What is the magnification?

Everything relating to microscopy hardware: Objectives, eyepieces, lamps and more.
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Greg Howald
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What is the magnification?

#1 Post by Greg Howald » Fri Jul 15, 2022 5:49 pm

I stacked two 10x/18 eyepieces in a tube, resulting in an overall length of 125mm, well, just for grins and giggles. It resulted in a much larger image and reduced fov with minimal distortion and fair resolution. But what is the level of magnification with a 10x objective?
I don't know the math .
Greg :roll:

MicroscopyUniverse
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Re: What is the magnification?

#2 Post by MicroscopyUniverse » Sun Jul 17, 2022 6:53 am

I think you should multiply all magnifications, for example:

10x Eyepiece and 10x eyepiece and 20x objective results a magnification of 10x10x20 = 2000x final magnification.

Regards
Last edited by MicroscopyUniverse on Sun Jul 17, 2022 4:11 pm, edited 1 time in total.

Scarodactyl
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Re: What is the magnification?

#3 Post by Scarodactyl » Sun Jul 17, 2022 7:23 am

I wouldn't bet on it. Eyepieces are designed to take an intermediate focused image and project it to infinity. Stacking two is going to involve pushing at least one of them well out of spec. Not sure how you'd measure it except comparatively with an eyepiece of known mag and field number.

Alexander
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Re: What is the magnification?

#4 Post by Alexander » Sun Jul 17, 2022 9:33 am

MicroscopyUniverse wrote:
Sun Jul 17, 2022 6:53 am

10x Eyepiece and 10x eyepiece and 20x objective results a magnification of 10x10x20 = 400x final magnification.
???

10x10x20=2000

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blekenbleu
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Re: What is the magnification?

#5 Post by blekenbleu » Sun Jul 17, 2022 11:56 am

Greg Howald wrote:
Fri Jul 15, 2022 5:49 pm
I stacked two 10x/18 eyepieces in a tube, resulting in an overall length of 125mm, well, just for grins and giggles.
It resulted in a much larger image and reduced fov with minimal distortion and fair resolution.
But what is the level of magnification with a 10x objective?
I tried this with a pair of CNSCOPE WF10X-18mm oculars without an objective,
and results depended on their orientation, distance to imaged target and distance to my eye.
  • Least distortion with magnification wanted stacked oculars "head-to-head".
  • Field diameter with a single eyepiece was 6 to 7cm.
  • Field diameter for a head-to-head eyepieces was 2 to 3cm, about the same as for stacked head to tail, but different spacing.
Last edited by blekenbleu on Mon Jul 18, 2022 8:23 am, edited 1 time in total.
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

GerryR
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Re: What is the magnification?

#6 Post by GerryR » Sun Jul 17, 2022 12:31 pm

I don't know your setup, so don't know if these simple lens formulas will help:

1/Do + 1/Di = 1/f Do=distance of object from lens, Di=distance of image from lens, f = focal length of lens.

Si/So = Di/Do Si=size of image, So=size of object

With virtual images involved, it will require drawing the lens system out and extending rays of light to get image locations. A good physics book might help and a picture of your setup with some dimensions is worth a thousand words.

MicroscopyUniverse
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Re: What is the magnification?

#7 Post by MicroscopyUniverse » Sun Jul 17, 2022 4:41 pm

Alexander wrote:
Sun Jul 17, 2022 9:33 am
MicroscopyUniverse wrote:
Sun Jul 17, 2022 6:53 am

10x Eyepiece and 10x eyepiece and 20x objective results a magnification of 10x10x20 = 400x final magnification.
???

10x10x20=2000
I’m sorry, you are right. These very Hot days blurred my head when doing the maths. :?
I edited the post.
Thank you!

Greg Howald
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Re: What is the magnification?

#8 Post by Greg Howald » Mon Jul 18, 2022 4:33 pm

I believe that 10x10=100. 100x20= 2000

But if the eyepieces and objectives meet at a focal point of 160mm, then eyepiece to eyepiece must also have at least one of the focal points at 160mm. An 80mm tube is half of 160mm.
Therefore, 10 x 10 x 20 is 2000 x.5 ÷ 1000, and that's very close to the field of view at 10x x 100x = 1000.
I believe the only way to solve this is to take calibrated measurements .

wabutter
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Re: What is the magnification?

#9 Post by wabutter » Thu Jul 28, 2022 10:28 pm

If you want to know the final magnification, measure the field of view in mm and decide by the FOV of the eyepiece. So if the FOV through microscope is 18mm the total mag is 1x. If the FOV is 1.8mm your total mag is 10x. Etc as long as you know the FOV of the eyepiece, you can determine the total mag including the intermediate mag components.

Greg Howald
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Re: What is the magnification?

#10 Post by Greg Howald » Thu Jul 28, 2022 10:54 pm

Thanks. That's a real answer. :D

wabutter
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Re: What is the magnification?

#11 Post by wabutter » Fri Aug 12, 2022 2:39 am

Did any of the proposed calculation provide an answer that was comparable?

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