MicrobeHunter.com Microscopy Forum

apochronaut wrote:Yes. I was very satisfied with the results the two higher end Chinese objectives in the test here, provided. They performed exactly as expected.

viewtopic.php?f=5&t=4963&p=45168#p45168

Apo, thanks for reminding of this comprehensive comparison, highly relevant to the subject of current posts, although not really in line with the purpose of the suggestion . Pics 2361 and 2368 of the infinity corrected, in comparison to the excellent performance of so much older objectives... the results are self-explanatory. If those are infinity corrected, how would the 160mm objectives from the same source perform...

It seems to me that no one asking questions on a microscope forum should be frightened by a little 'technobabble'. It's like someone asking the question on a forum for four-wheel-drive vehicles: which is better, a Jeep Model x or a Land Rover model y. You are going to get a lot of technobabble, and you should. That's what forums are for, a cacophony of opinions and rationales. If the person asks (on the four-wheel-drive forum), which is better, a Geo Metro or a SmartCar, the question is somewhat troll-like, and responders are going to be freaking out, shouting to themselves and each other, "WTF!???". In no time at all, someone gets snarky and the whole conversation goes off the rails. Some will insult or support the vehicles, some will insult other responders, and some will eloquently respond with extensive technobabble about why neither car is suitable.

If I was a troll, I know exactly the question to ask on this forum to ignite a war: "I think I'm interested in microscopes but don't know what to get for my $150." I can hear the skulls exploding already.

I reiterate that the forum needs positive reviews from members to which total newbies can be referred. Maybe a new forum category, Oliver? "Entry-level microscope reviews and pitfalls"?

wporter wrote:

I reiterate that the forum needs positive reviews from members to which total newbies can be referred. Maybe a new forum category, Oliver? "Entry-level microscope reviews and pitfalls"?

Why just positive reviews?

Why just positive reviews?

I believe the reason is Forum Rule #3

viewtopic.php?f=29&t=4193


Anyway, an area where which of these microscopes should I buy? and a myriad other similar questions can reside has been suggested.

It would have the virtue of concentrating not only the questions but the answers as well. A sort of informal FAQ for a first microscope purchase.

75RR wrote:

Why just positive reviews?

I believe the reason is Forum Rule #3

viewtopic.php?f=29&t=4193


Anyway, an area where which of these microscopes should I buy? and a myriad other similar questions can reside has been suggested.

It would have the virtue of concentrating not only the questions but the answers as well. A sort of informal FAQ for a first microscope purchase.

I get that but the forum is already littered with negative comments about certain equipment, negative comments about certain ebay or on-line sellers and the illiterate lambasting of members. If one has an unqualified comment about a new instrument they bought that is one thing but if they have a negative comment about an instrument they just bought and can offer information as to why they have the negative comment, then that can only serve to assist in the education of those that are still at the stage of kicking tires. I'm sure most of them would like to know what instruments need to be considered with caution, new or used.
I mean, where are these imaginary legal ramifications going to come from and in the direction of whom? If the administrator of the forum is afraid of a certain post, then take it away. There; problem solved.

I mean, where are these imaginary legal ramifications going to come from and in the direction of whom?

How unlikely they are is not the issue, sleeping soundly is.

If the administrator of the forum is afraid of a certain post, then take it away. There; problem solved.

I believe that Oliver would rather not spend his days policing the forum. Hence the rule.

apochronaut wrote:Yes. I was very satisfied with the results the two higher end Chinese objectives in the test here, provided. They performed exactly as expected.

viewtopic.php?f=5&t=4963&p=45168#p45168

That's a very interesting comparison, thanks for the link ...
But I'm struggling to understand the test conditions.
The only mention of an eyepiece seems to be two occurrences in your final posting [Thu Jun 01, 2017 10:06 pm]; yet presumably, at least some of these objectives require compensation.
So ... what was your photographic optics arrangement please ?

[perhaps the more established forum members knew this already, and didn't need telling]

MichaelG.

I tested the 160mm optics in an AO series 4, trinocular. The 170mm optics were also tested in the series 4 but I adjusted the camera position to extend the tube appropriately. The one AO/Reichert 34mm parfocal objective I tested in a series 10 trinocular. The 45mm parfocal infinity corrected objectives I tested in an AO/Reichert Diastar trinocular. In all cases the camera can be moved relative to the eyepiece, in order to obtain a desired field capture.

I have an array of eyepieces. For each objective, I used the eyepiece in the trino tube that best corrected for the objective being tested. For the B & L apo for instance, I used a B & L compens .... 10X , I think. Spencer 60X 1.25 oil achromat was done with an AO 1054 focusing eyepiece. For a lot of most of in fact older objectives a Wild 6X K seemed best. I have various photo eyepieces; Kyowa 2.5X, Olympus Fk 5X, 6.7X, NFK 5X, Nikon CF 5X K photo, a couple of unbranded older 5X that have various compensating characteristics. I chose the one that seemed to compensate the best for each objective.

The D.I.N. infinity corrected objectives were a bit different. Those two Chinese objectives I purchased to use in an AO/Reichert 200mm infinity corrected system because aside from a 50X .80 oil planachro, and two 63X planachro immersion objectives( oil and glyz.) there are no dry objectives in that magnification for those instruments. In both cases the retailers of the objectives assured me that they would work and correct well in my system. By and large they both seemed to work and correct as well as the objectives built in both Vienna and Buffalo and in normal use were not too bad but then it was difficult to judge due to the lack of an original factory comparison. When I compared them to the AO/Reichert SPL 63X .80 in a 34mm infinity system though, it clearly completely blows them away.
Previously, I had been using 15X cat.# 181 eyepieces with a 40X .70 planfluorite to get the same magnification in the Diastar and in comparison, the two brand new and almost new(n.o.s.) Chinese objectives just fail to perform to it's standard as well, and are downright terrible when the magnification is pushed only a little, as is evidenced by the cropped images. If you are wondering if the system might exert a technical prejudice against them; i.e. not correct properly for them, that isn't the case. The corrections are excellent with the 60X .80 visually it's just that the objective lacks resolution and contrast. One can also easily see that on axis, where corrections matter little, the resolution and contrast is poor. I used the 60X .80 a little because it is convenient due to it's dry specification and it's annoying to swap eyepieces but I subsequently bought a Reichert 63X glycerin immersion and even using it dry, it is better than the Chinese objectives. The Prior objective I bought later, hoping it would be better but it is in fact worse, mainly because it is not plan. The fact that one can take two objectives, one an immersion type and the other a high N.A. dry type of the same magnification, and in use the immersion type when used unimmersed, outperforms the dry type , is pretty condemning of the quality of the dry objective.

Thank you for the clarification
...Much appreciated.

MichaelG.