[meteorite-list] [Fwd: Re: USB 2.0 mp Digital Camera]

From: Starsinthedirt at aol.com <Starsinthedirt_at_meteoritecentral.com>
Date: Tue, 6 Jul 2010 21:17:34 EDT
Message-ID: <66311.4ffe7804.39652fae_at_aol.com>

Hi Mike and List, Thanks for the generous compliment Mike!

I am often asked about the best microscope to buy. I wrote a MT article
called "The Right Microscope For You"
http://www.meteorite-times.com/Back_Links/2008/may/Micro_Visions.htm

The key is to decide what you want to accomplish before any microscope
selection. These USB microscopes with Xpol features are not bad. Any
incident (reflected) light microscope will not give the intense color of
transmitted (pass through) cross polarized light. These USB Xpol set ups are cheap
and they do a good job of what they are designed to do.

Some of my favorite images are reflected light chondrule shots. Largely
true color. The NWA 6075 Lodranite images on my gallery show just how
interesting reflected light can be. Please take a look.
http://www.meteorite.com/meteorite-gallery/articles/nwa-6075/

These images are taken in the same principle as the USB microscopes.

If you want a low cost color producing thin section machine you can still
use the simple USB microscope but the USB microscope lighting must be
turned off and you will need to set up a polarizing fixture. I like a fiber
optic light panel with two large camera linear polarizing filters. I bought
several huge polarizers on eBay for less than $10 each. You will need two.
Simply place the thin section between the filters and use a bright light
source of your choice. The USB microscope can then be used to magnify the
cross polarized light colors.

Over the past few years I have picked up a few old polarimeters. The kind
used for thin film study or strain gauge set ups like those from
Strainoptics. These make for nice full thin section viewing and are often equipped
with retardation plates which will intensify the colors.

For high magnification however, there is no substitute for quality optics
and that is seldom cheap.

Tom Phillips

In a message dated 7/6/2010 6:28:16 P.M. Mountain Daylight Time,
mlblood at cox.net writes:
Hi Bob & all,
Unfortunately, Jim Tobin quit making the MBC-10
And the universal adaptors for Xpolarized lighting. Those
Who got one are most fortunate, as I treasure mine, for
Sure.
You can always get one of those $15K polarized microscopes
Or Jerry-rig a set up yourself - however, beware that
The vast majority of polarized filters for cameras are
Now CIRCULAR and cannot be used. (You must have
Two linear polarized filters - one of which can rotate for
The maximum effect.
At one time, I had a substantial array of TS s for sale,
But trash flooded the market from other sources and I
Stopped having TS s made, though I still offer some of the
Better ones as well as some of the Rarer ones left over from
the old days.
However, since Anne Black is currently the leading seller of
Meteorite thin sections in the world (she also has all of
ET's world class collection for sale) perhaps she would
Be willing to contribute information on the best, the cheapest
Set ups for viewing and for photography.
However, No one should hope to replicate cheaply the
following:

the astonishing work of Tom Phillips:

http://www.meteorite.com/meteorite-gallery/

or of John Kashuba:

http://www.meteorite-times.com/Back_Links/2010/june/Micro_Visions.htm

(both brought to us by METEORITE TIMES)

Or the work of Bob Walker's friends he generously shares
(note - Bob changes these photos from one fall/find to another
Without notice - his current selection is low in color, but past
Postings of Mossgiel, NWA 1955 & Cole Creek were all FABULOUS):

http://www.qmig.net/thin-slides.htm

Perhaps Tom or John would be willing to write an article
For us in METEORITE TIMES on how to most economically
Produce high quality Thin Section viewing and photos for ourselves???
RSVP anyone?
Warm regards, Michael Blood




On 7/6/10 4:40 PM, "Met. Bob Walker (Oz Dog)"
<qwalkra at mailbox.ezadsl.net.au> wrote:

> ---------------------------- Original Message
----------------------------
> Subject: Re: [meteorite-list] USB 2.0 mp Digital Camera
> From: "Bob WALKER" <qwalkra at mailbox.ezadsl.net.au>
> Date: Wed, July 7, 2010 9:02 am
> To: cynapse at charter.net
> Cc: meteorite-list at meteoritecentral.com
>
--------------------------------------------------------------------------
>
> Darren
>
> I fear you have confirmed what others and I may have thought...
>
> The ebay sale of the 1.3 mp camera infers a digital polarized microscope
-
> however this appears to be a polarize fuction to reduce ambient glare
> rather than true xpol light as your photos tend to confirm ?
>
> I worry just how many buyers have been misled if not gypped by this
> seemingly misleading sales title
>
> Most listoids would agree that whilst it is wonderful to view
> thin-sections in plane polarised light... the outcome we ultimately seek
> is to see the vivid colours and patterns we so much enjoy that are only
> viewable under true cross polarized light
>
> Perhaps we should address this discussion to other listoids who may be
> able to suggest the most cost effective solution to take pictures under
> true xpol light but I fear there is no quick and easy elegant and
> inexpensive solution ???
>
> I do have a vague memory that Michael Blood had a cost-effective solution
> for sale but then again my memory can betray me
>
> Best
> Bob WALKER
> http://www.qmig.net
>
>
>
>
>> On Tue, 6 Jul 2010 14:46:02 -0700, you wrote:
>>
>>> I've been thinking of getting one of these for a while. Has anybody
used
>>> this for taking pics of micros and larger slices of meteorites? Is the
>>> cheaper 1.3 mp a better deal?
>>>
>>
>> I have a 1.3 megapixel version, with only 4 LED lights (paid more than
the
>> price
>> for the one you linked.) There was a thread about it on the list at
the
>> time.
>> I put up some photos taken with it here:
>>
>> http://www.angelfire.com/d20/darren_garrison/index.htm
>>
>> (Photos tweaked in software in post.)
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Received on Tue 06 Jul 2010 09:17:34 PM PDT