Reichert Stereo Star 580 vs B&L Stereozoom 7 vs Nikon SMZ-U vs Olympus SZH vs Leica M80

[einman]

Just acquired a "new" Reichert Stereo Star 580. I will be writing a detailed comparison for next months Microbe Hunter magazine for anyone interested. All three of these stereo scopes have magnifications without auxiliary objectives of 60X plus.

Should make for an interesting comparison.

[gekko]

Congratulations for another nice acquistion. I, for one, will look forward to your comparison.

[einman]

Sold an objective. More than paid for the scope. Given I have pretty much stopped looking for compound scopes with my purchase of the Leitz Diaplan, I have some extra objectives I am selling. Whether I keep the 580 is another story. I have always wanted to know how the AO (Reichert) 580 compared to the SZ7. the B&L SZ7's are quite common. Not so for the AO 580. Once I have satisfied my curiosity it may go the way of many other scopes..to another owner that appreciates it.

As an AO fan I will try and not be biased. However, My appreciation for the SZ7 is quite apparent by some of my earlier posts.

[tbarnes]

Looking forward to your assessment as well. Especially the SMZ-2T

[einman]

I am writing it up now and hope to have it in the next Microbehunter magazine. I think I will include a generic Chinese scope as well just for comparison.

[einman]

Ok. So I am very late on the article. I got carried away. What started out as a simple comparison bloomed into a much larger dissertation. I intend to divide it up into multiple articles soon.

[einman]

Updates soon. However I have since dropped the SMZ-2T and instead will be comparing the Nikon SMZ-U. Part of the delay has been due to my inability to obtain actual optical data on the 580 as well as the fact it turned into a an evaluation spanning many pages that I need to pare down.

[75RR]

However I have since dropped the SMZ-2T

Dropped as in landed on the floor? Yikes!!!

[einman]

Ha. No dropped as in I am leaving it out of the evaluation. For simplicity I am including the "Top" research scopes of that era and in actuality the Nikon SMZ-2T was not really considered a "research" scope and was out gunned by the SMZ-U.

Although it performed admirably.

[zzffnn]

Wow, I am surprised B&L SZ7 can even stand in that list. The last 3 are much more expensive, aren't they? I would be happy enough, if SZ7 can get close to those 3. Even the 580 costs quite a bit more. Besides 580 (?), which ones are CMO design?

No need to write an academic paper, einman. Just a quick comparison or your personal experience is more than good enough. Or give us your quick take first, then write that manuscript

What do/did you use to evaluate resolution, by the way? USAF resolution test targets or diatoms?

Thank you for sharing!

[einman]

The 580 is not a CMO design it is greenough. The Cycloptic was CMO.

The B&L SZ7 has on many forums, especially the photomacrography forum, been undermined. Primarily due, in my opinion, to the individuals having inferior examples, no doubt out of alignment or the optics corroded by flux vapor etc. Prime examples are simply superb!

In terms of measuring resolution I considered at the USAF resolution charts but wanted a more real world comparison. That is if you utilize a test method that is able to discern differences not consumer perceivable than the consumer tends to be indifferent especially if there is a cost associated with that "technical" difference. Using diatoms for scopes having numerical apertures less than 0.2 and magnifications only going to 75x with a 1.0x objective is pretty much a waste of time.

CMO vs Greenough is an academic discussion as according to Nikon’s microscopyu website, “It is a difficult task to determine which of the two designs (CMO or Greenough) is superior, because there are no universally accepted criteria for comparing performance between the stereomicroscope systems.”

You generally pick one or the other based on your intended use. CMO designs tend to yield "brighter" images and better chromatic corrections but are expensive. I will make comments accordingly.

For resolution I use various samples of very small species of ants (Dacetines). I will give resolution in terms of LP/mm and NA as well.

[einman]

The Bausch & Lomb SZ7 and the AO 580 did not give optical resolution data in any of their brochures. That was an issue. I found an old ad for the B&L SZ7 where B&L gave the resolution as 300 lp/mm.
LP=Line pairs mm=mm. A line pair is designated as a pair of adjacent dark and light lines. so 300 lp/mm translates to 600 lines/mm.
If you use the generally accepted formula that Numerical Aperture is equal to (LP/mm)/3000 then you get a numerical aperture of 0.1. That is pretty amazing given it exceeded or matched many of the top stereoscopes produced by the Germans (Zeiss) and Japanese ( Nikon, Olympus).

What many fail to take into consideration when comparing the older scopes to newer models is the effect of lighting. The B&L SZ7 was introduced in the late 70's whereas the Nikon and Olympus in the late 80's early 90's. Improvement in resolution was not the sole objective of the Japanese. In fact most of the literature touted improvements in zoom ratio, chromatic aberration and color/contrast. They were experimenting with new coatings and optical designs.

Which brings me back to the lighting. If you do not get the lighting right on the SZ7 and the 580 their performance suffers considerably compared to the Nikon and Olympus which are more forgiving, owing in part to superior coatings. For example using a flat black stage plate is essential for optimum performance. Glass or white stage plates reflect light resulting in significant deterioration of the image when using a B&L SZ7 or AO 580. Although no longer in this comparison this is true of the Nikon SMZ-2T a well.

The Nikon SMZ-U with a 1.0x objective had a NA of 0.09 or 270 lp/mm. That would seem to be less than the B&L SZ7
The Olympus SZH had a na of 0.084 or 252 lp/mm. Again this is inferior to the B&L SZ7.

However I can not put too much weight on the B&L SZ7 optical spec as it is based solely on an ad where B&L could very well have been exaggerating somewhat.

Have you ever seen a brochure where one scope manufacturer compares themselves to another?? Given there are no standardized tests for assessing optical performance of microscopes B&L could have exaggerated a bit knowing they would not be challenged. Just some food for thought!

[zzffnn]

NA 0.1 sounds slightly higher than what I expected for SZ7 (I have a decent-good sample), though I have never tried to push it for resolution. Was that NA 0.1 with 2x ancillary lens or with stock 1x lens? I won't be surprised, if it is with 2x aux lens.

You are surely right about coating.

[einman]

Here is some more to think about. Optical performance or the lack of can also be impacted by the stand supporting the optics. How can you "fine" focus a stereoscope if there is no fine focus?

One scopes superiority could simply be a reflection of your ability to control the focus. There is a reason the newer research scopes including the Olympus SZH and SMZ-U have a fine focus.

This is one reason why I put the SZ7 on the R-stand, where it only has a fine focus, and is far superior to any of the other available stands for the SZ7 pod.

Now do you understand how this evaluation escalated into a huge project!!

[einman]

NA 0.1 sounds slightly higher than what I expected for SZ7 (I have a decent-good sample), though I have never tried to push it for resolution. Was that NA 0.1 with 2x ancillary lens or with stock 1x lens? I won't be surprised, if it is with 2x aux lens.

You are surely right about coating.

Good question! Most manufacturers cite resolution using a 2.0x objective rather than the 1.0x objective. Somewhat deceiving I think. The ad did not say. However- based on my observations I do not believe that was based on a 2.0x objective. Most brochures will insert the words "up to" when using a 2.0x objective. That particular ad simply stated with 300 lp/mm ...etc.

The question is was B&L capable of making a scope with 0.1 na at that time. Well they definitely knew optics as exemplified by their compound scopes.

Plus the performance is really quite striking if not comparable. It is very close to the other scopes. You also have to take into consideration DOF. As the mag climbs what is perceived as poorer optics is in reality a reduction in DOF which can be perceived or concluded to be poorer resolution. DOF was one aspect the Japanese improved upon with the SMZ-U and the SZH.

[einman]

Just to be clear I am by no means touting or alluding to the B&L SZ7 as being superior in this test. It has poorer DOF, Smaller FOV, and is significantly "dimmer" than others in this line-up.


However, when all is considered, and you get past the bad rep it has earned from poor examples on the market, it is an incredible scope. Sorry for digressing.

[einman]

Ok. To make this evaluation short I will rank the scopes based on resolution, DOF, FOV, W.D, image brightness, color/contrast and last but certainly not least for most hobbyists, average price on E-bay.

[zzffnn]

That will be very helpful and informative. Thank you einman!

[einman]

Using 40X as the selected magnification I would rank them as follows:

Leica M80> SZ7,SMZ-U, AO580>Olympus SZH

I utilized the same lighting and viewed the specimen from multiple angles attempting see it in the best context possible. There were significant differences in image seen through the eyepieces in terms of color/contrast, DOF and FOV. However, my attention was on evaluating the resolution. The other attributes will be reviewed later. I went back and forth between scopes. Trying to discern a difference was not that easy and in fact they were all quite close with the Leica M80 definitely at the top end and the Olympus SZH at the other extreme. You might have expected the Leica M80 to have the best resolution given it is the newest scope of the bunch and should benefit from better technology. Interestingly the Olympus which scored at the bottom has the lowest "known" NA.

Again this is resolution only. If we put these rankings based on year of introduction it would go like this:

Leica M80(2012)>SZ7(1976),SMZ-U(1990),AO580(1980)>Olympus SZH (1984)

Note that despite the SZ7 being the oldest it still performed quite well. Perhaps this is why Leica continues to market it under the name GZ7. I have seen prices from $2000-$5000 from microscope dealers currently and around $400-$500 on E-bay. Although I have purchased 2 designated as GZ7 and found them to be inferior in optical performance and construction to my example designated as the B&L SZ7. It is also of interest to note that Olympus quickly updated the SZH calling it the SZH10 improving resolution to 0.10 and zoom ratio to 10:1. I have not had the opportunity to evaluate one.

Don't be quick to draw conclusions as to which scope is better on the basis of resolution alone. There is much more to a scope than simply its resolution. I would be hard pressed to choose one simply on that basis. Also keep in mind these are "used" scopes so I am sure there is variation from one example to another. If they were all new, the results could be quite different. I purchased over 8 examples of SZ7's before I settled on the one I have. I bought 2 SMZ-U's before settling on this example. I purchased 2 Olympus SZH's and selected this one. I have purchased more than 7 AO 580's before selecting the one I currently own. Given I was able to examine more examples of the SZ7 and the AO 580 increased my chances of finding a prime example of each.

Trying to obtain actual resolution numbers for the older stereoscopes has been a daunting task. Very little literature exists and brochures are not easy to come by. I have seen advertisements by resellers which vary in their claims for resolution of older scopes, perhaps because of the actual lack of data and/or knowing the claims are not likely to be challenged by the existence of said brochures. One such example can be found on an ad for the B&L SZ7 from Optitech, claiming 600lp/mm (with 2x objective no doubt), whereas an old actual ad from B&L claimed only 300 lp/mm. In addition, it is my opinion the manufacturers did not want to place too much emphasis on resolution, as little advance was made in that area for decades. Rather technology tended to focus on improving the coatings on optics, reducing glare and internal reflection between optical elements and ergonomics. As a result color, contrast, and ergonomics improved over the years whereas resolution, not so much. In addition attention was paid to reducing image distortion introduced as a function of “stereoscopic” design such as flare, chromatic aberration and pin cushion etc. Manufacturers also emphasized “zoom ratios”, that is the ratio of highest to lowest magnification. The lack of improvement in resolution is evident when reading current brochures for Nikon, where they continually compare resolution (numeric aperture and lines/mm) of the newer models back to the SMZ-U. The Brochure for the SMZ1000 indicates a resolution of 300 lines/mm which is identical to that of the Bausch & Lomb SZ7. The SMZ1500 equipped with the standard 1X objective in 2006 still had an na of 0.1 only slightly better than the earlier Nikon SMZ-U and Olympus SZH 10. However, if you opted for the much costlier 1X plan apo HR objective na increased to 0.131 . Adding the 1.6 planapo HR objective brings resolution to 630 lines/mm and an na of 0.21. Using a higher magnification objective increases resolution. You have to take that into consideration when evaluating manufacturer’s claims. The manufacturers tend to quote figures utilizing higher mag objectives rather than quote what the base resolution is with a 1x objective. So an SMZ 1500 using the std 1 X objective would have a resolution about 300 lines/mm, about equal to the SZ7 despite decades between the development of the two scopes. Olympus claims a resolution of 600 lp/mm and an na of 0.2 for their SZX10 model but that is only with their 2X objective.

[einman]

There are stereo scopes available with significantly better na but at costs well out of reach of most hobbyists. So I am not discussing those. NEXT: FOV

For FOV the scopes are being compared with their std 10 x eyepieces, 1.0x objective at 1x magnification for a total magnification of 10X.

Bausch Lomb SZ7= 20 mm
Leica M80=23 mm
American Optical 580 =20 mm
Nikon SMZ-U=24 mm
Olympus SZH= 24mm

So we have Nikon SMZ-U,Olympus SZH>Leica M80, AO 580,B&L SZ7

The Nikon and Olympus have a 20% greater FOV than the AO 580 and B&L SZ7.

That is rather significant. The views through the Leica, Nikon, and Olympus are quite spectacular. Not only are they larger but the amount of light allowed results in a significantly brighter image. In terms of brightness the Leica leads followed by the Olympus and then the Nikon. The AO 580 is brighter than the SZ7.

There has been discussion of the 15X Ultra Widefield eyepieces( cat# 31-25-74) originally made by Bausch & Lomb for the SZ7. Use of these eyepieces still only yields a 20mm FOV although it is 42% greater than the FOV you get with their std 15X eyepieces at 14 mm ( Cat #31-05-68). If you use 15x eyepieces on the Nikon and Olympus you get a fOV of 17.0 mm which is which is inferior to the FOV of the UWF 15X eyepieces for the SZ7.

Perhaps one of the best views can be found peering through the 10X/25 mm eyepieces of a Zeiss Stemi SV8 or SR!! I own this scope but did not include it in this comparison.

Generally speaking stereo scopes that use CMO technology tend to give a much brighter image due to more light entering the objective.

[KurtM]

Bausch Lomb SZ7= 20 mm
Leica M80=23 mm
American Optical 580 =20 mm
Nikon SMZ-U=24 mm
Olympus SZH= 24mm

Maybe a bit out of left field, but is there a correlation of alphabet letters to features in the designations such as 'SMZ', 'SZH', etc.?

[zzffnn]

I enjoy reading your spots, thank you einman!

Isn't apparent DOF affected by perceived contrast? One would think resolution/NA determines DOF for the same optical design. But then, those scopes probably do not have the same optical design.

I agree that resolution is not that important for dissecting scopes. They are used for their long WD and sample preparation mainly, at least in my hands. Critical high resolution examination or focus stacking is always best left for compound scopes.

You made a good point about providing good strong lighting. Even though NA 0.1 sounds about good enough for 40x total visual magnification, all those scopes herein go up to 60x or more (so they need better light at higher magnification). After reading your posts, I can remember this now; it was indeed at around 50-60x, where I saw image degradation, from my SZ7. 30x and below did look pretty good.

[apochronaut]

[quote="einman"]g

For FOV the scopes are being compared with their std 10 x eyepieces, 1.0x objective at 1x magnification for a total magnification of 10X.



There has been discussion of the 15X Ultra Widefield eyepieces( cat# 31-25-74) originally made by Bausch & Lomb for the SZ7. Use of these eyepieces still only yields a 20mm FOV although it is 42% greater than the FOV you get with their std 15X eyepieces at 14 mm ( Cat #31-05-68). If you use 15x eyepieces on the Nikon and Olympus you get a fOV of 22.67 mm which is still superior to the SZ7 with the UWF 15x eyepieces.
quote]

I'm a bit confused here.
I take it that you are measuring the f.o.v. with a micrometer for each eyepiece? With a f.o.v.of 22.67mm then , the Nikon and Olympus 15X eyepieces would have apparent fields of 34mm? The 15X U.W.F. eyepieces from Bausch & Lomb were not designed for the SZ7. They were a design originally included with the 240Z package. Subsequently they were maintained for various applications but they don't show up in the SZ7 catalogue.

I did some measurements with the B&L, 31-25-74 and the 31-05-62 at 15X( 1X objective) and I get different actual fields, than you are listing. I measured the field on the stage with a machinist's scale. The 31-05-62 was the 15X eyepiece for the Stereo 1,2 and stereozoom 3,4 and 5. I can't place my hands on my 31-05-68s right now but the two are very similar and I doubt the eyepiece for the SZ7 has a narrower F.N.#. So, at 10X , I get 22mm actual field with the 15X U.W.F. and 18mm actual field with the catalogued 15X for the 1,2,3,4 and 5 stereos.

[einman]

Hmm..let me go back and check again. I did verify with my micrometer the 20 mm.

[einman]

Nope I get 20 mm with the UWF 15X and just checked to make sure I read the correct table at it confirms my measurement of 20 MM for the uWF 15X eyepieces.

I will send you the brochure with the tech specs. It was s surprise to me but despite my preconceived impressions the numbers do not lie.

If anyone wishes a copy of the Leica Brochure PM me with your e-mail address.

I used a Pittsburgh digital caliper place on a line intersecting the diameter of the field of view. Perhaps not what you would expect but matches the technical specs from the Brochure.

Recall my earlier posts extolling the virtues of these eyepieces! It was a surprise to me. Thus the reason I sought the brochure.

[einman]

I did make a mistake on the Nikon SMZ-U FOV it comes to 17.00 not 22.67 with the 15X eyepiece. I was at 0.75X not 1.0X. So I will correct my post on those numbers but my numbers on the SZ7 still hold.

[apochronaut]

If I put a metric ruler on the stage and with a 1X objective and those two sets of 15X eyepieces the ruler measures 22mm across the field for the 15X U.W.F. and 18MM for the 31-05-62. I'm pretty sure the 31-05-68 is the same. You are quoting 14mm for the catalogued B & L 15X eyepieces.

[einman]

I used a digital caliper and repeated my measurements for the 5th time. I get 20 mm for the cat 31-15-75 15x UWF eyepieces at 1.0x. They coincidentally match Leica's technical specifications which gives me more confidence in my results. Would you like a copy? You have not commented at all on the fact my data is supported by Leica. Here is a pic I just did. This time I marked the lines at the widest section of the FOV. I then measured the marks. A slightly different method but with the same results.

[PeteM]

Is the purpose of the evaluation to help folks who want to buy a superior stereo scope, while paying as little as needed in the used market?

[einman]

Is the purpose of the evaluation to help folks who want to buy a superior stereo scope, while paying as little as needed in the used market?

Yes that is pretty much the idea and to demonstrate what your extra money can purchase should you decide that some of the extra features such as FOV, DOF modular components etc are of interest.