Wednesday, 10 November 2004

Miniature photography - part 2: camera settings

After the [previous entry]( discussing lighting, this entry will focus (ahem) on the camera settings I use to do miniature photography.

### Focus ###

The entire purpose of photographing miniatures is to be able to see them clearly, so an in focus, sharp shot is mandatory. Most cameras have a decent autofocus that should be able to focus on the miniature easily, especially if it is well lit and there are no distractions for the camera (i.e. put the miniature in front of a uniform background so the camera has no troubles deciding what it should focus on). However, the rub usually lies in trying to get close enough to the figure to get a decent frame filling shot -- for this you need a _macro_ lens or setting on your camera.

What this does, is enable the camera to focus much closer to the lens than usual. With the macro setting on [my camera](, I usually can get to within 7-8 cm of the figure, which for a 25mm figure results in a shot that is just slightly smaller than the frame, so that's OK. I have recently [read]( (and verified) that my camera can support an external macro lens wich has a shorter focal lenght and will allow me to get even closer, so I might look into that and modify my Christmas wishlist a bit :)

A further important point focus wise is _depth of focus_. A camera focuses on a point at a certain distance from the lens, and has an area around that point where it focuses -- this is the depth of focus. For a miniature, bad depth of focus might mean that the face of a miniature is in focus, while the back of a hat, or a forward pointing arm is not. It is important to get a good depth of focus to make sure the entire miniature is in focus (for a shot where I got this wrong, see [this photograph]( ). This is done by reducing the aperture of the camera: the smaller the aperture (the physical opening through which light enters the camera body), the better the depth of focus. Which brings us nicely to the next point.

### Aperture ###

As mentioned above, a good depth of focus is essential for photographing miniatures. The way to achieve this with consumer level cameras is to manipulate the _aperture_ settings of the camera. This, of course, assumes that your camera comes with a way to override the automatic aperture settings (on my camera, this is called _Av_ or _aperture priority_ mode), or that you have a SLR where you can set the aperture on the lens (the camera then selects an appropriate exposure time).

If you can do this, the rule is simple: smaller aperture means greater depth of focus. The smaller the aperture, the more of your miniature will be in focus. So should we simply set the aperture as small as possible? Not really, as a small aperture also means that less light will enter the camera (logically), so the camera will select longer exposure times, which come with their own set of problems (stabilisation, see further on). So, you need to compromise -- I usually take my photographs with an F-stop of 9.8 or so, leading to exposure times of about a quarter of a second, so I do need some extra tricks to get a stable image.

### White balance ###

Take a painted miniature, or even a piece of coloured paper, and look at it in daylight, under fluorescent light and in the light of a standard incandescant light bulb. You will notice that the colours will look different under these different lighting conditions. This is because every light source has a certain 'temperature', which reflects the distribution of colors it has in it (it is called a 'temperature' because it is linked to the radiation of a perfect black body at a certain temperature - if light has the same color distribution as a black body of temperature X, it is said to have a color temperature of X. X is usually in the high thousands, BTW). Because different sources of light have different colors in them at varying amounts, they show other colours in biased ways (as color in a miniature is determined by reflection of incipient light, the color percieved is dependent upon the color of that incipient light).

For a camera to correctly show the colors of a miniature, it needs to be told about the color temperature of the light illuminating the miniature. This is done through the _white balance_ setting. In conventional cameras, this is done using filters and special attachment, but most digital cameras have facilities on board to correct the colors on the fly. Most cameras have a few preprogrammed white balance settings (e.g. fluorescent light, incandescent light, daylight...), and if you're lucky, as I am, your camera allows you to manually set the white balance. In my case, I simply have to take a quick snapshot of a white object (I use the paper backdrop I put miniatures against) under the same light, and the camera adjusts its white balance from that. Easy.

If your camera does not have a manual white balance setting, you'll have to experiment with the automatic settings to get a good result. Of course, if your camera does not have a way of specifying a white balance, you'll just have to go with what you get, and possibly do some image manipulation later (that's part 3 of this article series).

### ISO ###

Traditional photography films have an ISO rating, which reflects the coarseness of the silver halide grains on the substrate (can you tell I have a chemical background?). The standard ISO ratings are ISO 100, 200 and 400. The higher the ISO rating, the bigger the grains and the more light sensitive the film is. Unfortunately, high ISO ratings naturally also mean more grainier photographs, so as usual it's a case of balancing pros and cons.

For a digital camera, ISO ratings make no sense (as they do not use films), but most of them do provide an ISO rating, which simply reflects the voltage set across the CCD to increase light sensitivity. High ISO ratings in this case have the same effect as with films: better light sensitivity but noisier photographs (more voltage means more noise). For this reason, I always set my camera to use the lowest possible ISO rating (100). You will need more light and longer exposure times, though.

### Light ###

Did we not talk about this already? [Yes we did](, but let's now quickly go over the ways to increase the cameras light sensitivity, most of which we've already covered. First off, there's aperture and exposure time. Bigger apertures and longer exposure times lead to better light sensitivity, but have their problems as well: loss of depth of focus and increased need for camera stabilisation, respectively. On some cameras, you can also deliberately over (or under) expose a photograph. I usually do this to a certain extent, but too much will lead to extra noise in the photograph. Finally, you can also increase the ISO setting, as mentioned above, but that introduces more noise as well.

So, as with most, all of these have their checks and balances, so it's a question of doing some experimenting and seeing what works best (and providing enough light in the first place, of course).

### Camera stabilisation ###

As you take pictures in low light and/or with longer exposure times, you will get into the region where moving the camera while taking the picture will blur the picture (this is from about 1/30s exposure times or so), which is not good. Unfortunately, I regularly find myself taking photographs of miniatures with exposure times of quarter seconds, half seconds or even longer. For this, good stabilisation of the camera is an absolute necessity.

The holy grail of stabilisation is a tripod, of course, but I don't have one of those yet (it's on my wishlist :) ), so I use another common trick. I put the camera on a flat stable surface (read -- the kitchen table) and use its timed shot feature, where it takes a picture ten seconds after you've pressed the button. This is intended for photographs where the photographer wants to be on as well, but it works very well for taking long exposure photos, as your shaking hands are not on the camera and there's no button push to move the camera when taking the shot.

Whew, that's it for this installment. The next one will be the final one and talk about what you can do with an image manipulation program to increase the quality of your pictures.

* [Part 1 - Lighting](
* [Part 2 - Camera settings]( -- You are here
* [Part 3 - Post processing](
* [Part 4 - Stage setup](

1 comment:

  1. Ah, nice tip on the time delay feature. I had been cursing my camera for not allowing a shutter release cable to get my unsteady hands off of it. I will definitely try this.