Re: Boosting bright field resolution with dichroic filters

Posted by Sergey Tauger on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Boosting-bright-field-resolution-with-dichroic-filters-tp7583983p7583984.html

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Dear Mr. Smith,

It is a common practice to insert a light filter into optical path, but more
common way is to place 50 mm wide filter (a cheap one, like stained glass)
between lamp and condenser. A common choice is blue-green to green light
(500-550 nm). The reasons are:
1. Condensers are not usually compensated for blue or red. Surprisingly,
Nikon manufactures good objectives, but their condensers really suffer from
chromatic aberrations.
2. When speaking about brightfield we should not forget about light spread
and absorbance. Both are in reverse proportion to wavelength
3. When limited to a narrow light spectrum, we should increase lamp voltage
that can shorten its life significantly.

Best,
Sergey Tauger