Search found 6345 matches
- Fri May 03, 2024 12:05 am
- Forum: Microscopes and optics
- Topic: How sensitive are objectives to slide or stage crashes?
- Replies: 8
- Views: 228
Re: How sensitive are objectives to slide or stage crashes?
Whether the seller has to bear the cost of shipping is entirely based on how the item is described. Used condition is pretty vague because there is no condition report. What you really want to see are words like fully functional, works as intended etc If there is a dispute , ebay will read correspon...
- Thu May 02, 2024 9:11 pm
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
Rorschach, could you measure across the thread of one of your condenser barrels?.
- Thu May 02, 2024 2:39 pm
- Forum: Microscopes and optics
- Topic: How sensitive are objectives to slide or stage crashes?
- Replies: 8
- Views: 228
Re: How sensitive are objectives to slide or stage crashes?
That is a very good synopsis. To add about phase annuli. The visual effect that occurs when phase objectives are used for BF seems like a loss of contrast and very slightly resolution. The annuli cause phase retardation in either the area of the annulus or it's surround depending on whether the obje...
- Thu May 02, 2024 2:25 pm
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
The English 1978 and German 1982 catalogues/brochures I referenced are available from Gordon Cougar's site, accessible from the P.S. Neeley cataloge page.
Use Reichert A-4, not klein.
Use Reichert A-4, not klein.
- Thu May 02, 2024 2:16 pm
- Forum: Microscopes and optics
- Topic: Zeiss infinite condensers
- Replies: 1
- Views: 62
Re: Zeiss infinite condensers
Refracting condensers have a front focal length and a back focal length. The back focal length is very similar between condensers because they all have to focus at a similar distance to the object but the front focal length will vary , depending on the location of the illuminator or field plane if f...
- Thu May 02, 2024 1:46 pm
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
It makes me wonder if they made an apochromat/aplanat for a while, then just went with an achromat/aplanat. If such a condenser exists, it might have been the only one made by anyone. I have come across no other. Prior to the 1960's some companies made condensers that had R.M.S. threads. Researchers...
- Thu May 02, 2024 1:16 pm
- Forum: Microscopes and optics
- Topic: How sensitive are objectives to slide or stage crashes?
- Replies: 8
- Views: 228
Re: How sensitive are objectives to slide or stage crashes?
Returns are getting trickier but an objective that doesn't achieve a level of performance that matches the description is supposed to be returnable on the sellers coin. They have to send you a trackable shipping label : if that is an ebay purchase? Here is my worst ebay return experience for general...
- Thu May 02, 2024 12:05 pm
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
See the edits re: 1982 in my earlier post. That explains the .90 vs. .92 difference, yes.
Can you see any reference to an apochromat/aplanat 1.30 condenser in your literature? I am confused by that 1978 reference.
Can you see any reference to an apochromat/aplanat 1.30 condenser in your literature? I am confused by that 1978 reference.
- Thu May 02, 2024 10:50 am
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
It is understandable that there is no mention of the aux condenser in the 1978 Polyvar manual as it seems that this aux condenser did not appear until some time in the early 80ies. Oh but it does. If you read the section it clearly mentions the 0.32 and 0.90 options( not 0.92 for some reason) plus ...
- Thu May 02, 2024 3:06 am
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
Interesting. I see both a 25X .45 Plan and 25X .65 Planapo on that order guide, contrary to previous information received. That guide doesn't indicate the correction level of the universal condenser but the section above in post # 138, extracted ftom a 1978 manual clearly states that it is an apochr...
- Thu May 02, 2024 1:25 am
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
21-40/1B Polyvar E 7/78 Section 3.5 .The Brightfield Condenser is of a novel optical design which gives correct illumination of the wide fields as well as the corresponding illumination apertures for all magnification steps. When chang - ing to lower magnifications not only the high aperture front l...
- Wed May 01, 2024 7:50 pm
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
.92 is pretty high for an aux. condenser and would require at least a doublet plus highly curved plano convex back lens to achieve that on it's own with acceptable corrections. It seems that the unit might be a very low N.A. reducing aux. condenser that interchanges for an intermediate performance ...
- Wed May 01, 2024 12:57 am
- Forum: Identification help
- Topic: Unidentified structures in lichen. A diatom?
- Replies: 5
- Views: 174
Re: Unidentified structures in lichen. A diatom?
The second one is a size 5 , women's , Lilliputian clog shoeprint. Just kidding. That's a wild yeast..... maybe schizosaccharomyces or commonly called a fission yeast. Fission yeasts longitudinally divide like bacteria. The line separating the heel from the sole of the shoeprint is the division betw...
- Wed May 01, 2024 12:42 am
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
.92 is pretty high for an aux. condenser and would require at least a doublet plus highly curved plano convex back lens to achieve that on it's own with acceptable corrections. It seems that the unit might be a very low N.A. reducing aux. condenser that interchanges for an intermediate performance l...
- Tue Apr 30, 2024 4:52 pm
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
Is that wide field condenser a stand alone condenser or a suplemental condenser?
- Tue Apr 30, 2024 3:20 pm
- Forum: Microscopes and optics
- Topic: How sensitive are objectives to slide or stage crashes?
- Replies: 8
- Views: 228
Re: How sensitive are objectives to slide or stage crashes?
It is hard to see how that degree of abrasion and scoring over such a wide area could take place as a result of contact with a glass cover slip, especially when lubricated with oil. That looks like it is damage caused by something harder than the metals used for the front bezel and lens mount. Somet...
- Tue Apr 30, 2024 9:44 am
- Forum: Microscopes and optics
- Topic: Reichert Polyvar
- Replies: 155
- Views: 1839621
Re: Reichert Polyvar
I can't believe anyone at Leica would care. They seem to have long ago forgotten their legacy, except to brandish certain aspects of it that they deem useful for marketing. You might consider contacting Steve Neeley and sending a scan to him as well. He provides or has links to AO related info., inc...
- Mon Apr 29, 2024 7:37 am
- Forum: Camera systems and imaging
- Topic: Is this genius or madness ?
- Replies: 25
- Views: 4234
Re: Is this genius or madness ?
Seems the package is more armed to suit photographers who are willing to anti up. Interchangeability of lenses across brands is a selling feature that microscopists don't really need. For the output involved , a microscopist can buy a dedicated microscope camera with pretty high end targeted microsc...
- Wed Apr 24, 2024 10:42 pm
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 995
Re: Partially blocked Leica objective
Perhaps I didn't explain properly. The 360° polarizer and slit condenser are two separate units, mateable by virtue of an akehurst slide. Here is an authentic PZO polarizing attachment being sold on ebay for instance. https://www.ebay.ca/itm/325886635516?itmmeta=01HW93SRP0WBH522M6BNE3D756&hash=item4...
- Wed Apr 24, 2024 11:48 am
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 995
Re: Partially blocked Leica objective
PZO had a version of a slit condenser interference contrast system between about 1970 and the early 90's. The slit condenser has sadly become somewhat popular, so it is unlikely you will find one, nor the dovetailed polarizer that slid in under it for the $30 or so that they sold for only a couple o...
- Tue Apr 23, 2024 9:23 pm
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 995
Re: Partially blocked Leica objective
Are you able to view the slit in a bertrand lens? I was going to suggest using the jaws of a vernier caliper as a slit mock up or a small straight jawed clamp, such as a small Jögensen clamp, then transfer the dimensions to a filter disc.
- Tue Apr 23, 2024 11:47 am
- Forum: Pictures and Videos
- Topic: Broken
- Replies: 6
- Views: 263
Re: Broken
Really interesting and carefully constructed image, potentially created millions of times per day. Yes, thank you for taking the time to post it. One question I have is that the fully illuminated circle , appears to be somewhat oval, conforming more or less in it's length by width ratio to the princ...
- Sun Apr 21, 2024 12:57 pm
- Forum: Microscopes and optics
- Topic: Leitz/Leica Labovert DIC/ICT
- Replies: 13
- Views: 503
Re: Leitz/Leica Labovert DIC/ICT
Supplemental condenser lenses lead double lives and end up in strange places. My best acquisition of a needed one was from ebay and came complete with it's 1.4 achromat aplanat condenser. I picked it up on a Sunday morning and had to wait a while because the seller who looked like Keith Moon, especi...
- Sun Apr 21, 2024 10:02 am
- Forum: Illumination Techniques
- Topic: Darkfield Illumination
- Replies: 17
- Views: 958
Re: Darkfield Illumination
It was my understanding the BF achieved the highest resolution possible, while others illumination techniques helped to gain contrast at the expense of a lower resolution. But of course, I might be wrong. Just talking about my personal experience This seems to have been the understanding and experi...
- Sun Apr 21, 2024 8:38 am
- Forum: Illumination Techniques
- Topic: Darkfield Illumination
- Replies: 17
- Views: 958
Re: Darkfield Illumination
I agree with all that, Javier and you can mathematically show that DF should have lower resolution than BF but I am consistently finding fine details in DF that do not show up in BF. Part of that is probably caused by visual handicaps related to either the brains response to low light levels or poss...
- Sun Apr 21, 2024 7:41 am
- Forum: Microscopes and optics
- Topic: Leitz/Leica Labovert DIC/ICT
- Replies: 13
- Views: 503
Re: Leitz/Leica Labovert DIC/ICT
It appears you have the required componnents for DIC The Polarizer, Analyser and the objective prism for the 25X L on the slider. It appears the condenser has a matching prism for the 25x (S25) as well? If so, it is complete for DIC on that one objective. Also, in a Labovert brochure there was this...
- Sun Apr 21, 2024 6:53 am
- Forum: Beginner's corner
- Topic: A few newbie questions - advice sought
- Replies: 11
- Views: 443
Re: A few newbie questions - advice sought
Best to get a 3rd eyepiece and mount a reticle in it. For some eyepieces there is a focusing version that can focus on the reticle separately, so it is as sharp as the field stop. The 3rd eyepiece goes in and out as needed. Reticles install easily with the precaution that every spec. is visible on t...
- Sun Apr 21, 2024 2:09 am
- Forum: Beginner's corner
- Topic: A few newbie questions - advice sought
- Replies: 11
- Views: 443
Re: A few newbie questions - advice sought
Hi I am interested in getting started with microscopy. My primary interest would be in observing and measuring mushroom spores, but also looking at tardigrades and other small critters, plant parts from my yard, etc. My budget is approx 500-900 USD, depending. I would rather pay a little more upfro...
- Sat Apr 20, 2024 4:14 pm
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 995
Re: Partially blocked Leica objective
I recognize that you have a system that you have evolved that works for culturing and live mounting but I see a few major red flags that could limit your attempts to increase resolution with higher N.A. objectives. 10X .25 is very forgiving. Anything over .30 or .35 increasingly not so The other thi...
- Sat Apr 20, 2024 1:45 am
- Forum: Illumination Techniques
- Topic: Darkfield Illumination
- Replies: 17
- Views: 958
Re: Darkfield Illumination
You are certainly getting your money's worth out of that scope/camera. I am curious why you say that DF lowers resolution?