Search found 2722 matches

by apochronaut
Tue Oct 22, 2019 1:15 pm
Forum: Beginner's corner
Topic: Am I doing something wrong?
Replies: 8
Views: 107

Re: Am I doing something wrong?

Bacteria are about 1µm in diameter. The resolution of a light microscope with oil immersion objective is about 20µm. This means that you can resolve the bacterium and roughly see it's shape (. or - or ~) but not much more. To see it you have to adjust your condenser for maximum resolution - this is...
by apochronaut
Tue Oct 22, 2019 1:08 pm
Forum: Beginner's corner
Topic: Illuminator for Bausch and Lomb Phase Contrast Microscope
Replies: 5
Views: 78

Re: Illuminator for Bausch and Lomb Phase Contrast Microscope

Your microscope has a 2:1 zoom feature. The head is fairly complicated and probably shouldn't be dismantled unless you determine that there is a problem. Your eyepieces do not appear to be original to the microscope. They may not provide the best corrections for your objectives. They also may be a h...
by apochronaut
Mon Oct 21, 2019 11:20 pm
Forum: Pictures and Videos
Topic: Help identifying suspected bacteria
Replies: 2
Views: 62

Re: Help identifying suspected bacteria

# 1 is a fiber of some sort, probably cotton. # 2 is being caused by an air pocket, which allows dry or partially dehydrated material to image differently than the surrounding hydrated area.
by apochronaut
Mon Oct 21, 2019 11:17 pm
Forum: Microscopes and optics
Topic: Sorry, but need a quick answer
Replies: 1
Views: 58

Re: Sorry, but need a quick answer

If it is a series 410 Microstar, with a 24 watt halogen illuminator the nosepiece will not fit a 20 in the reversed position because it is too big but the dovetail does fit, so it will fit in the forward position. If it is the 420 Diastar, with the 100 watt remote illuminator housing, the nosepiece ...
by apochronaut
Mon Oct 21, 2019 7:46 pm
Forum: Beginner's corner
Topic: Illuminator for Bausch and Lomb Phase Contrast Microscope
Replies: 5
Views: 78

Re: Illuminator for Bausch and Lomb Phase Contrast Microscope

Phase contrast requires a fairly precise illumination system. Moreso than BF. One can get lucky and achieve passable results with a retrofitted illuminator but one can also have a failure. I'm pretty sure this is the original illuminator socket for your microscope. https://www.ebay.com/itm/MICROSCOP...
by apochronaut
Mon Oct 21, 2019 1:18 pm
Forum: Specimens, samples and slides
Topic: Help to identify slides
Replies: 2
Views: 65

Re: Help to identify slides

I repaired a microscope for a pigeon breeder once, so I have some idea of what you are looking for. Apparently, there are over 50 avian parasites they can carry. Although, the images are pretty low quality, it does seem that you have zeroed in on some structures that probably should not be there. In...
by apochronaut
Mon Oct 21, 2019 12:40 pm
Forum: Microscopes and optics
Topic: Question on Leitz objectives
Replies: 5
Views: 93

Re: Question on Leitz objectives

I am not sure about objectives in the Leitz 170mm D.I.N. system but it is not uncommon for very low power objectives to have a very long working distance and be not parfocal with the higher power objectives. In certain instances, manufacturers offered two options; a standard l.w.d. option and a parf...
by apochronaut
Sun Oct 20, 2019 9:41 pm
Forum: Introduce yourself
Topic: Hi just starting in Microscopie Almere The Netherlands
Replies: 6
Views: 132

Re: Hi just starting in Microscopie Almere The Netherlands

Hello Baboon. The numbering system on microscope eyepieces is only partially universal. The number following the actual magnification can be confusing, because sometimes it is the field of view being designated and sometimes it is the eye relief and sometimes it is the diameter of the eyepiece tube....
by apochronaut
Fri Oct 18, 2019 11:46 am
Forum: Home-made microscope adaptations
Topic: Fixed TL and Infinity Inter-company Compatibly
Replies: 3
Views: 68

Re: Fixed TL and Infinity Inter-company Compatibly

One of the failings of this forum is that there are no stickies. Unfortunately, such a list would eventually sift down into the mud and only those who knew of it's existence would know how to find it. It's a good idea and should have been done long ago . I would participate . Probably just routinely...
by apochronaut
Fri Oct 18, 2019 11:36 am
Forum: Beginner's corner
Topic: Nikon Plan APO 40x 160 TL in an OMAX (Chinese Microscope) 160 TL?
Replies: 7
Views: 143

Re: Nikon Plan APO 40x 160 TL in an OMAX (Chinese Microscope) 160 TL?

That is kind of a personal choice. One of the principal reasons for mid-magnification oil objectives to exist is that they are more user friendly with oil immersion high magnification objectives. Having to use oil is a little annoying but if you are in a session with a 60 or 100x oil immersion objec...
by apochronaut
Fri Oct 18, 2019 12:34 am
Forum: Beginner's corner
Topic: Nikon Plan APO 40x 160 TL in an OMAX (Chinese Microscope) 160 TL?
Replies: 7
Views: 143

Re: Nikon Plan APO 40x 160 TL in an OMAX (Chinese Microscope) 160 TL?

There are some provisos with the adoption of objectives higher up on the food chain. The first is tube length,, which has been dealt with. #2 is parfocality. Your OMAX is 45mm. Nikon made both short barrel( 34mm?) and long barrel 45mm objectives corrected for a 160mm tube . The short tube objectives...
by apochronaut
Thu Oct 17, 2019 6:09 pm
Forum: Microscopes and optics
Topic: Field diaphragm problem
Replies: 21
Views: 597

Re: Field diaphragm problem

Thanks for the very comprehensive explanation. I think I have to read this through a couple of times to understand... I know and use practically only microscopes of the pre 1985 era, mostly from the 1960s Interesting. This is not the first time I have heard the microscopes before 80s are better. Wh...
by apochronaut
Wed Oct 16, 2019 1:31 pm
Forum: Microscopes and optics
Topic: Field diaphragm problem
Replies: 21
Views: 597

Re: Field diaphragm problem

Yes, through the glass surface. There are two ghost images visible blow and only one above. Thanks! So, in fact your illumination beam is travelling through a glass refractor to the reflecting surface. 3 ghost images of the iris is typical but if there is enough intensity, 4 can be seen; 3 below in...
by apochronaut
Tue Oct 15, 2019 10:07 pm
Forum: Microscopes and optics
Topic: Field diaphragm problem
Replies: 21
Views: 597

Re: Field diaphragm problem

So, the illumination beam was passing through glass. Could you tell, if there was in fact a fourth ghost image but quite reduced in intensity when compared to the other two?
by apochronaut
Mon Oct 14, 2019 8:44 pm
Forum: Home-made microscope adaptations
Topic: AO-Reichert 1973A condenser DIY help request
Replies: 12
Views: 757

Re: AO-Reichert 1973A condenser DIY help request

yes. there is a meniscus lens. Give me a few days and I will take the 1.3 N.A. condenser and the 1.4 apart and see what the differences are . Some extrapolations about the meniscus lens for the 1.4 might be possible by comparing the meniscus lens of the 1.3 N.A. condenser to the specifications in th...
by apochronaut
Mon Oct 14, 2019 4:57 pm
Forum: My microscope
Topic: DIY DIC Effect on Darkfield.... unreal
Replies: 6
Views: 587

Re: DIY DIC Effect on Darkfield.... unreal

One of the problems when using offset and or partially occluded illumination is the high degree of chromatic aberration that can occur and distort the image. Virtually all internet sourced Chinese microscopes are fitted with condensers only a shade above the basic; a two lens abbe, which provide a v...
by apochronaut
Mon Oct 14, 2019 4:33 pm
Forum: Home-made microscope adaptations
Topic: AO-Reichert 1973A condenser DIY help request
Replies: 12
Views: 757

Re: AO-Reichert 1973A condenser DIY help request

The picture is very fuzzy but they look correct. The fit is supposed to be very snug in the bore. You just have to get each cell into correct alignment in the barrel and very gently push them up to their required location. The pressure needs to be very light but with correct alignment. If the cells ...
by apochronaut
Mon Oct 14, 2019 1:45 pm
Forum: Microscopes and optics
Topic: Field diaphragm problem
Replies: 21
Views: 597

Re: Field diaphragm problem

I would not think normally for average BF observation, or most observation where the lamp is critically centered to the condenser ,because you are using the central mirror reflected lamp image for koehler adjustment. It might be a problem for oblique, where a ghost image might cause unwanted edge fl...
by apochronaut
Mon Oct 14, 2019 12:32 pm
Forum: Microscopes and optics
Topic: Field diaphragm problem
Replies: 21
Views: 597

Re: Field diaphragm problem

Probably at some point, the mirror has been replaced with a backsurfaced or second surface mirror. You are getting reflections caused by the glass surface of the mirror causing ghost images.
by apochronaut
Sun Oct 13, 2019 11:54 pm
Forum: Microscopes and optics
Topic: Field diaphragm problem
Replies: 21
Views: 597

Re: Field diaphragm problem

Is this the correct orientation of the image, with the ghost images of the field diaphragm left and right of the reflected image, rather then above and below?
by apochronaut
Fri Oct 11, 2019 4:52 pm
Forum: Illumination Techniques
Topic: Relief Phase Contrast Microscopy - Article by Prof J. Piper in Microscopy and Analysis, vol 21, 2007.
Replies: 15
Views: 871

Re: Relief Phase Contrast Microscopy - Article by Prof J. Piper in Microscopy and Analysis, vol 21, 2007.

[/quote] (side note: Piper calls this condenser type a "Zernike phase contrast condenser"; perhaps, Prof Zernike influenced Zeiss to manufacture specifically turret PC condensers; Piper in his article used Leitz to my to do list. [/quote] What is the date of the earliest phase contrast condenser tha...
by apochronaut
Fri Oct 11, 2019 2:51 pm
Forum: Microscopes and optics
Topic: Early patents related to phase contrast
Replies: 7
Views: 588

Early patents related to phase contrast

A couple of patents related to the early years of the development of phase microscopy.

1942 application /1947 grant
https://patents.google.com/patent/US2427689A/en


1948 application/1951 grant
https://patents.google.com/patent/US2565419A/en
by apochronaut
Fri Oct 11, 2019 1:50 pm
Forum: Home-made microscope adaptations
Topic: AO-Reichert 1973A condenser DIY help request
Replies: 12
Views: 757

Re: AO-Reichert 1973A condenser DIY help request

That would work on the series 15/35 through the 2/4, for sure. Basically, all of the post war lab scopes with a 160mm tube. The red lettering designates it as having been tested for strain. Has the polarizer. The microscope it is probably from is the series 2/4 Polstar. S.F. objectives are scarce fo...
by apochronaut
Thu Oct 10, 2019 4:27 pm
Forum: Beginner's corner
Topic: Newbie with information overload looking for first microscope
Replies: 22
Views: 919

Re: Newbie with information overload looking for first microscope

Frits Zernike invented phase contrast, licensed it to Zeiss and shortly thereafter, numerous other companies. All phase contrast systems , whether the annulus being used is in a rotary dial or a fixed condenser housing are Zernike phase contrast. In fact Zernike's prototype microscope had a single a...
by apochronaut
Thu Oct 10, 2019 3:44 pm
Forum: Beginner's corner
Topic: AO 1036A Touch-Up Paint?
Replies: 5
Views: 370

Re: AO 1036A Touch-Up Paint?

PeteM wrote:
Thu Oct 10, 2019 3:37 pm
I'd guess, given the age, that the A.O. gray is an oil-based enamel with hardener (on edit, but defer to Apo's judgement above that it's an epoxy).
It's not a judgement. It's in black and white in AO literature.
by apochronaut
Thu Oct 10, 2019 2:20 pm
Forum: Pictures and Videos
Topic: Amoeba yeast feast
Replies: 15
Views: 858

Re: Amoeba yeast feast

...Phase does offer a rather flat image but it can be fiddled with to squeeze some relief out of it. It does offer a more real representation of the image than D.I.C., which in addition to putting up fake relief, always looks like something is struggling under a freshly applied layer of latex paint...
by apochronaut
Thu Oct 10, 2019 1:56 pm
Forum: Beginner's corner
Topic: AO 1036A Touch-Up Paint?
Replies: 5
Views: 370

Re: AO 1036A Touch-Up Paint?

I think Einman did some touch up . I'm not sure but some of the forum members have been in the business of selling/repairing AO microscopes in the past. It is an epoxy. I looked for a bit of a thread that was here, with some good tips and found it. http://www.microbehunter.com/microscopy-forum/viewt...
by apochronaut
Thu Oct 10, 2019 12:49 pm
Forum: Pictures and Videos
Topic: Amoeba yeast feast
Replies: 15
Views: 858

Re: Amoeba yeast feast

Many thanks apochronaut, mintakax and 75RR! An interesting comparison, I find that phase tends to get ignored when one gets DIC - this clearly shows that it shouldn't be. I completely agree, when I got all the components for setting up DIC I ignored other illumination techniques. Its interesting to...
by apochronaut
Thu Oct 10, 2019 12:03 pm
Forum: Beginner's corner
Topic: Newbie with information overload looking for first microscope
Replies: 22
Views: 919

Re: Newbie with information overload looking for first microscope

PeteM wrote:
Thu Oct 10, 2019 4:53 am
One of the cool things about a Zernike type phase condenser is that it's usually possible to get decent oblique effects by rotating the phase stops out of position (so only a portion of a phase ring illuminates the specimen).
What other types of phase condensers can't you do this with?
by apochronaut
Wed Oct 09, 2019 9:33 pm
Forum: Pictures and Videos
Topic: Amoeba yeast feast
Replies: 15
Views: 858

Re: Amoeba yeast feast

great images. i guess yeast are the potato of the protistatariat.