I am wondering if such move gives real advantage? In simple words is there anyone who compared resolution of the images taken with 'dry' NA0.9 setup versus NA1.4 in DIC and could advice if it really makes a difference (and can also show results)?
I am having Nikon 'dry' setup and I am wondering if any upgrade is justified here in order to get much better resolution.
Please advise.
NA 0.9 vs NA 1.4 DIC is it worth to go for it?
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abednego1995
- Posts: 84
- Joined: Tue Nov 01, 2016 11:53 pm
The answer to your question depends on what you are imaging and the resolution that is required for the subject matter (which you don't mention). All else being equal a 1.4 oil optic will give you a significant resolution bump but also significant contrast improvement - if done correctly. Higher NA optics have greater constraints and less wiggle room for error to get the best performance vs. dry optics.
A 0.9NA dry objective will get you ~300nm in lateral resolution provided you are sampling correctly on camera. The 1.4 will get you ~200nm.
Using a 1.4 optic will also mean a move to oil immersion. To get the best performance out of such a lens you will also need to precisely choose coverslips that are 170 microns thick (#1.5 in the US) and use mounting medium that has a high RI (as close to 1.518 as you can get) such as glycerol or permount.
If you are imaging specimens in water then moving to an oil lens doesn't make a ton of sense because the RI mismatch will reduce the effective NA of the objective.
A 0.9NA dry objective will get you ~300nm in lateral resolution provided you are sampling correctly on camera. The 1.4 will get you ~200nm.
Using a 1.4 optic will also mean a move to oil immersion. To get the best performance out of such a lens you will also need to precisely choose coverslips that are 170 microns thick (#1.5 in the US) and use mounting medium that has a high RI (as close to 1.518 as you can get) such as glycerol or permount.
If you are imaging specimens in water then moving to an oil lens doesn't make a ton of sense because the RI mismatch will reduce the effective NA of the objective.
I am imaging aqueous specimens and also botanical samples coverslipped using Leica CV Ultra mountant. I was unable to find what RI index this mountant has. If anyone knows please let me know.
I am referring to both, objectives and condensers. I have 40x, 60x and 100x oil objectives that are not 100% utilized when used with dry condenser (and dry condenser DIC prisms). I am thinking if getting oil DIC would increase resolution significantly so I would have best of my NA1.4 objectives. But in my case it would be extremely expensive.
Did someone here make comparison between NA0.9 and NA1.4?
Probably best for me will be taking brightfield pictures with same objective using dry and oil condenser.
I am referring to both, objectives and condensers. I have 40x, 60x and 100x oil objectives that are not 100% utilized when used with dry condenser (and dry condenser DIC prisms). I am thinking if getting oil DIC would increase resolution significantly so I would have best of my NA1.4 objectives. But in my case it would be extremely expensive.
Did someone here make comparison between NA0.9 and NA1.4?
Probably best for me will be taking brightfield pictures with same objective using dry and oil condenser.
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Ichthyophthirius
- Posts: 1152
- Joined: Thu Mar 07, 2013 5:24 am
Hi,
I haven't done that test either. A complete state-of-art NA 0.9 system versus an NA 1.4 system from the same company.
Before you buy I would recommend testing it with your own eyes (if you can buy new, contact your Nikon rep; if you find a friend with a complete NA 1.4 system, set it up with condenser oil immersion and then stop the condenser down to NA 0.9 - this should have the exact same effect as using a dry condenser!).
The effect on resolution should be small. Consider an object in water (max. illumination NA is 1.3). The resolution using an NA 1.4 Planapo objective is 244 nm with the oil immersion condenser, and 270 nm with a dry condenser NA 0.9. Reference: Baker (1952): Remarks on the Effect of the Aperture of the Condenser on Resolution by the Microscope. Quarterly Journal of Microscopical Science 93 (4): 375-377
http://jcs.biologists.org/content/s3-93/24/375.full.pdf
Some companies, like Leica, sell mainy NA 0.9 DIC condensers because they are much more convenient to use and resolution is only slightly reduced.
One the other hand, using an NA 1.4 condenser without immersion is quite bad for DIC quality. That's because the front lens requires immersion for correction. This is something I have tried myself. With immersion (I use water immersion), the image is brighter and with higher contrast, the effect is quite strong. So if you have an NA 1.4 condenser, you always have to use condenser immersion for the 60x and 100x objectives, it's not optional, in my personal experience.
Regards, Ichty
I haven't done that test either. A complete state-of-art NA 0.9 system versus an NA 1.4 system from the same company.
Before you buy I would recommend testing it with your own eyes (if you can buy new, contact your Nikon rep; if you find a friend with a complete NA 1.4 system, set it up with condenser oil immersion and then stop the condenser down to NA 0.9 - this should have the exact same effect as using a dry condenser!).
The effect on resolution should be small. Consider an object in water (max. illumination NA is 1.3). The resolution using an NA 1.4 Planapo objective is 244 nm with the oil immersion condenser, and 270 nm with a dry condenser NA 0.9. Reference: Baker (1952): Remarks on the Effect of the Aperture of the Condenser on Resolution by the Microscope. Quarterly Journal of Microscopical Science 93 (4): 375-377
http://jcs.biologists.org/content/s3-93/24/375.full.pdf
Some companies, like Leica, sell mainy NA 0.9 DIC condensers because they are much more convenient to use and resolution is only slightly reduced.
One the other hand, using an NA 1.4 condenser without immersion is quite bad for DIC quality. That's because the front lens requires immersion for correction. This is something I have tried myself. With immersion (I use water immersion), the image is brighter and with higher contrast, the effect is quite strong. So if you have an NA 1.4 condenser, you always have to use condenser immersion for the 60x and 100x objectives, it's not optional, in my personal experience.
Regards, Ichty