LED vs. Halogen

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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Radazz
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LED vs. Halogen

#1 Post by Radazz » Sat Jan 04, 2020 5:26 pm

After experimenting with LED lighting for a few years now, I must say, for me anyway, LED is very nice for observation, but I get much better photographs with Halogen.

My experience, can’t speak for anyone else.

Radazz
Arnold, Missouri
Olympus IX70
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david_b
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Re: LED vs. Halogen

#2 Post by david_b » Sat Jan 04, 2020 6:16 pm

Would be interested to see a side by side comparision of the same slide under LED and Halogen lighting if possible
This article is helpful but the images are small:
http://www.microscopy-uk.org.uk/mag/ind ... mpare.html
To me, some of the images shown look better under LED and some under halogen.

Chris Dee
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Re: LED vs. Halogen

#3 Post by Chris Dee » Sat Jan 04, 2020 8:14 pm

Having used only 25w halogen my preference for LED may be skewed in some aspects. The high power LED I currently use enables me to capture at faster shutter speeds/lower ISO via liveview, with less radiated heat, reducing sample drying. The main reason I prefer LED however is rendering and contrast. Perhaps its my ageing eyesight but I find it much better for observations. Details seem to pop more.

I suspect there's no overall winner, personal preference and differences in eyesight being what they are.

Hobbyst46
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Re: LED vs. Halogen

#4 Post by Hobbyst46 » Sat Jan 04, 2020 9:50 pm

david_b wrote:
Sat Jan 04, 2020 6:16 pm
Would be interested to see a side by side comparision of the same slide under LED and Halogen lighting if possible
This article is helpful but the images are small:
http://www.microscopy-uk.org.uk/mag/ind ... mpare.html
To me, some of the images shown look better under LED and some under halogen.
The examples of stained tissues and other colorful objects, shown by David Walker, are impressive. However, I would love to see similar comparisons of less brightly colored and contrast-rich specimens: cells or protists under phase contrast/DIC/brightfield, for example.
A potentially interesting direction is the more natural-like balanced illumination from a new kind of LEDs, mentioned months ago by MichaelG.
MichaelG wrote:...
Michael, please help! where were those special LEDs you mentioned, that sport a better balanced spectrum ?

MichaelG.
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Re: LED vs. Halogen

#5 Post by MichaelG. » Sat Jan 04, 2020 10:14 pm

Hobbyst46 wrote:
Sat Jan 04, 2020 9:50 pm
A potentially interesting direction is the more natural-like balanced illumination from a new kind of LEDs, mentioned months ago by MichaelG.
MichaelG wrote:...
Michael, please help! where were those special LEDs you mentioned, that sport a better balanced spectrum ?
My pleasure ...

YUJI ... High ColourRendering Index
See this discussion: viewtopic.php?f=28&t=7536&p=66124&hilit ... dex#p66124

MichaelG.
Too many 'projects'

david_b
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Re: LED vs. Halogen

#6 Post by david_b » Sat Jan 04, 2020 10:18 pm

Hobbyst46 wrote:
Sat Jan 04, 2020 9:50 pm
A potentially interesting direction is the more natural-like balanced illumination from a new kind of LED's...
Are you referring to Olympus True Color?
https://www.olympus-lifescience.com/en/ ... color-led/

Hobbyst46
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Re: LED vs. Halogen

#7 Post by Hobbyst46 » Sat Jan 04, 2020 10:38 pm

david_b wrote:
Sat Jan 04, 2020 10:18 pm
Hobbyst46 wrote:
Sat Jan 04, 2020 9:50 pm
A potentially interesting direction is the more natural-like balanced illumination from a new kind of LED's...
Are you referring to Olympus True Color?
https://www.olympus-lifescience.com/en/ ... color-led/
Hi david_b, not these ones, there was some other brand of LEDs, not as yet in microscope illuminators I thing, just the chips... in Australia maybe...
Here, Michael pointed them out...
Last edited by Hobbyst46 on Sat Jan 04, 2020 10:42 pm, edited 1 time in total.

Hobbyst46
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Re: LED vs. Halogen

#8 Post by Hobbyst46 » Sat Jan 04, 2020 10:41 pm

MichaelG. wrote:
Sat Jan 04, 2020 10:14 pm
Hobbyst46 wrote:
Sat Jan 04, 2020 9:50 pm
A potentially interesting direction is the more natural-like balanced illumination from a new kind of LEDs, mentioned months ago by MichaelG.
MichaelG wrote:...
Michael, please help! where were those special LEDs you mentioned, that sport a better balanced spectrum ?
My pleasure ...

YUJI ... High ColourRendering Index
See this discussion: viewtopic.php?f=28&t=7536&p=66124&hilit ... dex#p66124

MichaelG.
YES!!! thanks.

david_b
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Re: LED vs. Halogen

#9 Post by david_b » Sat Jan 04, 2020 11:42 pm

Hobbyst46 wrote:
Sat Jan 04, 2020 10:38 pm
david_b wrote:
Sat Jan 04, 2020 10:18 pm
Hobbyst46 wrote:
Sat Jan 04, 2020 9:50 pm
A potentially interesting direction is the more natural-like balanced illumination from a new kind of LED's...
Are you referring to Olympus True Color?
https://www.olympus-lifescience.com/en/ ... color-led/
Hi david_b, not these ones, there was some other brand of LEDs, not as yet in microscope illuminators I thing, just the chips... in Australia maybe...
Here, Michael pointed them out...
Oh dear, after reading the Olympus paper I want a BX53 :roll:

MicroBob
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Re: LED vs. Halogen

#10 Post by MicroBob » Sun Jan 05, 2020 8:26 am

Hi together,
the limited output of typical LEDs in the blue-green range around 500 nm wavelength is probably especially disadvantageous for pathologists who look at tissue that is stained in the red-orange range. Warm white LEDs do better in this range and combined with filtering should give a quite nice colour rendering. The LED is very powerful to begin with and can handle some light loss due to the filtering.
I'm planning experiments with the combination of warm-white LEDs and blue-green LEDs for room lighting but haven't really started yet.

Bob

Hobbyst46
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Re: LED vs. Halogen

#11 Post by Hobbyst46 » Sun Jan 05, 2020 10:51 am

MichaelG wrote:...
MicroBob wrote:...
Looks like some progress since what I have previously seen.
https://store.yujiintl.com/collections/ ... d-emitters

Here are potential candidates, although I did not look at the specs:
BC Series High CRI COB LED - 135XL - Pack: 10 pcs . 70 USD, say, for a pack of 9W or 5W LEDs, plus shipping. For someone that can build illuminators (including the heat sinks, constant current control etc etc) might come out much cheaper than ready-made Olympus illuminators.

For some very old microscopes, original halogen did not exist, and buying a complete halogen lamp and modifying it to fit the microscope is not inexpensive either.

EDIT: I found an old forum that discusses these LEDs and shows results - for home lights and photography, not microscopy, and even a spectrum, cited in the image below.
I do not know that forum, neither did I compare the spectrum with the manufacturer's data sheet, but anyway, one should look carefully at the specs before purchasing.
Attachments
YUJI LED SPECTRUM.jpg
YUJI LED SPECTRUM.jpg (70.12 KiB) Viewed 9033 times

MichaelG.
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Re: LED vs. Halogen

#12 Post by MichaelG. » Sun Jan 05, 2020 7:33 pm

I have no actual evidence to support this, but: I would be very surprised if Olympus makes its own LEDs
... It seems more likely that they buy-in the chips from someone like YUJI, and have simply registered a nice descriptive name for the product.

MichaelG.
Too many 'projects'

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Radazz
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Re: LED vs. Halogen

#13 Post by Radazz » Mon Jan 06, 2020 3:26 pm

david_b wrote:
Sat Jan 04, 2020 6:16 pm
Would be interested to see a side by side comparision of the same slide under LED and Halogen lighting if possible
This article is helpful but the images are small:
http://www.microscopy-uk.org.uk/mag/ind ... mpare.html
To me, some of the images shown look better under LED and some under halogen.
Hmmm the only stand I have that I can easily switch between LED and Hal with a trinocular head is my Zeiss Standard with Phase Contrast.
Also equipped with POL, and I have Reinberg and darkfield filters.
Quite a few comparative options. Sounds like fun, might take a while.

Cool discussion!

Radazz
Arnold, Missouri
Olympus IX70
Olympus BX40
Olympus SZ40

mintakax
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Re: LED vs. Halogen

#14 Post by mintakax » Mon Jan 06, 2020 7:00 pm

I have put Nanodyne LED units on both of the scopes I've used (Olympus BHS/BH2 DIC and Nikon TMD DIC 100W ). Both scopes came with 100W halogen. In both cases the LED was substantially brighter. I mainly went with LED to avoid heating up organisms, so I was less concerned with the photographic aspects.

david_b
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Re: LED vs. Halogen

#15 Post by david_b » Mon Jan 06, 2020 7:41 pm

Did you find the 100w BHS to be a microbe-boiler?

mintakax
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Re: LED vs. Halogen

#16 Post by mintakax » Tue Jan 07, 2020 1:49 am

david_b wrote:
Mon Jan 06, 2020 7:41 pm
Did you find the 100w BHS to be a microbe-boiler?
The samples certainly dried out much faster with the 100W , but I honestly cant say that I saw any creatures being harmed by it, I just figured that they were.

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