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New microscope! AO Stereostar 570

Posted: Fri Nov 08, 2019 4:56 am
by jb89
I've been looking for a stereo scope for a few months and just managed to snag this for about $100 shipped

The optics look fantastic, the light is not great but it definitely gets the job done. It came with a 1.5x aux lens which I hadn't even noticed in the original pictures, eventually I would like to get the 0.5x and 2.0x aux lenses but no rush on those.

Re: New microscope! AO Stereostar 570

Posted: Fri Nov 08, 2019 5:07 am
by Scarodactyl
Nice find! The 570 is a beautiful scope and it works great.
That 1.5x aux is a bit rare, so that's a good bonus. I have a 0.5x on hand at the moment, but your current stand will not work with it iirc. At the very highest extension the glass stage will almost be in focus.

Re: New microscope! AO Stereostar 570

Posted: Fri Nov 08, 2019 7:38 am
by Hobbyst46
A very enjoyable stereoscope, the AO 570. Does yours have dual light sources or just the top one ?

Re: New microscope! AO Stereostar 570

Posted: Fri Nov 08, 2019 4:40 pm
by PeteM
Nice scope. Just FIY, you can adapt these to bright LED flashlights instead of the old tungsten illuminator and power supply. Cheap, bright, portable. Brings 'em into the 21st century.

Re: New microscope! AO Stereostar 570

Posted: Fri Nov 08, 2019 5:08 pm
by jb89
Scarodactyl -- Ahh gotcha, most of my samples will be pretty large height wise so if it's already close to my max height adjustment it almost certainly wouldn't be practical for me, is that just the specific one you have or is that all of the 0.5x aux lenses?

Hobbyst46 -- It's just one light source but it can be swapped between top or bottom illumination in a matter of seconds

PeteM -- I'll have to check that out! My biggest complaint with the light is that its got a very noticeable yellow tone to it but it still doesn't bother me much

Re: New microscope! AO Stereostar 570

Posted: Mon Nov 11, 2019 2:02 am
by einman
Any 0.5 Aux objective extends the working distance significantly making boom stands more desirable over stands such as the one you are using.

Re: New microscope! AO Stereostar 570

Posted: Mon Nov 11, 2019 2:19 am
by einman
Very nice scope though. I enjoy them! The stand you have allows for dark field as well.

Re: New microscope! AO Stereostar 570

Posted: Mon Nov 11, 2019 3:22 pm
by apochronaut
The convenience of one of AO's original illuminators should not be diminished. They fit snugly into their intended ports and are easy to use under the stage with the transillumination base for transmitted illumination and DF.They can be moved into almost an infinite number of positions in order to gain the correct lighting angle and the nose of the lens system is small, so they can be fitted into tight situations. They provide a focused beam. They are actually, quite a neat system. Using the basic physical design and improving their illumination characteristics seems preferable to the boyscout approach.

If you unscrew the two screws that fasten the lens section from the base, you can slip out the reflector and install a light blue filter over the collecting lens. Any size from 25mm to 35mm will do, because the filter rests in a little relief created by the sides of the reflector. Small filters may rattle a little but they cannot fall out of place. This solves the colour temperature problem of the tungsten filament .
AO made a dual transformer for those lamps, being fully aware that the standard 18 watt bulb was a little dim, yet serviceable for classroom situations where lower magnifications might be implicated. More professional set ups used two illuminators, which can be driven from the one model K 1991 transformer or two single transformers. The K 1991 transformer has dual on offs and dual variable intensity settings for critical cross illumination adjustment. I have one and even with the 18 watt tungsten bulbs it is a joy to use.
In lieu of having a dual transformer, an option is to use the one illuminator in it's overhead port and another of the type fitted to a scissors adjustment on the transformer; a so-called nicholas illuminator. In this way , one can illuminate with varying degrees of shadowing, in various directions simply by moving the second illuminator around and slight reorientation of the sample. If one wants almost completely shadowless lighting, that can be accomplished too.
Tungsten illuminators work quite well when used by a qualified user and when properly set up.

AO had three of those basic external illuminators with the ability to articulate into desirable positions for stereoscopic microscopy. They also had several flexible halogen/fiber optic units and fluorescent ring illuminators. I also like the halogen fiber optic system but not the fluorescent ring illuminators.
I have retrofitted a couple of the external tungsten illuminators to led with varying degrees of satisfaction. Firstly led illumination alone, does not give the best results. Tungsten or Halogen plus led I found to be best, so two illuminators are needed. Secondly, the tungsten bulbs used in the three Nicholas type illuminators are all different. The older Cyclospot uses a GE 1497, the starlight( like the one you have jb89) uses a GE 1460 and the Universal uses a GE 1493. The former two a dual pin bulb and the latter uses a single pin bulb with a grounded base.

The GE 1493 used in the Universal can be directly replaced with one of these https://www.ebay.com/itm/2pcs-set-6V-24 ... SwtYRdwTzW. The lamp is cooler but the intensity a little less. It is also a very stark brilliant white with a slight blue cast. It works well, when coupled to a halogen or tungsten aux. lamp as well. I have used it in an older self illuminated DF condenser, which originally had a 14 watt tungsten lamp and it works pretty good there.

The other two bulbs have a ground pin and a line pin. The only real difference between them , is that the Cyclospot has a two pin push and turn car type bulb and the other has a locking ring type bulb. Otherwise the actual bulb is the same; a 17.88 watt with a short tight focused tungsten filament.In order to "upgrade" one of these to led, a two pin option needs to be found and in the case of the # 1460, the locking ring needs to be desoldered from a dead bulb and soldered to the base of a replacement....if one can be found.
A possible option for an led replacement for the 1460 bulb I have found is an led 6v. motorcycle headlamp. With this type of lamp the base is the ground , and each pin is the line for the high or low beam. I have one enroute, which I hope to be able to disassemble and rewire so both the high and low go to one pin and the ground is removed from the base to the other pin. There is even a version with a metal flange that conceivably could used to replace the locking flange on the 1460 bulb. We'll see how it goes. Not sure what wattage equivalent these will be but I would think around 35 and the housing of the illuminator may also turn out to lack enough ventilation to prevent the electronics of the bulb from overheating. There is the aluminum reflector, which might work as enough of a heat sink.
https://www.ebay.com/itm/1-x-P36D-Motor ... Sw3F5dw~G9

Re: New microscope! AO Stereostar 570

Posted: Mon Nov 11, 2019 11:11 pm
by jb89
Scarodactyl wrote:
Fri Nov 08, 2019 5:07 am
Nice find! The 570 is a beautiful scope and it works great.
That 1.5x aux is a bit rare, so that's a good bonus. I have a 0.5x on hand at the moment, but your current stand will not work with it iirc. At the very highest extension the glass stage will almost be in focus.
The accessories list/manual says that the #575 Aux lens works with this stand, it has a working distance of 5.7" and the stand maxes out a little over 6.5" so I think it may work.
einman wrote:
Mon Nov 11, 2019 2:19 am
Very nice scope though. I enjoy them! The stand you have allows for dark field as well.
-- I'd love to figure that out but haven't seen anything about it in the manual, do you have any more information on it?
apochronaut wrote:
Mon Nov 11, 2019 3:22 pm
The convenience of one of AO's original illuminators should not be diminished...
I absolutely love how easy it is to move and switch around, my brother does electronics design and I asked if he could come up with a more modern version, I'll have to show him your post and see if it helps him out