Jonathan's blog

This week, I decided to have a look at some statistics about photos I’ve taken with my Canon 450D. Using a little Perl magic, I extracted the EXIF data from almost 7,000 photos that I’ve taken since purchasing the camera 10 months ago.

The first graph shows the different focal lengths used in the photographs. Among my lenses, I have the ability to work between 8mm and 300mm. The three large spikes to the left are apparently where I’ve taken lots of photos with my primes, at 8mm, 50mm and 90mm. The general area of bars is my 18-55mm kit lens. Finally, the spike at the far right is the 70-300mm zoom lens, which I always seem to use at full zoom. (Incidentally, the EXIF data doesn’t record whether I used my 2× teleconverter, so some of the 300mm records should be 600mm).

What can I learn from this? Maybe that I would benefit from buying a longer zoom lens, but that’s a different story.

The graph of shutter speeds is perhaps more expected. Under “normal” conditions (where normal means outdoor daylight, or indoor flash photography) the shutter mainly gets used at decent everyday handheld speeds like 1/250 – 1/30. The sudden spike at 30″ is where I’ve used my camera for long-exposure night shots, including many of the night sky. My 450D doesn’t allow for anything longer than 30″ unless in bulb mode, where continuous drive doesn’t work.

And finally, we come to apertures. Clearly the most-used aperture setting is f/5.6. This is a sensible middling value, probably giving optimum sharpness for most of my lenses. It’s the kind of thing I’d choose in manual mode, and I bet the camera would readily choose it in semi-auto mode too.

f/1.8 is slightly more common than you might expect, and is probably from shooting in low light or where I’ve tried to maximise the depth of field.

A while back I took an interest in infrared photography, and I bought a couple of rolls of Maco 820c infrared film. Using infrared film involves a huge amount of trial and error, and unlike digital cameras, you can’t take one or two pictures and check after each one. You have to shoot a whole film.

My camera’s light meter seemed to be responsive to infrared light, so I let it handle the exposures. Unfortunately I now know that the readings were nonsense, because the film came out almost entirely blank. The pictures that I salvaged weren’t good enough for my photo blog but I did write about the experiment.

This time, with my last roll of Maco film, I decided against trying to do any formal kind of metering. I left the aperture either at f/5.6 or f/8, as it seemed sort of sensible. You don’t want the aperture too small, because the longer wavelength of infrared light will cause diffraction at the diaphragm more easily. Equally, you don’t want it too big because this makes the depth of field smaller. Focussing infrared is already difficult as you can’t see it with your eyes, and has to be done using a red dot on the focus ring. By having a larger depth of field, you can get away with a larger inaccuracy before it looks blurred.

I put the camera in bulb shutter mode and guessed at the exposure time, judging by how brightly the sun was shining, and how warm it felt on my face. I generally exposed for between 5 and 30 seconds.

This time – great success. Practically every image was exposed well. A handful were a bit under- or over-exposed and had lost detail in shadows or highlights, but what can you expect when you choose the exposure time by looking at the sky?

I took a few pictures of a fire in a chimenea. These came out completely blank, so I guess the fire wasn’t emitting anywhere near as much infrared radiation as I thought. I suppose while it feels very hot, it isn’t that bright to look at. The film is sensitive up to 820nm and the filter allows wavelengths longer than 720nm. This is a reasonably wide range, but it’s still “near infrared” (almost-red light) rather than “far infrared” (heat).

The end result is that I’ve created images that are ghostly and every bit as “odd” as I had hoped, from looking at other people’s work. You can see the best pictures from the film on my photo blog.

Since using my Braun Paxette, I’ve had to learn about the Sunny 16 rule to get the exposure right. The details on this page are shamelessly stolen from Wikipedia.

The rule is simple.

• Set your shutter speed to the inverse of your film speed.

ISO	Shutter
100	1/100 (or 1/125)
200	1/200 (or 1/250)
400	1/400 (or 1/500)

• Pick your aperture according to these conditions.

Aperture	Lighting Conditions	Shadow Detail
f/22	Snow/Sand	Dark with sharp edges
f/16	Sunny	Distinct
f/11	Slight Overcast	Soft around edges
f/8	Overcast	Barely visible
f/5.6	Heavy Overcast	No shadows
f/4	Open Shade/Sunset	No shadows

I’ve shot a couple of rolls of film in the Paxette now, with good success when it comes to exposure. Unfortunately the Paxette has a fixed shutter speed of 1/40 so it’s more a case of choosing the ISO to match the shutter. Fortunately Ilford produce a film with ISO50.

For a laugh, I also spent a day practising with my DSLR in full manual, exposing with the Sunny 16 rule. It worked!

I think all photographers should be aware of it, because it’s extremely useful. Give it a go!

After I posted the other day about building a pinhole camera, I immediately ordered a body cap from eBay. Last night it arrived, and here’s how I made my pinhole camera.

Making the pinhole “lens”

Not only do pinholes have to be tiny in diameter, they should also be made through a thin material. I didn’t even attempt to make a pinhole directly in the body cap. I drilled a 10mm hole and superglued a piece of tin foil over the hole. Using a fine pin, I made a small hole.

Uh, that’s it. Most guides I write have more steps than this, but making a pinhole “lens” for an SLR really is this easy.

What’s the f-number?

The formula for working out the f-number is pretty simple:

           focal length
f-stop = -----------------
         aperture diameter

The aperture diameter is the diameter of the pinhole, and the focal length is the distance between the film and the pinhole.

The Canon AE-1 Program has a small mark on the side to indicate the position of the film plane. The rough distance between this mark and the pinhole is 36mm. Getting a decent estimate of the pinhole is a little trickier, as I need to measure the diameter of the pinhole. The best I could come up with was to take a picture of the pinhole next to a ruler with my Fuji S9600 and a macro lens.

I reckon that’s approximately 0.2mm across.

          36
f-stop = ----- = 180
          0.2

So this is a pretty tiny aperture, and we are going to need long exposures to get it to make a decent picture on film.

Earlier on I pointed the camera out of my window. With the shutter set to its slowest value of 2 seconds, the meter reckoned it wanted an aperture of 8. 180 is 22 times greater than 8, so I need to make my shutter 22 times longer than 2. So we are talking 40-odd seconds for outdoor landscape photography in daylight on ISO200 film. In lower light conditions and perhaps on ISO125 film (such as my Ilford FP4) it’s easy to see that I might need to expose for 2 or 3 minutes.

Although 2 seconds is the longest my SLR can do automatically, it has a mode where the photographer can hold the shutter release for as long as necessary. Never thought I’d need a stopwatch for my photography!

The advantage of making a removable pinhole lens is that I can carry it around and easily change between lenses.

Keep an eye on my photo blog. When I’ve got this film developed I’ll scan and post the pinhole images there.

Update: I have now uploaded some of the pinhole photos.

Most cameras, even compacts, have at least some manual settings that you can adjust if you want to explore what your camera can do. As I mentioned in my introduction, the three most common settings to play with are the aperture, shutter speed and ISO.

What the settings do

Let me go into a little more detail about these.

Setting	Low value (approx)	High value (approx)
Aperture	f/3 – large aperture Lets lots of light in – good for dark situations where you don’t want to increase exposure time or ISO Large aperture increases the depth of field (makes things go out of focus more quickly as they move towards or away from the camera	f/12 – small aperture Can be used to reduce the amount of light entering the camera You can also use an ND filter1 to reduce the amount of light Very small aperture of f/10 or smaller can make points of light become star-shaped Smaller apertures increase the depth of field so more of the photo is in focus
Shutter speed	1/4000s – short exposure or fast shutter Use a fast shutter in bright sunlight Use a fast shutter to freeze a point in action, e.g. sports	30s – long exposure or slow shutter Exposures of longer than 1/250s will probably need a tripod or at least a place to rest the camera on a firm surface If you are increasing the exposure simply to capture more light, consider making the aperture larger instead If you want to take a long exposure of a moving object in bright light, make the aperture small and use an ND filter
ISO	100 – low ISO Camera less sensitive to light Use low ISO in bright conditions or for long exposures	1600 – high ISO Camera more sensitive to light Use in darker situations where you don’t want a long exposure Be aware that ISO 800 or more can cause speckly “noise”. This can happen with digital or film!

[1] Don’t worry – we will discuss filters in a later post.

How you can use the settings

So know you know a little bit of the basics, I can say something about the different modes on your camera.

Taking full manual control of the camera can be a little daunting and can produce unpredictable results until you are familiar with the camera. But most cameras semi-automatic modes known as shutter priority (or S for short) and aperture priority (or A for short). This allows you to set one value, either the shutter or the aperture, and the camera picks the other settings for you. Full manual is usually known as M.

This table shows what combinations of settings are available on my camera.

	ISO	Shutter	Aperture
Auto	Either auto, or you choose	Auto	Auto
S	You choose	You choose	Auto
A	You choose	Auto	You choose
M	You choose	You choose	You choose

Examples

The best way to explain when you should choose a particular mode and what settings you should choose is by example – and experimentation, of course.

Blurred photo of moving cars on a sunny day

---

To achieve blur we need a relatively long shutter speed, and the challenge is compensating for this long exposure so the picture isn’t overexposed.

Mode	M
ISO	Choose the lowest available ISO
Shutter	Choose the shortest shutter speed that you can get away with while still achieving the desired blurred effect. Maybe 2-5 seconds.
Aperture	Choose the smallest available aperture (largest F number)
Notes	You will need a tripod, and probably an ND filter to limit the amount of light.

Blurred photo of moving cars at night

---

This is actually much easier than blurred photos by day as compensating for the long exposure in low light conditions is easy.

	I recommend…	I used…
Mode	S	S
ISO	Choose the lowest available ISO	80
Shutter	Choose a really long shutter speed – 10 or 30 seconds perhaps	10s
Aperture	Auto	Auto: f/10.9
Notes	You will need a tripod, and possibly an ND filter to limit the amount of light for very long exposures

A closeup of a flower

---

The primary objective here is to open the aperture wide to decrease the depth of field and cause the background to be out of focus.

	I recommend…	I used…
Mode	A	A
ISO	Choose a medium ISO like 200. Adjust according for the daylight conditions.	80
Shutter	Auto	Auto: 1/340s
Aperture	Choose a fairly large aperture	f/2.8
Notes

Sports and action

---

The object here is to keep the shutter as fast as possible, to freeze the action without blur.

	I recommend…	I used…
Mode	S	S
ISO	Choose a medium ISO like 200. Adjust according for the daylight conditions.	80
Shutter	Choose a fast shutter such as 1/400s or less, according to the speed of the object you want to freeze, and the light conditions.	1/450s
Aperture	Auto	Auto: f/7.2
Notes

The best thing you can do is practice, and try new things. Chances are you’ll go to your local motorway bridge and take tens of photos. Some will be good, and some will be awful. But you’ll quickly learn what works for your camera.

If you can’t remember what settings you used to take each picture, you can find out on your computer later. If you’re on Windows, right-click on the image file, click Properties and click on the Details tab. Scroll down to Camera you’ll see the details, like in the screenshot below.

Next time, we will go over how to choose and use filters in your pictures.

I started getting into photography a couple of years ago, and I have been helped along the way by a colleague and various books and websites. I’ve been learning about cameras continuously, and a few months after I got interested, my brother took an interest too.

I made some notes about basic camera settings for him, which he says he found very useful. So I’ve decided to try and write them up a bit more formally for my blog, in the hope that they will be useful for someone.

I wrote this guide mainly using my Fuji Finepix S9600, with the intention that my brother would use it with his Fuji Finepix S5800. Some of the numbers may vary, but pretty much all of the advice is transferable between digital cameras and even 35mm film cameras.

For someone who has never used manual settings on a camera before, there are a few terms you need to be familiar with.

Aperture	Also known as F-stop. This is the size of the hole behind the main lens of the camera. It can be adjusted in size to let in more or less light.
Shutter speed	Also known as the exposure. This is simply the amount of time that the camera exposes for. Long exposures mean blurry photos while short exposures can freeze action shots in time.
ISO	This is the sensitivity of your camera to light.

In the next post, I’ll talk about the modes on your camera, and how they come into play with the three concepts I’ve just explained.