Upgrading a Nikon E Plan PH3 Objective

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Sauerkraut
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Upgrading a Nikon E Plan PH3 Objective

#1 Post by Sauerkraut » Thu Sep 26, 2019 4:09 pm

The Optiphot has a Nikon E Plan 40/0.65 160/0.17 PH3 DL objective. It doesn't produce the best image and I'm interested in upgrading. This is the safest choice, as it would directly match the other 20x PH2 and 40x objectives on the scope (not at that asking price though):

https://www.ebay.com/itm/143139961938?s ... Track=true

But would any of the others, say a fluor objective, be an even better choice? Maybe this:

https://www.ebay.com/itm/Nikon-Fluor-40 ... SwRwddM0ik

Could an Olympus objective work or is that asking for issues?

Also, I'm curious what the DL (dark low) designation means from a practical standpoint. In case anyone is interested, I found this comprehensive Nikon objective selector and glossary:

https://www.microscope.healthcare.nikon ... objectives

My phase condenser has a 1.25 NA.

Many thanks for any input.

Heather

apochronaut
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Re: Upgrading a Nikon E Plan PH3 Objective

#2 Post by apochronaut » Thu Sep 26, 2019 6:03 pm

Basically that is dark phase low contrast. . Companies that do not have a comprehensive selection of phase objectives, such as the biggies: AO,Leica,Leitz, Nikon,Olympus,Reichert, Vickers, Zeiss have only phase contrast, which is dark medium. Dark phase is the default phase. You cannot normally mix phase objectives on a stand, nor can you normally mix phase objectives from one brand with phase annuli from another brand. Accidental harmony , however could take place but that would be discovered by chance, unless someone out there knows of a specific brand match.

The fact that the image is " not the best" is suspicious. Low contrast phase should still produce a good image, just a little lower in contrast then the default dark medium would be. Certain samples are best viewed at a lower contrast. Check if all the other segments of the system are adjusted and working properly. Normally, phase is done with a dry condenser and usually for good phase an achromat. The condenser must be engineered for phase. The better phase systems are very specific about what condenser(s) can be used for the various phase systems they offer. Kohler illumination is necessary for an even background illumination and the annulus must be the one designated for the specific objective being used.
Is it possible the objective is defective? Could you post an image of what you are getting?

Sauerkraut
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Re: Upgrading a Nikon E Plan PH3 Objective

#3 Post by Sauerkraut » Thu Sep 26, 2019 6:54 pm

Thank you Apochronaut, especially for clarification of the DL designation. I'll try to take a closer look and post images in the next few days, time permitting.

One thing I'm not clear on is whether the condenser diaphragm should be mostly open for extra light or mostly closed for extra contrast. I've tried both settings with seemingly little difference in the image. Also, the objectives have correction collars on them but I'm not certain how to best use them. Under a stereo scope, all of the objectives look clear and undamaged, and the phase contrast itself seems about right.

Maybe part of it is I start getting disappointed with loss of depth of field above 20x, which is made worse by the use of deep well slides.

MicroBob
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Re: Upgrading a Nikon E Plan PH3 Objective

#4 Post by MicroBob » Thu Sep 26, 2019 7:12 pm

Hi Heather,
are you unhappy with the performance in actual phase contrast use or in bright field use?
Some phase objectives do bright field fairly well, some don't

Bob

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Re: Upgrading a Nikon E Plan PH3 Objective

#5 Post by Sauerkraut » Thu Sep 26, 2019 8:14 pm

I have a 40x plan objective so don't use the e-plan for BF. But I'll do a comparison of the two objectives in BF anyway. The PC itself seems decent. The specimen, underwhelming. It may be my stubbornness in using deep well slides to keep from crushing the 'elders.'

I started a batch of yeast so I can get some good comparisons on a flat slide in a few days.

viktor j nilsson
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Re: Upgrading a Nikon E Plan PH3 Objective

#6 Post by viktor j nilsson » Thu Sep 26, 2019 9:19 pm

While I don't own all of the Nikon objective grades in their phase contrast versions, I have fairly significant collection of Nikon CF/CFN objectives so that I should be able to provide a fairly informed opinion about the optical quality of each series.

Nikon 40x: I have an E plan 40x 0.65, a CFN plan 40x 0.70 Ph3, a Fluor 40x 0.85 (correction ring), and a Fluor 40x 1.30 (oil).

Nikon 20x: I have a CFN Plan 20x 0.50, a 20x 0.40 Ph2 DL (correction ring), a Fluor 20x 0.75 and a CFN PlanApo 20x 0.75.

At first, I thought that I would be quite content with the E plans, and got myself a set of 4x, 10x, 40x and 100x E plan. But I never liked them, and I found the 40x E plan to be especially poor. Especially in terms of lateral chromatic aberration, but I also found the resolution to be underwhelming. So I have since upgraded to better corrected objectives (as you can see above!).

E Plan to CFN is a huge step up. The CFN 40x Ph3 gives a nice, clean and high-resolution image in brightfield, the E plan 40x is very underwhelming in comparison.

CFN to Fluor is again a fairly large step up. Comparing the CFN 20x to the Fluor 20x, the CFN has pretty good resolution, but is considerably worse in terms of chromatic aberration. The Fluor is simply clean and devoid of false color. I haven't compared the CFN 40x Ph3 to the Fluor 40x in brightfield directly, but I remember that the CFN had at least a bit of CA, whereas the Fluor is very, very clean.

The Fluor 40x 1.30 (with iris) is incredible, but plays in it's own league.

Fluor to PlanApo is a smaller step. The Fluor's are really, really good. All of them. I'm happy I bought the 20x PlanApo, because it is a beautiful objective... but honestly, even though I got it for a fairly good price, I can't really say that it was worth it over the excellent Fluor objective.

In summary, I think that it would be worth it to go for the Fluor 40x 0.85 Ph3 objective. But the CFN 40x Ph3 is also going to be a big improvement over the E plan.

PeteM
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Re: Upgrading a Nikon E Plan PH3 Objective

#7 Post by PeteM » Thu Sep 26, 2019 11:12 pm

Heather, a few thoughts:

1) Can I assume your phase telescope shows that the phase rings are perfectly aligned? Everything clean? Specimens under a cover slip? The E plan Nikon 40x should give a decent image. I've also had a bad example, used, with no obvious external damage.

2) On the condenser iris question, you want to be sure the condenser and field diaphragms are open beyond the phase ring.

3) If you're using standard coverslips with your upright microscope, there's little need for the added cost and complication of a correction collar IMO. These objectives typically sacrifice a bit of numerical aperture to allow the correction and are especially suited to inverted microscopes. However, the example you show from Ebay is Fluor with a higher N.A. (good). It's not marked as Plan, though, and might have more field curvature.

4) The Nikon CFN objectives are very nice, sort of like the difference between Olympus D Plan and S Plan objectives. They actually have a bit higher numerical aperture than normal achromats. The Nikon Plan Fluor even nicer, as noted above.

5) You could substitute and Olympus phase objective, but it would be a hassle to find and insert a matching phase ring, and either use Olympus eyepieces or suffer a bit of mismatch with the Nikon (their CF and CFN objectives don't need eyepiece corrections).

apochronaut
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Re: Upgrading a Nikon E Plan PH3 Objective

#8 Post by apochronaut » Thu Sep 26, 2019 11:25 pm

Sauerkraut wrote:
Thu Sep 26, 2019 8:14 pm
I have a 40x plan objective so don't use the e-plan for BF. But I'll do a comparison of the two objectives in BF anyway. The PC itself seems decent. The specimen, underwhelming. It may be my stubbornness in using deep well slides to keep from crushing the 'elders.'

I started a batch of yeast so I can get some good comparisons on a flat slide in a few days.
That well could be your problem ; the well slides. Once you scoot over .40 N.A. , all bets are off. Some objective designs are remarkably forgiving and some are as sensitive as an impacted tooth. Even pedestrian .65 objectives that do well with .17 covers on a slide , get spherical aberration once you deepen the sample. Since you say it has a coverslip correction collar, rather than just setting it at the .17 point, start with the greatest setting and adjust down from there. With a well slide, I think you will find that you need to adjust to a higher coverglass thickness than you are using, or get some 0 coverslips and do some testing to determine what setting on the objective is required to accomodate for the extra sample thickness. It's possible with well slides, the correction collar cannot fully accomodate for the extra depth.
Beware , ramping up the potential resolution with increasing N.A. objectives and or better corrected designs. It will make matters worse, if you do not change your sampling procedure because those objectives require better control of the thickness of the sample in order to achieve their stated specification.

PeteM
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Re: Upgrading a Nikon E Plan PH3 Objective

#9 Post by PeteM » Thu Sep 26, 2019 11:53 pm

I missed your post #5. Phil may very well have it. Not much depth of field at 40x and a higher NA objective is likely to make it even worse.

Sauerkraut
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Re: Upgrading a Nikon E Plan PH3 Objective

#10 Post by Sauerkraut » Fri Sep 27, 2019 3:42 pm

viktor j nilsson wrote:
Thu Sep 26, 2019 9:19 pm

At first, I thought that I would be quite content with the E plans, and got myself a set of 4x, 10x, 40x and 100x E plan. But I never liked them, and I found the 40x E plan to be especially poor. Especially in terms of lateral chromatic aberration, but I also found the resolution to be underwhelming. So I have since upgraded to better corrected objectives (as you can see above!)...

...In summary, I think that it would be worth it to go for the Fluor 40x 0.85 Ph3 objective. But the CFN 40x Ph3 is also going to be a big improvement over the E plan.
Many thanks, Viktor, for this excellent summary. It aligns with what I'm observing at 40x with the E Plan and gives me confidence to upgrade. It's good to know that from a value standpoint, fluor (or plan fluor) has more bang for the buck than plan apo.

It's also possible I'll have to change my slide mounting techniques at 40x to get cleaner images.

Sauerkraut
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Re: Upgrading a Nikon E Plan PH3 Objective

#11 Post by Sauerkraut » Fri Sep 27, 2019 3:49 pm

PeteM wrote:
Thu Sep 26, 2019 11:12 pm
Heather, a few thoughts:

1) Can I assume your phase telescope shows that the phase rings are perfectly aligned? Everything clean? Specimens under a cover slip? The E plan Nikon 40x should give a decent image. I've also had a bad example, used, with no obvious external damage.

2) On the condenser iris question, you want to be sure the condenser and field diaphragms are open beyond the phase ring.

3) If you're using standard coverslips with your upright microscope, there's little need for the added cost and complication of a correction collar IMO. These objectives typically sacrifice a bit of numerical aperture to allow the correction and are especially suited to inverted microscopes. However, the example you show from Ebay is Fluor with a higher N.A. (good). It's not marked as Plan, though, and might have more field curvature.

4) The Nikon CFN objectives are very nice, sort of like the difference between Olympus D Plan and S Plan objectives. They actually have a bit higher numerical aperture than normal achromats. The Nikon Plan Fluor even nicer, as noted above.

5) You could substitute and Olympus phase objective, but it would be a hassle to find and insert a matching phase ring, and either use Olympus eyepieces or suffer a bit of mismatch with the Nikon (their CF and CFN objectives don't need eyepiece corrections).
Hi PeteM, thank you for your thoughts.

1> Yes phase is aligned, everything is clean, specimen is under coverslip. I will run the yeast experiment soon to given the E Plan a look on a flat slide.

2> Thank you.

3&4> I'll keep my eye out for a suitable upgrade. Even if the E Plan is okay, part of the fun of microscopy is upgrading, tinkering, and being unreasonably obsessive.

5> Apochronaut's and your point taken - no mix and match.

Thank you.

Sauerkraut
Posts: 211
Joined: Tue Apr 16, 2019 2:07 am
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Re: Upgrading a Nikon E Plan PH3 Objective

#12 Post by Sauerkraut » Fri Sep 27, 2019 3:54 pm

apochronaut wrote:
Thu Sep 26, 2019 11:25 pm
Sauerkraut wrote:
Thu Sep 26, 2019 8:14 pm
I have a 40x plan objective so don't use the e-plan for BF. But I'll do a comparison of the two objectives in BF anyway. The PC itself seems decent. The specimen, underwhelming. It may be my stubbornness in using deep well slides to keep from crushing the 'elders.'

I started a batch of yeast so I can get some good comparisons on a flat slide in a few days.
That well could be your problem ; the well slides. Once you scoot over .40 N.A. , all bets are off. Some objective designs are remarkably forgiving and some are as sensitive as an impacted tooth. Even pedestrian .65 objectives that do well with .17 covers on a slide , get spherical aberration once you deepen the sample. Since you say it has a coverslip correction collar, rather than just setting it at the .17 point, start with the greatest setting and adjust down from there. With a well slide, I think you will find that you need to adjust to a higher coverglass thickness than you are using, or get some 0 coverslips and do some testing to determine what setting on the objective is required to accomodate for the extra sample thickness. It's possible with well slides, the correction collar cannot fully accomodate for the extra depth.
Beware , ramping up the potential resolution with increasing N.A. objectives and or better corrected designs. It will make matters worse, if you do not change your sampling procedure because those objectives require better control of the thickness of the sample in order to achieve their stated specification.
Thank you Apochronaut. I may have to change my sampling ways a bit to get decent resolution above 20x.

It will be interesting to apply the above to the correction collars and see how results vary.

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