Re: Brightness difference Hg vs LED

Posted by Watkins, Simon C on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Brightness-difference-Hg-vs-LED-tp7581211p7581224.html

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We actually did a lot of work on this a year or so back.  Specifically
with the Lumencor Spectra X.  There is a lot more power with these newer
diode sources.  These numbers are using Chroma filter sets, the effort was
spent because we wanted to maximize speed (see our PLOS one paper last
year on imaging danio blood flow).  Essentially the folks at Chroma came
up with a design which only involves two cubes, a dapi/fitc(GFP)/tritc/cy5
cube and a cyan/yellow/red fp cube. So as the exciter filters are part of
the light source we could maximize switching speed for most expts (no cube
change), using triggered acquisition and a sub arrayed CMOS detector this
can be hundreds of multicolor images/second
All powers are measured at the end of the light guide with a Coherent
power meter. The open power is total light coming down the guide with no
filter in place, filtered is self explanatory as is the filter wavelength,
powers are total mW not/unit area.
Hope this helps

 
 
 
 
 
  Nominal wavelength Open Power   filtered Filter Wavelength
 
 
  390nm 220 185 395/25
 
 
  440nm 322 190 440/20
 
 
  475nm 191 147 470/24
 
 
  514nm 91 70 508/24
 
 
  550nm 366 220 550/15
 
 
  575nm 800 230 575/22
 
 
  632nm 265 208 640/30


Simon Watkins Ph.D

Professor and Vice Chair Cell Biology
Professor Immunology
Director Center for Biologic Imaging
University of Pittsburgh
Bsts 225 3550 terrace st
Pittsburgh PA 15261
Www.cbi.pitt.edu <http://Www.cbi.pitt.edu/>
412-352-2277






On 11/5/13, 5:09 PM, "Julio Vazquez" <[hidden email]> wrote:

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>
>A quick comparison in our lab gave the following:
>
>488 nm (FITC) band of an LED-based light engine (Lumencor): 40 mW
>300 W Xenon Sutter illuminator (probably our brightest light source) with
>FITC EX filter: 70 mW
>
>both measured at the exit of the fiber or light guide.
>
>I agree that LED based light engines are probably at least as good
>(power-wise) as most lamps, plus they have other benefits. Charts such as
>the one found here should be a good guide regarding relative power:
>
>http://lumencor.com/wp-content/uploads/2011/09/SpectraX-LE-User-Manual1.pd
>f
>
>
>Julio Vazquez, PhD
>Fred Hutchinson Cancer Research Center
>Seattle, WA 98109
>
>http://www.fhcrc.org/en.html
>
>
>
>
>On Nov 5, 2013, at 1:50 PM, Kurt Thorn wrote:
>
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>>
>> My sense is also that the new LED sources are brighter than Hg lamps,
>>except possibly at the very brightest mercury peaks (365, 546 nm).  For
>>GFP, they are for sure brighter.  True LEDs have been somewhat dim in
>>the 560 nm range, which is why Lumencor uses an LED-pumped phosphor for
>>those wavelengths.  This gives very bright 560 emission.
>>
>> Kurt
>>
>> On 11/5/2013 10:21 AM, Armstrong, Brian wrote:
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>>>
>>> Hi Phil I would say that the new LED sources and Light Engines will be
>>>brighter than mercury sources. For example I compared an Exfo to a SOLA
>>>light engine and the light engine is brighter. The new Lumen Dynamics
>>>XLED should provide much better illumination than a mercury source.
>>> Hopefully, mercury sources will soon be a thing of the past.
>>> Cheers,
>>>
>>> Brian D Armstrong PhD
>>> Associate Research Professor
>>> Director, Light Microscopy Core
>>> Beckman Research Institute
>>> City of Hope
>>> Dept of Neuroscience
>>> 1450 E Duarte Rd
>>> Duarte, CA 91010
>>> 626-256-4673 x62872
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: Confocal Microscopy List
>>>[mailto:[hidden email]] On Behalf Of Philip Oshel
>>> Sent: Tuesday, November 05, 2013 9:57 AM
>>> To: [hidden email]
>>> Subject: Brightness difference Hg vs LED
>>>
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>>>
>>> All,
>>>
>>> I had this question put to me by a new faculty member, and don't have a
>>> ready answer:
>>> "Is there a ballpark percentage for how much less bright an LED vs a
>>> standard mercury lamp light?"
>>> This is for regular epifluorescence, not confocal.
>>>
>>> This is in the realm of arm-waving over a picture of beer (a good, dark
>>> stout), ignoring brands, how old the Hg bulb is, ex/em cubes, which
>>>part
>>> of the spectrum is used, and all that. Personally, I'd think the answer
>>> is more like, "Doesn't matter, the dimmer system is still too bright to
>>> use all the available light and not damage the specimen." But ... ?
>>>
>>> Phil