Hole in my microscope...
Posted: Sun Nov 27, 2022 4:59 pm
I purchased a microscope from a retired research scientist.
After owning it a while I realized that once he decided what he wanted to do with a microscope and which brand, he had very few, if any, options for an optimal (for him) configuration. As when he purchased my microscope he had been working as a scientist for about 30 years, he knew how to buy a microscope.
His primary consideration was obviously ease of use. He needed both DIC and Phase and the ability to switch back and forth quickly.
That drove his objective decision. He used semi-apochromatic FL objectives that had phase rings.
The invoice says of these objectives: "for brightfield, dark field, phase contrast, Nomarski DIC, polarization and fluorescence". That kind of covers it.
Although he didn't seem budget constrained there were no APO objectives that covered all these bases. (No phase available)
However, although the manufacturer says that you can use these objectives for DIC they acknowledge that the unused phase ring limits DIC results. Under "DIC" they state "limitation" where the APO lens says: "excellent".
Having said that I am getting great (in my opinion) results using these objectives for DIC. My microscope photography is improving but I still only get about 80% of what I can see to the "film".
These are three photographs taken at 400x of blood cells in tissue at three different DIC prism settings.
https://www.flickr.com/photos/196001110 ... ed-public/
https://www.flickr.com/photos/196001110 ... ed-public/
https://www.flickr.com/photos/196001110 ... ed-public/
When I purchased the microscope it had three objectives UplanFL phase 10x, 40x, and 100X.
So now my problem: I had two empty holes in the objective turret.
I have filled one with an old 4x 160 although my microscope is infinity corrected. At that magnification it doesn't seem to matter especially as I only use 4x to orient myself on the slide before going to 10x or above.
So what to fill the last hole with?
I thought about a 60x because I hate cleaning up oil. Not much of a problem unless you are OCD (I am) so it must be CLEAN, not just wiped down.
However I have some 15x eyepieces and looked at a chart that said that I had more than enough resolution with my 40x to use a 15x eyepiece with it. That kind of made a 60x redundant.
I considered a 100x APO but I hate oil and more importantly I got on the Nikon site and found a chart that shows that going from an FL to an APO at 100x oil only increases resolution from .21 to .20 nanometers. Unless you are looking for early signs of cancer for a living, I can't see that that justifies the exorbitant expense if you already have the FL.
Now I am looking at a 40x apo that takes my 40x resolution from .37 to .29 (kind of).
My dry condenser lens only goes to .9 and the APO objective has an NA of .95 so I would only get about 3/4 of the additional resolution (The FL lens has an NA of .75).
Can anyone comment BEFORE i spend the money?
I am also confused as to why such a small difference in the 100X range. This is the link to the Nikon site.
https://www.microscopyu.com/microscopy- ... resolution
One other question that may be too esoteric for anyone to answer. My current 40x Nomarski prism is an Olympus U-DP40. The spec sheet for the APO lens calls for a U-DPA40. I assume the "A" stands for APO and just means that it is manufacturered to a higher tolerance? (Or maybe it is built the same and is selected? That was the way we got "high temperature" transistors back in the day.)
I assume my U-DP40 will work but if anyone knows better please let me know.
Neal
After owning it a while I realized that once he decided what he wanted to do with a microscope and which brand, he had very few, if any, options for an optimal (for him) configuration. As when he purchased my microscope he had been working as a scientist for about 30 years, he knew how to buy a microscope.
His primary consideration was obviously ease of use. He needed both DIC and Phase and the ability to switch back and forth quickly.
That drove his objective decision. He used semi-apochromatic FL objectives that had phase rings.
The invoice says of these objectives: "for brightfield, dark field, phase contrast, Nomarski DIC, polarization and fluorescence". That kind of covers it.
Although he didn't seem budget constrained there were no APO objectives that covered all these bases. (No phase available)
However, although the manufacturer says that you can use these objectives for DIC they acknowledge that the unused phase ring limits DIC results. Under "DIC" they state "limitation" where the APO lens says: "excellent".
Having said that I am getting great (in my opinion) results using these objectives for DIC. My microscope photography is improving but I still only get about 80% of what I can see to the "film".
These are three photographs taken at 400x of blood cells in tissue at three different DIC prism settings.
https://www.flickr.com/photos/196001110 ... ed-public/
https://www.flickr.com/photos/196001110 ... ed-public/
https://www.flickr.com/photos/196001110 ... ed-public/
When I purchased the microscope it had three objectives UplanFL phase 10x, 40x, and 100X.
So now my problem: I had two empty holes in the objective turret.
I have filled one with an old 4x 160 although my microscope is infinity corrected. At that magnification it doesn't seem to matter especially as I only use 4x to orient myself on the slide before going to 10x or above.
So what to fill the last hole with?
I thought about a 60x because I hate cleaning up oil. Not much of a problem unless you are OCD (I am) so it must be CLEAN, not just wiped down.
However I have some 15x eyepieces and looked at a chart that said that I had more than enough resolution with my 40x to use a 15x eyepiece with it. That kind of made a 60x redundant.
I considered a 100x APO but I hate oil and more importantly I got on the Nikon site and found a chart that shows that going from an FL to an APO at 100x oil only increases resolution from .21 to .20 nanometers. Unless you are looking for early signs of cancer for a living, I can't see that that justifies the exorbitant expense if you already have the FL.
Now I am looking at a 40x apo that takes my 40x resolution from .37 to .29 (kind of).
My dry condenser lens only goes to .9 and the APO objective has an NA of .95 so I would only get about 3/4 of the additional resolution (The FL lens has an NA of .75).
Can anyone comment BEFORE i spend the money?
I am also confused as to why such a small difference in the 100X range. This is the link to the Nikon site.
https://www.microscopyu.com/microscopy- ... resolution
One other question that may be too esoteric for anyone to answer. My current 40x Nomarski prism is an Olympus U-DP40. The spec sheet for the APO lens calls for a U-DPA40. I assume the "A" stands for APO and just means that it is manufacturered to a higher tolerance? (Or maybe it is built the same and is selected? That was the way we got "high temperature" transistors back in the day.)
I assume my U-DP40 will work but if anyone knows better please let me know.
Neal