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Tel: 07900 802453   Email: stuart@opulentopals.co.uk  

Our earth glows like an opal against the jet black sky of our wondrous galaxy   

How To Photograph Opal

I have worked in the photographic industry for many years before getting into gemology, with years of experience of lighting I thought photographing opal would be straight forward, how wrong was I.

Opal photography is not easy there is a lot of planning, setting up and some luck.  To get the best results from your Opals you need to watch how the opal reacts to the light source you are using.  The strength of light and the Kelvin temperature of the light you are using will be key to get the best results from your camera.

The first thing to state is natural sunlight is the best quality of light to photograph opal in as this the light opal should be viewed in to enjoy the true beauty of opal, naturally no one has the luxury of perfect sunlight on tap 24 hours of the day to photograph their opal when you need to fit it in to a day’s work.  As normal when you want to get your photos done the sun is nowhere to been seen or she is so bright and strong it’s not the right light to use.  The introduction of digital cameras has made the job a lot easier as now we can balance the camera to the light source we are using so you can get the best results from most light sources.  However some light sources are still best for the job and must be played with to get your system down to suit your opals.

I have played with most light sources and have some great results and some very bad results to my surprise.  The first area is strength of light, some people think if you photograph in lower light and force the opals colour out with a computer programme you will get the best results as the low light will not burn out the colours with reflections, especially with white opal, this is false, a good strong light as you get in daylight will yield the best results as this brings the colour alive.  Opals need light to live.

The left image below has be exposed under 500 watts of light and the right hand side has been exposed under 60 watts, notice the washed out look of the lower watt photograph.  As opal is a day light stone you need to create a strong light source to photograph in so the full colours come out.

The example stone is from Mintabie, 13.6 carats Crystal Opal

The second is colour temperature, this is the Kelvin level of the light source you are using.  I will explain a little on this because if you are using a digital camera you can set the camera to the level of the temperature your light source emits.  This procedure allows the camera to convert the white balance to the correct level so your photos do not end up with a colour haze that is not correct to your subject.

I use a tungsten high watt studio light unit which can throw out 1000 watts at a colour temperature of 3000 Kelvin.  I find this the best light source second to natural light but hence being in the UK I do not have a good supply of the stuff so the studio light with a Professional camera has made the photography side a lot easier.  3000 Kelvin is close to the conditions I would look for if I was photographing in sunlight, just after early morning sun is best so around 4/5000 Kelvin.

I chose to invest in a professional Digital SLR with a 100mm macro lens but you do not need to go this far if you don’t want to spend the money.  Some good priced digital compact cameras have the feature of my SLR and have great macro functions.  So you ask why I bought the professional unit instead well the professional unit gives me the functions and the quality I insist on when photographing for sale and cataloguing, with inter changeable lenses I also get to fine tune my composition which most people will not even notice.  For general photographs any choice is good just test the camera before you buy to see if it suits.

Your next investment should be a good tripod, strong, sturdy and versatile is essential as you will need to get close in and normally over a workbench where your opal is set up.  You will also need to get the right angle as not to get in the light sources way.   I use a Benbo Trekker Tripod, I have used one for years for close up work and it is great indoors and outdoors as it can be put in nearly any angle and has great strength.

Look at your background next, you will have to play with this to suit your opals or the results you wish to get.  I use a black slate background as it gives off nearly no reflections so I can control the exposure of the opal itself not any light leakage from the surrounding area, also it has a nice texture to it for some detail.  People think this can be to dark for some opal but I have had no problems photographing any type of opal with this background, the main concern is for black opal from my tests it helps improve the final results as the camera concentrates on the opals fire and nothing else.  Again, play with different backgrounds to suit your needs.

When selecting the exposure for your photograph don’t just select auto, you need to play with the aperture setting of the camera to get the right amount of light in rather than the length of the exposure.  This might not sound right, are they not the same?  What you are trying to achieve is getting the wavelengths of light carrying the opal colours into the camera without restricting them with say a small aperture which cuts out the spread of wavelengths or too wide so you get to much surrounding light in.  I find around 2-3 stops higher than the lowest setting for your camera will work best.  The length of the exposure time is not an issue apart from if you get into camera shake.  Now you should not have camera shake if you have a good tripod and a good strong source of light.  Last thing to do when setting the camera for the photograph is to tell it what Kelvin temperature your light source is, I set my camera to 3000 Kelvin Tungsten.

An important point to make when setting up your shot is the angle which you photograph your opal, when viewing opal in the hand the opals fire will change from all angles, stronger in some weaker in others green one moment then blue.  So what is the best angle well if you know how to grade an opal you will know certain opals will only perform well as one type of jewellery, will it look good from the top for a ring or set vertical for a pendant? This is important to know as it will help you get the best shot from your opal as you will need to adjust the angle slightly depending which category it falls into.  So make sure you photograph your main shot from the best angle then of course from 3-6 different angles as an opal should be played with when viewed, if you are like me I play with the opal in hand so I can see every angle and appreciate the opal for it’s full beauty.

The example stone is from Opal Ridge, 29.4 carat Grey N5 Base

With all the above done and the final shots on the camera, it’s time to get them on the computer to print.  You may be tempted to alter the photographs through an image processing programme well don’t, if you practice with your set up you will not have to change the saturation, colour balance etc.  If there is one thing that I would except in any adjustments on the computer would be brightness and contrast.  Adjusting these two levels you can correct some of the hazes you get and of cause any over or under exposures,  these don’t falsify the colours and mislead any future customer.  There are ways now to tell if an image has been adjusted by checking the photos digital make up so don’t think you will get away with it.   The two images below are an example of this the left hand side one is correct to the opal the second is only adjusted by a couple of percent in Photoshop, this makes a huge difference and is misleading.  The main thing to look for is the aluminous colours that seem to float above the stone and of course looks too good to be true. 

The example stone is from Opal Ridge Semi-Black, 11 carats and is 4.8 out of 5 for brightness

The last thing to do is enjoy the results, send them out to friends and get some feedback.  Feedback is essential as these people could be your customers so what you may think is good may not work well for the general public who may not really understand what they are looking at.

Stuart Wheeler

www.opulentopals.co.uk

stuart@opulentopals.co.uk

Treating Andamooka Colour Matrix

Non Acid Andamooka Treatment By David Sahadi and Stuart Wheeler

This is a loose description of my experience of the treating process of Andamooka matrix. Now there are different types of Andamooka matrix.  The process included here is intended for opalised sandstone sometimes referred to concrete by the Australians. During the opalisation process, opal material seeped to crevices or openings in the host stone. Large areas, or seams, would be where you would today find solid opal. As this material seeped though the porous sandstone to these seams, the small cup like structures of the sandstone would retain some of the opal material. While not true opal, the opalised sandstone structure retains enough opal to be extremely colourful.


The Steps

The host sandstone is white to off-white as it comes out of the ground.  It is also very porous. It requires two major steps to bring it to a state where it realizes its potential as a great looking opalised stone. The first step is to darken the host stone. Step two: As the sandstone is very porous it will not take a polish. By using a two part sealer before you do you final sanding and polishing of your cut stone you can have a finished gem stone that will rival a black opal costing literally thousands of dollars. As for some peoples disdain of  treated opal, let me remind you that Tanzanite is treated to get a rich blue red colour as are yellow and blue diamond’s to deepen their colour.

Step 1: Colourising The Host Stone

This is the darkening process. You will need the following:
1) A medium size oven safe bowl, about the size of a large cereal bowl
2) About 1/2 pound of sugar
3) Your Oven
4) A pair of Tweezers
5) Acetone (You can substitute denatured alcohol)
6) Water

Most all the Colour Matrix I sell has been treated at least once already with this process. This is to you show where the colour is when you buy the stone. It is not as dark as it can get. You will want to cut the stone to its intended shape. Stop before you do your final sanding, before you start polishing. Now we can darken up the host stone. Note: 
the opal in the sandstone is unaffected by this process.

Preforms cut down to 3000 grit.

1) Set the cut stone(s) in a small bowl just covered with acetone (make sure you do this is a glass dish of some kind. The acetone can melt some types plastic). This cleans the stone and removes any oil left by your fingers. Remove the stone from the acetone with the tweezers.  Allow to thoroughly dry.

2) Pre heat your oven to warm, but in any case less then 200°F. We do not want to boil the stone in the solution you are about to prepare. While your stone(s) are drying you can prepare the sugar solution. Heat an appropriate amount of water (just enough to 3/4 fill the oven - safe bowl you are going to use) to a boil and then turn down the heat. Start adding sugar to the water, stirring as you go. You will stop adding sugar every so often to allow the sugar to devolve. Do not stop stirring. You will know when you have enough sugar in the water when you can no longer add any more sugar to the solution and have it dissolve. You will be surprised just how much sugar you can add to the water to reach this state. You have created a super saturated sugar solution, much the same way Kayo syrup is made. Fill your oven safe bowl about 1/2 to 3/4 with the sugar solution.

3) Put the dried stones in the sugar solution and put that bowl in the oven. Let cook for 3 to 4 hours. Check to make sure the solution is not boiling. If the solution appears to get too thick during the cooking you may add a little water. You do not want the solution to harden up.

4) IMPORTANT STEP! After about four hours turn the oven off and let the stones cool overnight, at least 4 hours. This forces the sugar into the stone.

5)  Remove the stones from the solution using the tweezers and place on a paper towel. Wipe excess sugar solution from the stone. DO NOT RINSE THE STONES OFF.

6) Using your tweezers place the stone on the sugared stones on a metal cookie sheet and pop them into the oven. Turn the oven on to the highest temperature possible. Allow to cook again, this time for about 1 1/2 hours. Turn the oven off and let cool (cool enough to be handled by your delicate fingers).

7) The stone will be black. Using a soft scrubbing brush clean the surface of the stone. Then lightly sand the surface of the stone careful not to reshape the stone, just enough to remove the carbonized sugar.

8) Complete your pre-polish sanding.


Step Two: Prepare to Polish


This is an easy step for me to describe, a little more difficult for you to do but trust me it is worth it. What you will need

1) A two part sealer.  I use Opticon (manufactured by Hughes and available at any Lapidary Supply store). All the directions I give will be based on this material.

2) I use disposable aluminium cup cake cooking sheets available at the grocery store. I cut out the individual cup cake tins and use them to mix the two part sealer.

3) Those tweezers we have been using.

Using the Opticon is a three step process. (Until the stones are finish the curing process it is best to use the tweezers to handle the stones. This keeps your body oil from interfering with the process)

1) The pre-soak.  Using one of the aluminium cups, pre-soak the stones in the Opticon resin per directions on the Opticon box. (Yes, the unused resin can be returned to the bottle)

2) Remove and wipe the stones off with a paper towel.

3) Mix resin with hardener per instructions. Use the 1 to 8 ratio.

4) Indent an aluminium cup and place the stone in the indentation. Cover the stone with the mixed Opticon. Let the stone and Opticon cure for at least 48 hours. Now the Opticon will appear to cloud up or sometimes you will see small bubbles form during the curing process. This is not unusual and will not affect the finished product.

5) The curing process is complete when the surface is no longer tacky.  Carefully trim off the excess Opticon. Using a 320 grit or better sand paper, sand to the surface of the stone. Complete your pre-polish sanding and polishing process.

Finished stones showing the colour change after treatment.