Bausch + Lomb U.L.W.D. Lens question

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Chris S.
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Post by Chris S. »

Lothar, since I'm in the U.S., I can probably ask the questions on your behalf. If you want me to do this, just PM me.

--Chris

Chris S.
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Post by Chris S. »

Following up for Lothar, I wrote eBay vendor maurym (Maury Morgenstein), who responded very helpfully. I'd made it clear that I was asking for information for this forum, so I'll post his response here. The italicized questions are mine.

1) Is this an infinite objective that requires a tube lens, or a finite that does not?

This is a finite objective.

2) If infinite, what is the focal length of the intended tube lens? If finite, what is the expected tube length?

The expected tube length is 160 mm for the 50x to be true; if however, if there is no need for the 50x to be true, one can use almost any tube length scope (170, 210, etc.) and calibrate by digital means with a stage micrometer.

3) Is this lens corrected to be used with a cover slip, or without?

One is better off without a cover glass as it is not corrected for a cover glass. The NA is however adjustable (0.15 to 0.45).

The only issue with this lens, is it is very long: 2.8 inches (over 71 mm). It however is by far the best 50x ULWD lens I have used to stay far away from my sample. You do not want to use this lens with other objectives on the turret as there will be parafocus issues. Also, one gets a huge amoount of light in because of the distance and the large diameter of the glass in the lens. Thus, it is great for photo work.

We have a large microscope lab with confocals, pol scopes, fluorescence and phase (over 15 scopes active, and about 50 scopes in total). We are trying to reduce our lab footprint and just utilize the scopes we actually need on a monthly basis. Our parts inventory has become too large.

Maury Morgenstein, PhD, RG, RPA
President GMI, Inc.

Lothar-Gutjahr
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Post by Lothar-Gutjahr »

This are clear words and i think on my homebrew scope it has the right home. Hoever it is not to be compared with crisp behavier of normal lenses in transmitted light. It will be be my "Lupenobjektiv 50 x fold".

Thank you verry much Chris ! And express my thankfullnes to Mr. Morgenstein.

Greetings Lothar

g4lab
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Post by g4lab »

Cambridge Instruments was a successor owner of Bausch and Lomb. Also of American Optical, C. Reichert, Wild/Leica as well as most or all of the English microscopes companies such as Ealing, Beck , Cook Toughton and Sims and heaven only knows who and what else.

The linked to manual does point to the scope not being "infinity corrected" because then it would likely have stackable accessories and it does not seem to. However I would still warn that it's design may require a lens inside the scope body that is common to all the objectives in the series, similar to other models from Bausch and Lomb right before they were sold. (The 1970s and 80s)

Perhaps maurym can look at one of these bodies and say whether or not there seems to be an optic in the body when there is no ocular and no objective. If there is such an optic it may be similar to such an optic that appeared in the Dynoptic and DynaZoom series and you may be able to use one of those scopes which can be gotten for much less money than a MicroZoom II.

These tube lenses probably presented as one of their benefits to the design committees , that they could prevent the scope end user from using another manufacturer's objectives on their scopes. This is something I KNOW that they thought about, back in the day.

Lothar-Gutjahr
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my first stacks beyound 500 x fold magnification

Post by Lothar-Gutjahr »

Hi,

yesterday the B&L eyepieces arrived and i started work arround this U.L.W. D-lens 50/0.45 a little bit. The model a dead stink bug from last sommer .

Ocelle

both pics B & L 50/0.45, bellow with ocular projection adapter, variable hight m42 ring to Canon 1000D on "UFOMI" 70 fotos 2µm apart, Zerene Dmap ,55%
Image

part of the eye
Image

I am not totaly happy. To get the shown quality, i had to use intense imaging tools.
The question left, is towards a tubelens.? On the other hand one could estimate, that stacking in that magnification range is not too easy.

Do you think this are agreable results for this magnification ?

Greets Lothar

rjlittlefield
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Post by rjlittlefield »

Are these 100% actual pixels crops, whole frame resized for web, or something else?

If these are not 100% actual pixels crops, then can you post a couple of those so we can see what you're getting.

--Rik

Lothar-Gutjahr
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Post by Lothar-Gutjahr »

Hi Rik,

thanks for your fast responce. Both pic´s are run trough CLAHE ( enhance local contrast) and trough PSE8 unsharp masking and rise the contrast and remove noise.

Than sized down for forum size.

By the way it was interesting to watch Zerene progressing and to find out the 2 µm steps are realy done each time mecanicly. 50% enlarged shows this easy.

Greets Lothar

Lothar-Gutjahr
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Post by Lothar-Gutjahr »

Here is one of the stack; sized down only:

Image

Lothar-Gutjahr
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Post by Lothar-Gutjahr »

Hi Rik,

looking back on those activitys ia am almost convinced, that the extrem precise stacking has a big part in the fotos. So just for the try, i did one more in 1 µm steps:

Image

i even left the "overruns from stacking (Dmap) the contrast treshold was also set at 55 % sharping a little and enhance contrast, than sized down.

What do you think ?

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Post by rjlittlefield »

OK, these are full frame images resized for display. So then at 50X and NA 0.45, the system should be running at effective aperture 50/(2*0.45) = f/56. That will certainly explain a lot of softness. Other than the softness and some color fringes in the corners, I don't see anything clearly wrong here. I assume you've checked to be sure the aperture is wide open.

1/4 lambda DOF at NA 0.45 is 2.7 microns. 1 micron seems like overkill, but ultimately the image knows best so if you're getting better results with 1 micron rather than 2, that's what you should use.

Yes, stacking at these magnifications is always interesting. With deep subjects I'm often surprised that the software can figure out as well as it does.

--Rik

Lothar-Gutjahr
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Filament of tungsten 100 W 12 v

Post by Lothar-Gutjahr »

Hi Rick,

today i did a wild experiment. I used my canon 135 mm lens together with a telextender 2 x as a tubelens and got realy surprised, what the B + L 50 ULWD turned over. Stacked 100 Fotos 1,2 µm apart.

Image

Some parts of the surface looks brocken of but the shapes are verry interesting.

Greetings from Bavarya

Lothar

Lothar-Gutjahr
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Post by Lothar-Gutjahr »

Hi,

still experimenting a little with that nice B+L lens, yesterday i did this bonding wire in a pentium cpu i opened.
Image

Tubelength was 200 mm using the original 10 fold W.F. B+L eyepiece.
New is the ilumination setup. I use two 7,5 Watt Osram LED´s designed to replace a ordinary 40 W matt lightbulb. Thanks to high flexibility of UFOMI the adaption is easy done using hand full old lab clamps and little plumbing. :D To overcome a dullness from highly diffused light the foto was taken to dxo labs clarity and also i used unsharp masking relativ strong.

E27 230 volt setup on stage
Image

This soft light together with a diffusor seems to be a good system for stacking. >500 x fold iluminating from the side is real fun. Thanks to B+L´s U.L.W.D.

Image

Weekend greetings

Lothar

Rorschach
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Post by Rorschach »

Chris S. wrote:
g4lab wrote:This lens was probably for a Bausch and Lomb MicroZoom. . .
I just found a reference that seems to confirm this, with the added wrinkle that at least some of specimens were badged as “Cambridge Instruments,” instead of Bausch and Lomb. (Was Cambridge Instruments a B&L nameplate, spinoff, or integrator?)

Anyway, available here is a pdf instruction manual for a “Cambridge Instruments MicroZoom II Microscope.” At the top right corner of page 12, Lothar’s lens is listed among the available objectives. The manual contains other information about the instrument, though not, so far as I could see, whether it is finite or infinite in design, or requires matched eyepieces.

There is a specimen of this lens currently on eBay, with a “Cambridge Instruments” sticker placed where Lothar’s says “Bausch & Lomb.” It is item #321087876711, offered by vendor “maurym.” This vendor seems to sell a fair number of microscope objectives, and might know something about this one.

--Chris
The link to the Microzoom II manual isn't working any more. Would you happen to still have the pdf file?

A very interesting thread by the way!

Edit: found the manual, thanks to a friendly user here. This is a great community!

patta
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Post by patta »

Hello
I just got one of those lens; mine is branded "Leica - Made in USA"! but it's the old B+L 50x.
Haven't tried yet since it is huge and doesn't fit in the microscope. And on the camera with tripod, well 50x is painful. We'll see!

Edit:
managed to fit it somehow into the microscope.
This objective appears NOT to be made for 160mm tube length; on the 160mm microscope it gives a magnification around 35x. (while it is rated 50x)

I really couldn't find on which instrument it was originally mounted.
The closest is the Bausch + Lomb "Industrial Microzoom" which has a 50x 0.45 ULWD, (seems longer and slimmer than this one); the Microzoom has some zooming optics into the tube, that may bring this objective to the correct 50x.
http://www.microbehunter.com/microscopy ... php?t=6680

Scarodactyl
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Re: Bausch + Lomb U.L.W.D. Lens question

Post by Scarodactyl »

It is a microzoom objective for sure--they labeled them all 'high performance.' This is the more deluxe 50x, including an iris and likely with a shorter body to allow a bit more wd without decreasing resolution. The microzoom is based on the balplan, which has a fixed lens in the nosepiece, above which it is an infinity system. It is not surprising it's hard to get original performance out of it sans microscope, since not only does it need more lenses they also probably had some correcrions included.
When I had a microzoom it had the normal slender 50x, and while it was nice to use there was a fair amount of axial ca and almost no wd. This one does seem substantially better.
Plus side, microzooms sometimes come up very cheap, and they're built like a mitutoyo finescope, very solid and nice.

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