Using Flash

Towards evening, or when moving indoors, as the daylight decreases on your subject you start by increasing your aperture, using slower shutter speeds and increasing your ISO setting. Eventually you run out of adjustment and must supplement the light, normally by using a flashgun.

If you use the flash mounted on your camera then you will get a very flat looking picture, and maybe with blown out highlights. Continue reading

When Does Your Camera Have Enough Pixels?

Cameras have a history of increasing the number of pixels with each new product release. We have seen digital cameras starting off around 1.5 to 2.5 million pixels (MPx) and now you can get up to 20 MPx readily and even more for big, and expensive, pro cameras.

Your Smartphone probably has something between 4 and 8 MPx even though the actual camera occupies a small corner of a hand sized technology packed package.
So what is a pixel and when does the number of MPx matter?

What is a pixel?

Digital pictures are made of small squares of photo information and each individual square is called a 'pixel'; it's a name derived from the concept of a 'picture cell'. These are the individual elements of the digital picture that are connected back to the separate parts of your camera's sensor that respond to the light falling on it.

Before we go on to the examples it is important to view this web page on a computer monitor as the size effects will not show on many smart phone screens, the size and resolution is too small.

Computer displays and resolution

Gears-200x150-2This picture shows an image at a resolution of 200 x 150 px, that's 30,000px or 0.03 Mpx. You can clearly see the jaggedness imposed by the large blocks cause by the individual pixels that comprise the image.

Gears-20x15This is the same image but now at an even lower resolution of 20x15 pixels, 300Px. It is now impossible to tell what the object is.

Gears-1000x750This picture has bee recorded at a resolution of 1,000 x 750 pixels, 0.75 Mpx; it is shown here as only 300 pixels wide. Click on the picture to see it at full size (use our browser's Back button to return here). On any monitor or projector (other than the highest professional equipment) it is practically impossible to discern the blocks.

For on-screen display the largest resolution that can be displayed is that of the display itself. In recent years that has come to mean 1,600 x 1,280, i.e. a fraction over 2MPx. In practice, on a website, the picture only occupies a proportion of this space and our example of 1,000 x 750 will normally display well.

Photo Printing and resolution

However, the picture changes when we look at photo printing. Prining is inherently a higher resolution process as the final printed image is an analogue object and the resolution is not limited by pixel size. The limitation is now the acuity of your eyes.

Many experiments have been undertaken and it is established that the resolution necessary for a good quality printed image is 300 dpi (that's dots per inch, or pixel). Really top quality prints will go further, but you stray into Pro territory here.

Given the 300 dpi and the standard sizes of photo printing, what resolution do you need from your images to get good quality prints through the process?

Width (ins) Height (ins) MPixel Image PX width
6 ins 4 ins 2.2 1800
8 5 3.6 2400
10 8 7.2 3000
12 10 10.8 3600
Width (mm) Height (mm) MPixel Image PX width
297 (A4) 210 8.7 3507
210 (A5) 149 4.3 2480
420 (A3) 297 17.4 4960

So, from this it is clear that if your camera has 10MPx then you can print up to 12 x 10 or A4 with good results.

Smartphone cameras are now 4 to 5 Mpx so should print up to 8 with excellent quality and be quite acceptable up to 10 x 8, quite remarkable for such a tiny device. But there's a lot more to know about Smartphone cameras; but that's for another time.

The effect of cropping on picture quality

Another factor to take into account is cropping. When you crop a picture you reduce the number of pixels that make up the image. To see the size of the effect, let’s do a simple calculation.

Let’s use some small numbers so the math is clear, say we start with an image that’s 400 by 300 and crop 10% from each edge. Our original image has 120,000 pixels.

Now let’s do that cropping. The width is reduced by two lots of 40 (10% each side) and, similarly the height is reduced by two lots of 30. Thus we have an image that has shrunk to 320 x 240 pixels, that’s 76,800 pixels.

The new image has only 64% of the pixels of the original image. Ouch!

So it really is important to fill your camera’s frame with your picture to get the best printed quality!


Portrait examples

One of the bestt hings you can do to improve your portraits is practice. But it helps if you hacve some inspiration too. On this page you will find links to some expert portrait photographers, we hope you will enjoy them - and learn something valuable.

How to learn? Look at a protrait that you enjoy. Now look again carefully. Can you identify what it is about the photo that appeals?

Now look at the techniques used. Studio or on location? Can you tell?

Did teh photographer use natural light, flash, floodlights or maybe some of each?

Where is the light coming from?

How would you do it better? That's a tough question, but one that helps you to get to the heart of the shot.

Use your curiosity to 'reverse engineer' the image.

Thomas Blue photography

Striking and dark potraits from Malte Pietschmann

Amazing self portrait photography by Heather Hanrahan

Creative Portrait Photography by Nava Monde

Gritty portraits that make you think by Jack Davison

A selection of portraits from minsk, Belarus

A study of Nadar's portraits. Nadar was a Parisian photographer in the lastter half of the 1800s. His work was groundbreaking and still has many lessons for today's photograpner. Note the simple use of lighting and do take the time to view the video at the end of the post.

Into the mind of a master portrait photographer Arnold Newman. Iconinc potraits for you to study.


Compact camera scene modes

Most compact cameras, withor without zooms, have a range of pre-set scene modes. These include things like portrait, landscape, sunrise/ sunset, macro (close up) and fireworks modes. What these modes do is to set up the camera to a preset group of settings to maximise your chances of getting a great photo - without you having to learn the best combination of settings.

Some cameras go further and have an Intelligent Auto mode which attemptst o analyse the scene and then select the appropriate scene mode for you.

When do you first go beyond the simple Auto mode and go for a scene selection?

It's when the lighting conditions get out of the ordinary. If you are in a snowstorm the camera wil probably give you a dull grey picture - so select the Snow scene mode. If you are taking a picture close up of a flower, select Macro mode. Photos taken early in the day or towards evening also demand special care.

Here's a quick primer about scene modes.

And here's a detailed guide to many scene modes.

Taking portraits of older people

Most people love snapping the kids, who never sit still long enought for a "proper" portrait. But there' so much action that it doesn;t matter - they are still endearing.

So we then try out our photography skills on the teenagers and younger adults in the family. We can be wonderfully rewarded with some great shots, espeacially if you have been following the portrait hints and tips on this blog.

But what about the older family members? When people have gatheredd 50, 60 or 70 years of life experience this can become more of a challenge. Their skin doen't retain its youthful tension and plumpness; bags and wrinkles arise and the photographer faces a challenge. The subject can also become very self concious and may take some careful reassurance.

We all want pictures of our parents and grandpappy to treasure when they are not around. But making such a picture flattering without straying too far from capturing their character is quite a challenge.

So here's a series of excellent tips to help you on your way.