Comparing Zeiss PMIII internal camera to a Canon AE-1 and Sony a6000
Posted: Sat Mar 24, 2018 10:41 pm
In recent attempts to achieve theoretical resolution on the microscope, all aspects of the microscope subsystems are being tested and optimized. This optimization has also included the best possible camera setup to image what is seen in the binoc eyepiece. It was of interest to compare the acquisition properties of the PMIII internal camera with other afocal cameras PMIII photo tube option.
Little comparison info was found on the internet, so this endeavor wamay be interesting to some. Testing was performed using ISO200 35mm film in both the PMIII 35mm camera and the Canon AE-1 camera, and similarly, the Sony a6000 was set to ISO200. A halogen source (running at 12V) was used and a blue conversion filter for the internal camera and the AE-1. No filter was used for the Sony but an auto white balance setting was used instead. In hindsight, it may have been better to set the white balance specifically for the source illumination. A Canon Photomicro Unit F camera adapter attached to the Zeiss 473024 camera port was used in the focal setup
Various considerations were tested including:
PMIII mask image of full binoc FOV
PMIII internal 35mm camera capture are of the PMIII mask
Best eyepiece to mimic the PMIII mask and internal PMIII camera fiew
Camera Port image comparison to the PMIII 35mm camera
Eyepiece lift testing
Comparison of images taken between the PMIII camera and a photoport camera in brightfield and with various enhancement techniques
Results Summary:
The PMIII only sees 38% of the full binoc FOV. Is this choice by Zeiss related to the film area or could it also be influenced by the understanding that in the wide FOV of the human lens, a similar portion is actually only in "brain" focus at one type; equivalent to what a 50mm lens might seen on a full frame camera? Furthermore, the PMIII camera only captures 92% of this masked area, even further reducing what image is acquired from the original binoc FOV. Interestingly, a camera using the photo port camera with 2.5X eyepiece actually captures a bit more of the binoc field of view (actually 23.3% more area) than did the PMIII internal camera.
Testing showed that the 2.5X and 5X eyepieces to more accurately mimic the view obtained through the PMIII camera system. Similarly a Zeiss Beam splitter system 47 60 10 also using the 2.5X or 5X eyepiece also gave similar results to the PMIII mask. The outer mask through the beam splitter view port
appears to match the same area as does the PMIII mask. It is noted that the Olympus NFK 2.5X L.D. eyepiece as well as the Zeiss C5X eyepiece did show significant chromatic aberration in other testing. However, in this study, that aberration did not play a significant or perceptible role. The KPL eyepieces are far superior, however, I am not aware that a KPL 2.5X eyepiece was ever made?
Finally, in comparison the PMIII camera appeared to provide images with greater hue and saturation, however the image quality of the Sony far exceeded that obtained with 35mm film in both the PMIII camera and the external Canon AE-1. Comparisons were not only made in bright field, but also phase, Hoffman Modulation, and DIC - images attached.
Hopefully, this information might be of interest or use to someone else.
Note in picture 5, it did not copy that the middle row center is 40X phase with green, and outer is 40X phase without a green filter. The bottom row is a 40X phase with a dark field stop.
Little comparison info was found on the internet, so this endeavor wamay be interesting to some. Testing was performed using ISO200 35mm film in both the PMIII 35mm camera and the Canon AE-1 camera, and similarly, the Sony a6000 was set to ISO200. A halogen source (running at 12V) was used and a blue conversion filter for the internal camera and the AE-1. No filter was used for the Sony but an auto white balance setting was used instead. In hindsight, it may have been better to set the white balance specifically for the source illumination. A Canon Photomicro Unit F camera adapter attached to the Zeiss 473024 camera port was used in the focal setup
Various considerations were tested including:
PMIII mask image of full binoc FOV
PMIII internal 35mm camera capture are of the PMIII mask
Best eyepiece to mimic the PMIII mask and internal PMIII camera fiew
Camera Port image comparison to the PMIII 35mm camera
Eyepiece lift testing
Comparison of images taken between the PMIII camera and a photoport camera in brightfield and with various enhancement techniques
Results Summary:
The PMIII only sees 38% of the full binoc FOV. Is this choice by Zeiss related to the film area or could it also be influenced by the understanding that in the wide FOV of the human lens, a similar portion is actually only in "brain" focus at one type; equivalent to what a 50mm lens might seen on a full frame camera? Furthermore, the PMIII camera only captures 92% of this masked area, even further reducing what image is acquired from the original binoc FOV. Interestingly, a camera using the photo port camera with 2.5X eyepiece actually captures a bit more of the binoc field of view (actually 23.3% more area) than did the PMIII internal camera.
Testing showed that the 2.5X and 5X eyepieces to more accurately mimic the view obtained through the PMIII camera system. Similarly a Zeiss Beam splitter system 47 60 10 also using the 2.5X or 5X eyepiece also gave similar results to the PMIII mask. The outer mask through the beam splitter view port
appears to match the same area as does the PMIII mask. It is noted that the Olympus NFK 2.5X L.D. eyepiece as well as the Zeiss C5X eyepiece did show significant chromatic aberration in other testing. However, in this study, that aberration did not play a significant or perceptible role. The KPL eyepieces are far superior, however, I am not aware that a KPL 2.5X eyepiece was ever made?
Finally, in comparison the PMIII camera appeared to provide images with greater hue and saturation, however the image quality of the Sony far exceeded that obtained with 35mm film in both the PMIII camera and the external Canon AE-1. Comparisons were not only made in bright field, but also phase, Hoffman Modulation, and DIC - images attached.
Hopefully, this information might be of interest or use to someone else.
Note in picture 5, it did not copy that the middle row center is 40X phase with green, and outer is 40X phase without a green filter. The bottom row is a 40X phase with a dark field stop.