Search found 459 matches

by viktor j nilsson
Thu Jul 22, 2021 10:24 pm
Forum: Microscopes and optics
Topic: Please advise, please offer comments on objective lens etched specs ed specs
Replies: 13
Views: 265

Re: Please advise, please offer comments on objective lens etched specs ed specs

Here is an example from the old Zeiss catalogue, displaying the same variety of significant figures: Nice, the table likely display true "significant digits" that are omitted in the objective lettering. Like, magnification. NA seems to have loose tolerance. The last "100x" is a bit puzzling though....
by viktor j nilsson
Wed Jul 21, 2021 10:27 pm
Forum: Illumination Techniques
Topic: DIC Question
Replies: 202
Views: 7325

Re: DIC Question

I have only one question, how to find the back focal plane? https://www.researchgate.net/post/Is_there_a_rule_of_thumb_to_determine_the_back_focal_plane_of_objective_lens The method suggested by Paolo Pozzi works really well: shine a laser pointer through the objective and measure the size of the p...
by viktor j nilsson
Mon Jul 19, 2021 10:45 pm
Forum: Microscopes and optics
Topic: I received my Nikon CFN PlanApo 60/1.40 Oil, is completely ruined
Replies: 39
Views: 2183

Re: I received my Nikon CFN PlanApo 60/1.40 Oil, is completely ruined

My £30 Nikon CFN PlanApo 100x 1.40 arrived today, and it is in much better shape than I could ever have hoped for. The front lens is pristine, and I can't see any defects internally besides a little dust on the rear element. A quick test with a calibration slide revealed a very sharp, contrasty imag...
by viktor j nilsson
Sun Jul 18, 2021 10:24 pm
Forum: Microscopes and optics
Topic: Strange Bedfellows
Replies: 8
Views: 269

Re: Strange Bedfellows

Nikon never made an objective that says CF or CFN on the barrel.
by viktor j nilsson
Sun Jul 18, 2021 4:53 pm
Forum: Microscopes and optics
Topic: Strange Bedfellows
Replies: 8
Views: 269

Re: Strange Bedfellows

Is it one like this?

Image

If it is, then it is definitely a CF objective.
by viktor j nilsson
Wed Jul 14, 2021 7:00 am
Forum: Illumination Techniques
Topic: Converting Brightfield Microscope To DIC
Replies: 30
Views: 1026

Re: Converting Brightfield Microscope To DIC

You don't need fluorite or apochromatic objectives for DIC. That is interesting; not what I had heard. The folks who sold me my system said you need fluor or better and the only test I've been able to perform indicates that my 60X achromat doesn't work with my 40X/100X DIC components. There could b...
by viktor j nilsson
Wed Jul 14, 2021 6:26 am
Forum: Illumination Techniques
Topic: Converting Brightfield Microscope To DIC
Replies: 30
Views: 1026

Re: Converting Brightfield Microscope To DIC

You don't need fluorite or apochromatic objectives for DIC. For best performance, you want the objective the system was designed for. In many cases that will be the better corrected objectives, but sometimes it is not. The BH2 era olympus DIC systems, for example, was designed for the SPlan Achromat...
by viktor j nilsson
Sun Jul 11, 2021 8:58 am
Forum: Beginner's corner
Topic: Should the condenser diaphragm work when using DIC?
Replies: 9
Views: 255

Re: Should the condenser diaphragm work when using DIC?

I, too, am very excited to see how this will perform!
by viktor j nilsson
Tue Jul 06, 2021 4:14 am
Forum: Microscopes and optics
Topic: Nikon Plan objective - washed out colours
Replies: 15
Views: 854

Re: Nikon Plan objective - washed out colours

CFN = CF New. Nikon gradually updated the lens designs of the original CF series, calling the updated versions CFN (NCF in Japanese literature). They didn't change all at once, which is why you see a combination of CF and CFN objectives in the catalogue. Some designs were never changed before the sh...
by viktor j nilsson
Sat Jul 03, 2021 5:56 pm
Forum: Illumination Techniques
Topic: How does objective strain show up in DIC images?
Replies: 8
Views: 279

Re: How does objective strain show up in DIC images?

Is this a symptom of a small magnification mismatch between the prisms? For example say one prism shows retardance varying -500 to 500 nm across the pupil and the other a slightly broader fringe pattern 450 to -450 nm. Then together the residual goes -50 to 50 nm and the dark band seen crossing the...
by viktor j nilsson
Sat Jul 03, 2021 6:30 am
Forum: Illumination Techniques
Topic: How does objective strain show up in DIC images?
Replies: 8
Views: 279

Re: How does objective strain show up in DIC images?

Interesting, I had noticed the cross pattern before when using polarized light and read a little about conoscopy but still don't understand how exactly the cross is formed, much less how the rotation of the cross shown in (c) would be expected to interact with the DIC fringe pattern. The view in (c...
by viktor j nilsson
Fri Jul 02, 2021 10:21 pm
Forum: Illumination Techniques
Topic: How does objective strain show up in DIC images?
Replies: 8
Views: 279

Re: How does objective strain show up in DIC images?

The easiest way to check for strain is too look at the back focal plane with crossed polarizers. It should look like (a): https://micro.magnet.fsu.edu/primer/techniques/polarized/images/polmicroalignmentfigure4.jpg But if an objective has strain the cross won't be black and irregular. When I was pla...
by viktor j nilsson
Wed Jun 30, 2021 3:46 pm
Forum: Microscopes and optics
Topic: I received my Nikon CFN PlanApo 60/1.40 Oil, is completely ruined
Replies: 39
Views: 2183

Re: I received my Nikon CFN PlanApo 60/1.40 Oil, is completely ruined

That is very impressive, apo. And I, too, am very happy for Seta. Looking forward to seeing the results!
by viktor j nilsson
Wed Jun 30, 2021 3:17 pm
Forum: Microscopes and optics
Topic: Are there low-power oil immersion objectives?
Replies: 26
Views: 829

Re: Are there low-power oil immersion objectives?

Could it be a set of telan lenses creating a miniature infinity space?
by viktor j nilsson
Wed Jun 30, 2021 12:39 pm
Forum: Microscopes and optics
Topic: I received my Nikon CFN PlanApo 60/1.40 Oil, is completely ruined
Replies: 39
Views: 2183

Re: I received my Nikon CFN PlanApo 60/1.40 Oil, is completely ruined

Any updates on this? I'm very curious to see how it worked out! I just picked up a very risky as-is Nikon CFN PlanApo 100x 1.40 for £30, hoping that it would, at worst, be similarly oil-filled.
by viktor j nilsson
Wed Jun 30, 2021 6:50 am
Forum: Pictures and Videos
Topic: Amphipleura pellucida 95µm
Replies: 13
Views: 314

Re: Amphipleura pellucida 95µm

That image is absolutely fabulous. Inspiring work!
by viktor j nilsson
Tue Jun 29, 2021 10:07 pm
Forum: Illumination Techniques
Topic: DIC Question
Replies: 202
Views: 7325

Re: DIC Question

I got it from a post by abednego: https://www.photomacrography.net/forum/viewtopic.php?p=244784#p244784 I am not really planning to shell out the dough needed to put together a DIC system, but I have been reading a lot of DIY DIC threads with great interest lately. (is that the first symptoms of DI...
by viktor j nilsson
Tue Jun 29, 2021 9:04 pm
Forum: My microscope
Topic: New to me: early 1950s Leitz BS 48/92k with Heine
Replies: 16
Views: 650

Re: New to me: early 1950s Leitz BS 48/92k with Heine

Look at those prices! , yet only 6.00 to add graduations to the XY axes. I have some Leitz 37mm parfocal objectives of you are interested. I can send a list, if you like. I think there is an 8mm(24:1) apo. Maybe some condenser stuff. It's kind of silly that they gave it a different model designatio...
by viktor j nilsson
Tue Jun 29, 2021 9:01 pm
Forum: Illumination Techniques
Topic: DIC Question
Replies: 202
Views: 7325

Re: DIC Question

The size of the fringe pattern is supposed to match when taking into account the magnification between the respective conjugate planes. Viktor posted an equation representing that in #80 : In regular DIC, the following criteria needs to be met to achieve proper DIC... I do wonder what the source of...
by viktor j nilsson
Tue Jun 29, 2021 8:40 pm
Forum: Illumination Techniques
Topic: DIC Question
Replies: 202
Views: 7325

Re: DIC Question

So that just means when I look at the bfp then the apparent view of the fringes should match between the two prisms? That is my understanding, but I have never actually used a DIC microscope... Exactly. It's as simple as that, the fringes of both prisms should look the same when observed at the BFP...
by viktor j nilsson
Tue Jun 29, 2021 7:53 am
Forum: My microscope
Topic: New to me: early 1950s Leitz BS 48/92k with Heine
Replies: 16
Views: 650

Re: New to me: early 1950s Leitz BS 48/92k with Heine

This was most likely used as a photo microscope. I am not familiar with your particular stand but the quick change optical tube feature on other similar stands I am familiar with, allows for a rapid interchange between the binocular tube assembly and a dedicated photo tube assembly with mounted cam...
by viktor j nilsson
Sun Jun 27, 2021 7:15 pm
Forum: My microscope
Topic: Nikon Optiphot with DIC
Replies: 21
Views: 953

Re: Nikon Optiphot with DIC

Very glad to hear it has worked out so well! Not exactly the right ones, but if you want to try a Nikon CF E plan 10x 0.25 and E plan 100x 1.25, I have some that I don't need and could sell for cheap. You are in Europe somewhere? I'm in Sweden.
by viktor j nilsson
Sat Jun 26, 2021 9:07 pm
Forum: My microscope
Topic: New to me: early 1950s Leitz BS 48/92k with Heine
Replies: 16
Views: 650

Re: New to me: early 1950s Leitz BS 48/92k with Heine

I've heard people say this before, but it's really true: the black horseshoe stands looks really small in photographs, but are much bigger, and a lot heavier, in real life than what you expect. Even when I'm looking at my own photos it looks a lot smaller than it really is.
by viktor j nilsson
Sat Jun 26, 2021 9:05 pm
Forum: My microscope
Topic: New to me: early 1950s Leitz BS 48/92k with Heine
Replies: 16
Views: 650

Re: New to me: early 1950s Leitz BS 48/92k with Heine

Very cool! Amazing that it came with the Heine. Where did you find it? On a local swedish classifieds site. It was actually available for sale for several months just over a year ago. I tried to buy it then, but the pandemic prevented me from traveling to meet the seller. I even mentioned it in a t...
by viktor j nilsson
Sat Jun 26, 2021 8:13 pm
Forum: My microscope
Topic: New to me: early 1950s Leitz BS 48/92k with Heine
Replies: 16
Views: 650

Re: New to me: early 1950s Leitz BS 48/92k with Heine

And what’s that silver lever or clamp thing below the head? Does the tube somehow slide vertically for some reason? Yes! It's a clamp for the binocular head. Release it, and you can slide the head up and remove it. The nosepiece slides on the same dovetail and can be removed after taking off the he...
by viktor j nilsson
Sat Jun 26, 2021 11:17 am
Forum: My microscope
Topic: New to me: early 1950s Leitz BS 48/92k with Heine
Replies: 16
Views: 650

New to me: early 1950s Leitz BS 48/92k with Heine

I just recieved this beautiful Leitz BS 48/92k microscope. Serial number in the 435,000 range should date it to around 1952 or so. https://i.imgur.com/mbhzgfr.jpg https://i.imgur.com/mpQwQkz.jpg To be honest, I mostly picked it up for the Leitz Heine condenser, and in particular the Heine oil cap, s...
by viktor j nilsson
Mon Jun 21, 2021 10:00 pm
Forum: My microscope
Topic: Nikon Optiphot with DIC
Replies: 21
Views: 953

Re: Nikon Optiphot with DIC

I remember seeing this microscope listed online a while ago (I just compared the photos, and it's 100% the same microscope). I asked about it in the Nikon microscope users group on Facebook and got the following answer from one of the most knowledgeable persons there: The DIC condenser and nosepiece...
by viktor j nilsson
Sun Jun 20, 2021 8:05 pm
Forum: Microscopes and optics
Topic: alternatives for a dissecting microscope
Replies: 20
Views: 549

Re: alternatives for a dissecting microscope

A good 10x or possibly 15x folding loupe is extremely useful in the field. I use a Belomo 10x, extremely good value Belarusian loupe. I would never buy a 30x loupe. Even 20x is too much, IMHO. Dim, small field of view, razor thin focus depth. Works better if it has a built-in LED light, but even the...
by viktor j nilsson
Thu Jun 17, 2021 8:24 pm
Forum: For forum members who want to buy and sell equipment
Topic: Zeiss Hybrid Eyepieces
Replies: 9
Views: 608

Re: Zeiss Hybrid Eyepieces

Think I may be able to dig up a KPL 10x that looks a lot like the one in the eBay ad you just posted. Will have a look tomorrow.
by viktor j nilsson
Wed Jun 16, 2021 10:49 am
Forum: Resources (online, books etc.)
Topic: Microscope objectives design
Replies: 2
Views: 132

Re: Microscope objectives design

It's a very interesting series of papers. We talked about them a bit earlier:

https://www.microbehunter.com/microscop ... 75&p=74908