Search found 166 matches

by phil m
Fri Nov 23, 2018 5:22 am
Forum: Equipment Discussions
Topic: Odd behavior: Bausch & Lomb 0.8x MicroZoom objective
Replies: 15
Views: 2778

Hope that works out for you. I would also be interested in hearing about anything Miller says about the subject. In the past , they have been pretty close mouthed about the B & L systems. All I ever got from them was " there's a negative lens up in there" . The impression I was left with was that th...
by phil m
Wed Nov 21, 2018 7:59 am
Forum: Equipment Discussions
Topic: Odd behavior: Bausch & Lomb 0.8x MicroZoom objective
Replies: 15
Views: 2778

I have a diagram from about 1964 that illustrates the rays coming from a B & L semi-objective, it's native focal distance and the diversion caused by the telescope lens to the eyepiece. There are no measurements but the drawing is to scale by one of the original engineers of the B & L development pr...
by phil m
Mon Nov 19, 2018 2:54 pm
Forum: Equipment Discussions
Topic: Odd behavior: Bausch & Lomb 0.8x MicroZoom objective
Replies: 15
Views: 2778

On the Balplan it is positioned right above the nosepiece, as the back lens of the objective, only about 15mm above. That is really where it has to be. You might be able to see it right there, if you look up through the nosepiece from below. Maybe with a mirror?
by phil m
Mon Nov 19, 2018 2:32 pm
Forum: Equipment Discussions
Topic: Odd behavior: Bausch & Lomb 0.8x MicroZoom objective
Replies: 15
Views: 2778

I was hoping you would chime in on this, since you have one. No the Balplan does not have an erect image. It has the same features in that regard as any other diascopic microscope. The reversal no doubt ytakes place in the zoom head. If you were to take the head apart, you would probably find the te...
by phil m
Mon Nov 19, 2018 11:03 am
Forum: Equipment Discussions
Topic: Odd behavior: Bausch & Lomb 0.8x MicroZoom objective
Replies: 15
Views: 2778

I thought you might have a Microzoom but I guess, just the objectives. I have never had a MIcrozoom in my hands but have had lots of Balplans. My understanding is that the Microzoom head and the Balplan head are basically the same, except that the Microzoom has dual diopter adjustments and I think a...
by phil m
Mon Nov 19, 2018 10:20 am
Forum: Equipment Discussions
Topic: Odd behavior: Bausch & Lomb 0.8x MicroZoom objective
Replies: 15
Views: 2778

Does the MIcrozoom have a compensating lens just above the nosepiece?
by phil m
Tue May 08, 2018 7:00 am
Forum: Equipment Discussions
Topic: Adjustable darkfield condenser
Replies: 11
Views: 2252

I'm a bit confused by this. Available DF oil immersion condensers aren't limited to higher magnifications because they don't work at lower magnifications, it is because the cone of light falls inside the f.o.v. Simple adaptions such as putting a toric lens under the condenser, such as AO, DF condens...
by phil m
Thu Apr 12, 2018 8:31 am
Forum: Equipment Discussions
Topic: Diameter of black disc for darkfield?
Replies: 31
Views: 5893

I will dig out my version of this, sometime today and offer up some measurements. Many condenser diaphragms use brass pins at each end of the leaves, to actuate the motion of the leaves. Some have the pins set into the leaves but some have the pin set in the outer ring and the leaf has a hole in it ...
by phil m
Thu Apr 12, 2018 8:17 am
Forum: Equipment Discussions
Topic: Markings of microscopic objectives - help
Replies: 1
Views: 899

On Leica, these letters denote, the distance the back focal plane of the objective is from the rear shoulder of the objective.. A,B,C,D or E, in increasing distance. This serves to select the correct DIC prism and allows the facility to use the same DIC prism for several objectives. I don't know abo...
by phil m
Fri Apr 06, 2018 6:12 am
Forum: Equipment Discussions
Topic: Diameter of black disc for darkfield?
Replies: 31
Views: 5893

I searched high and low for these and only ever found reference to then on somewhere like micrscopyU. I'd love to find one of them. If it ever comes back to you where you saw it, there are a few of us who'd love to know. also called a variable dark field stop. the maker , I'm pretty sure was in Ind...
by phil m
Fri Apr 06, 2018 6:09 am
Forum: Equipment Discussions
Topic: phase contrast q's
Replies: 16
Views: 1972

Im tempted to do shots with phase vs normal objective, and check if you can see the difference. In the meantime, Charles Krebs already did similar comparision, tho without pixel level and not brightfield: http://www.photomacrography.net/forum/viewtopic.php?t=6647 40 and 100x comparisons would be in...
by phil m
Tue Apr 03, 2018 2:51 pm
Forum: Equipment Discussions
Topic: Diameter of black disc for darkfield?
Replies: 31
Views: 5893

There are devices made called Df rosettes. They are a reverse iris diaphragm, with a group of leaves that expand as you move the lever.They fit into the filter carrier under the condenser . I have an older one but recently I saw a new one for sale, somwhere and was surprised that they still make the...
by phil m
Tue Apr 03, 2018 2:30 pm
Forum: Equipment Discussions
Topic: Suggestions for a DIY PZO Biolar lamphouse/illuminator
Replies: 28
Views: 3704

I have heard of this on those Zeiss models and it apparently works well for DF at 10 watts, although somewhere I recall a comment from one DIYer that 20 might be better at 100X. I assume that it has to do with the relatively short distance between the emitter and condenser on those models because 10...
by phil m
Tue Apr 03, 2018 7:09 am
Forum: Equipment Discussions
Topic: Leitz Wetzlar - PZO
Replies: 20
Views: 3614

The Leitz DF condenser may be a paraboloid type. Many companies produced both a cardioid oil condenser as well as a paraboloid oil condenser. I have a similar vintage cardioid type, Leitz DF condenser and as Ichthyophthyrius mentions, yours doesn't look the same. I am not sure dry condensers were ma...
by phil m
Tue Apr 03, 2018 6:58 am
Forum: Equipment Discussions
Topic: Suggestions for a DIY PZO Biolar lamphouse/illuminator
Replies: 28
Views: 3704

It looks to me that the examples provided are lower power 200-300 lumen systems that can be retrofitted fairly easily. However, the level of illumination required out of a rear mounted 100 watt illuminator is a whole other thing. I have used a lot of 100 watt DF systems and I have yet to be convince...