Why is the Center of My Microscope Image Lacking Contrast?

Click For Summary
SUMMARY

The discussion centers on achieving uniform contrast in microscope images, specifically with an Olympus BX60M microscope using H and E stained tissue samples. Users noted that while peripheral contrast is excellent, the center lacks clarity, likely due to field curvature and improper stop adjustments. Recommendations include ensuring proper alignment and experimenting with different objectives and eyepieces to enhance contrast across the entire field of view.

PREREQUISITES
  • Understanding of microscope components, specifically field stops and aperture stops.
  • Familiarity with H and E staining techniques in histology.
  • Basic knowledge of image capture techniques using smartphones in microscopy.
  • Awareness of field curvature effects in optical systems.
NEXT STEPS
  • Research proper alignment techniques for the Olympus BX60M microscope.
  • Explore different objective lenses compatible with the Olympus BX60M to improve image quality.
  • Learn about field curvature and its impact on microscopy images.
  • Investigate smartphone photography techniques for capturing microscope images effectively.
USEFUL FOR

This discussion is beneficial for novice microscope users, histologists, and anyone interested in improving image quality and contrast in microscopy, particularly with Olympus BX60M microscopes.

remorris44
Messages
5
Reaction score
0
https://www.dropbox.com/sc/eo2c8j4kd12pdvn/AACGJ8YZvk35BSX1BsBoKIIsa

Please view the above image. I am getting awesome contrast on the periphery of the image but hardly any in the center. The sample is an H and E stained tissue and I just got the microscope in today.
I am a rookie with microscopes so any ideas as to how to get this nice contrast across the image? Adjusting the brightness doesn't change much.
 
Physics news on Phys.org
What microscope are you using?
 
Drakkith said:
What microscope are you using?
It is an olympus BX60M. Got it for free from the university surplus department.
When I adjust the field stop/aperture stop just right I can see the good contrast around the center but otherwise the entire field of view is at comparable resolution but very poor contrast.
 
remorris44 said:
When I adjust the field stop/aperture stop just right I can see the good contrast around the center but otherwise the entire field of view is at comparable resolution but very poor contrast.

I'm sorry, I'm not actually too familiar with microscopes. Are you saying that if you adjust the stops just right it fixes the problem and you no longer have a contrast issue?
 
Drakkith said:
I'm sorry, I'm not actually too familiar with microscopes. Are you saying that if you adjust the stops just right it fixes the problem and you no longer have a contrast issue?

No worries, just glad to have someone to bounce ideas with.
No, the problem is with nearly every setting. Only when the stops are just right can I get a glimpse of the good contrast.
I want to say that it is a vignetting type of refraction artifact but if so it's pretty sad to say that an artifact region provides the best image...
 
Is the center bright spot just a contrast issue, or is the camera being saturated? You said adjusting the brightness doesn't help, but is that the brightness of the illuminating lamp, or just the brightness setting of the camera?
 
Drakkith said:
Is the center bright spot just a contrast issue, or is the camera being saturated? You said adjusting the brightness doesn't help, but is that the brightness of the illuminating lamp, or just the brightness setting of the camera?

The photo was taken via smartphone so it did pretty much get saturated in the center. The effect is less dramatic in the microscope when looking with the naked eye but still drastic (contrast difference between stained tissue and nothing). With a dimmer setting on the scope the color contrast is still dramatically different. I want the colors to 'pop' like they do on the periphery of the posted photograph.
 
Okay, so the contrast issue is a problem both visually and photographically. Honestly I'm not sure what to do. If I find something that may help you I'll let you know. Hopefully someone else here on PF has more experience in this area and can help you.
 
  • #10
Does it happen with other objectives and/or eyepieces? (i.e. did you get any other objectives or eyepieces?)
 
  • #11
remorris44 said:
https://www.dropbox.com/sc/eo2c8j4kd12pdvn/AACGJ8YZvk35BSX1BsBoKIIsa

Please view the above image. I am getting awesome contrast on the periphery of the image but hardly any in the center. The sample is an H and E stained tissue and I just got the microscope in today.
I am a rookie with microscopes so any ideas as to how to get this nice contrast across the image? Adjusting the brightness doesn't change much.

Assuming you have aligned everything correctly (http://www.well.ox.ac.uk/_asset/file/zeiss-guide-to-microscopy-from-the-very-begiining.pdf is a fantastic place to start), that looks like field curvature- the center may be in focus, but as you move towards the edge of the field of view, the image becomes defocused. What objective lens did you use?
 

Similar threads

What Unique Microscopy Samples Can Engage Kids in STEM Learning?
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad Why is the Fourier transform of a sinusoid assumed as this?
  • · Replies 4 ·
Replies
4
Views
2K
Admissions Could I please get critique on my SOP? (Experimental Biophysics)
  • · Replies 8 ·
Replies
8
Views
815
Terrell Revisited: The Invisibility of the Lorentz Contraction
  • · Replies 184 ·
7
Replies
184
Views
23K
Mastering Golf Club Making: Tips and Techniques for Better Performance
  • · Replies 2 ·
Replies
2
Views
7K
A suggestion for dolphin communication.
  • · Replies 6 ·
Replies
6
Views
6K