PMT.
>>The Gain is the amplification of the signal from the PMT.
>>hope this helps.
>>best
>>James Beals
>>[hidden email]
>>734.936-2051
>>
>>205 Zina Pitcher Place
>>2038 MBNI
>>Molecular and Behavioral Neuroscience Institute
>>University of Michigan
>>Ann Arbor, Mi
>>48109
>>
>>
>>
>>
>>
>>On Sep 3, 2008, at 11:28 AM, Ohkyung Kwon wrote:
>>
>>>Search the CONFOCAL archive at
>>>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>>>
>>>Hello listers,
>>>
>>>I am wondering the difference between HV and gain in the operational
>>>software of FV1000. Please educate me. Thanks very much in advance.
>>>
>>>Ohkyung
>
>
>--
>_______________________________________________________________________

_________
>Mario M. Moronne, Ph.D.
>
>[hidden email]
>[hidden email]
>[hidden email]

Dr Barry O'Brien
Dept of Biological Sciences,
University of Waikato
Private Bag 3105
HAMILTON
New Zealand

Fax [phone]
Phone [phone]


This communication is intended only for the named recipient and may contain information that is confidential, legally privileged or subject to copyright; the Ludwig Institute for Cancer Research does not waiver any rights if you have received this communication in error.
The views expressed in this communication are those of the sender and do not necessarily reflect the views of the Ludwig Institute for Cancer Research.

[Stanislav Vitha]

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Hi,
I agree with Steve that the "Gain" on FV1000  should be left untouched (set
to 1). And that is also what the Olympus specialist told me during the initial
training on our system.  If I understand correctly, the Gain control just
multiplies the digitized pixel intensity by the set number (e.g., 1.25). This can
be  done during post-processing in image analysis software of your choice.    
Perhaps someone from Olympus could comment when using "gain" would be
beneficial?

When the signal is weak and would require high HV (above ~ 750V on our
system) leading to high noise,  I use lower HV and adjust the lookup table to
make the image look brighter, or even better, switch to photon counting (in
that case, you definitely have to tweak the LUT to see anything in the image).

Stan


Dr. Stanislav Vitha      
Microscopy and Imaging Center
Texas A&M University
BSBW 119
College Station, TX 77843-2257

http://microscopy.tamu.edu

On Thu, 4 Sep 2008 12:15:34 +1000, Stephen Cody
<[hidden email]> wrote:

>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>G'day Ohkyung,
>
>I'm only new to the FV1000, so if others disagree please correct me.
>
>HV refers to High Voltage and is the number of volts applied to the PMT.
>To add to your confusion this is sometimes also called "Gain" or "PMT
>Gain" by other manufacturers.
>
>As you and others have pointed out the FV1000 also has a "Gain"
>function, and this is an amplification of the PMT signal as previously
>pointed out.
>
>Generally speaking I think it is preferable to have this amplification
>gain switched off (ie. set to 1), and use only the HV to increase
>signal. I presume as the Amp. Gain feature is offered by Olympus, there
>must be situations where if the signal strength is low, and if
>increasing the HV further results in more noise (Lower signal/noise
>ratio (S/N) ), then using some Amplifier gain and a little less PMT HV
>may produce a better S/N ratio (ie. a less noisy image). I have not yet
>found that set of circumstances. Can anyone comment in what set of
>circumstances the Amp. Gain becomes useful?
>
>Cheers
>Steve  
>
>Stephen H. Cody
>Microscopy Manager
>Central Resource for Advanced Microscopy
>Ludwig Institute for Cancer Research
>PO Box 2008 Royal Melbourne Hospital
>Victoria,      3050
>Australia
>Tel: [phone]    Fax: [phone]
>email: [hidden email]
>www.ludwig.edu.au/labs/confocal.html
>www.ludwig.edu.au/confocal
>
>Tip: Learn how to receive reminders about you microscope booking:
>www.ludwig.edu.au/confocal/Local/Booking_Hint.htm  
>
>-----Original Message-----
>From: Confocal Microscopy List [mailto:[hidden email]]

On

>Behalf Of Barry O'Brien
>Sent: Thursday, 4 September 2008 8:07 AM
>To: [hidden email]
>Subject: Re: FV1000 : HV vs gain
>
>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>On the FV1000 the gain is applied after the A/D conversion. This becoms
>evident if the histogram is studied closely on images collected at gain
>settings higher than 1.0.  We confirmed this through dialogue with the
>local consultant and the manufacturer.
>I understand that other makes have a gain stage prior to this step, as
>Mario suggests.
>
>Regards,
>
>Barry
>
>
>At 05:16 a.m. 4/09/2008, you wrote:
>>Search the CONFOCAL archive at
>>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>>
>>Ohkyung, James,
>>
>>I admittedly have never used an FV1000, but I am surprised that the HV
>>refers to current rather than PMT operating voltage (which drives the
>>current). Current generated in a PMT is exponentially sensitive to the
>>voltage applied and each tube will have an optimal voltage (usually
>>several hundred) that gives a linear current output over a range of
>light
>>intensities. Gain, on the other other hand, would be normally pertinent
>to
>>amplification of the PMT current output to something suitable for the
>A/D
>>converters that digitize the signal.
>>
>>A clarification would helpful. Thanks,
>>
>>Mario
>>
>>>Search the CONFOCAL archive at
>>>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>>>
>>>Hello Ohkyung,
>>>The HV is the current supplied to the PMT.
>>>The Gain is the amplification of the signal from the PMT.
>>>hope this helps.
>>>best
>>>James Beals
>>>[hidden email]
>>>734.936-2051
>>>
>>>205 Zina Pitcher Place
>>>2038 MBNI
>>>Molecular and Behavioral Neuroscience Institute
>>>University of Michigan
>>>Ann Arbor, Mi
>>>48109
>>>
>>>
>>>
>>>
>>>
>>>On Sep 3, 2008, at 11:28 AM, Ohkyung Kwon wrote:
>>>
>>>>Search the CONFOCAL archive at
>>>>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>>>>
>>>>Hello listers,
>>>>
>>>>I am wondering the difference between HV and gain in the operational
>>>>software of FV1000. Please educate me. Thanks very much in advance.
>>>>
>>>>Ohkyung
>>
>>
>>--
>>________________________________________________________________

_______

>_________
>>Mario M. Moronne, Ph.D.
>>
>>[hidden email]
>>[hidden email]
>>[hidden email]
>
>Dr Barry O'Brien
>Dept of Biological Sciences,
>University of Waikato
>Private Bag 3105
>HAMILTON
>New Zealand
>
>Fax [phone]
>Phone [phone]
>
>
>This communication is intended only for the named recipient and may contain

information that is confidential, legally privileged or subject to copyright; the
Ludwig Institute for Cancer Research does not waiver any rights if you have
received this communication in error.
The views expressed in this communication are those of the sender and do not
necessarily reflect the views of the Ludwig Institute for Cancer Research.