23 Aug Opal Photography
Opal photography is a rewarding but also challenging endeavour. Most gems rely on trace elements to give their body a colour and on the cut, to reflect it towards you. Opal works due to a different principle entirely. Its complicated internal structure refracts and reflects incoming white light into an amazing display we call the play of colour or simply, opals’ fire.
When photographing an opal, you must consider many more variables than with other gems. It changes its appearance with a slightest movement of the light, the camera or the stone itself. In addition, you will never be able to capture as much colour on a picture, as you can see with your eyes. It is because our brain allows us to see the opal from two different points in space, at once- our eyes. The camera, on the other hand, has only one lens available to create the image. It has another advantage though. The power of magnification of a camera lens is far beyond what our eyes are capable of. It is a perfect tool to access the microcosm of opal fire.
If you think about opal photography you will need to prepare a setup for it. The first piece of equipment you should secure is the appropriate light source. As photography in general relies on capturing the light, it is arguably the most important part of your gear.
Opal is more demanding than other gems, requiring a good quality light. What I mean by that is a full spectrum light or as close to it as possible. White light is composed of all rainbow colours, or rather different energy wavelengths that we perceive as colours. Essential for opal is the fact that if a certain colour is missing from the mix, you will not see it in your gem. It may not be noticeable if the spectrum is almost full otherwise but certainly will be if you get a cheap bulb that produces the impression of white light by using a couple of selected bands only.
Daylight is generally considered the best, with most wavelengths present and of similar intensity. While making pictures in daylight is possible, it isn’t recommended as the conditions vary with the weather and time of the day. Daylight may also be too bright, cannot be re-positioned and can create a glare. For all of those reasons, it’s better to take your pictures in a controlled environment.
Many of our artificial lights; however, create an impression of white light by using only a few selected colours. This is especially true with modern, energy saving bulbs. How do you choose the good ones then? Luckily we have the Colour Rendering Index (CRI) to help with that. It indicates how good the light source is at reproducing colours, which translates into how full it’s light spectrum is.
Another factor to consider is the colour temperature.
The term indicates the balance between cool-blue tones and warm-red tones. It is independent from the spectrum itself being full or not. It simply indicates which end of the spectrum is stronger. Easy to observe in nature if you compare the evening light to that of the midday. Both are full spectrum but in the evening the red end gets stronger and the light has a different tint.
You should only look at light bulbs with CRI index over 90%.
Preferably with about 4000K to 5000K light temperature. While colour temperature may be offset by the white balance setting on your camera, there’s no escape from a bulb with selective spectrum that will distort colours by default
The best types are incandescent and halogen bulbs. They give a full spectrum light but most tend to be on the warmer colour temperature of about 2700K, which gives them a yellowish tint. There’s also an issue with excess heat they create and the fact they are being phased out in favour of more energy efficient options.
LED’s are becoming the new standard today. They are not all created equal, as their main purpose is saving the energy. Many have CRI around 80 and I would not recommend them for photography. However, there are better models with a rating of 95 or more and you certainly can use those.
Fluorescent bulbs are probably my least favourite option, as their light spectrum is generally poor and may affect opals’ play of colour badly. There are no true full spectrum fluorescent bulbs, even though some are being sold as such.
A very important, thing to remember in opal photography is to use a direct light.
Virtually all pictures of gemstones, jewellery and most other macro shots are made using a diffused light. Direct light is harder to control. It can create too many bright reflections, particularly with reflective surfaces, like a metal. For opal; however, it is virtually a must as diffused light may cause opal fire to look washed out and not sharply defined. I come across this issue quite often, while looking at pictures of opal jewellery. Particularly when the photographer has no previous experience in opal photography.
That is a good news actually, as you will not need a light tent or any other type of diffuser for your setup.
Getting a suitable camera is less of a hassle today than it used to be.
What you should keep in mind, is for it to have an interchangeable lens system. You will need a dedicated macro lens to take good and sharp images. Second thing is to have a manual mode, so you can adjust all the setting to your needs. I use DSLR personally but modern mirrorless cameras are getting better by the day. The important bit here is to familiarise yourself with your camera. Some settings will be in the menu, while others are assigned to various buttons and dials.
Good lens is actually more important than the camera itself.
You will most likely change your camera after a couple of years but a high quality lens may serve you a lifetime. Look for a lens that is capable of 1:1 zoom. That means, the image of an object you photograph, hits the sensor that records it, at its original size. It ensures no detail is being lost at that stage. It is not always necessary to zoom in that close but you will appreciate it when you need it. Also, larger lenses, like 100mm are better than smaller ones (50-60mm). They allow you to zoom in from further afar. It makes working with your lights much easier.
A sturdy tripod is another thing you just won’t do without.
While shooting macro we operate at a minute scale and any shaking will ruin the image. It doesn’t mean you need to spend hundreds on a tripod but you need one that’s stable and easy to adjust.
Last in the equipment section comes the background.
One thing to keep in mind, is to avoid coloured backgrounds, as the light reflected off of them will be tinted and distort the colour accuracy of your pictures. Most gems and jewellery are shot on a white background. It makes the picture look brighter overall and helps gems to look brighter too. In my opinion it is sometimes used to make badly cut gems (not opals), look like they are brighter than they really are. It’s rather unlikely that you will have white, well lit surface behind your gem while wearing it in a piece of jewellery. Your gemstone should return the light due to a properly executed cut, without relying on what’s behind it.
As far as opal is concerned, white background may wash out the play of colour in transparent and translucent stones. That’s what happens when opal gets illuminated from the direction opposite to the viewer. It will make opal look worse than when it is set in a jewel, when there’s usually no light behind the stone. For all of those reasons I prefer black background for my opals. With no reflected, or scattered light to spoil my efforts.
Camera settings and preparations.
Before you start, try to make sure there’s no dust, especially on your opal. Small particles are generally hard to spot while you are taking pictures but you will see them later. You can actually clean up your pictures at a later stage but you will save yourself a lot of time if you get rid of the dust in advance.
In opal photography I recommend setting your camera to the full manual mode. You control the environment and can use all the settings for your benefit.
ISO– Leftover from analogue times when you could buy a film of different sensitivity to match the expected conditions. Higher value of ISO helps with poorly lit scenes but the overall quality gets worse and pictures will eventually get grainy. Set it to 100 or 200. In general, it should be low if lighting is adequate. Definitely avoid auto.
White Balance– It’s there to adjust colour settings to the light conditions to make your shots look neutral in colour. Try to set it up according to your light temperature, you can adjust it afterwards but it’s better to get it right in advance.
Exposure Metering– it’s there to tell you if your shot at current settings will be successful, not too bright or dark. Use spot metering, that will make your camera judge the brightness of the stone you’re aiming at, and not that of the background. In opal photography it is more tricky for your camera to judge this correctly. Luckily it does not matter that much, since you are in a full manual mode and can adjust it by trial and error.
Active D Lighting/Extended Dynamic Range– artificial boosting of the image by your camera. As with other automatic settings, I recommend those to be turned off.
Save File Format– Cameras usually offer a choice between jpg or raw files. Choose raw, as it saves more visual information and allows post processing of all aspects of the picture.
Focus– set to manual as macro photography has an extremely shallow depth of field and auto function doesn’t really perform well.
VR/Image Stabilisation– I recommend to turn it off if you are using a tripod. It is helpful while shooting from hand and works by generating micro vibrations that counter the shaking of your hand.
Exposure Delay Mode– in DSLR, when you press the shutter button, the internal mirror gets raised. Then, a photosensitive sensor gets exposed to the light and a picture is created. This setting allows for a couple seconds of delay between raising the mirror and exposing the sensor. It helps to dissipate any vibrations caused by the movement of the mirror. Especially useful for stationary subjects and macro photography in general. I set it on 2 second delay and don’t have to use timer or a remote. It is enough time for all vibrations to dissipate if you’re also using decent quality tripod.
Now, that all of the above are set, we can proceed with the actual picture taking. You will be using two settings here to ensure the results you intend.
Aperture– adjusts the size of the hole through which the light passes to strike the sensor. Minimum and maximum values here are dependant on the lens. The rule here is that, the lower the f number, the bigger the hole and the less time needed to record the image. That’s called large aperture and is especially useful with all fast moving objects you want to capture sharp or when shooting without a tripod. Why would anyone use smaller aperture then? It’s because large aperture causes a shallow depth of field, which is thickness of a layer that will be recorded sharp on the image.
Depth of field is probably the main issue in macro photography because the greater the zoom the thinner it gets.
To increase the depth of field you can do two things, zoom out or set a smaller aperture. You may start thinking now that with an immobile subject, adequate lighting and a tripod you could set your aperture as small as possible. Unfortunately there’s a catch- when aperture gets too small it causes light interference and in effect the resolution of the image drops. The phenomena known in photography world as lens diffraction. Your subject simply starts to look blurry without any apparent reason. In the end I recommend setting your aperture somewhere in the mid range and never pushing it to the max f values. I will include a link about lens diffraction at the bottom.
Shutter speed– the last thing you adjust before taking a shot. It determines for how long the sensor will be open to the light. The smaller the aperture the longer the exposure must be. It should be extremely short for fast moving objects but with stationary ones you can use it to balance all other settings. As we are also using a stable tripod and have the Exposure Delay Mode switched on, vibrations should be virtually non existent. You can set your exposure to whatever value is necessary to obtain properly exposed pictures.
When you already have all those amazing pictures done, it’s time to transfer them to your computer and prepare for their intended use.
If you used the raw format to save your images it may be impossible to simply view them in any default program. You need to open them in the editing software like Photoshop or Lightroom. That will allow you to adjust white balance, any overblown colours individually, clean the dust particles and more. It’s necessary to do at least some of these steps as photo sensors are not perfect at capturing true colours. Particularly affected are the blue and red parts of the spectrum. You can read about Foveon vs Bayer sensor technology if you want more details. I’ll link to an article about that topic at the bottom.
Virtually all images will have to be cropped.
You will usually have a lot of empty background left around your stone. If that’s the case, it’s a good idea to cut out some of that useless space. You will make your opal bigger in the final frame. Unless you plan to print a huge poster, there will be more than enough resolution left for digital purposes, even if your opal occupied only a minor portion of the frame originally.
At the end of the process, you can choose your desired file type, its size and then export your final image. Some programs, like Photoshop, offer excessive manipulation capabilities, others just overall setting adjustments. It’s important to make the picture look like what you can see with the opal in your hand. Far too often I see the effects of pushing saturation over the limit. Either done automatically by modern cameras, or by hand. It makes colours look overexposed and causes the play of colour to loose sharpness.
In the end I take opal photography as a journey into a fascinating realm of colours and shapes. Mastering your technique only helps you to capture it better and with more detail. Opal definitely has a habit of surprising you, even when you thought you saw it all already…
To read about difference betwen Foveon and Bayer sensors go to https://www.anandtech.com/show/2507/6
The article about lens diffraction https://photographylife.com/what-is-diffraction-in-photography