Lighting the stage on a compound microscope

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Mikeltee
Posts: 6
Joined: Thu Feb 18, 2021 9:05 pm

Lighting the stage on a compound microscope

#1 Post by Mikeltee » Sat Apr 03, 2021 9:15 pm

Greetings all,

I recently purchased a 380T to diagnose critters in my mixed reef tank and to show my kids how cool science can be with the right toys. I have been successful in this but I recently came across another use for this scope.

I sharpen knives as a hobby. I use both the Wicked Edge system for perfect, repeatable angles and I am now starting to freehand sharpen my Japanese steel kitchen knives. This is an artform to say the least and I would like to bring as much science into the equation as to offset my inability of being artistic. I want to study scratch patterns from the different stones in order to maximize my ability to get the perfect edge for each technique I need on an edge.

I know a stereo scope is the best tool. I need 50x with a good amount of area in focus and I am not trying to focus stack with software. I have 2 USB handheld scopes which I have read to be satisfactory for the job at hand but I find them highly unsuitable. One was $40 and the other was $140. I refuse to pay $700+ for the dino-lite which would be my best option. I want to reuse what I have.

What is the best way to light my stage on my 350t in order to see the tip of an edge of a blade at 50x? Light needs to be controllable as the edge of the blade are approaching mirror like repeatability. I also need 2 free hands to move the blade and the other to maintain focus.

Thank you for your thoughts and opinions...

PeteM
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Location: N. California

Re: Lighting the stage on a compound microscope

#2 Post by PeteM » Sat Apr 03, 2021 11:59 pm

You can probably get a small LED lamp (on a gooseneck, articulated holder, etc.) to come in from the side and have enough clearance with a 4x objective (40x total magnification). Polarizers might help a bit to see the scratch detail (one over the LED, one above the objective).

Closer to an ideal tool for this would be an old "epi" wafer inspection microscope with brightfield and darkfield. These sometimes show up under $200, especially in areas that had semiconductor fab facilities going back a couple decades or more.

Mikeltee
Posts: 6
Joined: Thu Feb 18, 2021 9:05 pm

Re: Lighting the stage on a compound microscope

#3 Post by Mikeltee » Sun Apr 04, 2021 12:24 am

PeteM wrote:
Sat Apr 03, 2021 11:59 pm
You can probably get a small LED lamp (on a gooseneck, articulated holder, etc.) to come in from the side and have enough clearance with a 4x objective (40x total magnification). Polarizers might help a bit to see the scratch detail (one over the LED, one above the objective).

Closer to an ideal tool for this would be an old "epi" wafer inspection microscope with brightfield and darkfield. These sometimes show up under $200, especially in areas that had semiconductor fab facilities going back a couple decades or more.
This is the answer I was hoping for. I saw the 6w gooseneck lights that are intensity selectable but a 6w is $140 and a proper 100+wall is $300min. A used, reporposed scope for less than $200 is what I was hoping to find. I just don't know what to look for.

Mikeltee
Posts: 6
Joined: Thu Feb 18, 2021 9:05 pm

Re: Lighting the stage on a compound microscope

#4 Post by Mikeltee » Sun Apr 04, 2021 12:27 am

If anyone has any recommendations for solutions that are less than $200ish please help me.

crb5
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Re: Lighting the stage on a compound microscope

#5 Post by crb5 » Sun Apr 04, 2021 1:00 am

Why do you need such high wattage lamp? Wouldn't a simple gooseneck lamp work https://www.amazon.com/Flexible-Goosene ... 25&sr=8-13? I presume a knife would reflect much of the light when held at the right angle. Given the field of view with 50x magnification is only a few millimeters, an additional lens could be added in front of the LED to focus it down to a small area if the built-in zoom is insufficient. Having a more powerful multi LED light source doesn't gain you much since it cannot be focused to such a small spot, so most of the power is wasted. If the light source is too intense it can be defocused, moved further away or an ND filter added. Attached is a quick trial with a hand-held LED flashlight (torch in my native tongue!) with a kitchen knife using my Swift 350T 4x objective, and 1.3MP USB camera.
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Last edited by crb5 on Sun Apr 04, 2021 2:04 am, edited 1 time in total.

PeteM
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Re: Lighting the stage on a compound microscope

#6 Post by PeteM » Sun Apr 04, 2021 1:09 am

As Crb5 suggests, you should be able to get a 1 to 3 watt gooseneck lamp for maybe $20 from Ikea, Amazon, Ebay, etc.. I also use higher power LED flashlights (around 800 lumens) and hold them in anything from articulated stands to table mount microphone stands. This isn't a recommendation (just one of the first that popped up -- and crb5's looks better if you want battery powered), but an idea of what is available:

https://www.ebay.com/itm/Clip-on-Lamp-R ... SwHzpgZzLb

For the epi type scope - where are you located - something might show up locally.

Greg Howald
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Joined: Tue Oct 20, 2020 6:44 am

Re: Lighting the stage on a compound microscope

#7 Post by Greg Howald » Sun Apr 04, 2021 3:47 am

I purchased a simple goose neck led desk lamp with a flat lighting surface about 4 inches in diameter. It had three brightness levels and was bright enough to do what you want to do. They can be purchased from Amazon for fifteen bucks.
Plenty of options out there without breaking the bank.

BramHuntingNematodes
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Re: Lighting the stage on a compound microscope

#8 Post by BramHuntingNematodes » Sun Apr 04, 2021 4:08 am

Mikeltee wrote:
Sat Apr 03, 2021 9:15 pm
Greetings all,

I recently purchased a 380T to diagnose critters in my mixed reef tank and to show my kids how cool science can be with the right toys. I have been successful in this but I recently came across another use for this scope.

I sharpen knives as a hobby. I use both the Wicked Edge system for perfect, repeatable angles and I am now starting to freehand sharpen my Japanese steel kitchen knives. This is an artform to say the least and I would like to bring as much science into the equation as to offset my inability of being artistic. I want to study scratch patterns from the different stones in order to maximize my ability to get the perfect edge for each technique I need on an edge.

I know a stereo scope is the best tool. I need 50x with a good amount of area in focus and I am not trying to focus stack with software. I have 2 USB handheld scopes which I have read to be satisfactory for the job at hand but I find them highly unsuitable. One was $40 and the other was $140. I refuse to pay $700+ for the dino-lite which would be my best option. I want to reuse what I have.

What is the best way to light my stage on my 350t in order to see the tip of an edge of a blade at 50x? Light needs to be controllable as the edge of the blade are approaching mirror like repeatability. I also need 2 free hands to move the blade and the other to maintain focus.

Thank you for your thoughts and opinions...
I usually use epi darkfield from around 160x-400x to look at edges although generally speaking much smaller edges than kitchen knives such as found on chisels and cutters. You may have some good luck with oblique lighting using an old illuminator such as used to be used with a compound scope with a mirror. These direct light through a series of lenses into a concentrated and collimated beam which I have found perfect for oblique lighting of stereo scope subjects.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

EYE C U
Posts: 288
Joined: Wed Jul 15, 2020 5:18 pm

Re: Lighting the stage on a compound microscope

#9 Post by EYE C U » Sun Apr 04, 2021 8:21 am

LIGHT IT UP :D
Screen Shot 2021-04-04 at 3.20.07 AM.png
Screen Shot 2021-04-04 at 3.20.07 AM.png (373.35 KiB) Viewed 2992 times

Mikeltee
Posts: 6
Joined: Thu Feb 18, 2021 9:05 pm

Re: Lighting the stage on a compound microscope

#10 Post by Mikeltee » Sun Apr 04, 2021 2:04 pm

BramHuntingNematodes wrote:
I usually use epi darkfield from around 160x-400x to look at edges although generally speaking much smaller edges than kitchen knives such as found on chisels and cutters. You may have some good luck with oblique lighting using an old illuminator such as used to be used with a compound scope with a mirror. These direct light through a series of lenses into a concentrated and collimated beam which I have found perfect for oblique lighting of stereo scope subjects.
Would you happen to have any samples? What is your setup? My edges are MUCH smaller than any chisel blade. I don't know if you have ever seen a real Gyuto made by an 80 year old man with a recipe that have been handed down since the 1200s fro. The same steel they made Samurai swords with. A Japanese knife is made with maybe 15% of the material they use to make your normal German Knives. What I need to see is the "burr" from a 1000 grit stone. Surely you know what I am talking about. Thanks for your help.

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