Re: Darkfield Condenser

Kevin:

Are you again bashing DF for biological applications? :-)

Dan might be talking about the one depicted at http://www.tfttools.com/BM100FL.htm

This scope isn't exactly what you would use for "scientific" work. But then again, what is "scientific" work? If that's the scope in question, we can forget about adding Phase or DIC.

You are talking about the "standard for researchers" without being too specific. I know that you only refer to biological applications (e.g. life cell analysis). But you may want to clarify this in your next conquest against DF.

Regarding the resolution advantage of DF vs. DIC and Phase, I completely disagree. It does not only depend on the size of the subresolution particle but also on the fact that you can detect them at all. DIC is useless with any cell tissue that is birefringent (e.g. nerve cell cultures). That's why Zeiss introduced a newly improved interference technology to capture this very important market segment. Phase has limitation in resolution. DF can easlily accomplish a resolution of up to NA 1.10. With Phase, the maximum obtainable NA is around 1.15 (assuming NA(obj) = 1.40 and NA(cond) = 0.90).

It really does not matter how many times you have sold a DF setup. You told us this already several times. Ironically, Nikon still offers DF components for their new Eclipse series scopes. Maybe they are just catering to some life blood vampires out there. Maybe you were just in the wrong market trying to sell DF.

Anyway, I use DF almost everytime I need to get some answers from certain samples (...yes, they are not biological samples).

BTW, why do you think that most "researchers" are using DIC instead of COL? - Because, they don't know how to setup proper oblique illumination. The same applies to DF. Most people fail misearbly because they just don't have the skills. But then again, why sell a $300 COL setup when we can sell a $6000 DIC setup? - DIC is good for business.

Cheers,

Gregor


"Kevin Cunningham" <smskjv@xxxxxxxxxxxxxx> wrote in message news:VYUNh.16614$tD2.15683@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

<mythirdeyeisopen@xxxxxxxxx> wrote in message news:1174885352.307049.58750@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I recently bought an M Series microscope (Model BM-100FL). I want to
get a darkfield condenser to look at live cells, but I'm having
trouble determining which would be the correct one to buy. The
specifications provided in my manual indicate:

Condenser - Abbe N.A. 1.25

I'd like to buy a cheap one off ebay if possible. Can I buy a
condenser rated "D 1.20A" ? Are all condensers the same diameter? How
do I know if it will fit my scope, and lastly, how difficult is it to
install?

I really appreciate any answers you can give me.

Thanks,
- Dan


You've made just about every mistake you could have. Phase contrast or Differential Interefenece Contrast (DIC) are the standards for researcher. These techniques fully support live cells. I've been in the microscope industry since the late '70's and I've sold one dry dark field condenser.

Now the first question would be what microscope is an M? We need to know the maker. Next do you have a diaphragm or a stop with your 100X? If not it doesn't matter which condenser you get the 100X won't work. You can't get high resolution with dark field since you have to reduce the NA of the objective. If you want to use an oil dark field then it will say "oil dark field". The type of condenser you get will be based on the kind of microscope you have, different types of mounts are used by different makers. There is an old fashioned type that is kinda universal but it only applies to some student microscopes.

Thanks, let us hear back from you.

Kevin Cunningham
SMS





.

Relevant Pages

  • Re: Nikon, Leica, or Zeiss?
    ... Axiostar (the Axiostar and Axiostar Plus are 99.9% the same scope!); ... Similar used parts for older Zeiss models sell ... objective with out the condenser. ... I chose Olympus WHK10x 20L high eye point eyepieces rather than Zeiss ...
    (sci.techniques.microscopy)
  • Re: Accu-scope questions
    ... I was leery about buying a used scope, especially on eBay, as it ... As I said, some images are as sharp as a tack, while others ... I never before used an iris diaphragm for taking pictures, ... Never before used a scope with a condenser that could be moved up ...
    (sci.techniques.microscopy)
  • Re: microscope for bacteriology ( lomo or leica )
    ... > For this application you need an aplanat-achromat condenser. ... I would not buy either scope you mentioned even for standard ... I wanna buy a microscope that is capable of getting ... >> I was thinking about lomo multiscope BMH4-BH ...
    (sci.techniques.microscopy)
  • Re: Photomicrography ... objective questions (and general advice)
    ... E200-F only supports Koehler illumination with its Abbe condenser. ... uses a quirky relay lens to make Koeher illumination work. ... Don't buy a new scope if you budget is below US$3000. ...
    (sci.techniques.microscopy)
  • Re: Darkfield Condenser
    ... really care which technique a researcher uses, ... cell analysis). ... get a darkfield condenser to look at live cells, ... microscope industry since the late '70's and I've sold one dry dark field ...
    (sci.techniques.microscopy)
Loading