There’s an excellent Labs round-up of Superzoom cameras (also commonly called “bridge cameras”) in the latest issue of PC Pro. My only criticism is that it doesn’t makes a strong enough case for its subject.

Most people tend to think that there are only two types of digital camera to choose from: point-and-click compact cameras majoring in convenience, and high-end DSLRs majoring in picture quality. Anything in between is – almost by definition – seen as an uncomfortable compromise. However I think that the vast majority of users would actually be far better off with this intermediate format.

From my own experience I think that the bridge cameras offer two overwhelming advantages.

The first is the zoom. I just don’t understand why this is generally seen as an optional extra – and an incredibly expensive and awkward one for DSLRs where you have to buy and carry separate lenses. Taking a good photo is as much about content and composition as it is about light gathering, and a good optical zoom opens up so many more creative options. Go to the zoo or park with a superzoom – anything from around 20x to the Nikon Coolpix P500’s amazing 36x – and you really can bring back genuinely interesting and exciting photos; go without and your photos will almost certainly be as dull as everyone else’s.

The second is video. I have to admit that this was very low down on my list of priorities when I bought my Panasonic Lumix a few years back (a long way below full manual control and RAW support). However I was amazed by the quality of the 720p HD video, which was actually far better than that from my admittedly ancient, dedicated device. Now the latest Lumix DMC-FZ100 is offering 1080i.

Having impressive video handling conveniently to hand dramatically increases your creative options. There are just so many occasions where a static image doesn’t do the subject justice and other scenarios where video is the only way to be sure of getting the still. Now I would find it as unthinkable to buy a camera that doesn’t also shoot HD video (complete with a dedicated video record button) as I would to buy one with an ordinary zoom.

Ultimately bridge cameras don’t just offer a bridge between two camps, they offer a bridge between three. Moreover, the result isn’t an awkward compromise that is neither-one-thing-nor-another, but a creative mix that is greater than the sum of its parts (including zooming video).

Of course dedicated DSLRs and video cameras will still be required for professionals and the keenest enthusiasts, but compact cameras and Flip-style video devices are disappearing into the smartphone where they belong. That leaves the bridge camera holding the high centre ground – precisely the ground that most users are looking to occupy.

Is it time for a new A-List category?

And I wrote what I considered to be an innocent line: “…for landscape shots, place your camera on a tripod, use a remote shutter release to minimise the risk of camera shake, and apply a small aperture (f/16 is ideal) to get as much of the frame in focus as possible.”

This prompted subscriber Simon Barnes to write to PC Pro’s editor, Tim Danton, to say: “he makes a canard, suggesting f/16 is good for depth of field in landscapes, when in fact, even at full frame this is already straying into diffraction, which will be worse with smaller sensors. He’s not the only one saying this of course, it’s regularly trotted out.”

Quite apart from teaching me a new word, Simon was raising an interesting point, which I’ll attempt to tackle here. I should add that the pratical effect of diffraction in photography is to limit the resolving power of the camera as a whole – in other words once diffraction sets in, your images will in theory be softer, with less detail.The “sweet spot” for lenses is normally f/8 – f/11, so shooting f/16 might not get you the absolutely sharpest possible image you could possibly, possibly get.

What it will get you is very good depth of field – i.e. if you’ve focussed properly on one point in the frame it’s likely the rest of the landscape will be focussed as well. If I had the choice between a 100% focussed image that was slightly soft or an image where focus fell off towards the back of the scene I’d take the 100% focussed image and either live with the softness or sharpen it out afterwards.

Most of my favourite landscape images (such as the one above) are taken between f/8 and f/16 and I’ve got no problems with the sharpness of the images taken at f/16. Every lens is different, obviously, so a thousand pound wide-angle lens will perform much better at f/16 than the lens that comes with a 1000D.

Tim passed my comments on, to which Simon responded: “But again there is no mention of the sensor size which is critical in this! Also diffraction cannot be mitigated by better lens design as it’s a property of the light and aperture, not the glass.” Hands up: he’s absolutely right (for more details, visit Cambridge in Colour, which has an excellent discussion of this very subject).

But: the odds of a landscape being ruined by diffraction or sensor size are tiny compared to the odds of it being ruined by misjudging composition/focus/exposure/using a non-professional lens. In other words, it isn’t, personally, something I’d worry about. The lens attached to a camera has a much bigger impact on image quality than the camera it’s attached to (caveats apply as always… in most cases… with some exceptions… etc).

Then again, photography is a personal thing and if Simon has found a way of working that produces sharp, beautiful images that he’s proud of then I’d absolutely urge him to ignore me totally and carry on.

For people looking for a general guideline I’d still say f/16 is a good starting point. (If you have the inclination, look on that Cambridge in Colour page for the section headed “Notes on real-world use in photography” and read the first two paragraphs – that’s what I’m getting at.)

f/16 is a pretty general rule. As with most aspects of photography the rules change depending on what you’re using, what you’re shooting and what kind of light you have available. And it’s true that if you’re shooting with a compact then different rules apply once again.

In particular, when the “what you’re using” is a compact rather than a Digital SLR, diffraction becomes a much bigger issue. As the Cambridge in Colour article points out, the sensor size in a compact is so tiny that diffraction is an issue at quite large f-stops, which means far more pictures will be affected.

It makes sense to me, though, that with the image quality/lens quality on offer from compacts being so much lower than that of DSLR, that diffraction will never be noticed before the other flaws in an image. I confess, though, that’s a bit of an assumption, so I’d be fascinated to know if people have encountered diffraction issues with their compacts – or indeed their DSLRs at f/16.

Digital SLRs have become so easy to use that anyone can take great photos with one. But beginners quickly hit one question without an obvious answer, namely: should I be shooting in raw mode?

It’s an issue we’ve touched on before, and of course it’s covered in depth in our Ultimate Guide to Digital Photography. But it comes up so often that I thought it might be useful to give a simple overview of what raw mode means, and a few examples of its benefits.

A visible difference?

Most DSLR cameras – and newer SLD (single-lens direct view) models like the Panasonic Lumix DMC-G2 – can be set to save each picture you take as both a JPEG and a raw file. This makes it easy to compare the two formats — but if you do so you probably won’t spot much difference. Here, for example, are two images of yours truly on a recent winter holiday, shot on a Sony α700 and shrunk down to a typical viewing size. The shutter was only pressed once: the images below show the same scene, recorded above in JPEG mode, and below in raw. (For convenience and accuracy I’ve reproduced them here in lossless PNG format.)

You can take a closer look by clicking on the images to see larger versions (I suggest you open them in adjacent tabs and click back and forth to compare). But even when you peer closely, the two images appear almost identical — the main difference being that the raw version has slightly better brightness and contrast.

Yet though the pictures are similar, they’ve been processed in quite different ways. When your camera records a JPEG image, it makes a snap judgment (ho ho) about what exposure, colour and contrast settings would suit the picture, applies them to the image, and then compresses it — shrinking the file by throwing away detail that it considers too dark, too bright or simply too subtle for you to notice.

With the raw image, the camera doesn’t make these kind of judgments: it might apply some basic corrections to account for (e.g.) the characteristics of the lens, but effectively you can think of a raw file as containing everything the camera originally saw. For this reason, the resulting file is typically about four times the size of the JPEG version. To turn it into a usable picture file, you must use software on your PC to apply settings for exposure, white balance and so forth. You can do this by following your own artistic instincts, or the software can do it for you automatically: the raw image above was processed using Adobe Camera Raw with default settings.

When JPEG is good enough

If you only want to view your photos on screen, or produce small album-sized prints, the truth is that JPEG will probably be fine. In both cases your picture is going to be shrunk down enormously: a twelve-megapixel original must be reduced in size by a factor of fifty to make a 600 x 400 web image, and if you print it onto 6in x 4in photo paper each pixel will cover an area of just 0.0014 square inches. Any loss of detail introduced by the JPEG process will be entirely invisible.

But what if you want to print out your photos at a larger size, or crop out a section of the image and blow it up? Then the difference between JPEG and raw starts to become significant. Here’s a zoomed-in detail from the previous picture: again, the first image is JPEG and the second is raw, again produced with Adobe Camera Raw.

Even at this scale you may be able to see that the JPEG has a murky, blurry quality compared to the raw file. Click to see the larger versions and the difference is unmissable. If you wanted to make a print of this image, or simply enlarge it for online use, you could expect the raw file to give a visibly cleaner image.

Correcting for exposure

The difference between JPEG and raw is especially pronounced when your original image is underexposed. Here’s another detail from a JPEG that was taken near some floodlights: the camera has tried to pick exposure settings that don’t burn out the brightest elements of the picture, but as a result the actual subject has come out very dark.

There is little that can be done to fix the JPEG image. We can adjust the curves in Photoshop, but much of the detail from the dark areas has already been discarded by the camera, so what we recover is very noisy: you can see the effect in the first image below. With the raw file, there’s much more information to work with, even if it’s not immediately visible. And it doesn’t hurt that Adobe’s software is able to automatically identify and remove noise from the raw version, which isn’t currently possible with JPEG originals.

So if we load the raw version of the image into Adobe Camera Raw and boost the exposure, the result (the second image below) is much more agreeable:

Obviously they’re still both a little noisy and unclear, but if you wanted to share or print this image, the raw file would certainly give better results.

A second shot

Of course, if you’re a careful photographer then really you shouldn’t be underexposing your photos in the first place. But nobody takes a perfect photo every time, especially if you’re still learning to get the best from your camera. Shooting in raw gives you a better chance of rescuing the shot when your shutter skills let you down.

Meanwhile, more advanced photographers can exploit the tonal depth of raw mode to artistic effect — for example, by lightening shadow tones to expose more detail than a regular photo would normally show.

No matter what standard you’re at, if you want to do anything more adventurous than taking simple snapshots, it makes sense to give yourself the best possible source material to work with. If you’re willing to make an investment in the software, and in the time and techniques involved in processing your photographs to their best advantage, then without a doubt that means shooting in raw mode.

To the embarrassment of my family I had items from my bag confiscated at both.

This often happens to me, as an inveterate tinkerer and technology hoarder; bike parts taken by Science Museum staff, USB drives and mobile phones at a laptop manufacturer’s design centre. It’s no big deal to me, as long as it’s justified.

On the Eye it was a small toolkit I carry in case my bike falls to pieces. Fair enough; the spanner could be used as a weapon, perhaps, or to undo the capsule and send it plunging into the Thames. At the concert, though, it was my DSLR which was flagged up, as I was told that on the second day of the two-day event, staff had been told to stop “big cameras” from entering. This has been happening more and more in the last year or two.

The problem here was nothing to do with security, but more to do with copyright. The organisers didn’t want people to take shots of the bands on “professional” cameras, even though everyone there had paid a considerable fee to see said bands. Strangely, no compact cameras or mobile phones were being taken, though.

So, at the entrance I was told that I needed to hand in my Nikon D40 at a steward’s office, and was ushered through the gate. I’m ashamed to admit that after a very, very brief search for this office I instead walked straight towards the stage, and as a result managed to get some lovely shots of my family relaxing in the sun. None of the stage, though – a shot of Sting from a quarter of a mile away isn’t much of a memento as far as I’m concerned.

The true piracy, as the concert organisers see it, was being perpetrated not by us “big camera” users, but with mobile phones. Cheap memory cards can handle lengthy clips now, and several hundred people seemed to be recording the whole concert from various angles. For what reason I may never know, as a two-hour set filmed in YouTube-quality seems like a waste of time to me.

Try taking 35,000 people’s mobile phones away, though, and see what happens…

Although the Eye was practically made for cameras, it seems strange that they are welcomed with open arms there, but (half-heartedly) banned elsewhere. Strange, also, that the organisers of the concert were happy to let me take a toolkit full of pointy metal things into their gig, but not a camera.

Perhaps technology needs to offer the solution here, as well as being the problem. Anti-camera technology has been around for a while, and could stop people taking pictures of certain copyrighted areas, designs, people, etc. while allowing photographs of friends and family without the intervention of security guards. Of course, another solution would be for people to lighten up about copyright a little.