🔬 Making microscope filters: Darkfield, Rheinberg, Oblique 

Hey Olivier, just wanted to tell you that what you say about the blue filter isnt correct. The main function of the blue filter is to get sharper image (higher image resolution) and reduce effect of light diffraction. It is because the wave length of the light perceived by human is between 400nm and 700nm. 400nm is blue while 700 nm is red. It means that the wave length of the red light which is around 700nm is almost two times longer to the shortest wave length human can perceive. Using the shorter wavelength can make a big difference when we deal with very high magnification levels. Just saying since I study color since years now and thought you might find it useful.. unless you already found it in a future as this video is 3 years old :). Thank you for all great job you do with your videos. They are really super helpful and I love them all. Cheers!

This is fantastic, thank you! I'd love to see more videos about small modifications/different techniques like this!

If you want to use glass, you can find 32mm (or just about any sized) watch glasses really cheaply on Amazon. I got 10 glasses, 32mm by 1mm thick for less than £5! They fit perfectly in my filter holder.

I just made a dark field filter for my microscope. For the dark spot, I stuck some black electrical tape on the bottom of a triple A battery, for a pattern, then cut around that with scissors, peeled it off and stuck that on my clear plastic disk. Works great, thank you for the information.

A disk of tin foil might work as well to make the light stop totally opaque just glue it into the glass disk and paint it with a sharpie so it isn't reflective.

Love your channel - content that's actually useful, clear explanations of why and what you're showing, comparisons (including failed / mistakes / less effective), all the details. Just wanted to let you know that you are appreciated!

using adhesive vinyl (can be opaque or transparent with colour) or even using insulation tape would be quite effective. even those tins of chocolates have a very good variation in colour films that wrap the chocolates you could sandwich them between two filter lenses with ease. just a suggestion :) im still choosing which microscope to get i had one as a child years ago which since has vanished :(

Thank you, Oliver! I am very interested in DIY modifications like this for photography. Your experimental findings about Rheinberg filter color density was very instructive.

Unfortunately, I dropped and broke my blue filter that came with my microscope in half while taking it out of the box in excitement.. I found your resources and used some tinfoil, sharpie marker, and scotch tape to both repair the blue light filter and turn it into a dark field patch stop. It looks amazing, but I had to change the size of the center 3 times before it performed correctly... My microscope has the swing-out filter holder and I can get some of the oblique illumination effects with the dark field stop I made and swinging the filter holder in and out! Thanks again for the awesome resources! You're the best!

You're videos are so expertly done. Thank you for sharing all of your valuable knowledge and expertise.

Really well put, with so much practical information. Oliver, this technical channel of yours is a gold mine.

I tried it and felt great. Thank you for your input

I can watch your vids for hours

silkscreen and photo etching, similar to circuit board making, would be my choice for producing one offs. or for thicker material water jet cutting.

a dremel and some variety of choice tips would help in making the dark field filters out of harder metal type discs. this is an awesome video! it gives me lots of ideas im going to experiment wif regarding making my own filters, etc. cheers!

I can see how excited you are. Thanks for sharing that excitement along with the info keep it up! Science is fun

Oh wow. I was about ready to a few hundred on a dark field condenser cause I thought it was the only way to do dark field 😬 Thanks for the video 😁

Very useful! I'm gonna try this out

Fabulous, thank you! You've provided the answers I was looking for.

LED and halogen filament are both small point sources of illumination. I think better dispersion of the led light would improve the side illumination say with a prismatic lens. Great instructional video btw as usual excellent and easy to follow information well done

Awesome.Thanks...

Very concise and easy to understand!

This will be extremely helpfull for me, thank you !

Love your channel. Thank you for your generous contribution of time in making these videos. I'd like to suggest a topic for a video if you haven't already done it: A video on how to clean slides and what to expect from new slides from a box. We just got a very nice stereo microscope for the kids. But the biggest problem I have encountered is that the slides / covers that were included with the scope are absolutely horribly corrupt right out of the box, handled with much care. There are many different types of corruptions: flaw / bubbles in the glass, foreign matter on the glass, scratches, etc. It's almost as if they included recycled, poorly cleaned slides. I won't mention the company because I LOVE the scope. But would be very valuable for us to see a video on how to clean slides and covers. Best wishes!

Man every time I get an idea to save money I see you already done it happy to see it works thank you for the video

Do you have a pdf or image file of the filters as you printed them out?

Thank you very much

i've found your videos to be one of the best resources shopping for a microscope. hard shopping for something you know little about

Great explanation thx .

Estaba esperando un vídeo sobre este tema!! Gracias, estaré pendiente de los siguientes!! Saludos desde Guatemala!!

Very good video, thanks Sir for increasing my knowledge but one request could you upload videos without music in background? Because I don't like music.

Excellent and interesting video, can't wait to try it out :) thanks for posting

Have you tried a filter with a dark center but different colors around the edge. Could be interesting to see the effect of rotating the filter.

Some of these samples/ images would be striking with stacking several images at different focal lengths. Have you done any experiments with stacking? It's more computer oriented than microscope, but would be fun. I have not tried stacking but it's on my to-do list.

Darkfield seems to have two interpretations: the first is the one shown here using a filter disk; the second seems to be a ring of light shone through the objective lens itself. Olympus has objective lenses that do this. I guess as long as there's a dark background surrounded by a ring of light then it gives the same effect but the first method shines light through the bottom of the specimen and the second from the top. This must surely give very different views.

I love it! Cheap and easy!

i learn so much from watching your video...thank you

Thanks for this great information

Beautifully done! 👍

Seems like for many microscopes, instead of darkfield being a filter, it's a whole different condenser. Not very convenient for this type of experimentation--not really that convenient in general since swapping out condensers is a lot more of a hassle than just swapping filters. Are darkfield condensers inherently better in some way?

I bought clear acetate sheets today from a craft store for $2.60. I am going to use cardboard, and colored markers to make a variety of filters for relatively free of cost. Your thoughts?

For single LEDs, placing a fly-eye lens over the light source should do the trick

9:11 … I am an astronomer and if you touch my optical surfaces like that i would probably kill you !!!! 😂

Thx

Спасибо! Огромное спасибо!

you explain evreythin do great i love to see your videos

One may also be able to utilize a 3D Printer in order to make some interesting filters. I'm not sure at what temperature the halogen bulbs operate (if I had one, I'd put a temperature probe on it and see), so one may have to print the filters with ABS, PETG or another plastic which has a higher melting point than PLA.

Fantástico!!!

SUPERB (as usual).

Thank you!!

can you place the patch stop right on top of the Kohler illuminator if you don't have a filter holder

Great video. Very informative!

Thank you 😍😍

You are a superman!! Woooww incredible work! greetings from mexico!

Thanks for this, very interesting. :)

I got a Leica DM300, which set of filters do you recommend (I mainly will use it for mycology purposes) thank you in advance

Can you recommend a darkfield filter holder and replacement objective lenses for an old Swift International colligate microscope? Model number #75E6020 M220-400 series. Thank you!

why do u not make phase contrast filters

man, you are the best

Hi for all of these last images specially the one you said you had no filters (~min 17:24/21:21 ), you still had the blue filter in and then added additional filters to it for the additional images. I ask because my microscope the image is reddish/ yellow and its difficult to get the contrast of the samples (single layer transition metal dichalcogenides, opaque sample)

Do you just use extension tubes and a c mount adapter for dslr/mirrorless recordings? I heard the Amscope multiplier ef to c is really soft. Wondering if anybody has tried any other type of magnifiers out there?

Excelente...muchísimas gracias

Do you have a formula or a plan that guide you in the size of the inner darker circle in your homemade filters?

Very useful. Thanks for sharing. Which filter would be best to observe live bacteria? Thanks.

Is that the Tyndall effect you are talking about?

My microscope's manufacturer sells a specific "darkfield condenser" for a hundred bucks. Why do they do that if I can just use a patch stop?

very cool!

What is 1.27k ? What # is that supposed to be? 127,000!? Or 1,270? Or 1,027?

Looks like my laser cutter is going to get some use pretty soon :D

Thank you very much for your very good videos! If this works that good, so why is a separate darkfield condenser so expensive? Is it much better?

What magnification do you use the most in your videos. My Brunel microscope is 10x60 at it highest.

Nice really, do you have any idea about inverted microscope to convert dark field or phase contrast?

Very useful video! Thank you! You are making really nice educational series! And I have a question about the condenser - Can a DarkField filter be used with an Abe condenser or it's necessary to install a different type of condenser in order to observe samples in a DarkField? I'm asking this because some microscopes require to replace the Abe condenser with a Phase Contrast condenser in order to use a DarkField illumination which is not clear to me why.

Would it be at all possible to add a or make a dark field filter for the telmu microscope or no ? If so how would I do that?

really amazing, learn something

why don't you start selling them, people would be interested in buying them :)

Thanks so much, that's amazing!!! Do you have tried it for Stereomicroscopes? They don't have a condenser and I don't know exactly if that would work. I'll try it in any case. Thanks :)

great.

DO you have the dimensions for the blocker? Thank you!

Can you post a link to a commercial darkfield patch stop like the metal one you show? I cannot find one on Olympus' site or elsewhere.

Great video thanks for you explanation. I’d like to encourage my children in science currently we have access to a 4- 10- 40 middle school type microscope I want something better. Can you recommend a couple for us that won’t make me have to work overtime. They are going to need to last from 4th to at least 12 grade. I’d like to encourage my daughters desire to be a doctor or research scientist. Please offer suggestions.

Hello! Please tell me will the Olympus CXH41 fit?

it won't work in high magnification how to make it works in higher magnification? answer please .. . . Iam from Indonesia

5:18

What is the diameter of this circles?

Has anyone tried this with an led light source?

What's the purpose for filters with colored nested circles red-yellow-blue-black? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Pku4T8s-0lg.html

I have a celestron lab cm 2000 Cf, it has problem with the light ,is bluish all the time and in photos come intense blu .Anyone knows why?

Are these filters able to be used in inverted microscopes also?

Does this work with sw380T?

A poor's DIC.. 🤭🤭 thanks a lot!!!

❤❤❤ ⚘️🌷⚘️🙏🙏😊😊😊👍👍👍

the oblique illumination was extremely dark almost don't see anything so I blame my light source.

:D

Plz come to the point fast...you are so lagging and it's become bored over time