Search found 2989 matches
- Fri Mar 29, 2024 6:11 am
- Forum: Microscopes and optics
- Topic: Olympus X-Line Objectives
- Replies: 2
- Views: 44
Re: Olympus X-Line Objectives
To me, the video sounds like the Evident marketing department just discovered "something called aberration" and decided they'd convince customers (who they apparently think need to be informed about "something called aberration") that their new private equity owners are doing something about it. Who...
- Fri Mar 29, 2024 1:06 am
- Forum: Microscopes and optics
- Topic: Field number vs. field stop diameter in "negative" eyepieces
- Replies: 3
- Views: 86
Re: Field number vs. field stop diameter in "negative" eyepieces
This may be QWERTY vs. Dvorak keyboards. Having gotten used to field numbers, FN certainly eems simple enough. Use a 10x/22 eyepiece and I expect to see a 22mm wide field with a 1x stereo objective and a 2.2mm field with a 10x compound objective. Put a ruler or micrometer slide down and take a look....
- Fri Mar 29, 2024 12:10 am
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
Fair point about objective quality. In my experience, the cheaper Chinese 60x dry plan achromats with no correction collar are commonly a disappointment. I'd rather add a drop of oil to a 50-60-63-100x plan achromat oil objective. The 50x oil immersion finite objectives from Nikon and Olympus with a...
- Thu Mar 28, 2024 11:27 pm
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
On edit, I see you've addressed this, Zondar: What's not clear to me is if Snell's Law, ray tracing, and the Abbe diffraction limit entirely describe what happens when a specimen is illuminated and then attempts to illuminate the entire angle "seen" by an objective and described by its numerical ape...
- Thu Mar 28, 2024 10:04 pm
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
A dry (air-gapped) condenser will strictly limit the effective NA of any subsequent objective to a theoretical maximum of 1 (meaning somewhat less than 1 in practical terms). . . . As Hans noted above, it's likely a bit more complicated. The formula here (Thorlabs site) suggests an additive effect,...
- Thu Mar 28, 2024 9:28 pm
- Forum: My microscope
- Topic: Euromex Microscopes?
- Replies: 4
- Views: 101
Re: Euromex Microscopes?
. . . I collect microscopes and love to compare and contrast the various models both new and vintage from around the world :-) Thanks, Gary They're serviceable microscopes, but I wouldn't consider most of their models collectible—unless you were interested in the financial acquisition history of L ...
- Thu Mar 28, 2024 4:17 pm
- Forum: Beginner's corner
- Topic: Leica DMLB Condenser
- Replies: 9
- Views: 497
Re: Leica DMLB Condenser
The slider coming in at an angle just under the DMLB lettering is for a DIC prism. The one for the analyzer is at about the same height, on the left side (facing the microscope).
- Wed Mar 27, 2024 9:47 pm
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
Given that you're shooting at higher magnifications, you're probably OK. I was imagining all those extra and fat pixels. But as you say; the extra or larger pixels from one of the newer mirrorless cameras won't help much at 400X and above. I have heard of vibration complaints from some Canon EOS use...
- Tue Mar 26, 2024 9:47 pm
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
Harry, The 60x Plan Apo oil 1.40 objective is wonderful for thin, often stained, and stationary specimens. While lower magnification than the 100x Plan Apo oil, it has the same theoretical resolution and (if memory serves) can peer a tiny fraction (something like .02mm is typical) further below a co...
- Tue Mar 26, 2024 9:22 pm
- Forum: Beginner's corner
- Topic: Leica DMLB Condenser
- Replies: 9
- Views: 497
Re: Leica DMLB Condenser
For polarization, I suggest buying a decent-quality (so it goes to near full extinction) linear camera polarizer with a diameter that matches your field lens. It doesn't have to fit in or on the condenser. Should be under $20 or so on eBay. You'll also need a polarization slider to fit from the side...
- Tue Mar 26, 2024 4:14 am
- Forum: For forum members who want to buy and sell equipment
- Topic: For trade: microscope (DIC etc.) scopes & optics
- Replies: 39
- Views: 23407
Re: For trade: microscope (DIC etc.) scopes & optics
The first post has been updated once again. I'm now hoping to find - for trade or sale:
- UCL phase contrast condenser for Leica DMLS/DMLB
- Leica 2S1 (Ph2) phase ring
- Nikon 50/55i stage
- Nikon Eclipse PA20 DIC prism
- UCL phase contrast condenser for Leica DMLS/DMLB
- Leica 2S1 (Ph2) phase ring
- Nikon 50/55i stage
- Nikon Eclipse PA20 DIC prism
- Mon Mar 25, 2024 7:27 pm
- Forum: Microscopes and optics
- Topic: Substituting LED bulb for incandescent bulb
- Replies: 7
- Views: 332
Re: Substituting LED bulb for incandescent bulb
I've used the LED Edison-base tiny bulb replacements in a few scopes that needed them. The pluses are low cost, less heat, and longer life. However, while adequate, they don't seem much brighter. You do get the higher color temperature.
- Mon Mar 25, 2024 2:26 am
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
Thanks, Phil.
- Mon Mar 25, 2024 12:17 am
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
Phil, did you basically use a stop at the backside of the Bestscope water immersion objective for darkfield - maybe cut it down to around .90 na?
- Sun Mar 24, 2024 11:18 pm
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
FWIW, I do like my 60x oil version with the 1.40 na and a dry condenser - but that is usually with tissue samples, not protists under a cover slip.
- Sun Mar 24, 2024 7:06 pm
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
Dang. Should have asked if you had spares.apochronaut wrote: ↑Sun Mar 24, 2024 5:57 pmI could have sold you one cheaper and had it there in 10 days, Pete.
- Sun Mar 24, 2024 7:04 pm
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
Harry, Can you share your experience with the 50x Plan oil 0.90 an objective? The minus, for protists under a cover slip, is the oil immersion atop the cover slip. Perhaps there's a simple way to fix the slip in place. The pluses are likely the .30 or so working distance, a decent DIC prism match, t...
- Sun Mar 24, 2024 4:41 pm
- Forum: Microscopes and optics
- Topic: Do I need another objective?
- Replies: 46
- Views: 1338
Re: Do I need another objective?
I can share a bit of personal experience with Nikon DIC prisms and the 60x Pl Fluor dry objective. This is the 0.85 n.a. version with 0.30 working distance and a .11 to .23 correction collar. Both the PF60A and PA/PF100 prisms yield a banded background on my first-generation (E600, since ported to a...
- Sun Mar 24, 2024 12:03 am
- Forum: Microscopes and optics
- Topic: Oxidation on front assembly / retraction stopper
- Replies: 7
- Views: 376
Re: Oxidation on front assembly / retraction stopper
Oxidized metal (rust, tarnish, etc.) won't clean up with typical solvents. And, as noted above, the most volatile ones can affect cements and coatings. Since your glass is good and the damage is cosmetic, you might best consider it a sign of revered older age. If it really bugs you (and occasionally...
- Fri Mar 22, 2024 3:55 pm
- Forum: Microscopy accessories
- Topic: Anti-Static for lenses.
- Replies: 26
- Views: 1381
Re: Anti-Static for lenses.
Wow I had no idea! I just need to find someone with a Geiger counter now... Here's a result from a quick Google search: https://orau.org/health-physics-museum/collection/consumer/miscellaneous/static-eliminators.html Apparently, polonium-210 has a half-life of 138 days. If your brush is as old as t...
- Thu Mar 21, 2024 5:22 pm
- Forum: Microscopy accessories
- Topic: Anti-Static for lenses.
- Replies: 26
- Views: 1381
Re: Anti-Static for lenses.
I believe the old photo/film anti-static brushes had a "lightly" radioactive element incorporated with the hairs to produce ions. Not sure if they're still available today.
All the hip kids today use muons . . .
All the hip kids today use muons . . .
- Thu Mar 21, 2024 4:23 am
- Forum: Microscopes and optics
- Topic: Leica Reichert Jung Polyvar (models)
- Replies: 88
- Views: 34620
Re: Leica Reichert Jung Polyvar (models)
Thanks for all that additional information, Wayne.
- Thu Mar 21, 2024 1:54 am
- Forum: Beginner's corner
- Topic: Leica DMLB Condenser
- Replies: 9
- Views: 497
Re: Leica DMLB Condenser
There are typically two or three knurled screws holding the condenser in place. You'll want to rack the stage up and the condenser down to get clear space. I'm pretty sure your model has a small one on the right side that fastens it to a carrier. (#5, Figure 5, on your diagram) Unscrew that. Then un...
- Wed Mar 20, 2024 7:32 pm
- Forum: Beginner's corner
- Topic: Leica DMLB Condenser
- Replies: 9
- Views: 497
Re: Leica DMLB Condenser
Assuming I guessed right that the top lens slides in and out of position, you should have wide field coverage for your 2.5x objective with it out and excellent images at higher magnification with it in. You probably want to switch it "in" once you're at 10x and maybe even at 4x or 5x. There should b...
- Wed Mar 20, 2024 3:46 pm
- Forum: Beginner's corner
- Topic: Leica DMLB Condenser
- Replies: 9
- Views: 497
Re: Leica DMLB Condenser
Nebulous, I'm only seeing the first image. It's new to me but looks to be a step up from the standard condenser by having a slide-in and slide-out top lens to accommodate low-power (e.g. 2-2.5x) objectives. Could be wrong - you can easily see if it slides in and out. The standard condenser has a slo...
- Wed Mar 20, 2024 3:33 pm
- Forum: Microscopy accessories
- Topic: Motorized Rotating Display Stand
- Replies: 16
- Views: 689
Re: Motorized Rotating Display Stand
A classic ringing table will typically have a good bearing, a platen (table) heavy enough to have some inertia, a secure way of centering and holding the slide, and some sort of built-in bridge to steady the pen (brush, etc.). Having a motor to turn it seems the last of the requirements, since almos...
- Mon Mar 18, 2024 7:37 pm
- Forum: Miscellaneous
- Topic: The Place of Value in a World of Fact
- Replies: 3
- Views: 352
Re: The Place of Value in a World of Fact
There's a huge literature on consciousness - which is somewhere between a twin to a kissing cousin to awareness. Julian Jaynes thought we didn't become conscious until 3000 years ago (Origin of Consciousness in the Breakdown of the Bicameral Mind). However, more recent research with primates shows t...
- Sat Mar 16, 2024 4:53 am
- Forum: Beginner's corner
- Topic: unmarked long silver objective lens?
- Replies: 1
- Views: 238
Re: unmarked long silver objective lens?
The objective is missing its outer shroud, which would have had the markings. Just guessing from the Nikon turret and the size of the visible lens, I'd guess that it's a Nikon finite objective around (+/-) 10x. It will work without the shroud and it should be possible to figure the magnification eit...
- Fri Mar 15, 2024 3:06 am
- Forum: Microscopes and optics
- Topic: Reichert U.S.A. and Leica. Why the undercorrection?
- Replies: 10
- Views: 677
Re: Reichert U.S.A. and Leica. Why the undercorrection?
"I would be interested to know if anyone has used a Reichert Austria objective in a Delta based stand" Here's a quick test using a Delta-era Leica 501055 head with L Plan 10x/20 eyepieces. The stand is a DMLS that just came in. It has a yellow hot spot in the illumination—maybe the wrong bulb or ill...
- Thu Mar 14, 2024 7:22 pm
- Forum: Microscopes and optics
- Topic: Reichert U.S.A. and Leica. Why the undercorrection?
- Replies: 10
- Views: 677
Re: Reichert U.S.A. and Leica. Why the undercorrection?
Here's a shot at summarizing the discussion of eyepiece corrections in a table. There are surely omissions and likely errors. Let me know and I'll update it.
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