Why is the Center of My Microscope Image Lacking Contrast?

In summary, the center of a microscope image may lack contrast due to several factors, including improper lighting, incorrect focus, and low-quality lenses. These issues can result in a lack of differentiation between the objects in the center of the image, making it difficult to see details and distinguish different structures. It is important to properly adjust the microscope settings and use high-quality lenses to achieve optimal contrast in the center of the image.
  • #1
remorris44
5
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.
 
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  • #2
What microscope are you using?
 
  • #3
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.
 
  • #4
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?
 
  • #5
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...
 
  • #6
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?
 
  • #7
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.
 
  • #8
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?
 

FAQ: Why is the Center of My Microscope Image Lacking Contrast?

1. What is contrast in microscopy?

Contrast in microscopy refers to the difference in brightness or color between an object and its background. It allows for clear visualization and differentiation of the objects being observed under a microscope.

2. Why is contrast important in microscopy?

Contrast is important in microscopy because it enhances the visibility of the object being observed, making it easier to study its structure and characteristics. It also allows for the differentiation of different structures within the same sample, providing a more detailed and accurate understanding.

3. What are the common causes of low contrast in microscopy?

There are several factors that can contribute to low contrast in microscopy, such as inadequate lighting, improper staining or preparation of the sample, or using an incorrect objective lens. Dust or debris on the microscope lens can also cause low contrast.

4. How can I improve contrast in my microscope images?

To improve contrast in microscopy, you can adjust the lighting by increasing or decreasing the intensity, using filters, or adjusting the diaphragm. Properly staining or preparing the sample can also greatly enhance contrast. Additionally, using the appropriate objective lens for your sample can improve contrast.

5. Are there any alternative methods for enhancing contrast in microscopy?

Yes, there are alternative methods for enhancing contrast in microscopy, such as using phase contrast or differential interference contrast techniques. These techniques use differences in refractive index to create contrast in transparent samples. Other methods include darkfield microscopy, which uses oblique lighting to create contrast, and fluorescence microscopy, which uses fluorescent dyes to enhance contrast in specific structures.

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