measuring the camera's power?

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cpsTN
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Joined: Mon Oct 12, 2015 1:14 am
Location: Murfreesboro, Tennessee USA

measuring the camera's power?

#1 Post by cpsTN » Sun Aug 07, 2016 11:50 am

I have Amscope's MD500 (5MP) camera for my scopes. I viewed the W in the word "we" on a U.S. Cent. I took a transparent plastic ruler and measured the width of the top of the W viewed through the eyepieces at 30x. It was 1mm or ever so slightly larger. I, then, measured the view of the top of the W on the computer screen made by the camera. It was 130mm.

With the camera view measuring 130 times larger than the direct-eye view at 30x, what is this telling me? Regardless of the view through the eyepieces seen at various powers, the view from the camera is constant. What is this telling me about the magnification of the camera? These views are through my Amscope SE305 Stereo scope.
Charles Sands
Murfreesboro, TN 37129

MICROSCOPES:
AO 110
...objectives, infinity:
10x plan #1021
45x achro #1116
50x plan, oil iris #1016
100x plan, oil #1024

Amscope SE305, Stereo
...objectives: 1x, 3x
...EPs: 5x, 10x, 15x

Peter
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Joined: Sun Oct 12, 2014 5:34 pm

Re: measuring the camera's power?

#2 Post by Peter » Sun Aug 07, 2016 6:43 pm

cpsTN wrote:With the camera view measuring 130 times larger than the direct-eye view at 30x, what is this telling me?
Your computer screen has a 4 1/3x magnification factor. If you where to connect the camera to an eighty inch TV what size would the "W" measure?

Peter.

cpsTN
Posts: 228
Joined: Mon Oct 12, 2015 1:14 am
Location: Murfreesboro, Tennessee USA

Re: measuring the camera's power?

#3 Post by cpsTN » Mon Aug 08, 2016 2:04 am

So, there's no way to tell what the power is because the image size changes according to the viewing screen size?
Charles Sands
Murfreesboro, TN 37129

MICROSCOPES:
AO 110
...objectives, infinity:
10x plan #1021
45x achro #1116
50x plan, oil iris #1016
100x plan, oil #1024

Amscope SE305, Stereo
...objectives: 1x, 3x
...EPs: 5x, 10x, 15x

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Oliver
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Re: measuring the camera's power?

#4 Post by Oliver » Wed Aug 24, 2016 10:27 pm

So, there's no way to tell what the power is because the image size changes according to the viewing screen size?
magnification = size of image / size of specimen

Because the size of the image can be made anything you want, the magnification changes. If you make it bigger on the screen, then the magnification is also larger, but the quality still might be low due to resolution limits. What is therefore more relevant is the size of the image which is produced on the camera's sensor. This now does tell you something about the total magnifying power of the system, but this is not only camera dependent, but also depends on the intermediate optics used and the camera to objective distance.

There is some math involved and this is necessary if you have to calculate the minimum camera pixels needed to capture all of the details that the microscope produces. The following website is in German but explains this (maybe you can translate with google translate):

http://www.mikroskopie.de/pfad/digitalk ... dapter.htm

The size of the pictured specimen = (Focal length of adapter/ focal length of photoeyepiece) * (With of sensor/magnific of microscope objective * magnification of intermediate optics)
So you see that there are many factors involved, which are not only limited to the camera.

Oliver.
Image Oliver Kim - http://www.microbehunter.com - Microscopes: Olympus CH40 - Olympus CH-A - Breukhoven BMS student microscope - Euromex stereo - uSCOPE MXII

apochronaut
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Re: measuring the camera's power?

#5 Post by apochronaut » Thu Aug 25, 2016 12:36 am

It also depends on how close you are to the computer screen.
When you view through a 20mm f.o.v. eyepiece, that represents an apparent field. It looks the same as a 20mm circle looks, if you were peeking right through it. Anything viewed in that field is a percentage of the apparent field. It's the same on the computer screen.
If you get an image capture of the full microscope 20mm field to cover a 16"( diagonal) screen edge to edge( there will be vignetting top and bottom), the magnification on the screen will be about the same as looking through the microscope , if you view the screen from about 18 " or thereabouts.

JimT
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Re: measuring the camera's power?

#6 Post by JimT » Thu Aug 25, 2016 9:07 pm

CPSTN, one of the accessories I recommend is a micrometer slide. I bought one from Amscope some time ago (SKU: MR095). I took images of it with the different objectives and overlay the appropriate one on the photos in post processing.

I really don't care too much about the camera or PC screen size as long as I can get a pretty accurate idea of the subjects size.

JimT

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