Photographing a large paper sheet

Once in a while you get landed with the job of photographing something which would be better off scanned, but due to the size of it, or design of it, photographing it is far more practical. In this case, it was a rather large A1 plan. While I can't show you the actual plan due to the contents not being mine to pass on, I can show you how it was done.

So what do we need for a shot of the plan? Well, there are some fold marks on it, so the most important thing is to get these as flat as possible. Having done this, all you need is very flat, low contrast, non-directional light. Any directional light will show up as highlights or shadows at the creases.

I set up two diffusers to the top and bottom of the plan. You'll notice if you look at the following image that they are angled away from the plan. If they were angled over the plan, there'd be more chance of getting worse highlights on the creases. The diffuser in this case the white diffuser from a Portaflash 5 in 1 Reflector set, supported by a Portaflash 5 in 1 Reflector Support which attaches to any light stand. Because I like them, and they're inexpensive, I used a Portaflash Light Stand

A couple of flashes were then positioned on the outside of the diffusers. I guessed at 1/4 power on the 550EX (equivalent to Canon 580EX II) flashes, and was spot on for ISO 400 f/5.6. Because the plan was sitting vertically, I was using a relatively wide angle lens, and didn't really need too much depth of field. I stood to one side and leaned out over the image. The flash is exposing the image, so I wasn't too worried about shaking the camera provided I got a reasonably good framing.



The light wasn't just the diffusers either. Because of the positioning of the flashes, I was getting a lot of fill light from the ceiling, with the exception of the area blocked by me and the camera.



Having got the shot, I brought it into PS and did a slight adjustment to square up the plan in the frame, and that was the job done. The result was just about as good as a scan, except the resolution wasn't too hot. A1 paper is pretty large to photograph with a 10 megapixel dslr (I use a Canon EOS 40D). Given a dslr with 16-25 megapixel, this image would have been every bit the match of a scanner. Still, everything was readable with a 10 megapixel shot, so it did the job.

The other option for improvement would be to pin the plan up, light it the same way, but everything set relative to the plan hanging on the wall and use a longer lens. This would help reduce the slight distortion I saw with the wide angle lens. Not only that, but with a long lens, you could take two or three shots across the plan, and then join them as a panorama style image. This isn't great done with a wide angle as the distortion makes a mess of the joins.

Product Photo: Spirit Level Rule

Sorry I haven't had time to be putting up any videos the last while. I figured I'd put this one up quickly though without a video. Pretty simple setup, so the shots at the end should let you see how to go about it.

Well, first thought for this shot was background colour. I figured something vivid was called for, so I opted for the brightest of the bunch - a nice bright yellow sheet.

Next thought was how I was going to light this. I wanted to get some light deep in that bubble to make it glow well. I opted for a ringlight which I knew would give a good "shadowless" light while showing up the colour of the bubble. I fired off a test shot to see how well it worked.



Pretty spot on for the bubble, brightness wise, but virtually no light comes back from the ruler because it's sitting at an angle. To deal with this, I needed to put some fill from the right hand side. I put in a couple of my small white foamboard reflectors and fired off another test shot.



At least you can see the effect even if it's subtle. The boards were angled to catch light from the ringlight. So I could either boost the ringlight power to get more light on the ruler, but thereby make the bubble overly bright, or I have to add another light source.

I grabbed another speedlight and put on a small softbox and honeycomb on the front. This had a couple of benefits. Firstly, the soft source of light would more evenly light the two reflectors. Secondly, placing it to the left and firing it over the top of the ruler meant I got a little spill on to the background which gives a nicer brighter image. Lastly, the honeycomb meant I'd not get flare from the light source being just off to the side of the shot. So here's the result. You'll note I've reframed the shot to try and give a better composition. The previous shots were purely tests.



Here's a couple of setup shots.

Portable Soft Lighting Studio

Just a heads up to let everyone know the Maplin Portable Soft Lighting Studio is on special deal again at £9.99 - half the normal price - so get in there quick if you want one!

Product Photo: Model Guitar

I took this photo of a model guitar today. Didn't have time to set up the camcorder for this one, but I did take a setup shot. I'll just talk you through it.



You should easily spot at least two of the flashes used, and extra points if you spotted the third source. The major component of lighting this shot is having precise control over light spill. Fire light all over the place and your shot is ruined. In fact, the light was so tightly controlled, that when I went to take a setup shot, it was almost black apart from the guitar and background. I had to notch the ISO speed on the camera right up.

So the first light is the main light on the the guitar. It is a long-snooted flash which is pointing at the lower part of the guitar, and also providing some light on the silver floor. You should have spotted that from the harsh shadows on and around the guitar.

The second light is a honeycomb snoot with a blue gel fired at the background. It was pulled back away from the background until it provided a large enough spot of light behind the guitar. The reason for this light is to prevent the guitar disappearing into the background.

The third light is a small softbox off to camera left with a wide angle honeycomb attachment. Yet another one of my diy light modifiers. It provides a relatively soft light which is fairly directional, so spill can be minimised on the background. This light was feathered up a bit so as to provide more light on the top of the guitar, while only adding slight highlights down below.



This is a closeup crop on the small softbox with honeycomb, because I suspect it's the one you'll have least likely seen anything about elsewhere. You get very large ones for studio strobes which are commonly used in portraiture and such like. Apologies for the high ISO noise, but as I said, the light was so controlled I had to notch up the ISO for the setup shots.

Inverse Square Law

The inverse square law seems to cause a fair bit of confusion among photographers. It is pretty natural to think that if you put your flash twice as far away from your subject, you'd simply need to double the power. The idea that you need to quadruple it seems rather alien.

Try to think of it this way. If you're standing to the side of the flash, watching the light go outwards, what is happening? Well, the beam is spreading from the size of the flash outwards to cover a larger size on the wall you fire it at, right? But it is actually spreading in two directions - the horizontal direction and the vertical direction.

So when you double the distance, you're doubling the spread in both directions. So two times the distance in two directions is 4 times the area covered on the wall. So, thinking in this way, it should be quite obvious why the flash needs to be 4 times the power for twice the distance.

Click on the image below to view an animation which might help a little in visualising a 3D beam of light.



The physics bit you don't have to read

For the geeks around, you'll realise that no flash applies to the Inverse Square Law. Why? Well the Inverse Square Law only applies to a light source which shines light in all directions at equal intensity. Strobes and flashguns fire out in whatever direction they are pointed, and use reflectors to modify the way the light travels.

So is the Inverse Square Law no use? Well, if your flash gun had a huge snoot, or is focussed in some other way to the point it behaved almost like a laser, then you'd find that the Inverse Square Law would fail. However, for most situations, where light comes out the flash and gives a reasonable size beam on a wall, you'll find that the flash acts just like a little beam within a more powerful point source of light, and therefore the Inverse Square Law gives a pretty good approximation of how the light fall off will behave.