Uneven color across photomicrographs
Posted: Sun Jun 30, 2019 11:13 pm
I'm not sure if this is the right section of the forum for this post, but I have a question for all you microscope heads out there pertaining to my microscope's optics.
My microscope setup: Olympus BH-2 BHS, Olympus halogen illuminator, Olympus achromat 0.9 condenser, Olympus Aplanat Achromat 1.4 oil immersion condenser, Olympus SPlan Apo objectives, and Amscope digital camera.
My photomicrographs have always suffered from an annoying uneven coloration across the field of view. All images (taken with any objective) have a yellow-ish circular center with cooler periphery. This discoloration is easier to see when zoomed out. Check these examples:
Example 1 - Cystoisospora felis (aka., feline coccidia) unsporulated oocysts found in the fecal flotation of a cat with chronic diarrhea, 200x magnification, 50 μm scale bar (© Lance Wheeler, 2018 | Photographer: Lance Wheeler | Owner of Specimen: Lance Wheeler) (more images available here: https://www.veterinaryparasitology.com/ ... spora.html): Example 2 - Cystoisospora felis (aka., feline coccidia) unsporulated oocyst found in the fecal flotation of a cat with chronic diarrhea, 600x magnification, 10 μm scale bar (© Lance Wheeler, 2018 | Photographer: Lance Wheeler | Owner of Specimen: Lance Wheeler) (more images available here: https://www.veterinaryparasitology.com/ ... spora.html): Example 3 - Heterobilharzia americana (aka., Dog Schistosome) egg recovered from canine feces on saline fecal sedimentation using the Flukefinder® technique. 400x magnification, 20 μm scale bar, stack of 10 exposures. (© Lance Wheeler, 2019 | Photographer: Lance Wheeler | Owner of Specimen: Lance Wheeler) (more images available here: https://www.veterinaryparasitology.com/ ... arzia.html): Example 4 - Canine visceral pentastomiasis. Cross-section of pentastome nymph. 20x magnification, 500 μm scale bar, stack of 2 exposures. (© Lance Wheeler, 2019 | Photographer: Lance Wheeler | Owner of Specimen: University of Georgia College of Veterinary Medicine Department of Veterinary Pathology | Handler of Specimen: Chloe C. Goodwin and Jillian Athey) (more images available here: https://www.veterinaryparasitology.com/pentastomes.html): All of my images are taken after establishing Kӧhler illumination and appropriately adjusting the condenser aperture diaphragm. The only time I feel I may eliminate the discoloration is when I use my 100X SPlan Apo oil immersion objective with the Olympus Aplanat Achromat 1.4 oil immersion condenser. I have several theories: 1) there is a defect in my halogen bulb/ lamphouse, 2) there is color distortion due to incompatibility between the Olympus and Amscope optics, 3) there is a defect in my Olympus achromat 0.9 condenser.
Any other suggestions? I'm ready to tackle this minor (but very irritating) imperfection. Also, if the coloration can be corrected using an affordable post-processing software, I'm open to any recommendations!
Edit: Additional detail - When taking images using the Amscope camera with my Amscope stereomicroscope (pictured above), the images do not show any color distortion.
My microscope setup: Olympus BH-2 BHS, Olympus halogen illuminator, Olympus achromat 0.9 condenser, Olympus Aplanat Achromat 1.4 oil immersion condenser, Olympus SPlan Apo objectives, and Amscope digital camera.
My photomicrographs have always suffered from an annoying uneven coloration across the field of view. All images (taken with any objective) have a yellow-ish circular center with cooler periphery. This discoloration is easier to see when zoomed out. Check these examples:
Example 1 - Cystoisospora felis (aka., feline coccidia) unsporulated oocysts found in the fecal flotation of a cat with chronic diarrhea, 200x magnification, 50 μm scale bar (© Lance Wheeler, 2018 | Photographer: Lance Wheeler | Owner of Specimen: Lance Wheeler) (more images available here: https://www.veterinaryparasitology.com/ ... spora.html): Example 2 - Cystoisospora felis (aka., feline coccidia) unsporulated oocyst found in the fecal flotation of a cat with chronic diarrhea, 600x magnification, 10 μm scale bar (© Lance Wheeler, 2018 | Photographer: Lance Wheeler | Owner of Specimen: Lance Wheeler) (more images available here: https://www.veterinaryparasitology.com/ ... spora.html): Example 3 - Heterobilharzia americana (aka., Dog Schistosome) egg recovered from canine feces on saline fecal sedimentation using the Flukefinder® technique. 400x magnification, 20 μm scale bar, stack of 10 exposures. (© Lance Wheeler, 2019 | Photographer: Lance Wheeler | Owner of Specimen: Lance Wheeler) (more images available here: https://www.veterinaryparasitology.com/ ... arzia.html): Example 4 - Canine visceral pentastomiasis. Cross-section of pentastome nymph. 20x magnification, 500 μm scale bar, stack of 2 exposures. (© Lance Wheeler, 2019 | Photographer: Lance Wheeler | Owner of Specimen: University of Georgia College of Veterinary Medicine Department of Veterinary Pathology | Handler of Specimen: Chloe C. Goodwin and Jillian Athey) (more images available here: https://www.veterinaryparasitology.com/pentastomes.html): All of my images are taken after establishing Kӧhler illumination and appropriately adjusting the condenser aperture diaphragm. The only time I feel I may eliminate the discoloration is when I use my 100X SPlan Apo oil immersion objective with the Olympus Aplanat Achromat 1.4 oil immersion condenser. I have several theories: 1) there is a defect in my halogen bulb/ lamphouse, 2) there is color distortion due to incompatibility between the Olympus and Amscope optics, 3) there is a defect in my Olympus achromat 0.9 condenser.
Any other suggestions? I'm ready to tackle this minor (but very irritating) imperfection. Also, if the coloration can be corrected using an affordable post-processing software, I'm open to any recommendations!
Edit: Additional detail - When taking images using the Amscope camera with my Amscope stereomicroscope (pictured above), the images do not show any color distortion.