Must Be This Way » Photo Project: Digital Compact v. Digital SLR

Photo Project: Digital Compact v. Digital SLR

Just what is the difference between a compact digital camera and a digital SLR (single lens reflex) camera?

At the outset I should say that if you’re happy with a digital compact, well, that’s just fine. Today’s digital compacts offer great quality at amazing prices. And they’re also very light, which is not an insignificant factor for hillwalkers and backpackers. But if you want to step up in quality, or have been inspired to take your photography more seriously, then there’s no doubt that a digital SLR will help you elevate you photographer to a higher level.

What is it that makes the difference?

The Thorny Issue of Megapixels

We judge the quality of a camera by the number of megapixels it features, yes? Well, no, not really. More megapixels can mean better images — or certainly better resolution at large size. But there are many other factors the influence the quality of a cameras image. And that’s the point.

The quality of the image taken by a camera – its clarity and its sharpness – is always more important the the pixel count. And although the quality of compacts seems to be improving at a dramatic rate it is nearly always the case that a good SLR with, say, 6 megapixels, will provide better images than a cheap compact that claims to have 12. But why is this?

It’s all in the sensor

One of the critical factors for quality is in the sensor, or computer chip, that received the image. This is the chip onto which light is directly exposed.

As megapixels have become the kind of accepted, macho, performance factor for digital cameras so the manufacturers have tried to cram more and more pixels – or mini sensors – onto one sensing surface. The smaller the pixels become the more indistinct they can be and image information can often be blurred and not captured as distinctly. This is not to say your images will be blurred, they won’t be. But as everything shrinks – and the pixels are crammed on – we get to a kind of diminishing return for quality.

A digital SLR will often work with a different, more advanced, larger and more expensive sensor. These sensors perform better, are more robust and are more able to cope with the latitude of an image — the range between the bright bits and the dark bits of an image.

It’s all in the lens

Another major factor that influences overall quality is the camera lens, indeed, this is probably the most significant factor in quality. Compacts have smaller lenses that simply capture less light and less detail. SLRs on the other hand almost all use lenses of quite amazing quality. The standard lens (or kit lens) that comes with a Nikon, Olympus, Pentax, Sony or Canon (and the rest) is of a quite amazing quality. Thirty years or so ago zoom lenses were coming into their own, but their performance was noticeably inferior to fixed lenses (ones that can’t zoom in or out). But these days the quality of the standard zoom is amazing. These bigger lenses operate with a sharpness that simply cannot be met by a compact.

Now, before we move on, I should point out that these are generalisations. There are some great compact lenses out there, for example, those made by Leica and that are used by Panasonic cameras. But these compacts will come at a real price.

Manual Control

The other advantage of the SLR is that it will almost certainly come with a range of exposure modes, including a fully manual mode. I’ll deal with exposure modes later on but, simply put, the difference is this. With automatic modes the camera assess the light of the scene using it on-board sensors. It then translates this in two key settings — a setting for the shutter speed, and a setting for the aperture of the lens.

Both shutter speed and apertures effect the amount of light that falls on the sensor. The darker the scene the more light you need, which means shutting with a wider aperture or a slower shutter speed (or a combination of the two).

Now, don’t get worried about this — everything will be explained later. But these two methods for regulating exposure have different effects on the image you’re taking. In many situations the camera will get its sums right and will come out with a good overall balance for your scene. But when you’re shooting more difficult scenes with, for example, a great range of light and dark, the photographer will have to make some important decisions. Should I set the exposure for the dark bit of the scene or the light bit? Well,as we shall see later, it all depends on what you’re trying to do. But manual mode allows the photographer to set these choices for themselves, and there are very real advantages in that.

We are beginning to see more and more high-end compacts that feature a fully manual mode. For me though, manual means SLR although once you’ve mastered manual exposure you can obviously do more with a compact. But, more or less, proper manual modes means an SLR camera.

Anyone buying an SLR for the first time is advised to shoot on manual until they can really understand how it works. Once you understand manual it is more easy to get better results from some of the automatic modes of your camera. For example, many landscape shots can be taken using aperture priority, automatic, modes. Here you select an aperture for your shot and the camera regulates light by raising or lowering shutter speed. But aperture itself makes a big difference to many shots, so it helps to know what aperture to use even when you’re using an automatic or programme mode.

Don’t worry about this now. All you need to know is that — in general — the digital SLR will give you a better sensor, better light metering and the ability to control exposure manually. And, critically, it will come with a very high quality lens.

I’ll look at manual exposure in more depth a little later, and I’ll recommend some books that are pretty good for beginners. A good book is a necessity. If you know a photographer, you may be lucky. They may be able to talk you through things easily. But a good guide should give you the helping hand that you need.

Next up: How to Choose a DSLR.

16 Comments so far
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More great stuff! Thank you

Interesting read

Although I do believe that the general view is that the quality of compact cameras has stagnated if not taken a bit of a dip(IQ wise)
Due mainly to manufactures cramming al those MP in to a tiny sensor. Do we really need all those MPs?

Anyways It does look like things maybe changing Panansonic new DMC-LX3 look to be a step in the right direction.

As for How to choose a DSLR, As long as it a Nikon you’ll be FIne

Paul – don’t start !!!

Interresting piece Andy. My experience is that sensor size is the critical factor in the difference in image quality between compacts and DSLRs. There is one compact with a sensor roughly the same size as a DSLR – the Sigma DP1. I haven’t used this camera but I have seen images and they are impressive.

As you point out cramming megapixels onto tiny sensors does not mean higher quality images. I reckon 8mp is the optimum for tiny sensors. On that score the best images from a tiny sensor I have seen come from the 8mp Ricoh GR-D. The GR-D has a proper manual mode.

Yes the pixel count issue is worth emphasising. The typical ‘consumer idea’ on this is the more the better, but in the last 2/3 years it’s started to reach optimum levels with current technology and cramming more in thus starts to get questionable. There are cases where a newer, higher pixel model gets tested and is found no better and possibly slightly inferior to its predecessor.

The Sigma did not get terribly favourable reviews Chris; there are some samples at http://www.dpreview.com and the overall conclusion was not good – though admittedly, that was partly because its a slow camera which is traditionally not very important for hiking. BUT – I have to say – that is not entirely true and I quite often find a fast automatic function gets me a shot I’d miss in fleeting light, or when its so cold I simply can’t stand and shoot for more than 30 seconds or so (once, memorably, coming down the back of Pavey Ark).

I understand the great attraction of a compact for its size and light weight, but I don’t think we’re there yet: even the Leica M8 did not measure up to the unassailable quality of its film cameras.

More pixels does mean you can get bigger pictures relative to the quality with no corresponding degradation, but the baseline quality is another matter.

However if you don’t want or need anything bigger than A4 or for internet publishing pixel count is not a major issue, and cameras gets weighed up, literally, with the weight cost of a larger sensor camera which really means an SLR.

Drive to Tesco and nothing more: A Ford Fiesta will do the job. Drive long distances or cruise the autobahn: a Ferrari wll be much better….though at a price.

I have been very happy with my Ricoh GX 100 (now 200) though I suspect that the Ricoh GrD is a little better and I would be happy with a better sensor, and less pixels. The GX 100 (200) does offer manual controls, a wide angle lens as well as a Tele converter. Also important is the ability to shoot in RAW. As for DSLR I am very happy with the Pentax K100d and 18-250 lens but it comes at a weight premium.

James, I have a Ford Fiesta and find it fine for driving all over the Highlands!

Some reviewers have criticised the ergonomics and speed of the DP1 but none I’ve read has criticised the image quality and it now seems generally accepted that this is the only compact camera that can produce results comparable with a DSLR. As I said, I haven’t used this camera so I can’t say if I’d like it or not. The handling of the GR-D is superb but the results are not DSLR standard (and by DSLR I mean Canon 350D and 450D cameras with kit lenses as that is what I use).

OK but did you cut the exhaust pipe in half to lose a few grams Chris?

Just kidding, joining in with the craic. Nice review on the Hitec Vlites 2/3 years ago incidentally…I bought 3 pairs in a bargain sale.

My impression from DPreview is the image quality of the Sigma compares very well with modest DSLRs but – and its a big but – only in good light, ie. before you increase the ISO above 200 or possibly even 100. That’s far too restricting for average hiking, I reckon. Think winter sunset over Torridon, moody dark skies over Scafell…you need some good ISO performance up to about 400, unless you have a tripod in which case a decent DSLR and no tripod might be a better option.

I currently use a Canon 5D and an L series zoom which is very heavy and quite bulky, but I’m happy with that for the quality it gets.

Hopefully its just a matter of time before we get a compact style camera matching both the quality and versatility of DSLRs. The Canon G9 for example is very nice but – and DPreview said this – it uses the same small sensor as its predecessors and what we really need is something like the G9 translated into something like the large sensor terms of the Sigma.

There was a rumour about Leica producing a full frame successor to the M8 but a Leica dealer told me no such thing was planned, and in any case it would be serious money.

I don’t need to cut the exhaust in half. The rough track to my house does that for me!

I get the impression from images I’ve seen that the DP1 is okay at ISO400 and usable at 800. But I could be wrong.

I use a Canon 450D (upgraded from a 350D a couple of months ago) and, mostly, the Canon 18-55mm IS lens. I always carry a light tripod too. Although 400 is okay with the 450D I prefer 200 and 100 ISO.

My ideal camera would be something like the Ricoh GX100 with an APS-C sized sensor.

I don’t even think about Leica – just too expensive!

I should perhaps point that I am usually taking photos for publication. If I was taking photos for personal use and the web the Ricoh GX100 would be fine.

I’m finding this all very interesting. I’m a point and shoot man and have been using an Olympus mju 770SW, which is a good, idiot proof and weatherproof camera. However, the results are a bit disappointing overall, which, I guess, is not surprising given what the camera is meant for. You can see the results on my Picasa page: http://picasaweb.google.co.uk/robinmevans . All the photos this year were taken using this camera. I should also point out that I have reduced the picture sizes to upload.

I’m not sure that I want to go a DLSR, but the Ricoh GX100 looks an interesting step up and not outrageously expensive.

I would be interested in some comments on protecting cameras from the elements as the major reason for getting the Olympus was to have a totally weatherproof camera.

Robin, I’ve never found that I needed a waterproof camera. Occasionally the bag I use gets soaked but so long as you don’t immerse your SLR in water you should be OK.

I have and occasions problems with condensation though. I missed some wonderful pictures in Spain this year because it took a day to clear!

There is a whole new topic here waterproof bags versus a waterproof camera. I am still looking for the lightest weight bag for my GX100 that will fit in my hipbelt pockets.

What about the super-zoom cameras – do they have any advantages over either compacts or DSLRS? They’re certainly cheaper than a DSLR.

Well I have just got a Panasonic Lumix LX3 so I shall be trying it out in the coming months. It seems to have everything I need (apart from a long optical zoom but it gives quality over quantity)
The camera is very intuitive and easy to use and is packed with features. The picture clarity is great although I need to test it in a variety of conditions to get a better feel for it
anyway I’ll let you know how I get on

To Mark:
IMHO what you do not get with a compact, apart from the creative control, is a real wide angle lens, and in the mountains, I really miss that. The lens is followed around by the camera! Optics trumps digital processing every time – remember you are painting with light!

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