Theoretical Resolution: Am I close?

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Sure Squintsalot
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Theoretical Resolution: Am I close?

#1 Post by Sure Squintsalot » Mon Aug 08, 2022 8:42 pm

Finally picked up a 0.01mm Zeiss slide scale to calibrate various fields of view on my Optiphot.

In looking at an old microprocessor at 1000x, epi illuminated using a 100x Dry objective (210mm NA=0.90), I calculate a theoretical resolution of 0.29 microns, or 29 nanometers for visible light at around 500nm. The image is projected directly onto an APSC sensor, from the objective. In the following image, I think I'm seeing around 30 nanometers at the edges of the tiniest holes (vias?):
Screenshot 2022-08-08 143609.jpg
Screenshot 2022-08-08 143609.jpg (161.56 KiB) Viewed 1259 times
Am I doing this right? Is this as good as it's going to get? Am I really seeing a resolution that's close to the theoretical for my system?

LouiseScot
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Re: Theoretical Resolution: Am I close?

#2 Post by LouiseScot » Tue Aug 09, 2022 12:32 am

Um, 0.29um = 290nm if that helps.
In principal, you could improve the theoretical resolution slightly by using monochromatic blue light e.g. wavelength of 415nm would give about 230nm at NA = 0.90

Louise
A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

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woyjwjl
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Re: Theoretical Resolution: Am I close?

#3 Post by woyjwjl » Tue Aug 09, 2022 2:32 am

From the picture, it is difficult to determine that the vias spacing is 290 nm.

Can you narrow down the Ratio Scale?
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Sure Squintsalot
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Re: Theoretical Resolution: Am I close?

#4 Post by Sure Squintsalot » Tue Aug 09, 2022 5:08 am

LouiseScot wrote:
Tue Aug 09, 2022 12:32 am
Um, 0.29um = 290nm

Louise
Details, details, details....I sure wouldn't want to owe you money.

Anyway, 290nm isn't anywhere near the theoretical resolution of this system, or is it? Maybe an order of magnitude difference is to be expected? But is there a difference between the theoretical resolution of epi-illuminated vs diascopic illuminated systems? Does it even vary depending on the illumination technique?
woyjwjl wrote:
Tue Aug 09, 2022 2:32 am
From the picture, it is difficult to determine that the vias spacing is 290 nm.
I was looking at the thickness of the circumferences of the smallest vias, not the spacing between them. I did make a sub 10 micron scale, and it does look like those are about one quarter to one third micron thick, though now that I think about it, that's probably not the best way to "see" the best resolution this system is capable of.

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Re: Theoretical Resolution: Am I close?

#5 Post by woyjwjl » Tue Aug 09, 2022 7:05 am

I just made a picture to show what is called the "Riley Judgment"
2.png
2.png (350.42 KiB) Viewed 1178 times
Translation:At 0.2 microns, it should be 1/4 of the eyepiece scale.
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apochronaut
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Re: Theoretical Resolution: Am I close?

#6 Post by apochronaut » Tue Aug 09, 2022 10:04 am

The Rayleigh Criterion, which includes the 1.22 constant to accomodate distortion between two point sources gives a more realistic 340nm at .90.

Sure Squintsalot
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Re: Theoretical Resolution: Am I close?

#7 Post by Sure Squintsalot » Tue Aug 09, 2022 5:23 pm

woyjwjl wrote:
Tue Aug 09, 2022 7:05 am
I just made a picture to show what is called the "Riley Judgment"

Translation:At 0.2 microns, it should be 1/4 of the eyepiece scale.
I looked up "Riley Judgement" and only found court cases. The rest might as well have been all Chinese. But it looks like you're doing what I'm doing: roughly measuring the thickness of a single high-contrast line, as opposed to measuring the visible separation between two very close lines.
apochronaut wrote:
Tue Aug 09, 2022 10:04 am
The Rayleigh Criterion, which includes the 1.22 constant to accomodate distortion between two point sources gives a more realistic 340nm at .90.
Thanks. My goal is to better understand this and make sure I don't confuse coincidence for knowledge.

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woyjwjl
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Re: Theoretical Resolution: Am I close?

#8 Post by woyjwjl » Wed Aug 10, 2022 1:51 am

Sure Squintsalot wrote:
Tue Aug 09, 2022 5:23 pm
woyjwjl wrote:
Tue Aug 09, 2022 7:05 am
I just made a picture to show what is called the "Riley Judgment"

Translation:At 0.2 microns, it should be 1/4 of the eyepiece scale.
I looked up "Riley Judgement" and only found court cases. The rest might as well have been all Chinese. But it looks like you're doing what I'm doing: roughly measuring the thickness of a single high-contrast line, as opposed to measuring the visible separation between two very close lines.
apochronaut wrote:
Tue Aug 09, 2022 10:04 am
The Rayleigh Criterion, which includes the 1.22 constant to accomodate distortion between two point sources gives a more realistic 340nm at .90.
Thanks. My goal is to better understand this and make sure I don't confuse coincidence for knowledge.
“Rayleigh Criterion” Forgive my English.

Rayleigh Criterion is knowledge.
https://www.olympus-lifescience.com.cn/ ... maperture/
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