January 24 Through February 4—TUCSON, ARIZONA: Annual show
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Fri Mar 29, 2024 1:43 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Fun with VO
PostPosted: Thu Feb 23, 2006 2:42 pm 
Offline
Platinum Member

Joined: Tue Nov 29, 2005 2:02 pm
Posts: 2646
Ars mentioned in another thread that he will be taking a Visual Optics class shortly. This inspired me to try and capture an interesting VO image.

Below is an image I managed to capture showing just a tiny portion of a VO landscape. I managed to situate the gem and camera from the penlight so it superimposed itself in the image.


Image


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 23, 2006 5:44 pm 
Offline
Platinum Member

Joined: Tue Nov 29, 2005 2:02 pm
Posts: 2646
OK, here's a question for those of you that have studied Visual Optics Gemology.

Below is a VO image of a color change simulant (Zandrite). If you notice, the line that connects the light source images and outlines the facets is red and green.

I've noticed that usually if the stone is large enough or you can get a close look at these lines, they appear as a full spectrum image, that is although they may be very thin, with a close look you can see all of the spectral colors width wise. Sometimes they just look like white lines.

I checked another color change simulant (alexandrite) and found these lines to be just red and green same as the Zandrite.

I wonder if this could be an indicator of a color change stone. Maybe you can check your stones and see if you get similar results.

Below the Zandrite so you can see what I'm talking about.


Image


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 23, 2006 6:06 pm 
Offline
Platinum Member

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2591
JB, I can't really comment on your question but I would love the see a picture of your setup.

This is a classic example of the VO that is taught by Donald G. Coughlin.
I think Hodgkinson does it a bit different. Anyway works for me.

Can you take more of these images for us?


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 23, 2006 6:34 pm 
Offline
Platinum Member

Joined: Tue Nov 29, 2005 2:02 pm
Posts: 2646
Hi Doos,

My set-up is basicly two shaky hands and a penlight. That's probably why the images are a little blurred. One thing I should note is...because of the nature of the images and the proximity of the stone to the camera lens, I don't really recommend trying to shoot these. I've scratched my lens in the name of science. :cry:

I know Coughlin and Hodgekinson teach different methods neither of which I have studied in any detail. The only reason I attempted shooting any VO images is that I can't find any although I understand Hodgekinson does have a book on this with images.

I'll post a couple more from my old archives. The images that follow may or may not be diagnostic. I just liked them because they were geometrically interesting. I haven't registered with image shack so I think I can only post one image per post.


Image


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 23, 2006 6:38 pm 
Offline
Platinum Member

Joined: Tue Nov 29, 2005 2:02 pm
Posts: 2646
One more.

Image


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 23, 2006 7:01 pm 
Offline
Platinum Member

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2591
This second image would clearly indicate a double refractive stone.

But do you use a third hand etc. Or are these taken with a microscope?


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Feb 23, 2006 7:24 pm 
Offline
Platinum Member

Joined: Tue Nov 29, 2005 2:02 pm
Posts: 2646
I've tried using third hand or other set-ups. What works best for me is the same as if you are doing it in the normal fashion. Usually you hold the gem tableside very close to your eye. This means you need to hold the stone very close to the lens of the camera with tweezers if it's a smaller stone.
Just as you would use your peripheal vision to see the outer regions of the image you must turn the stone and camera away from the light source to see the peripheal images. It's a ballet of hand coordination with the stone, the camera and the light source. One little move to far and you lose the image you want to shoot.

In general it's a pain in the a** for this sort of set-up with piles of camera batteries used to get a few decent shots. (you have to leave the camera on a long time while your manipulating the stone, camera and light source.)

If you're a novice like myself expect 1 decent image for every 25 or thirty shots.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Mar 05, 2006 5:08 am 
Offline
Gemology Online Veteran
User avatar

Joined: Sun Dec 11, 2005 2:33 am
Posts: 524
Location: East Coast
Visual Optics

Greetings One & All

I just attended two (2) seminars by Alan Hodgkinson, FGA
On Friday night March 3rd and Saturday morning March 4, 2006
at CIJT (California Institute of Jewelry Training)

I can’t begin to tell you all how much fun I had and how much I learned!!
TOTALLY AWESOME!!!!!!!!!!!!

All I can say is that every single gemologist owes it to himself or herself to take a VO seminar and if at all possible take it from Alan Hodgkinson himself!!!!!!!!!

It is kind of funny and strange because I learned this technique way back in 1980 just before I graduated from my first gemology course in Paris, TX.

Then this weekend it all came back in a full circle for me!!!

Alan Hodgkinson developed and pioneered this technique way back in the 70’s and an article was wrote about this very technique by Dr. Bill Hanneman in Lapidary Journal in 1978.

Only now has it really caught on and has really come to full fruition.

I lucked out and soloed under a lucky star because I got to spend almost 4 hours of quality personal one on one time chatting with Alan and his wife Charlotte during the time I was there at CIJT. I wish all of you could have been there to experience it!!!!!
Totally out of this world!!!!!

The best part of the whole experience is that I was amazed at Mr. Hodgkinson’s almost child-like wonderment, excitement and youthful curiosity that still fills him even to this day even though he has been an FGA since 1957!!!!!!

He will be publishing his book on Visual Optics very soon and all I can say is that I’m eagerly awaiting it so that I can burn the midnight oil to read it cover to cover.

I’m also going to be ordering the Hodgkinson/Hanneman Refractometer that is so simple and yet it does so much!!!!! And get this!!!!! It is like $79.00!!!!!!!!!!!!!!!!!! Yes you heard right, $79.00!!!!! and you can even take the RI of a diamond or CZ!!!! No moving parts, no smelly liquids. Totally unbelievable when you see what it is it will freak you out!!! LOL

To tell you the truth when I first saw it. It instantly reminded me of something the Professor on Gillian’s Island would build!!!!! LOL LOL

I too am going to be setting up my camera to play with and capture some Visual Optics and share them with you.

Oh I should also say that his book will have these pictures and will also include over 400 actual color spectrums!!!!!!

After spending 10 minutes with Mr. Hodgkinson showing us how to use a spectroscope going after and getting a spectrum, is a snap now!!!!

Talk about charging me up again. These two seminars were worth their weight in GOLD!!!

I’ll have more to say later on about this very interesting topic and subject.

Later

Take Care and Have Fun

_________________
High Sierra Gem Lab
La Shawn Bauer, G, G, GG, ASG/AGA, CGL/AGA, CGL/IJO, CDG/IJO, RMV, CM/NAJA



Coming Soon:

Bauer Gemological Products

From Simple Minds, comes Simple Answers & Even Simpler Solutions


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Mar 05, 2006 11:47 am 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 21602
Location: San Francisco
I couldn't agree with you more LaShawn!
I had the pleasure of presenting Alan Hodgkinson in my home for his VO Seminar a couple days before CIJT. It was a sold-out crowd. I've never had so many people over for dinner. He set up the Hodkidson-Hanneman Spectroscopes on my dining room table, and we had the slide presentation in the sitting room. I set up tables with 8" candles for the Visual Optics Hands On Training. (I prefer using candles to penlights myself).
Spending a few hours with Alan Hodgkinson is a magical experience. He patiently tutors us all to master his gemological wizardry based on his keen understanding of the optics of light and the biology of the human eye.
His enthusiasm is beyond contagious.

In a nutshell, here are a couple of VO links (Perhaps they have been posted before):
http://www.bovagems.com/eclectic/HTML/1 ... IDENT.html
http://www.cigem.ca/411.html


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Mar 05, 2006 5:20 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 3:36 pm
Posts: 192
Location: San Francisco
LaShawn;

I had the same experience here. We had a very small class for VO: 6 and it was worth every penny. We did hear about his new book and he had a few half-page ads but he said it is delayed. At first he thought it might be out in april, but now he thinks August-September might be more realistic.

He said the book will be advertised on http://www.scotgem.demon.co.uk when it is nearing completion or you could email him directly.

He also mentioned something about using the new low energy bulbs to easily read dispersion from his refractometer. Did he go into detail on that in your session?


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Mar 05, 2006 7:07 pm 
Offline
Gemology Online Veteran
User avatar

Joined: Sun Dec 11, 2005 2:33 am
Posts: 524
Location: East Coast
Greets ARS and All the Others

Yes he did as it actually served two (2) purposes.

#1 It served as a known scale so you can learn to draw your transmission and absorption lines as they have known qualities.

#2. It served as a quick scale so you could draw your lines to do the mathematical figures to calculate dispersion and also RI using his Refractometer/spectrometer setup.

Correct me if I’m wrong.

And we had only 7 in our class so it was small too like your class and he spent time with everyone to get them to grasp what he was showing and teaching.

All I can say was that hands-on workshop was a real blast!!!! It was cool because we had a real mix of people in our class. I was the only GG there and the others were working on their FGA Foundation and FGA Diploma courses.

Like I said before it was totally awesome!!!!

Later

OH!!!!!!

Yeah the book is delayed, as his grown up daughter wants to do the formatting and add things to the book so it isn’t all boring and dry LOL. It is a special project his daughter wants to do with her dad so yeah it looks like August or September when the book will be out.


Later

_________________
High Sierra Gem Lab
La Shawn Bauer, G, G, GG, ASG/AGA, CGL/AGA, CGL/IJO, CDG/IJO, RMV, CM/NAJA



Coming Soon:

Bauer Gemological Products

From Simple Minds, comes Simple Answers & Even Simpler Solutions


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Mar 06, 2006 12:04 pm 
Offline
Platinum Member

Joined: Tue Nov 29, 2005 2:02 pm
Posts: 2646
Here's a new one on me. A VO tool you can use with the spectroscope as well.

http://www.illumigem.com/what_is_illumi.htm


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Tue Mar 07, 2006 5:45 pm 
Offline
Gemology Online Royal Princess

Joined: Mon Oct 17, 2005 10:56 am
Posts: 6461
Location: The frozen north prairie :-/
Let us know how it works after you try it, JB!!


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Tue Mar 07, 2006 6:17 pm 
Offline
Platinum Member

Joined: Tue Nov 29, 2005 2:02 pm
Posts: 2646
Hey MoDo,

The funny thing is, I contemplated making up such a device when I first started using the spectroscope. That idea got lost when I found other alternatives. Glad to see somebody followed up on it.

Of course at the time, I had never heard of VO so I was thinking strictly spectroscope. Turns out it may serve a few purposes.

Anyway, I think I'll read Hodgkinson's book on VO first before investing. I find it extremely helpful knowing exactly what it is you're looking at. :lol:


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Fri Mar 10, 2006 11:28 pm 
Offline
Gold Member
User avatar

Joined: Mon Oct 17, 2005 2:14 pm
Posts: 1185
Location: Ozark Mountains, Arkansas
JB wrote:
Here's a new one on me. A VO tool you can use with the spectroscope as well.

http://www.illumigem.com/what_is_illumi.htm


This thing is intriguing. The spectroscope gives me fits so often I emailed to find out more. The owner, Noela, is very helpful, and this is part of the reply:

"If you are using a hand held SPECTROSCOPE the IllumiGem will come in very handy. The IllumiGem is about giving controlled light eliminating interfering light ( especially while in the field where this can be hard to achieve). When using the SPECTROSCOPE and IllumiGem together, the gemstone is placed on one of the washers supplies with a hole (biggest possible hole size for that stone). The washer and stone are placed on top of MagLite (cap removed) with the pavillion of the stone pointing down towards the light. The IllumiGem body is screwed onto the MagLite. The cap is left off the IllumiGem body as well. When you turn the MagLite on you will now only have transmitted light from the gemstone coming up through the IllumiGem body. Insert the hand held SPECTROSCOPE half way down the IllumiGem body. With only transmitted light from the gemstone and all other interfering light sources screened by the IllumiGem body, you will get a good reliable spectrum picture."

Has anyone used this with a spectroscope? If so, how did it do, and what do you think of it?
:?:

_________________
Crystal :smt086

Quantum Mechanics...the dreams stuff is made of. :smt047


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 12 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock