Leica : FusionOptics

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MichaelG.
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Leica : FusionOptics

#1 Post by MichaelG. » Wed Jul 03, 2019 11:15 pm

On today's visit to mmc2019, I had a brief look at the Leica S9 stereomicroscope
https://www.leica-microsystems.com/prod ... downloads/

This is the first 'relatively low cost' instrument to feature FusionOptics ... which cleverly puts a high resolution image to the right eyepiece, and a large depth-of-field image to the left.
... The result is stunningly effective.
https://www.leica-microsystems.com/scie ... al-images/

Quite how this is achieved, I have yet to discover ... but I was assured that it is not simply a matter of 'stopping-down' the left optical train.

Any informed [or uninformed] comments would be of interest.

MichaelG.
.
Edit: https://youtu.be/-4mEO6APca8 and https://youtu.be/TX355N2cgsw
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geo_man
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Re: Leica : FusionOptics

#2 Post by geo_man » Thu Jul 04, 2019 12:48 am

Thanks for posting Michael, this is very cool!

I used to wear one contact lens for reading. My brain could use info from my left eye for distance and right eye for up close. Sounds like a similar approach, at a high level.

Would love to try it!

Scarodactyl
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Re: Leica : FusionOptics

#3 Post by Scarodactyl » Thu Jul 04, 2019 12:55 am

I'm sure it isn't actually stopped down in a physical sense, just lower resolution higher dof optics bottom to top on one side. Hard to imagine it isn't the same fundamental principle at play.
I have not tried it myself, but have heard mixed to negative reviews. That being said, gem inspection is my main focus and I have heard it is especially poor for that in specific, so take it with a few grains of salt. It must be quite good for some applications or they wouldn't be going so whole hog on it.

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Re: Leica : FusionOptics

#4 Post by MichaelG. » Thu Jul 04, 2019 9:13 am

Thanks [both] for the comments

I would be very interested to see any actual reviews of this system.

As I mentioned; it is [on very brief acquaintance] effective ... but I have a lingering suspicion that it could be rather like some audio systems; impressive at first, but fatiguing in the longer-term.

One feature that surprised me a little is that the optics are not 'rotatable' [even, so far as I am aware, on the high-end incarnations] to have the high-res on either right or left ... Surely we each have our own naturally dominant eye [?]

MichaelG.
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Re: Leica : FusionOptics

#5 Post by Sauerkraut » Thu Jul 04, 2019 2:22 pm

Thank you for sharing this. Very interesting. It must be dangerous attending the Microscience Microscopy Congress where unbridled lust could arise from sampling the equipment therein.

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Re: Leica : FusionOptics

#6 Post by MichaelG. » Thu Jul 04, 2019 4:24 pm

Sauerkraut wrote:... where unbridled lust could arise from sampling the equipment therein.
Very true ... I'm having a very gentle day today, to calm down.

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Re: Leica : FusionOptics

#7 Post by zzffnn » Thu Jul 04, 2019 4:39 pm

Leica still calls S9 a Greenough scope. The video shows that the high resolution right size has much bigger (diameter) optics than the DoF left side and that right and left sides go through different optical path.

It still sounds like stopping down the DoF (left) side to me, in reality. It might be fatiguing for long term use indeed? Though most hobbyists may not use a macroscope for that long?

@MichaelG,

Was that a sale rep who told you that DoF was not simply achieved by stopping down? Sales people tend to be a lot more optimistic than technical people, when it comes to the same product :twisted:

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Re: Leica : FusionOptics

#8 Post by MichaelG. » Thu Jul 04, 2019 4:53 pm

zzffnn wrote:Leica still calls S9 a Greenough scope. The video shows that the high resolution right size has much bigger (diameter) optics than the DoF left side and that right and left sides go through different optical path.

It still sounds like stopping down the DoF (left) side to me, in reality. It might be fatiguing for long term use indeed? Though most hobbyists may not use a macroscope for that long?

@MichaelG,

Was that a sale rep who told you that DoF was not simply achieved by stopping down? Sales people tend to be a lot more optimistic than technical people, when it comes to the same product :twisted:
Agreed ... it looks like the left optics are simply smaller diameter [perhaps the Rep. saw that as differing from stopping-down with a diaphragm ... or perhaps I should have asked the question the other way round i.e. "does the right side have a higher Numerical Aperture ?"]

There was no obvious difference in brightness between the views, so either it's quite subtle, or maybe they have some ND in the right side.

... I'm hoping to find a patent number; but no joy so far.

MichaelG.

P.S. Not sure about the 'status' of the Rep. but I suspect he is more Sales than Tech.
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Re: Leica : FusionOptics

#9 Post by Scarodactyl » Thu Jul 04, 2019 4:54 pm

The s9 is a greenough sryle stereo, the distant heavily mutated descendant of the Bausch and Lomb stereozoom series. They do fusion optics on their parallel/cmo scopes too, at least on the m205.
That all being said, the A60 series also has fusion optics amd they're one of Leica's cheapest systems I think?

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Re: Leica : FusionOptics

#10 Post by MichaelG. » Thu Jul 04, 2019 5:46 pm

Scarodactyl wrote:The s9 is a greenough sryle stereo, the distant heavily mutated descendant of the Bausch and Lomb stereozoom series. They do fusion optics on their parallel/cmo scopes too, at least on the m205.
That all being said, the A60 series also has fusion optics amd they're one of Leica's cheapest systems I think?
All fine ...

But I still want to understand how it is done

Clearly, if it's available on both the Greenough and CMO 'scopes it can't be two completely separate optical trains.

MichaelG.
.

P.S. I think the Rep mentioned a figure of about £3K for the 'pod' of the 9i version [which has a built-in camera] ...

Not really sure how it would compare with
https://www.hswalsh.com/product/leica-a ... scope-tm66
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Re: Leica : FusionOptics

#11 Post by Scarodactyl » Thu Jul 04, 2019 6:36 pm

Both have separate light paths eye to eye. The difference is just one of their orientation and whether there are two separate bottom objectives or one.
An a60 can be bought for like 1700usd all in on Amazon.
As a side note about the a60, from talking with some jewelers the A60 has a compatible objective thread so you can attach earlier s series stereos, but if you put at least some of them on without a spacing adapter the front element of the a60 will collide with the lens at max zoom. Weird that it apparently doesn't have a fixed position for the front element, but there you have it. They sure don't design 'em like they used to...

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Re: Leica : FusionOptics

#12 Post by MichaelG. » Thu Jul 04, 2019 9:34 pm

Scarodactyl wrote:Both have separate light paths eye to eye. The difference is just one of their orientation and whether there are two separate bottom objectives or one.
Yes, I do realise that ^^^
What I am trying to understand is how they contrive to have higher resolution in one light path than t'other.

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Scarodactyl
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Re: Leica : FusionOptics

#13 Post by Scarodactyl » Thu Jul 04, 2019 9:45 pm

You just need a bottleneck in one light path. Same reason that iris attachments work on cmos, even though they are above the zoom body.

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Re: Leica : FusionOptics

#14 Post by MichaelG. » Thu Jul 04, 2019 11:11 pm

Scarodactyl wrote:You just need a bottleneck in one light path. Same reason that iris attachments work on cmos, even though they are above the zoom body.
From my opening post:
Quite how this is achieved, I have yet to discover ... but I was assured that it is not simply a matter of 'stopping-down' the left optical train.
You may be correct [and it was my original assumption] but ... ^^^

MichaelG.

.

Edit: getting close, I think:
https://patents.google.com/patent/US7586676B2/en
... bedtime now: I will study it tomorrow
Zzzzz
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Re: Leica : FusionOptics

#15 Post by Scarodactyl » Fri Jul 05, 2019 1:55 am

Point is, you can achieve this effect by effectively reducing the NA at almost any point in the optical column, so it isn't a problem with a CMO design. Working from the ground up you can do it much more effectively/cheaply by designing it to have an inherently lower NA/higher DoF on one side rather than just covering the edges of a high NA lens.
The micromirrors certainly add an interesting twist though.

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Re: Leica : FusionOptics

#16 Post by wabutter » Sat Jul 06, 2019 12:01 am

In the simplest of terms, the left and right side of both the CMO and the Greenough are completely different lens systems. One side providing more depth of field and the other side higher resolution. The brain has incredible ways of handling this mix, hence the name Fusion Optics. Leica did exhaustive studies with Ophthalmology researchers to prove that the technology worked and did not cause any additional eyestrain. The M205 was the first platform to offer the Fusion optics with proven superior resolution as well as documented higher depth of field. This technology has been in play for more than 7 years.
By the way, A60 was the first Greenough style scope to use Fusion Optics. It has become the favorite OEM scope for gemological workstations producers. I have not personally seen the S9 in action, but in addition to the Fusion Optics, it is Apochromatically corrected and truly has defined a new level of performance in the Greenough Stereo market segment.
IMHO.
Wayne

Scarodactyl
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Re: Leica : FusionOptics

#17 Post by Scarodactyl » Sat Jul 06, 2019 5:28 am

No offense, but that reads a bit like ad copy.

I don't see how the system would produce actual increased resolution. An illusion of simultaneous high resolution and high dof, yes (which is certainly cool) but no new details. The m205 has slightly higher max resolution than the m165, just as the 165 is higher than the 125, but that's just a matter of their zoom ranges and what they can squeeze from that same main objective.

Jewelers and gemologists use different microscopes in very different contexts. Gemological work is examining stones for identifying features, rather than benchwork like a jeweler. The a60 is a scope for working under, it doesn't even have a standard configuration to fit on an illuminated base. Gemological scopes typically use a more routine inspection head (like the leica s series) with brightfield and darkfield illumination on the base, particularly darkfield for closely examining gem inclusions. I have been advised by a few extremely experienced gem microscope enthusiasts to completely avoid fusion optics in this application. Nevertheless, a few sellers do offer the s9 on their gem bases, so presumably someone likes it even for this. If I get a shot I'll give it a try, but as is it isn't on my must have list.

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Re: Leica : FusionOptics

#18 Post by wabutter » Sat Jul 06, 2019 7:53 pm

Scarodactyl,

It may read like ad-copy, but the superior resolution, greater depth of field and user safety are all documented characteristics of the FusionOptics. The fact that Leica Surgical Microscopes have also incorporated FusionOptics is testament to the all three dynamics.

I will agree that Gemological work requires a different set up than a Standard A60, and I may have over simplified my reference to the industry. The A60 is a preferred optics head for Custom Jewelry Designers and Manufacturers, and that is completely different application from a Gemological scope. GIA has built a good business on putting together gemological microscopes and it is not trivial. As a user, you know how they differ.

All stereo microscopes are designed to be worked under. Hence the WD and angle of access from the optical body. The threading for the objective port on the A60 was not designed for aux mag lens although they will fit. It was to provide a protective cover for applications that might have had soldering taking place under the scope. Yes, the zoom range would be compromised with a 2x lens in use but that was not the intended design. I doubt that this is an issue with the S9.

Is it possible your esteemed Gemological user experts have some other underlying reason they don't like FusionOptics? Therefore they poopoo them. If you haven't tried it, you should test it first hand, and apply your criteria to the evaluation.

Best,
Wayne

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Re: Leica : FusionOptics

#19 Post by Scarodactyl » Sat Jul 06, 2019 9:32 pm

wabutter wrote:Scarodactyl,
It may read like ad-copy
It does, yeah. Do you work for Leica, and/or a Leica dealer, or an enthusiast? I'm asking not as a weird accusation, but because I have been trying to get my MZ95 set up in style and have been having an odd issue, but of course Leica support wasn't quick to get back to me about a product they haven't offered in some time. I don't blame them but it'd be awesome to be able to ask someone with deep specific knowledge of Leica stereos. That's sort of neither here nor there though.
wabutter wrote:but the superior resolution greater depth of field and user safety are all documented characteristics of the FusionOptics
Greater apparent DoF, absolutely. Definitely don't have any reason to believe it's unsafe to the user. But how does it produce increased resolution?
wabutter wrote:Is it possible your esteemed Gemological user experts have some other underlying reason they don't like FusionOptics?
One of them actually might, not for financial reasons but normal enthusiast ones--you may be familiar with how some hardcore Wild/B&L/AO fans feel like Leica can do no right. But the others, nah.
Last edited by Scarodactyl on Sun Jul 07, 2019 7:42 am, edited 1 time in total.

MichaelG.
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Re: Leica : FusionOptics

#20 Post by MichaelG. » Sat Jul 06, 2019 10:25 pm

Scarodactyl wrote:But how does it produce increased resolution?
It doesn't

What it does do though, is produce superb resolution for the right eye, and reduced [but still pretty good] resolution, with greatly increased depth of field, for the left eye.
The combined visual effect being 'the best of both'

MichaelG.
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Re: Leica : FusionOptics

#21 Post by wabutter » Mon Jul 08, 2019 1:00 am

I am retired from Marketing and Sales at Leica 5 years ago after 40 years OTJ. Started with the AO side of the business and lived through the M&A whirlwind. I was mostly involved on the Compound side of the business, but supported all products related to Forensic Business, so that included all types of microscopes. I have no commercial ties with any manufacturer or dealers.

Essentially, the right side optic has been optimized for the highest NA, This supports the available magnification range and is optimized for the range of supplemental lens. Like many competitive product comparisons, there tends to be the horsepower race to the top of the food chain. So 16:1 begot 20:1 and I think even Zeiss boasted a 20:1 zoom range before the M205 was introduced and for a short time claimed the highest resolution. About an month if I remember right.

What issues are you having with your MZ95. If I don't have the domain knowledge, I can reach out a few people. PM me at cmod24@gmail.com we can take this off line.

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Re: Leica : FusionOptics

#22 Post by Rorschach » Wed Oct 30, 2019 6:52 pm

At my work, we're getting a well equipped Leica M205C. I finalized the purchase today. It will be interesting to experience FusionOptics for sure!

At a later point, we will also purchase the Leica Planapo 2x corr. objective for it. This is a special objective with a dial with which you can take into account the refractive index of the medium (air or water/ethanol) where the specimen is. This leads to significantly better resolution with specimens in water/ethanol. We will use this microscope heavily for benthic macroinvertebrate id work and these are always in water or ethanol. Ethanol has an almost identical refractive index with water.

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Re: Leica : FusionOptics

#23 Post by Scarodactyl » Wed Oct 30, 2019 7:01 pm

All right! I bet it was fun to pull the trigger on that one.
Those Corr objectives do look cool, and I imagine they might have some benefit for imaging inclusions in gemstones as well (even though the RIs involved are much higher than water).
I will be looking forward to your opinions on this!

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Re: Leica : FusionOptics

#24 Post by MicroBob » Wed Oct 30, 2019 9:51 pm

Hi together,
I find this approach very interesting. All the time a lot of effort is taken to make both sides equal and then somebody comes and makes them different by intention.
For me lookin through a stereo microscope often feels as if the brain has to do a lot of work anyway. So it might in fact be not perfect but not worse than normal to use the fusion system, and make use of the advantages on the side.
It would be interesting to see a statistical analysis about how well people with a leading/sharp right eye like the system compared to those with preferred right eye. I can imagine that there will be a difference. I guess that i would prefer the high n.a. side on my strong left side.

What i find interesting too: Higher n.a. normaly means brighter image - how is it in this case?

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Re: Leica : FusionOptics

#25 Post by PeteM » Wed Oct 30, 2019 10:30 pm

Is there a loss of depth perception for manipulation under FusionOptics? Since they're being used (noted above) in surgical scopes, one would assume not. On the other hand, having one eye set to a sharp image at one depth and another with a fuzzier but deeper depth image might well throw things off a bit?

As for some users being delighted and others not - could be this is similar to the case with contact lenses where one is set near and the other far -- some users just don't get used to it.

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Re: Leica : FusionOptics

#26 Post by Rorschach » Thu Oct 31, 2019 2:42 pm

Scarodactyl wrote:
Wed Oct 30, 2019 7:01 pm
All right! I bet it was fun to pull the trigger on that one.
Those Corr objectives do look cool, and I imagine they might have some benefit for imaging inclusions in gemstones as well (even though the RIs involved are much higher than water).
I will be looking forward to your opinions on this!
Right you are :D It was absolutely a joy. What made it even better is that I was able to locate a used but pristine/as new one for 9000 euros. The value of that setup is actually 25 000 euros. I happen to have the current list prices at my disposal, so I know the price of all the parts.

So yes, perhaps a time to open a celebratory beer or two ;)

Who knows, perhaps the corr. objectives could be of help with the gems, too. Interesting to test at least.

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Re: Leica : FusionOptics

#27 Post by Rorschach » Fri Jul 17, 2020 1:26 pm

I finally had some time to do some quick testing of the Leica Planapo 2.0x Corr. objective (on a Leica M205C) on specimens that are in ethanol/water. I am very happy to tell that the resolution gain is very clear even for the naked eye. I did not test at low magnifications but starting from 50x onwards the difference is very pronounced. Really makes a difference.

Using the corr. ring at the end does mean that you have to refocus. However, in real use you don't need to do that because you just dial in the liquid depth in mm (max is 5mm) and leave it there - no reason to use the uncorrected setting if you are looking at something in water/ethanol.

Forgot to mention: the test specimens I looked at were one Trichoptera larvae (Rhyacophila nubila) and two Plecoptera larvae (an Isoperla and a Leuctra, did not bother to go to species level with them).

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Re: Leica : FusionOptics

#28 Post by Trigon » Thu Aug 27, 2020 3:42 pm

Scarodactyl wrote:
Thu Jul 04, 2019 12:55 am
I'm sure it isn't actually stopped down in a physical sense, just lower resolution higher dof optics bottom to top on one side. Hard to imagine it isn't the same fundamental principle at play.
I have not tried it myself, but have heard mixed to negative reviews. That being said, gem inspection is my main focus and I have heard it is especially poor for that in specific, so take it with a few grains of salt. It must be quite good for some applications or they wouldn't be going so whole hog on it.
this thread has affected my decision making in trying to purchase a new gemological microscope, specifically this post. Has anyone heard anything to update the information on this topic? I have patiently been sitting back waiting for GIA to commit to a new scope and close to a year later nothing has arrived.

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Re: Leica : FusionOptics

#29 Post by Scarodactyl » Thu Aug 27, 2020 5:02 pm

I wouldn't hold my breath on the GIA, the guy at the booth was optimistic last year and much less so this year. Frankly I don't expect much from them after the DLscope and presentationscope anyway, seems like too much involvement from marketing and not enough from people who actually use microscopes.

I still haven't had a chance to try a fusion optics scope properly myself. There were some a60s set up at Tucson but the dealers had no clue and while I didn't like the view through them it was almost certainly a setup issue more than anything to do with the fusion optics. With a working scope you already have tons of DoF anyway so I doubt the effect is that dramatic in that context. I'll jump if I get a chance though.

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Re: Leica : FusionOptics

#30 Post by esteruco » Thu Sep 03, 2020 7:20 pm

Hi!
Has anyone used Leica M205 for asbestos identification?

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