In a previous post, I illustrated how to make with some low-cost materials a black mirror backdrop for your glossy silver jewellery product photos. Today I’m going to discuss camera gear – to be specific, I’m comparing different approaches for macro photography of silver jewellery or any other object your are interested in. But let’s start from the beginning.
What is macro photography?
According to Wikipedia, macro photography is “extreme close-up photography, usually of very small subjects, in which the size of the subject in the photograph is greater than life size”. In simpler terms, in a macro photo a very small subject (or a part of it) fills the frame of the photo. Filling the frame, i.e the camera sensor, with a standard lens is easily possible for large subjects, for example if you make a portrait. However, for small subjects (5 cm and smaller), the minimum focus distance of the lens won’t allow you to close-up to fill the frame and focus on the subject at the same time. Have a look at this excellent article that explains magnification in macro photography with illustrative examples.
Why do I need macro photography for my jewellery photos?
Honestly, you don’t. You can likely use a standard lens (e.g. a 50mm with a minimum focus distance of 45cm) and produce good product photos that will work for your web shop. The sensor on your digital camera is capturing so much detail that you can crop your image and still have acceptable quality. All photos in this post are unprocessed (except RAW to jpeg conversion) and I did no cleanup of dust particles; this will be a topic for a later post.
The image above illustrates that cropping can produce acceptable results. However, image quality is not top notch, i.e. sharpness and contrast may be not as high as you would like to. If you want your shop visitors to zoom in on your jewellery, they are likely to see compression artefacts and pixels.
What approaches do exist to shot a macro photo?
When I started out to investigate macro photography, I was surprised that there are actually different technical means to shot a macro photo. In this post, I’ll cover four of them:
- Macro zoom lenses
- Macro prime lenses
- Extension tubes
- Reverse rings
I’m going to compare image quality of the produced photos by looking at the original, 100% and 200% crops. Furthermore, I’ll discuss ease of use and cost of the four methods. I’m not going to cover depth of field, focusing, lighting and image composition which are also very important aspects. You can find very useful material simply by asking your favourite search about macro photography.
All lenses were mounted on a Sony A6000, when necessary with the corresponding adapter. This means that no auto-focus was available, which is not an issue due to the focus peaking feature of the camera. Furthermore, the object of interest is not going to move, so you have plenty of time to get the focus right. Let’s get started with the comparison!
Macro zoom lenses
A macro zoom lens is a lens with a variable focal length that has in addition some limited macro capabilities. With limited I mean that the magnification is minimal and rather a marketing twist than an actual feature of the lens. I’ve used the Minolta AF Zoom 35-70mm which I bought on Tradera for ~300 SEK. The lens has a maximum magnification of 0.25 which means that an object that is 10 cm high will make a projection of 2.5 cm on the camera sensor. If you have a full-frame camera, the sensor has dimensions of 36x24mm. Therefore, this 10cm object will fill the frame (top to bottom) . The silver earring in the photo below has a diameter of 1 cm. Hence, filling the frame with this object and lens is impossible.
Macro prime lenses
A macro prime lens is a lens with a fixed focal length and has excellent macro capabilities. In general, prime lenses can produce superior images to zoom lenses as their construction and design is more simple and can be optimized for a particular focal length. Typical focal lengths for macro lenses are 30, 50 and 100mm. The question is then, what focal length should one choose for product photography? In my opinion, focal length should not be a major selection factor here. The reason is simple: the objects you are interested in are not going to be scared and move away because you are close to them. If you want to use the lens to make also macro shots of insects, a 100mm lens allows you to keep some distance. The small advantage I see for longer focal lengths in product photography is that there is more room to handle and rearrange the product without having the lens in your way.
I’ve used the Soligor AF Macro 100mm with a matched macro adaptor (1:1), also known as the “plastic fantastic” (the lens has legendary poor build quality but has nice glass). Without macro adaptor, which is a magnification lens you screw on the front filter, the lens has a magnification of 0.5. Comparing the macro zoom lens (0.25 magnification) above and the macro prime lens (1.0 magnification) below, you can see the advantage: no need to crop to get a more or less frame-filling product image of an object with 1cm in diameter.
Now we come to some more obscure ways to shoot macro photos. Extension tubes go between your camera body and your lens. What they do is simple: by increasing the distance between the lens and the camera sensor, the minimum focus distance is decreased. In other words, an extension tube lets you come closer with your camera to the object while still being able to focus on it (remember that lenses have a minimum focus distance, e.g. 30cm). Sounds great, considering also that extension tubes are not expensive and you can reuse your preferred and sharpest lens. Now here’s the rub: you won’t be able to focus with the focus ring on your lens, but you must physically move your camera towards or away from your object in order to focus. This is a major disadvantage if you need to make photos that show different objects consistently from the same angle (like for product photography).
Having said that, looking at the shots below, the magnification is comparable to the macro prime lens and sharpness seems to be even better (I’m not sure what happened here, it may be that I botched the macro prime shot by using a too large aperture. On the other hand, the Konica is a very sharp lens).
Ok, first I thought this one is a joke (like those people who drill a hole in their Iphone 7 to get the headphone jack back). But then I read-up on it and was surprised how well it works. The basic idea is that you mount a lens (preferably a prime lens with 50mm or less focal length) with the filter side at the camera body. Normally, a lens reduces the image of an object to be recorded on the camera sensor. Reversing the lens increases the size of the image. This has the disadvantage that the innards of your lens are exposed, making it more exposed to damage and dust. Furthermore, aperture must be set manually and focusing is again only possible by moving the camera.
The advantage is that reverse rings are really cheap (I paid 30 SEK for mine) and you can get more than 1.0 magnification, as the image below illustrates.
What should I use then?
It depends. Let’s discuss two scenarios.
Scenario 1: You are into product photography and need to shoot hundreds of consistent photos. Get a macro prime lens as you will spend less time on focusing and arranging the camera, increasing your throughput. It is worth the investment, even though they’ll set you back at least 1000 SEK for a used one. You can choose any focal length, although 100mm will give you more flexibility.
Scenario 2: You want to play around with macro photography and enjoy experimenting. You have already some prime lenses. Get a reverse ring or an extension tube. I personally prefer the reverse ring as you can achieve larger magnification.
The figure below summarizes the advantages and disadvantages of the different means to shoot macro photos that I have discussed in this article. Image quality is best for macro prime lenses and extension tubes / reverse rings (given a decent lens). Nothing comes close to a macro prime lens in handling. Cost of the kit lens is an advantage as the lens comes generally with your camera. While extension tubes / reverse rings are cheap, you still need to have a decent prime lens to get good results.
Note that you can also combine some of the above approaches. For example, you can use a macro prime lens and extension rings. You won’t be able to use the focus ring, but you can achieve larger than 1.0 magnification.
I hope you found this article on macro photography for silver jewellery informative. If you have any comments or suggestions, please leave them in the comment field below.