Let’s start with the camera. Although it would be possible to take a decent picture of a bracelet suitable for E-bay with any – even point-and-shoot – camera, this would be a quite daunting task once we tried to photograph a tiny 0.1 carat diamond set in a earring that is called stud. And if that photo needed to be printed as a poster, we would be really stuck. In short, to photograph jewelry, we need a DSLR (stands for digital single lens reflex) camera with interchangeable lenses. There are several reasons, some pretty obvious, some not so.
A point-and-shoot camera
DSLR (Digital Single Lens Reflex). Canon Rebel XTi, 10 megapixel camera that all the samples below were taken with.
90% of jewelry photography is what goes under the name of macro photography, that is when your camera acts as a microscope. The camera has to see much more than it is visible to a naked eye. Most point-and-shooters and regular photographic lenses seriously limit the proximity to the object and wouldn’t focus if you are too close. Some of those cameras and lenses have a “macro” switch allowing to get somewhat closer but even with such a switch most of the times it will be not close enough: you won’t be able to fill the entire frame with the 0.1 carat stud and will end up with a picture with plenty of void around your object.
An uncropped photo of a ring taken with a regular lens, Canon EFS 18-55mm, at the 55mm end.
The same ring shot with a macro lens, Canon EF 100mm
Cropping, that is cutting off all that empty space, is what comes to mind here but, unless you only need a small thumbnail size picture, most likely it will not work, for there will be very little sharp detail in the object and a lot of noise.
Trying to get closer by cropping. This is the EFS 18-55mm image. Notice how little detail there is in diamonds.
Same area from the image taken with the 100mm macro lens. Diamonds are much better now.
I will discuss the choice of macro lenses later. For now it will suffice to repeat that for jewelry photography you need a camera capable to accept an enlarging, or macro, lens.
The depth of field (DOF), the portion of a scene that appears sharp in the image, is another thing that limits the use of point-and-shoot cameras and regular lenses in jewelry photography and calls for a DSLR and a macro lens. The closer we get to the object the narrower becomes the zone in which everything is sharp in the photo. Outside DOF, that is in front of it and beyond, everything becomes blurry. The only remedy here is the size of the aperture in the lens, or f-number as it is usually called. The smaller the aperture (the bigger f-number), the greater is DOF. With that in mind, macro lenses are designed to have small apertures, smaller than it makes sense to have in a regular, non-macro, lens that has to deal with quite large objects.
F-number 11. Notice how blurry the back of the band and even the back of the ruby is. The lens here is Tamron AF 90mm macro.
Same lens just the f-number is 32, that is the aperture is 10 times smaller. DOF is much better now.
For more advanced information about these technical matters, there is a nice site I would recommend – Cambridge in Colour.
Did I mention image noise? I think I did. That is yet another reason to use a DSLR for macro in general and jewelry photography in particular. Once again, I would like to keep this text simple and easy for somebody who is just starting out in jewelry photography, therefore I won’t get into much detail. Think about image noise as film grain that can greatly degrade the quality of your photo. Noise increases for different reasons, like the sensitivity setting in the camera or exposure time, but in the first place the smaller the camera sensor, the more noise it generates. Larger sensors have bigger photosites and that means that these sites will be more sensitive to extremely small amounts of light and produce a distinctive signal, which will end up as a pixel in the final image. If the photosite is less sensitive, the signal it produces will be vague and will take over the clear signals. When the object we photograph is tiny, and that’s almost always the case in jewelry photography, those vague signals can really stand in the way of getting a clean sharp image.
Comparative DSLR and compact camera sensor sizes
Image noise sample
Noise is always present, no matter what camera you will be using. To a certain extent, it can be removed during the post-processing of the image on the computer.
Noise from the sample above quite successfully removed with Topaz Denoise filter
However, when there is too much noise,
Much noisier patch
there is practically nothing that could be done about it.
A failed attempt to denoise the sample above
(To be continued…)
Tags: aperture, blurry, camera, Canon, clean, compact, cropping, denoise, depth of field, detail, diamond, DOF, DSLR, f-number, focus, frame, image, jewelry, lens, light, macro, noise, picture, pixel, point-and-shoot, ring, sensor, sharp, signal, size, Topaz
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