As an event photographer, I'm often asked to cover conferences and presentations, and for this post I thought it might be useful to give some insights into how I tackle these assignments. I'll be looking at equipment, techniques, and post-processing, and I'll be describing these in the context of a particular event that I covered not long ago: a series of T-talks given by various distinguished members of the University of Oxford at Rhodes House and organised by Voices from Oxford.

First, a little bit about the venue itself. Rhodes House was completed in 1928 in memory of Cecil Rhodes, and in the picture above you can see Milner Hall in which the talks are taking place. The first thing I always look at is the lighting. This event is in the early evening in June, and there is a mixture of daylight streaming in from the large windows on the right, combined with tungsten light from the chandeliers and video lights. Note the light coloured walls and ceiling which help to bounce the light throughout the building. This mixture of lighting sources is one that I encounter frequently and presents an immediate problem. Some angles will be lit mainly by daylight, some by tungsten, and others by a mixture. I'll deal with that issue later, but first let's look at the equipment:

What's in the bag

Canon 5D Mk III: A superb full-frame camera delivering high quality results even at the high ISOs that are often necessary indoors. One of the key features of this camera is the two card slots, one for SD cards and the other for CF cards. By configuring the camera to write to each card in parallel I've got two copies of each image so am insuring myself against one of the cards becoming corrupted or otherwise unreadable.

Canon 6D: Another full-frame camera, not as highly specified as the 5D; in particular it has only one card slot so doesn't have the redundancy of the 5D but it does have built-in wifi, though I would only use wifi where on-site printing is require, which is not the case here.

Two cameras means I've got a backup if one of them fails. The batteries of course are fully charged, and I have two spare batteries and a supply of spare memory cards.

Canon 70-210 f2.8 L lens. Canon's 'L' lenses are among the finest ever made. I'm not sure what the 'L' stands for: Legendary, perhaps. Anyway with a fast 2.8 aperture and image stabilisation this is the go-to lens for events and weddings.

Canon 24-70 f2.8 L lens. This lens covers the wide shots that are a vital part of the coverage.

Each lens stays attached to its camera for the duration of the event. Thus no time-consuming lens changes are needed.

Gitzo carbon tripod with a Really Right Stuff ball head. For some shots a tripod is useful, and the RRS quick-release brackets mean that I can get the cameras on and off the tripod very quickly.

Speedlight: yes, there's a speedlight in the bag but it's rarely used at an event of this nature and only as a fill if I'm asked to do posed group shots.

Techniques

One of the iconic treasures kept at Rhodes House is a blackboard used by Albert Einstein when he delivered a lecture there. A rather well-known Einstein quote goes something like "Everything should be a simple as possible, but not simpler".  Now I suppose that the simplest possible way of using a camera would be to set everything to auto - white balance, exposure, ISO, focus - and that would certainly work, but it's not the best way and I'll explain why.

White balance

All light sources have a colour temperature, which roughly speaking, is the colour of light emitted by an object at that temperature, measured in degrees Kelvin. On the Kelvin scale of temperature, 0° K is absolute zero, or about -273° Celsius, and on a sunny day at noon with a cloudless sky the ambient colour temperature is about 5200°K. Why is this important? Well, we don't always take photographs under those conditions and definitely not inside Rhodes House! Tungsten light has a lower temperature (3000°K or thereabouts) and appears "warmer", and in shade where the light is predominantly from the blue sky the light appears to be "colder". Our eyes can compensate for this but the camera can't, and we end up with a colour cast. In the good old days of film we would use a tinted filter to adjust the colour temperature and remove any resulting colour casts, and digital cameras provide the equivalent functionality in the White Balance settings. So if your camera has selectable white balance, you will see options such as "tungsten", "fluorescent", "shade" etc. These options automatically correct the colour balance of the digital image by effectively shifting the colour balance back to "daylight". If you choose "AWB" - auto white balance - the camera assesses the scene in front of it and attempts to remove any colour casts by averaging out what it sees. Unfortunately, when we have mixed light sources, the camera doesn't always get it right and we could well end up with a set of images each of which shows a slightly different balance based on the exact nature of the light in that image.

To cut a long story short, I divide the venue into lighting "zones" and establish the correct colour balance for each zone in °K. So in this particular venue, there are really only two zones I need to worry about: the audience, lit mainly from the window light; and the speakers, lit mainly by the tungsten and video lights. 

If I were shooting in a venue where the lighting is consistent regardless of where I'm pointing the camera, I would use a neutral object such as a projection screen to establish a custom white balance and use that for the entire shoot. Because there are mixed sources at this venue, and the colour balance won't be consistent, I set the camera to AWB (Auto White Balance) and let the electronics figure it out. Then I can make any necessary adjustments in post-processing.

Exposure

I guess I'm fortunate enough to have lived through an era of totally manual photography, where film speeds were fixed (within narrow limits) and you set the correct shutter speed and aperture based on the reading from an incident light meter. While modern metering system are incredibly powerful, at the end of the day there is only one exposure that is "correct". However sophisticated the metering system, it can be fooled by unusually light or dark subjects. Take, for example, a speaker in front of a screen onto which a Powerpoint presentation is being projected. If you're not careful, the camera will see the bright screen and try to set what it thinks is the correct exposure, rendering the screen grey, not white, and the speaker underexposed. In this situation, I would use a manual exposure setting to obtain the best balance between speaker and screen. I now have the option of exposing for the screen or the speaker, depending on where I want to emphasis to be.

Focus

I almost always use back-button focus. Very briefly, the camera is configured so that the shutter button doesn't activate the autofocus. That function is assigned to a button on the back of the camera. So I can pick the focus point and press the back button to set the focus at that point. Then the subject will be in focus no matter how I compose the picture, and it stays that way until either I, or the subject, moves. Some speakers have the annoying (to me!) habit of walking around as they speak. That's where AI Servo mode is useful, to track focus as they move.

Delivering the brief

The client may or may not have specified particular shots. If they have, then it is essential that they are delivered and it helps to have a written list. The images can be categorised in various ways:

1 General scene-setting, showing as much of the venue as possible, with the audience and speakers. A wide-angle lens is obviously useful here. The image above is an example of this.

2 Close-ups of speakers. I'm looking for a good expression or gesture here, and I tend to take quite a few shots. It's also good to include images of both the speaker and the subject matter, which might be a screen or whiteboard, for example. This helps to place the event in context. Quite often the camera will be on a tripod.

3 Close-ups of the audience. If the speaker is engaging with the audience, often there will be interesting shots of the audience paying close attention, or laughing, or applauding. These little cameos add depth and variety to the shoot.

4 Photos of the speaker with the audience. These are the most iconic pictures and often the most challenging to obtain, because I need to be slightly behind the speaker to include the audience and speaker.  When I've identified a good spot to achieve this, I'll wait, wherever possible, for a pause in the delivery, for example for a drink or a question from the audience, to move quickly into position. The trick is to get the shots without being a distraction. 

Post-production

Back at the computer, and with a nice cup of tea, the workflow typically goes like this:

1 Import the RAW images into Lightroom, excluding the images that are obviously unusable because they are off focus, under or over exposed, or just badly composed. During the import, I assign relevant keywords and copyright metadata.

2 In Lightroom's Library mode, I now do a quick run-though of all the imported images, flagging the "keepers" with the "P" keyboard shortcut to mark them as "Picks". But I don't do this image by image; with 560 images to process, that would take too long, and the objective is to complete this stage as quickly and efficiently as possible. So I select groups of six from the film strip, and use survey mode ("N" is the keyboard shortcut) to view them side by side. I can then quickly flag the picks.

3 I now have a selection of usable images of which some will, with luck, stand out because they a particularly good; I flag these with 5 stars.

4 If any adjustments are needed, such as cropping, light balance or exposure, I make them now, but only to the 5* images. If several images need the same adjustments I use the "Sync settings" to replicate the adjustments across several images. This can be the most time-consuming step and that's why I always endeavour to get the best possible images in-camera to minimise the post-processing work. I only ever work with RAW images because this gives the maximum opportunity to tweak the images where necessary. I also try to do everything in Lightroom, although occasionally I might use Photoshop to make adjustments that can't be done in Lightroom.

5 I now need to make a selection of images for the client. I create a Lightroom collection into which I place all the 5* images. If I need any more to complete the brief then I add them from the remaining picks.

6 The final step is to export the images in the appropriate format and resolution.