Search found 6327 matches
- Wed Apr 24, 2024 10:42 pm
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 691
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: 691
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: 691
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: 160
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: 367
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: 713
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: 713
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: 367
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: 5
- Views: 193
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: 5
- Views: 193
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: 691
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: 713
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?
- Sat Apr 20, 2024 1:42 am
- Forum: Identification help
- Topic: Another mystery ciliate
- Replies: 2
- Views: 94
Re: Another mystery ciliate
Cilia are a widespread cellular mechanism for both locomotion and locomoting substances. There are ciliated reproductive bodies or lifecycle stages that mimic a ciliated organism in form. Flagellated too, some quite small. In the previous query for instance, I mentioned a blastocyte or more likely a...
- Fri Apr 19, 2024 2:48 am
- Forum: Illumination Techniques
- Topic: Darkfield Illumination
- Replies: 17
- Views: 713
Re: Darkfield Illumination
Those are very good. Curious what condenser and 20X objective you are using.
- Thu Apr 18, 2024 11:36 pm
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 691
Re: Partially blocked Leica objective
The problem with condenser WD I was thinking of is that standard petri dishes are 16mm high. When I flip a dish upside down, the condenser focus is something like 12-13 mm away from the bottom of the dish. Here's how it looks when I look through the bottom: IMG_3447.jpg This 10x has a WD of 18mm, s...
- Thu Apr 18, 2024 7:19 pm
- Forum: Identification help
- Topic: Any idea what this is?
- Replies: 2
- Views: 152
Re: Any idea what this is?
I suspect a blastocyst of some kind. I do see what looks like the movement of cilia. A contracted rotifer? They don't like to be squished.
- Thu Apr 18, 2024 12:45 pm
- Forum: Pictures and Videos
- Topic: Tons of Euglena sociabilis
- Replies: 4
- Views: 209
Re: Tons of Euglena sociabilis
You could set up a Euglena smoothee concession. Could be the next Spirulina ! Might tickle on the way down, though.
- Thu Apr 18, 2024 9:32 am
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 691
Re: Partially blocked Leica objective
Thanks all for the input. The catalog number is 506135. I've had a hard time finding info on older Leica parts, and even the current Leica website is sparse with details on their current offerings. I bought this for looking through agar petri dishes, so upright scope should be fine I thought. I did...
- Wed Apr 17, 2024 2:01 pm
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 691
Re: Partially blocked Leica objective
I would think so. Having the modulater in the objective is probably covering 80% of the engineering complexity of the mechanism. The rest is kind of plug and play, not dissimilar to the related components in phase contrast. The reduction in contrast and likely brightness you noted in BF would be a n...
- Wed Apr 17, 2024 8:44 am
- Forum: Microscopes and optics
- Topic: Partially blocked Leica objective
- Replies: 29
- Views: 691
Re: Partially blocked Leica objective
Looks like a modulation contrast gradient.
- Tue Apr 16, 2024 2:08 pm
- Forum: Illumination Techniques
- Topic: The Lucigen illuminator
- Replies: 6
- Views: 336
Re: The Lucigen illuminator
There were somewhat similar illumination systems made for DF use,, with a low wattage incandesdent bulb embedded inside a DF condenser.
- Mon Apr 15, 2024 11:30 pm
- Forum: Introduce yourself
- Topic: Outstanding Сasual Dating - Actual Women
- Replies: 4
- Views: 234
Re: Outstanding Сasual Dating - Actual Women
User name should be Spermatozoa not Protozoa.
- Mon Apr 15, 2024 11:27 pm
- Forum: Microscopes and optics
- Topic: how scared should I be of mercury lamps
- Replies: 14
- Views: 533
Re: how scared should I be of mercury lamps
I started wearing a tintoil hat when I eat Tuna. Then all my fillings fell out. Turns out I bought an industrial tinfoil hat, the kind that thermometer recyclers and chlor-alkali workers use : 18 gauge. You can be too cautious. All I really needed was a diy tinfoil hat made from Reynold's wrap. Deve...
- Sat Apr 13, 2024 4:21 am
- Forum: Microscopes and optics
- Topic: one last question on Leica objectives for DMRB
- Replies: 5
- Views: 267
Re: one last question on Leica objectives for DMRB
I don't know whether Leica continued with the Reichert and AO toric condenser or not. It is kind of a W.F. DF condenser and can cover a 2000 micron field, so can be used with a 10X objective and 10X/20 eyepieces. That would be the DF condenser to look for.
- Fri Apr 12, 2024 10:29 am
- Forum: Microscopes and optics
- Topic: Brand of this old condenser?
- Replies: 16
- Views: 1749
Re: Brand of this old condenser?
Hope it all works out for you. I use a somewhat similar condenser on a B & L Balplan Research stand. The chief engineer of the Balplan made a 125X 1.40 Flat Field Apochromat prototype and he and a colleague patented a really nice compatible condenser to go with it but I have never seen an example of...
- Fri Apr 12, 2024 3:34 am
- Forum: Illumination Techniques
- Topic: Darkfield Illumination
- Replies: 17
- Views: 713
Re: Darkfield Illumination
All DF condensers or condensers modified to produce DF have limitations, so understanding those helps one to choose which method is most suitable. Obviously, using stops and an existing available condenser is the cheapest option. Stops are o.k., even good with up to a 20X objective and possibly high...
- Thu Apr 11, 2024 10:59 pm
- Forum: Microscopes and optics
- Topic: one last question on Leica objectives for DMRB
- Replies: 5
- Views: 267
Re: one last question on Leica objectives for DMRB
If you ever plan on doing high resolution DF you will need the iris.
- Thu Apr 11, 2024 9:42 pm
- Forum: Microscopes and optics
- Topic: Brand of this old condenser?
- Replies: 16
- Views: 1749
Re: Brand of this old condenser?
Guessing but seems so. It is probably a very good condenser for higher N.A. objectives but it was for a microscope that utilized a mirror and remote illuminator, so it has a longer front focal length. It would work better on a microscope with a rear mounted illuminator, collimating optics , field di...
- Thu Apr 11, 2024 10:47 am
- Forum: Microscopes and optics
- Topic: Brand of this old condenser?
- Replies: 16
- Views: 1749
Re: Brand of this old condenser?
It was pretty hard to improve on a 1.40 achromat aplanat and most companies didn't need to because their objective range seldom exceeded a 1.40. Winkel made a 1.52 condenser in the 50's/60's. Leitz probably made that or a very similar condenser for 40 years, eventually marking the an N.A. on it. Lei...
- Thu Apr 11, 2024 2:59 am
- Forum: Microscopes and optics
- Topic: Brand of this old condenser?
- Replies: 16
- Views: 1749
Re: Brand of this old condenser?
Leica was not a microscope company until the 1991 merger. This condenser easily could be Leitz but not Leica. It is not a DF condenser.. It is a stacked BF condenser with sectional N.A. increases matching that required by the grouped objectives coupled to it's matched system. A DF condenser has to h...