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If you are buying a digital camera then you must get an SLR not a compact, you should be looking for one with a full size (33x22mm) sensor chip and if you have to choose between more pixels or better lenses then get better lenses, preferably fixed focal length ones, zooms tend to be soft, cheap ones even more so and if you replace the body in the future you will still have the lenses. If you are contemplating upgrading your 8 megapixel (or even your 10 megapixel) for the latest 13+ megapixel camera and you still use the standard zoom lens then you will get a much bigger improvement in quality by getting better lenses instead.
An alternative cause of softness is camera shake, zoom lenses tend to be slower than prime lenses and also both heavier and longer so movement is a problem. I know it is increasingly difficult to use tripods in public places and they are heavy and bulky to cart around, but where you can you should try and use one (with a cable release!), it does make a difference.
Most cameras these days seem to have auto focus, these are not necessarily too clever, make sure they are focusing on the object of your picture and not some overhanging branch or intruding boulder.
Since photographers started switching to digital I have noticed that I am rejecting more pictures because of distortion. Converging parallels are a much bigger problem now than they used to be and barrel distortion also seems to be worse. I have no doubt this is purely because of photographers using inferior lenses. Pictures are often badly framed as well, I assume that what you are seeing through the viewfinder is reasonably framed, but all too often what we get has the top or the sides cropped off. This may be a failing of the cameras or happening when the pictures are transferred from the camera (see below), but please make sure you leave plenty of space round your subject.
While I insist on a minimum file size of 26mb for scanned pictures this does not apply to users of digital SLR cameras. Most professional digital SLRs now boast at least 8 megapixel CCDs and higher. This will produce an uninterpolated file of about 24mb. 6 megapixel cameras produce 18mb files which should be too small. However, the quality of the picture is usually substantially better than anything you could do with current desk top scanners from film at the same size. We will be quite happy to accept these files even though they are smaller than the guidelines. Some cameras will create bigger files “in the camera”, I have not gone into the benefits of this too thoroughly, but have been informed that the results are better than enlarging the files on the computer. This obviously halves the number of pictures you can fit on the camera so we will leave it to you to decide your best option. We do insist that you store the pictures in the camera in an uncompressed form though, this may be referred to as tiff or RAW, which may have some form of lossless compression applied. If you use RAW then you will have to convert the file to tiff before sending it to me as every manufacturer, and in some cases different cameras from the same manufacturer, use different RAW formats that are not compatible and may not be supported by my software, in addition, as new cameras are introduced manufacturers seem to arbitrarily change their RAW format so if you store your files in the current RAW format there is a fair chance that the format will be dropped and the files become unreadable at some time in the future. DNG files store the conversion data from RAW files in the file header and use a lossless compression technique so should remain readable for longer, but I still want uncompressed TIFF's. Shooting in 16 bit mode doubles the file size without making the picture itself any bigger, don't be fooled into thinking you are sending large enough pictures when you are actually only doubling the information in each pixel, 8 bit should be quite adequate for all but the most difficult light conditions.
I have found that importing raw files produced on a Canon, Photoshop’s raw filter seems to crop the image. I don't know if this applies to all raw formats or if there is a way of avoiding it, but you should be aware that if importing your exquisitely framed pictures using Photoshop, it may be merrily chopping off the tops of your spires or the ends of your gables!
Sharpening. Some cameras include unsharp mask or sharpening software, you must disable any kind of sharpening tool or at the very least set it to it’s minimum setting. Many cameras incorporate an anti-aliasing filter, this is a piece of hardware and cannot be disabled without removing it. Logic would suggest this works by softening the image before it hits the CCD which would be a bad thing and may account for the presence of sharpening tools. I am not in a position to compare results from different cameras and set ups and would welcome feedback from any of you who have used this equipment. You should experiment to see what the best settings are, but remember that virtually all our sales are for print media so your pictures should be optimised for this use.
Please make sure that you keep the sensor free from dust and follow the manufacturers instructions regarding cleaning, I do not necessarily examine every picture at full size and may well miss the odd dust spot so make sure what you send is clean. I have been recommended by a contributor Visible Dusts Arctic Butterfly for cleaning sensors.
Unlike with film we can now send the same picture to many clients at the same time so we do not require multiple versions of the same scene. We have to pay for the space our web site uses and will not upload hordes of similars! This is also a consideration for you while shooting as camera memory is limited and expensive.
Compact digital cameras use cheaper CCDs and lenses, but I have seen excellent results from them. However, I do not recommend their use.