I'm new to the community but have been interested in colored gem stones for around 30 years. I did some very minor collecting of sapphires, rubies, and emeralds while traveling over seas.
Now that I have a bit more time and money I'm collecting even more and want to get a good used scope. I have a friend who is a gemologist and does appraisals. He suggested I get a GIA Mark V scope. I don’t want to spend the big bucks for a new one so I’m looking for a good deal on a used one. In my searches I’ve seen two models for this scope. The Bausch and Lomb version and the American Optical version.
I was wondering if any of you had a preference between these two or others. Also, do you know of anyone who is selling one of these? I’ve only seen two on ebay. Both have starting bids of between $600.00 - $700.00. That’s about what I would like to spend. That may not be realistic as I know they sell for between 2 and 5 grand new. But these models appear to be between 30 and 40 years old and sold for around $1800.00 when they were new.
Joined: Fri May 12, 2006 11:24 am Posts: 7523 Location: Rome, Italy
Hi Mitch and welcome to the forum.
those base are essentially identical, the only difference is on the pod's arm which, on the grey one is round shaped in order to accomodate AO pods, the black one is provided by the classical B&L frame to accomodate B&L Stereozoom series pods.
American optical:
PRO this configuration has an higher mag factor, furthermore, additional lenses (2x) are not expensive and quite easy to find. The overhead fluorescent lamp comes with the original plastic shield (not easy to find)
CONS not upgradable, that pod is the most powerful available for that arm.
Bausch & Lomb
PRO upgradable: purchasing separately an SZ/7 pod allows to have a 10/70x continuous zoom with standard 10X oculars. This may be really important if you usually grades both diamond and colored stones.
CONS less mag factor compared to the AO, the auction doesn't specify the kind of oculars, fluorescent overhead plastic shield is missing.
that said both are excellent scopes and seems to be in nice shape. the only issue i'm aware about gemolite bases is the overheating of the darkfield well during intensive session, if one is familiar with this kinda work it wouldn't be so difficult to add a little fan, i would also suggest to change the bulb type with a newer halogen model. hope this helps and good luck. ciao
Joined: Fri May 12, 2006 11:24 am Posts: 7523 Location: Rome, Italy
hey Lennie, why don't you send an email to the sellers? nothing to loose and it's my experience sometimes US folks sends overseas even if in the auction it's specified US only... ciao alberto
Thanks for the info. Sounds like either one would be a great scope. I did see reference to the heating issue. I've also seen a kit to upgrade the unit's darkfield well.
Chances are I will probably loose the bid anyway since I don't won't to spend more than about $800.00 on one.
Are there other scope options you would suggest in that price range either new or used?
Joined: Tue Oct 20, 2009 3:34 pm Posts: 381 Location: Sweden
Alberto wrote:
hey Lennie, why don't you send an email to the sellers? nothing to loose and it's my experience sometimes US folks sends overseas even if in the auction it's specified US only... ciao alberto
I´ve tried a couple of time but - no no! I´ll keep on trying but most oftenly I don´t know if the scope is anything for me... I just know that I "need" a god gemoscope to a descent price... One day I will have it but the question is WHEN?
Joined: Fri May 12, 2006 11:24 am Posts: 7523 Location: Rome, Italy
Lennie wrote:
I´ll keep on trying but most oftenly I don´t know if the scope is anything for me...
well basically it depends about your needs. Maybe you need for a professional scope, maybe not. Old gemolites are usually cheap nowadays, many folks doesn't like their "vintage" look.
Quote:
just know that I "need" a god gemoscope to a descent price... One day I will have it but the question is WHEN?
PRO this configuration has an higher mag factor, furthermore, additional lenses (2x) are not expensive and quite easy to find. The overhead fluorescent lamp comes with the original plastic shield (not easy to find)
CONS not upgradable, that pod is the most powerful available for that arm.
This is not correct. The AO 580 has six to one zoom and is easily available on fleabay and will drop right into any AO equipped gemolite. It also has a photo attachment available. The latter is a bit harder to find than the corresponding B&L but can fit any 580 not just ones made for photo use. A plate comes off with two screws and the photo adaptation is bolted into its place.
This one is sold by a reiliable seller who is known to me.
AO equipped Gemolites and I think B&L ones too usually came equipped with 15x oculars.
Joined: Fri May 12, 2006 11:24 am Posts: 7523 Location: Rome, Italy
G4Lab wrote:
This is not correct. The AO 580 has six to one zoom and is easily available on fleabay
Yes, the 10-60X is also available but it's still less powerful compared to the SZ/7 (10-70X) and according to my experience NOT easy to find, the seller himself pointed it out in the auction: "This is the rare extended range model 580, 10-60X magnification"
The AO 580 may not be easy to find in Italy, but it is EASY to find here. The auction I linked to was found by typing "AO580" into ebay's search. Usually several such auctions come up. I obtained two of them in very short order. The "seller" is merely trying to aggrandize his auction and sell his scope. He makes his entire living selling scopes on ebay. I don't consider him to be an authority on microscopes.
There are probably fewer 580s available than SZ-7 because they were probably 50% more expensive than the Bausch and Lomb model. GIA charged almost an extra thousand dollars for AO equipped Gemolites.
The difference between six to one and seven to one zoom is irrelevant. Most Gemolites in service are three or four to one. You stated that the 569/570 Gemolites were not upgradeable. They are just as upgradeable as Bausch and Lomb equipped Gemolites. And the auxiliary lenses for AO scopes were Apochromatically corrected starting with Cycloptic models. There are also many more illumination accessories for the AO than for the B&L almost all of which were sold as options by GIA.
The 2x auxiliary for the SZ-7 is much more difficult to find than a 580 and when you do find them they are more expensive than AO auxiliaries.
If the issue is "how powerful" then a Wild or Zeiss is called for. That is not what the original question was.
Joined: Sun Oct 29, 2006 11:43 pm Posts: 514 Location: North Carolina
Hi,
The magnification question is really irrelevant. Eyepieces can be 10x, 15x, 20x and 25x, so a 569 can be used from 32x to 80x, and the other models (both AO and B&L) can be used at different magnification levels with the same eyepieces as well.
I can get 120x on my 580, but find it too much for most of what I like to play with.
Question: I bought a bunch of microscopes for my gem and mineral club. One B&L arrived with a rattle and two pieces of the optical path were loose. I opened it up and found out that some parts of the optics are GLUED (!!) on!! I didn't try to fix that and returned it.
I'm quite surprised to find critical optical components glued in place, versus held in place mechanically. Is this common? Glue is subject to aging and vibrations and does not allow for adjusting. Doesn't seem like a good build method.
I'm quite surprised to find critical optical components glued in place, versus held in place mechanically. Is this common? Glue is subject to aging and vibrations and does not allow for adjusting. Doesn't seem like a good build method.
An interesting question.
Of course, G4Lab has much more experience with commercial instruments than I. But I think epoxy is a pretty common feature for optics elements in commercially-produced instruments. If a small shift lateral to the optic axis isn't critical, then almost certainly the element will be glued into place. For example, this thread is describing a common instrument where most the optics is epoxied, and where the old glue caused a problem, and where glue was the solution.
One place you don't see glue, at least with any "name" dealer, is with spherical (or compound) lenses. Not enough surface lateral to the optic axis. These lenses are almost always held in place by a mount with retaining rings. Personally I've invested some change in spanner wrenches to fix or unfix those rings, and so I can tell you that those pieces aren't exactly forgiving of the amateur who isn't so well-equipped.
So the glue only lasts a couple decades? What makes you think that mechanical position would hold longer? Mechanical mounts are subject to the same temperature changes and vibrations as glue, only (through my personal work experience) they react in a much shorter time period. In the work I do, I only use mechanical mounts, and as a result, my stuff needs tweaking every so often. If my setup has been shut down for three months, and I turn it on, something is going to require adjustment. Three months vs. couple of decades? Hands-off vs.adjustment? Glue has won that battle. Just like your car, the more hands-off it is, the better the consumer rating.
And besides, if you can position a designed mechanical system, you can position a designed epoxy system. Mixing an epoxy is trivial, and it only takes a sharp edge to remove sufficient amount of the old glue.
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