Bausch & Lomb modified for Water Immersion/Oblique

[einman]

Okay. So today I made some headway on my Stand for Water Immersion. I am using an older model Bausch & Lomb stand along the lines of a Galen 3 or even a Reichert 310. They are very similar in structure. I wanted to have a dedicated stand for water immersion. Given the LOMO objectives are so short (33.5mm) they are generally not compatible with other objectives. This is the reason I wanted a dedicated stand.

I have never been thrilled with the LOMO Biolam's construction and wanted to use a stand made by another manufacturer. This particular B&L stand was made in Japan.

I started by removing the stop so the stage could be raised sufficiently to focus the LOMO objectves. This worked quite well. I am using the following water immersion objectives:
30X/0.90,
60X/1.1,
70X/ 1.23
85X/1.0

I also wanted to be able to use the LOMO darkfield and Oblique condensers. The Lomo aplanatic oblique condenser has an na of 1.4. It is graduated to allow for consistent movement of the aperture and can be rotated to change the appearance of the specimen.

This required removing and machining the existing condenser holder to increase its internal diameter about 0.6mm.

Now I can use any LOMO condenser. Should I want to go back to the original condenser I have a spare mounting bracket.

I can not post actual photos of specimens yet as I do not have the trinocular set up for a camera. That is next.

I will post photos of the set-up once Photobucket comes up from maintenance.

The scope is not the prettiest I own as it was pieced together from several parts scopes.

[gekko]

Looking forward to seeing the pictures. Sounds like a very practical plan to have a dedicated stand for water immersion.

[lorez]

This particular B&L stand was made in Japan.

If you have a Galen 3 I am eager to see the photos. All the Galen 3s I'm familiar with were made in China.

The first B&L Galen was an Olympus KHC; then there was the Galen 2 which was also made in Japan; a Galen 2.5 which was a short lived model with a redesigned focus block, also made in Japan; and finally the Galen3 which was made in China.

The Galen and Galen2 were good microscopes at their level.

lorez

[zzffnn]

eiman,

I am highly interested in hearing your impressions on performance of LOMO water immersion objectives in darkfield and oblique.

If you have a Klaus Kemp test diatom slide, you don't have to post photos, you can simply tell me whether or not your rig can resolve dots/lines on XYZ diatoms (especially those most difficult two).

There may be some obstacles for your darkfield set-up.

Edit: I apologize, the LOMO darkfield condenser, in it new condition, actually has two centering screws. It was just that the one I saw on eBay was missing one screw.

For one, the LOMO darkfield condenser has only one centering screw. On a scope that lacks additional centering mechanism (such as LOMO Biolam), that single centering screw may not be adequate for high NA darkfield. I always need to turn both centering screws on my DF condensers.

For two, LOMO did not make darkfield funnel stops or disc diaphragms for 65/1.1, 70/1.23 or 85/1.0. Unless the LOMO darkfield (DF) condenser has an unusually big inner light cone NA, you may not be able to go above NA 1.0. I tried my 65/1.1 with a B&L paraboloid DF condenser and a Spencer 214F cardioid DF condenser, but both failed to produce DF without diaphragm or funnel stop (though NA 0.95 40x works beautifully). Phil thinks the funnel stop for AO Spencer C158 90x NA 1.3 apo objective works for my 65/1.1, but we cannot find one more of those (besides his own). Anyone else willing to let go one?

As with the LOMO oblique condenser, the question is whether or not its theoretical advantages are visually significant. Say, when compared to offset phase condenser or oblique mask. Supposedly its high level of correction and huge NA would make a difference at diatoms dots.

Please keep us posted.

[charlie]

If you have a Klaus Kemp test diatom slide, you don't have to post photos, you can simply tell me whether or not your rig can resolve dots/lines on XYZ diatoms (especially those most difficult two).

While I too hope for the best for einman in his Lomo project, you got my attention with your mention of a Klaus Kemp test diatom slide.

http://www.diatoms.co.uk/

Is it the 8 form test plate listed that you are referring to Fan?

I found this 15,000 species database amazing:

http://www.diatoms.co.uk/

[zzffnn]

Yes, you got it, Charlie. Many amateur microscopists use that as golden standard of resolution for protists.

[einman]

This particular B&L stand was made in Japan.

If you have a Galen 3 I am eager to see the photos. All the Galen 3s I'm familiar with were made in China.

The first B&L Galen was an Olympus KHC; then there was the Galen 2 which was also made in Japan; a Galen 2.5 which was a short lived model with a redesigned focus block, also made in Japan; and finally the Galen3 which was made in China.

The Galen and Galen2 were good microscopes at their level.

lorez

This stand is not a Galen 3 as I owned one at one time and it is different. But built along those lines. It is manufactured in Japan as indicated on the bottom of the stand. I am not really sure what it is other than a B&L. You could be correct in stating it is a Galen 2 as I have another stand nearly identical but with an improved focus block. However that focus block would not lift high enough to accommodate the LOMO objectives. I will post pictures and you can comment on what stand you believe it is..

[charlie g]

Sweet combo of LOMO/WI objectives,einman! Will you put much worry into the actual water you use for the water immersion bridge?


I finally made my LOMO 70X 1.23 DF and Phase work with DF stop on my Nikon Labophot! It took a combo of a Leitz Wetzlar Germany Plezy+ a Leitz Wetzlar Germany adaptor which simply has a black dot on it's barrel. Each adaptor thread couples together, each has a glass 'window'...I can't tell if these are optical lenses.

All to say I need to see if these perform properly...or if it's a configuration which reduces the optical performance of the LOMO APO.

So I love your LOMO WI combo,einman. Again, will you be useing any special water for the immersion...or these objectives would clean well with any decent water? charlie guevara

[zzffnn]

Charlie,

I use fresh bottled water for those water immersion objectives.

I am using LOMO water immersion objectives on my Nikon Labophot 2. I raised up the stage and condenser 12mm to focus on LOMOs, as there is no optical compromise for the objective that way.

LOMO did not offer factory darkfield set-up (no funnels top, disc diaphragm or iris) for 70x NA 1.23, 80x NA 1.1 or 65x NA 1.1. You meant you made a DIY darkfield stop for your 70x WI and it works very well, correct? What diameter is your stop and did you use your condenser dry, oiled or water immersed for darkfield? Thank you.

[zzffnn]

eiman,

So how do you scan a sample with such high magnification water immersion objectives?

You can use 30x with K7x or even a none-compensating 5x eyepiece to get 150-210x. However, that still sounds a bit much for scanning, isn't it? If you have tons of patience and time, that may work though.

Or do you scan at another stand, mark/remember subject location, then move to this water immersion stand? Protists can move away though..........

Maybe have a LOMO 8x or 9x there for scanning.

[apochronaut]

eiman,

I am highly interested in hearing your impressions on performance of LOMO water immersion objectives in darkfield and oblique.

If you have a Klaus Kemp test diatom slide, you don't have to post photos, you can simply tell me whether or not your rig can resolve dots/lines on XYZ diatoms (especially those most difficult two).

There may be some obstacles for your darkfield set-up. For one, the LOMO darkfield condenser has only one centering screw. On a scope that lacks additional centering mechanism (such as LOMO Biolam), that single centering screw may not be adequate for high NA darkfield. I always need to turn both centering screws on my DF condensers.

For two, LOMO did not make darkfield funnel stops or disc diaphragms for 65/1.1, 70/1.23 or 85/1.0. Unless the LOMO darkfield (DF) condenser has an unusually big inner light cone NA, you may not be able to go above NA 1.0. I tried my 65/1.1 with a B&L paraboloid DF condenser and a Spencer 214F cardioid DF condenser, but both failed to produce DF without diaphragm or funnel stop (though NA 0.95 40x works beautifully). Phil thinks the funnel stop for AO Spencer C158 90x NA 1.3 apo objective works for my 65/1.1, but we cannot find one more of those (besides his own). Anyone else willing to let go one?

As with the LOMO oblique condenser, the question is whether or not its theoretical advantages are visually significant. Say, when compared to offset phase condenser or oblique mask. Supposedly its high level of correction and huge NA would make a difference at diatoms dots.

Please keep us posted.

It matters whether the Lomo DF condenser is paraboloid which uses a refracting principle or a cardioid, which uses a reflecting principle. Presumably, Lomo matched their DF condenser to the performance levels of their objectives, and since they do not seem to have made a funnel stop for the 65x 1.1 objective, it might well give a sort of DF with it's own condenser. Using , oblique in advance of DF modulation, may give improved contrast with a paraboloid, although I doubt it. Due to the reflecting nature of a cardioid condenser and the relatively high N.A.s that DF condensers need to function , skewing the light rays , will likely allow only a partial cone of light to emerge and create DF. I would suspect that a degree of chromatic aberration will result as well. DF functions by excluding direct illumination and oblique functions by creating a shadow. DF must by it's very nature have a completely circular and precise cone of light to work perfectly and therefore well, otherwise it is a waste of time. Cardioid condensers give much higher resolution than paraboloid condensers, which in turn give much higher resolution than DF stops + abbe condenser.
The 65X 1.1 Lomo objective is just borderline as a functional objective for DF when used in conjunction with a paraboloid condenser working at between 1.2 and 1.33 N.A. . There is some effect in the center of the field but it is not fully dark and it is surrounded by a bright halo. If a set of eyepieces , as is the case with Lomo, that have a narrower field of view were used , one could say it gives a sort of DF. Stopping it down very slightly , to about .95 gives full DF. There is a specific DF stop , used for several objectives by Spencer, which fits right into the 65X 1.1 apo, and effectively stops the objective down to give a black background . Everything works well, with that stop , even when using a cardioid condenser.

[lorez]

I will post pictures and you can comment on what stand you believe it is..

The photo says it all. You have a Galen2 stand, made in Japan, as you said, with what I believe is a substitute triocular body. The next model I remember was what I called the Galen2.5 (an unofficial name) that had the co-axial focusing positioned on the arm rather than the substage. I liked this better, but it was not a robust as the original design and there were problems with it. The 2.5 did not last long as all the production soon moved to China with the introduction of the Galen3

lorez

[zzffnn]

Thank you, Phil.

Sorry for my confusing wording. I actually only encouraged eiman to try LOMO darkfield and oblique separately, not in combination. I did realize, through my previous experiments, that such combination would not work.

LOMO did offer a funnel stop for their 90x NA 1.25, if that matters.

It would be very interesting to see if 65x NA 1.1 can produce darkfield, along with LOMO darkfield condenser, without funnel stop/disc diaphragm/iris. If yes, I may get that LOMO darkfield down the road.

[billbillt]

I think you did a great job in conversion... I am anxious to see photos taken from it...

BillT

[charlie g]

Yes, yes...bottled water for use with these LOMO apo WI objectives.

Err...this is einmams thread, Fan...however...I clearly stated I have a: LOMO 70X,1.23,WI objective speced as: "Dark field and Phase"...I clearly stated that with a Plezy adaptor+ another Leitz Wetzlar adaptor...this:'DF and Phase objective' functions in DF with my Labophot DF condenser setting....no DIY dark field stops in the light train.

I can not 'alter my Labophots DIN stage setting to permit these LOMO 'short barrel/RMS ?33mm? objectives'...my Labophot is a work horse stand with Plan 2X, and multiple DIN objectives which these wonderful LOMO low cost apo's need to partner with...raising the Labophot stage...excluding the combo of Nikon DIN objectives is not sensible for my microscopy.

For LOMO to spec an apo/WI objective as: DF and Phase...LOMO must of had a condenser which supports this objective. I am pleased that my Nikon condenser DF stop works for this objectives DF contrast method.



Again, einman...with a turrent of LOMO WI objectives...I ask: what is your water immersion protocol? What do you 'pamper' these WI objectives with in shut down after a session Is an final alcohol wipe after water wipe...is this 'over doing shut down?' all the best, charlie guevara

[zzffnn]

Charlie G,

Since eiman is interested in getting his 70x NA 1.23 WI to work in darkfield, I am guessing this discussion may also be of interest to him. If not, we can continue in private message.

I think those Cyrillic letters "фA" on your 70x NA 1.23 means "dark phase" (or positive phase contrast, as opposed to bright phase or negative phase), but not "darkfield and phase". Yes, that "A" means "dark" and I know Raf listed it that objective as "darkfield and phase", but I doubt he is right. I really hope I am wrong, as I would gladly buy such a dedicated darkfield objective, rather than coercing my versions to work in darkfield.

Reasons are:

1) Raf also lists a 20x NA 0.4 and a 40x NA 0.65 with "фA" label. At NA of 0.65 of less, any objective will work in darkfield without special device (no iris, disc diatoms or funnel stop is needed). So it does not make sense for LOMO to label such objectives as "darkfield". It does make sense to label " dark phase" though, to distinguish those objectives from bright phase.

2) Raf also lists a 90x NA 1.25 with "фA" label. LOMO offered a darkfield funnel stop for that objective. It does not make sense to offer funnel stop and make a special "darkfield" version at the same time. In my humble opinion, the only sensible way to make a darkfield-specialized objective is to give it an iris, so it would work in both brightfield and darkfield and can switch quickly. Does your objective have an iris?

Also, are you using that Nikon 1.2-1.43 darkfield condenser (inner light cone NA 1.2)? Or do you know your inner light cone NA? If your inner light cone NA is indeed 1.2, then your Leitz Plezy adapter's optics may have helped your darkfield (normally, NA 1.23 objective wouldn't produce good darkfield with condenser inner cone NA of 1.2, objective NA should be 1.1 or less in that case).

[charlie g]

Yes, thanks for sharing that RAF vendor offering the LOMO apo 70X,1.23 WI dark field and phase objective and the $145 USD sounds terrific price to me. Thanks, Fan.

My 2010 Chicago seller gave the entire print out of this objectives specs..and Vlad listed in the specs: 'dark field and phase contrast'.

I will start a thread as I need coments on the two adapters which permit the BF and the DF&Phase objectives to work on my Labophot. Charlie Guevara.

Einman...have you ever attempted 'water bridge' of condenser to the slide undersurface with your WI turrent of objectives?

Does the spec: NA 1.23 even hold if a slide using these speced WI objectives ...is not 'water bridged'

to condenser lens face? Charlie guevara

[zzffnn]

Charlie,

Please do open a thread and I will follow you there.

If you can kindly do so, please also share with us print out of that objective. I have Russian friends who can translate it.

Like I said, I would be glad if I was wrong. I am having difficulties in making my brightfield WI versions to work in darkfield. I would like to learn what those "darkfield" versions have (iris? Smaller diaphragm or funnel stop?) to make them effective.

Yes, you need to immerse your slide underside for WI objectives to realize NA of 1.0 or higher. Dry condensers cannot provide NA of over 1.0. Most achromatic condensers max out at 0.95 or so, while Abbé may max out at around 0.8 of corrected area.

[einman]

Hey I have no problem with anyone interjecting into my thread! Go for it. The more the merrier. I was out traveling so I will try and respond shortly.

However I use distilled water and wipe after I am done using the scope. Given there is a coverslip between the objective and the specimen I do not wipe with alcohol. Though I have wipes and could do so easily.

In response to "scanning"-- I use the 30X and have lower power eyepieces. But if the specimens are alive and moving I just use the 30X with 10X eyepieces. Quite frankly I tend to use the inverted more for observing protists. I then extract anything really interesting and move it to the compound. That is how I did the video on youtube with the vorticella. Though I think I may have scanned that sample with a stereoscope first. I cant recall at this moment.

[zzffnn]

Please keep us posted, eiman. Thank you!

I am highly interested in:
1) getting darkfield out of 65/1.1 and 70/1.23 and
2) how much more resolving LOMO oblique condenser is, compared to DIY oblique, with Klaus Kemp test diatoms.