Photographers pay a lot of attention to exposure, white balance, image processing and printing, but we hear very few discussions on lighting the final framed print! This is perhaps because in the film only era, we had to make prints to see the image. Now we can of course just look at a screen. However, nothing has changed for those displaying prints: lighting photographs properly makes a huge difference to how they are perceived and ultimately enjoyed. This article is going to be concise and will take you through a few considerations to help anyone who is new to such things.
There are a number of key considerations when lighting photographs: Power, distance (light to subject), angle of incidence, beam angle and the colour of the light (otherwise known as colour temperature). While this may sound complicated, it isn’t at all!
I’m going to talk about LED lighting and this is because it is efficient, now commonly available, flexible and most new lighting for photographs is most likely to be using LED spotlights (like mine). They also don’t produce nearly as much light as halogen spotlights. In my case, I am using two six light ‘eyeball’ bars, totalling twelve lights. The principles will remain the same even if you are using lighting tracks with moveable spotlights, clusters or floor standing spotlights.
GU10 fitting LEDs range in power from about 3.4 watts to about 7, although the selection of top quality bulbs gets rather limited above about 5.5 watts. While power (in watts) does affect the amount of light being put out, not all bulbs are created equal. Two different 5w bulbs may therefore have a very different ‘look and feel’. The reasons will become clear as you read on.
The total amount of light being put out by a bulb is usually measured (and referred to by manufacturers) using Lumens. However, it is perhaps more useful to think about the intensity of light being produced and then to think about the beam angle, which determines the size of the light pool at the stated intensity. Intensity is usually referred to by manufacturers as ‘Luminous Flux’.
Clearly, the closer your bulb to the print, the greater the intensity of light on the print, so think about where your artwork or photographs are located and adjust power as required. A dimmer will dim all the bulbs on a bar or cluster equally. I therefore chose to use different bulbs in each ‘eyeball’ in my lighting bars, depending on the distance to the wall and anticipated size of image that would need to be illuminated. More on this later…
2. Distance and 3. Beam Angle
Distance affects not only the intensity of light on the print, but also the spread. A bulb will illuminate a larger area at a lower level of intensity as it is moved away from the print. The size of the overall ‘pool’ of light matters a lot, because the narrower the pool and more concentrated on the print it is, the better the print is ‘isolated’ on the wall and the better it stands out (in my experience). It should therefore be pretty clear that power, distance and beam angle are all inter-related and need to be considered together.
While there are some very wide angle LED lamps out there in GU10 fitting (such as 110 degrees), most photographers are going to want a much narrower beam angle than this. Philips make 25-40 degree LEDs, with the 25 degree bulbs tending to be twice the price of those with a wider spread. Various other manufacturers make bulbs around the 36 degree mark (in literature, the angle is offered referred to as a number followed by ‘D’.
I have used a mixture of 25D and 40D bulbs, between 3.5w and 5.4w.
4. Angle of Incidence
This is the greatest challenge when lighting photographs! Generally speaking you will want to avoid bright reflections of light bulbs on your prints. This means you cannot light prints ‘straight on’. With a framed photo hanging at typical levels, ceiling based lighting will generally be higher up. This allows you to create a downward angle onto the print. However, by directing lights from off to one (or both) sides of the print, you can minimise surface reflections. This is another advantage of narrow angle bulbs. They create far less light spill and you get less glare from lights used to illuminate photo A showing up on photo B.
My advice is to take the hit and buy 25B bulbs wherever you think they will improve things over 40D designs. Yes they are expensive, but top brands last for 15,000-50,000 hours, so they are an investment for several decades most likely. It certainly stings to spend £hundreds on light bulbs at the beginning though.
5. Colour of Light
The colour of light, referred to as ‘colour temperature’ is measured in Kelvin (K). When it comes to ‘white light’ bulbs, the lower the number the warmer the light and the higher the colder. For example, 2700K is considered a close match for LEDs intended to match the warm cosy glow of traditional incandescent bulbs. 3000K is considered neutral (it is in fact still somewhat warm) and anything above 4o00K is considered cool. When I bought my light bars they came fitted with 6500K bulbs and they had a decidedly bluish ‘operating theatre’ hue. They were also 110 degree and non-dimmable so unsuitable for my needs. In replacing them I decided to go for 3000K ‘neutral’ bulbs, as these lights are for the photographs and not really for ambient lighting (I have up-lighters and lamps for that). I am glad I did and would recommend avoiding 2700K bulbs along with anything significantly north of 3000K. I read a study which showed that observers considered lights at about 3500K to be the ideal for bringing out the natural colours in artwork; however, choices among main brands seem not provide anything in this range and its better to err on the side of slightly warm than slightly cold in a domestic setting. Certainly, the difference between 2700K and 3000K is quite significant and not as trivial and the numerical difference might suggest. Perception is a remarkable thing.
I lied. There are actually two more final (but important) considerations: 1) dimming and 2) quality
6. Dimming & Dimmers
If you intend to use a dimmer (and you most likely do), make sure your LEDs are dimmable. Seeing as they bulbs often cost more than the lights, it makes sense to buy dimmable ones even if you do not intend to add a dimmer right now. You may in five years time and this ensures you don’t pay twice. Some of the most powerful LEDs also seem only available as non-dimmable, which is a shame. Still, shining multiple lights at the same spot achieves the same thing.
Regarding dimmer switches, if you have older ones in your home, they may not be compatible with LEDs as LEDs have a much lower load than incandescent bulbs. I bought Varilight V Pro dimmers, which are programmable and allow you to alter the minimum brightness, as well as select one of three operating modes. This allows a greater performance across different types of lights. Mine came set to Mode 1, but I found Mode 2 gave noticeably smoother dimming and no flickering at all on one lighting bar. Oddly, Mode 2 gave some very faint buzzing on the second bar (it’s a double dimmer, also controlling the upstairs landing) which was fixed by using mode 3. Whatever works, right? At £14 for a single dimmer and £25 for a double, the price was certainly right too.
Buy cheap, buy twice! Bulbs from top manufacturers are quieter, dim more smoothly and flicker less (and that’s in addition to the fact they normally look better and the light is better (and more accurate to the stated colour temperature).
I chose Philips bulbs and I have no buzzing, no flickering and excellent light quality at 3000K. I also have read no reports of premature failure, whereas cheap manufacturers seem to grossly overestimate the lifespan of their bulbs with many consumers reporting that theirs lasted weeks, months or just a year, which is way below what you will get out of a Philips.
I have a total of 12 bulbs, of which I have:
2 x 5.4w 40D
4 x 4.3w 40D
5 x 4w 25D
1 x 3.5w 40D
Examples are shown below:
The only downsides I have seen from mixing bulbs is that they have a slightly different front face (and therefore look different). However, I considered lighting performance to be much more important (and all the Philips ones I used have a silver grey nose). Also, dimming performance is not as perfect at the low end. Some bulbs need more juice to get going, but can then be dimmed down. However, if the light is switched off in a heavily dimmed position, some of the bulbs may not come on when you switch them all back on. You have to increase the power, then back it off again. Overall I am very glad I varied the bulbs as I have been able to get the right intensity at each hanging location and the right beam angle. All match perfectly in terms of colour temperature. Seeing as I will be swapping out work fairly regularly, I will keep a variety of bulbs on hand so I can ensure I have the right power and beam angle. If given spot normally uses a 4.3 what but the print is a touch dark, a 5.4w may be just the ticket.
Well, there you go. Lighting photographs may be a bit off the usual trail, but I thought it might be helpful to share my experiences! With a total expenditure of around £280 invested in lighting photographs, I have spent almost the same as I did on picture rails. £560 (rails and lighting) to permit use of my home as a venue for private viewings is good value in my book. Over the coming years I will be able to show a lot of work here and not just for commercial purposes. It will be enjoyable to share work that is less commercial but much less likely to be encountered by those I will be inviting. I am particularly looking forward to showing my portraits of Afghan heroin addicts, whose faces are etched into my memory and which I would like others to see.