Nikon scope objectives.

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rjlittlefield
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Post by rjlittlefield »

Charles Krebs wrote:r = 0.61 × λ/NA seems to be more widely used and accepted
Right. That's because r = 0.61 × λ/NA gives you a feature size at which you still have contrast that's usable though small, while r = 0.5 × λ/NA (=λ/(2*NA)) gives you the feature size at which contrast disappears altogether.

As a small attempt at humor, I might say that Nikon's numbers come from a calculation that tells you the pixel size needed to minimally capture nothing at all (2 pixels per feature at 0% MTF).

On the other hand, there's another way to interpret the same calculation.

With perfect optics, the MTF is about 40% at twice the cutoff size (half the spatial frequency) and about 20% at 1.5 times the cutoff size. (See the graph HERE.)

So, Nikon's numbers also tell us the pixel size needed to give 4 pixels per feature at 40% MTF, and 3 pixels per feature at 20% MTF.

Somehow I find this second interpretation more comforting.

--Rik

Charles Krebs
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Post by Charles Krebs »

Rik,
I find this second interpretation more comforting.
If you want to get "uncomforted" plug in a 4/0.20 Plan Apo (at 1X relay magnification) and see how some camera sensors stack up :wink:

rjlittlefield
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Post by rjlittlefield »

Well, I'm still comforted that the calculation produces a meaningful number.

The fact that it says I need the pixel count of a scanning back, now that's impressive!

--Rik

Charles Krebs
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Post by Charles Krebs »

Also impressive to compare that 4/0.20 with the requirements of a 40/0.70.

Ohhh the heavy toll of diffraction :cry:

NikonUser
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Post by NikonUser »

Just sold on e bay

NIKON M PLAN 5x 0.1 MICROSCOPE OBJECTIVE
Item condition: Used
Ended: Oct 04, 200900:42:16 EDT
Bid history: 7 bids
Winning bid: US $203.50
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

ChrisR
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Post by ChrisR »

Hmm I saw that. I think I bid to about $50!
This one almost looks cheap then:
Nikon CF Plan 5x/0.13 inf/0 EPI objective BIN/offers on $199
I can't help wondering how much difference the tube length would matter...
Here

and I was surprised there were no bids on
Nikon microscope objective 4 Plan 0.1
at £6.99!
here

NikonUser
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Location: southern New Brunswick, Canada

Post by NikonUser »

$50.00! that would have been a sweet deal.
That 5x you referenced is an infinity lens; no use for camera/bellows setup?
The 4x looks the old style, and not chromatic-aberration-free.
Compare it to the one I recently bought
HERE
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

ChrisR
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Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

The 4x looks the old style, and not chromatic-aberration-free.
Ah. Nearly wasted £6.99 then!

That 5x you referenced is an infinity lens; no use for camera/bellows setup?
Has anyone tried it?

yes I saw the one you bought recently - I'd decided to let it go! I'm sure you'd get better images from it than me :wink:

ChrisR
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Post by ChrisR »

How very odd, serendipitous.
I've been incarcerated in a British Institution for 3 days.
Not what you're thinking, it was the NHS, c/o kidney stones.

While I was away a tiny parcel came. It was a "5xcf Eyepiece" I'd bought for £12.
Wifey forgot to give it to me.
I wasn't sure I wanted an eyepiece, but I was intrigued so bought it on a hunch. CF, I thought??
WHat do you think it is...?? (sitting in a brass plumbing fitting)
Image

NikonUser
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Joined: Thu Sep 04, 2008 2:03 am
Location: southern New Brunswick, Canada

Post by NikonUser »

In the early 1990's Nikon had a CF-E High-Eyepoint Widefield eyepiece "the standard, designed to be used with all objectives"; i.e., their CF 210mm objectives.

CF-E 5X focal length 40mm Field Number mm (width??) = 18.6. Retail (1993) US$76.00
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

ChrisR
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Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Well at US$19 that would have been okay. But in fact , when dehisced..

Image

I don't think I'll ask for my money back?

I'll obviously have to see if it's "any good". I have a few lenses, but specimens equipment and technique to make them all look bad though...:)

NikonUser
Posts: 2693
Joined: Thu Sep 04, 2008 2:03 am
Location: southern New Brunswick, Canada

Post by NikonUser »

So it has metamorphosed from an eyepiece to an objective, neat trick.
It looks like a Nikon objective for their Optiphot scopes.
You must let us know how it works on a camera as it is an infinity-corrected brightfield objective.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Yes, I chortled volubly when I discovered what it was. Wifey bemused at my reaction, but hey.
Unfortunately I don't have the lens you bought recently, so I can't make a direct comparison, but I'll see if it's terrible, I suppose.

I "feel" that the difference in optics will show less at the lower magnifications, and their lower NAs, though that may be total nonsense.
Making a 40ish mm lens work well at 200mm to infinity, with such a modest aperture, doesn't sound the hardest challenge, though I don't really have much clue and am conditioned by camera lenses.

NikonUser
Posts: 2693
Joined: Thu Sep 04, 2008 2:03 am
Location: southern New Brunswick, Canada

Post by NikonUser »

I'm confused. I thought the 'problem' was that infinity-corrected objectives need a specific eyepiece to actually form an image. This may have been covered elsewhere in the forums but I would be interested to see if you can get am image from it without using an eyepiece; i.e., camera, tube/bellows, lens.
Take a photo of a blade of grass and post it.
The lens has a WD of 22.5mm
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

rjlittlefield
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Posts: 23561
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

For the record, I'm betting it'll work fine. My rationale is this graph: http://www.science-info.net/docs/etc/Tube-Length-na.gif , where the tube length tolerance for NA=0.13 is literally off the chart. So I'll be very interested to see the pictures.

--Rik

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