Calabration with mirrorless camera

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elaniobro
Posts: 72
Joined: Thu Mar 11, 2021 10:00 pm

Calabration with mirrorless camera

#1 Post by elaniobro » Sat Aug 06, 2022 3:49 pm

Hi everyone, thank you all for your previous help in my earlier post found here: Canon Mirroless Adapter


I have since recieved my Canon M50 markII camera, and have set up my trinoc to recieve it. Pictures come out great!

So, I decided to throw my stage micrometer slide on, take some photos and calibrate it. Now, I use Fiji and a microscope measurement plugin. I have used both in the past, with my iPhone with great success.

To my surprise, after I "calibrated" and took spore measurements, all my spores in the photos were about .1µm wide! :ugeek: So, I knew something was off, went back, re-calibrated, but the problem persisted.

So, what exactly am I doing wrong? Am I not account for some magnifcation?

Camera is attached to this adapter

my iPhone setup was in the trinoc port, attached to a 10x eyepiece, fwiw.

Alexander
Posts: 402
Joined: Fri Jun 11, 2021 7:10 pm

Re: Calabration with mirrorless camera

#2 Post by Alexander » Sat Aug 06, 2022 4:42 pm

Most probably the problem sits in the process not in the equipment.

elaniobro
Posts: 72
Joined: Thu Mar 11, 2021 10:00 pm

Re: Calabration with mirrorless camera

#3 Post by elaniobro » Sun Aug 07, 2022 12:34 am

Thank you for your reply, what makes me believe its not the process, is the fact that I have been able to calibrate my iPhone with the same microscope :?

elaniobro
Posts: 72
Joined: Thu Mar 11, 2021 10:00 pm

Re: Calabration with mirrorless camera

#4 Post by elaniobro » Fri Aug 19, 2022 1:57 pm

Alexander wrote:
Sat Aug 06, 2022 4:42 pm
Most probably the problem sits in the process not in the equipment.
@alexander; right you were. I was miscalculating by a decimal point. :roll: :oops:

RichardK-M
Posts: 6
Joined: Wed Nov 02, 2022 9:38 am

Re: Calabration with mirrorless camera

#5 Post by RichardK-M » Wed Nov 02, 2022 8:11 pm

I calibrated my Canon M3 by simply photographing the stage micrometer through each objective, then in Photoshop I created a scale bar from that image. Whenever I want to add a scale, I simply put the image with the scale bar in as a new layer, copy out the scale bar and add as a new layer, then turn off the visibility of the layer of the original image with the scale bar and flatten the image. Sounds complex, but it's simple!

http://www.rakm.co.uk/bryophyte_pages/f ... us_04.html

ddy5
Posts: 78
Joined: Sun May 03, 2020 12:37 pm
Location: Maryland, USA

Re: Calabration with mirrorless camera

#6 Post by ddy5 » Fri Nov 04, 2022 4:18 pm

RichardK-M:

I also use Photoshop to put scale bars on photos using the same basic logic you do. An alternative procedure that's efficient: 1) convert distance on the photos of the stage micrometer to pixels using the Ruler tool (go to Analyze under the Image pull-down). 2) Then you can create a preset for the objective using that conversion. Once that's done, any time you want to make a scale bar for a photo taken with that objective, simply go back to the Analyze menu, do a Set scale using the preset, and then let Photoshop create the scale bar for you. Photoshop automatically puts the scale bar on a new layer. You have total control over font, font size, position, bar thickness, etc.

I validated the procedure by measuring a diatom using a calibrated reticle and comparing it to a Photoshop measurement of the diatom.

Zooming doesn't change the number of pixels in a measurement. I'm not sure about resizing, so it would be good to put the scale bar on before you resize the image.

Cheers, David

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