Jonathan's blog

Well that’s a question. There’s no easy answer, but I’ll discuss it a little here. If you just want the figures, scroll down to the table!

The number of film “pixels” (grains) does not equal to the resolution of the film – unlike pixels on a digital sensor. For now let’s ignore this fact and get down to some numbers.

I’ve checked in various places, and the consensus seems to be that a frame of 35mm film (24mm × 36mm in size) has up to 20 megapixels, assuming the film is fine-grained, and was exposed and developed properly. We arrive at this number by scanning a negative at progressively higher resolution (in terms of dots per inch, dpi), seeing smaller and smaller artefacts in the picture, until we reach a stage where increasing the dpi of the scan does not yield more smaller grains in the scan. At this stage, we see what digital resolution we have scanned the image at.

There’s massive scope for mishandling film and reducing the fineness of the grains, which means we will effectively lower the digital resolution of the negative. It’s extremely hard to judge this here, so we will assume that our hypothetical photographer was careful in handling his film. We will also ignore any loss of sharpness caused by imperfections in the lens.

Taking the optimum value of 20 megapixels for a 35mm frame, and extrapolating this to other film formats…

As I touched on earlier, raw “pixel” (grain) count doesn’t necessarily give better resolution with film. Grains on film are different sizes and not in a neat grid, like pixels in a digital camera’s sensor. True resolution, as seen with the eye, has more to do with resolving closely-spaced pairs of fine lines.

Given that you usually need more film grains than digital pixels to achieve the same optical resolution as seen by the eye, it’s a reasonable assumption that my 35mm SLR (~20 megapixels) is similarly performing to my Canon 450D DSLR (12 megapixels).

Some high-end digital cameras such as the Hasselblad H4D-60 can now achieve 60 megapixels but this still doesn’t come close to professional medium format cameras using 120 film (still used for lots of magazine and glamour photos), or large-format cameras (still almost exclusively used for landscape photography).

So there you have it. Film can produce a considerably higher optical resolution than digital cameras, when used carefully.

Most of the photography articles on this site are about advanced cameras and techniques. But recently someone asked me for advice on buying a compact camera for a holiday, so I decided to write this guide. Hopefully it will be useful.

Lens

There’s a lot to know about lenses, and they have a huge impact on the quality of your photos – yet they are hardly discussed when talking about compact or point & shoot cameras.

A good rule of thumb is judging the size of the front piece of glass in the lens. In a phone camera this is probably not more than a couple of millimetres in diameter, and the quality shows. Good lenses are expensive, but aim for at least a centimetre across, and preferably more.

You can also learn something from the focal length. Roughly speaking, the more the lens “pops out” of the camera, the better. Again, phone cameras are very thin with a focal length of a few millimetres at best. Modern compacts have a motorised lens that makes them a few centimetres deep when switched on. A longer focal length usually implies a larger image sensor, which is a plus for image quality.

On most cameras, you’ll find some numbers printed on the lens. Usually this will give the range of focal lengths of the zoom lens. You can use this information to compare cameras. For example, the Fujifilm J20 in the picture above has a focal range of 6.3-18.9mm.

There is usually another number printed on the lens. This is the maximum diameter of the aperture. You don’t need to worry about what this means, but a lower value (e.g. 2.8) is better. Lower values mean the camera works better in low light where you can’t use flash, and will give nicer background blur. In the Fujifilm J20 shown above, the range is 3.1 when fully zoomed out, and 5.6 when fully zoomed in.

It’s also worth briefly mentioning optical zoom. On compacts this is given as a number like 10x, which means you can zoom in ten times closer. In focal lengths, this would be represented as something like 5-50mm. In general, a higher optical zoom means a larger lens and a heavier camera. The Fujifilm J20 shown above offers 3x optical zoom. You might like to go for a higher-power zoom if you are planning on going on safari, etc. Avoid digital zoom.

Batteries and chargers

So far we’ve talked about image quality but there is a lot more to consider. Most cameras now come with lithium-ion battery packs, rather than AA batteries. This means longer battery life but also that it’s harder to get new batteries if you run out of juice on the move.

An important factor is how the batteries are recharged. Do they come out of the camera and go into a charger, or do you have to plug the camera into a charger? If you have to plug the camera in to charge the battery, you can’t also use it at the same time.

For most people it’s best to buy at least two batteries so you can be charging one in the charger while using another at the same time. If you carry spare batteries with you, you can easily swap when you run out.

Check that your battery charger can work overseas. Most can, and are marked with 110~240V. You might need a different cable or adapter, though. Amazon is probably a good place to look for alternative cables for your camera battery charger.

Memory cards

Memory cards are cheap now, so you might as well find out the largest size your camera can take, and buy that size. As a rule of thumb, most modern compacts take photos in JPEG format that are around 3-4 MB in size. You could save around 1000 photos on a 4 GB card.

Most importantly, buy two cards. If you haven’t the budget, it’s better to buy two small ones than one large one. If you are going on holiday, swap the cards over every day. That way if one breaks, or you lose one, you still lose half the photos but you lose every other day, rather than the first or second half of the holiday, or worse – all of them.

Always keep the cards in their little plastic cases to keep them clean. Consider keeping them in your wallet’s coin pouch so you don’t lose them.

If you run out of space, almost all tourist places sell memory cards these days, so you can easily buy another card and avoid deleting any photos.

Other features

Some cameras have other features that you may or may not want. Decide which you want in advance, and don’t let shop salesmen try to change your mind. Consider:

• Movies. Almost all cameras can record video now, but some do it in poor quality as a secondary feature, or limited to 1 minute. If you want to use your camera as a camcorder, pick one that does video properly.
• Panorama feature
• GPS geotagging (records where each photo was taken – can be useful on a tour)
• Image stabilisation (useful when you usually use full zoom)

Choosing the camera

It’s quite important to see the camera in real life before buying it. Some cameras feel right; others don’t. Some cameras have buttons that seem to be in awkward places.

Seeing the camera in a shop also gives you the opportunity to examine the build quality. Sure, it might tick all the boxes on your wish list, but if it’s plasticky and creaks when you squeeze it then it probably won’t last ten minutes in your pocket. It’s good to look for cameras with metal casing, and a sturdy lens cover. Some cameras have flimsy plastic lens covers that can easily be pushed open in a handbag.

Remember that it’s a bit rude to use a shop to play with a camera, and then buy online. You owe it to the shop to buy from them, but it’s a good idea to print out quotes from online retailers to show to the shop, and use to get a discount. Buying from a real shop gives you somewhere to return the camera easily if it isn’t quite what you were hoping for. Shops will often also do you a deal on a bundle – perhaps a camera, bag, memory card and second battery.

In today’s day and age of convenience, you might ask why bother using film to take photographs?

After all, a digital camera is cheap and easy. You can take hundreds of photos of anything you like. You can take photos like mad without thinking, and hope one turns out alright. You can delete the poor ones. What could be better?

This is why I have preferred to use my 35mm film camera in preference to my digital camera recently.

Each time I press the shutter on my film camera, I know it’s going to cost me something like 30p in the cost of buying the film, and developing it. So I think twice before I press the button, and the simple act of thinking a second time usually means my photos come out better. I make sure the composure is right, that the lighting is OK and that I haven’t made some mistake that I’ll regret later.

On top of that, I can only get 24 or 36 photos on a roll of film. Sure, I can change films on the move, but this limitation means I don’t want to waste all my exposures. So I save them for something worth taking a photo of.

And besides all the benefits of better photography, it’s fun to  develop a black and white film in my bathroom. I find it so satisfying to take a photo on a camera that is fully manual, take the film out, develop it, and then scan it, and the image on the screen has been almost entirely my own work. No assistance from a microprocessor that thinks it knows best.

Clearly film photography isn’t for everyone, and it’s not for every occasion. I still use digital for my Photo Challenge entries where it’s essential to get them from the camera to the web as fast as possible. But if you fancy learning to become a better photographer, then film is a great tutor. Why not have a look at some old cameras on eBay?

When digital cameras came out, people hailed it as a great revolution. You could now take thousands of holiday pictures and simply delete the ones you didn’t like. While this is certainly a bonus for some, it can encourage the photographer to be lazy about setting up the scene properly.

My first “real” camera was a digital one. I do try to think about the composition, the lighting and other things. But often I end up going with the trial-and-error approach, and sometimes for photos like this one I would take hundreds of photos with slightly different settings, just to get the perfect shot.

Since I’ve started using a 35mm SLR, I’ve noticed I think much more carefully when taking photos. Naturally, you think twice before pressing the shutter when you know that it will cost you 25p to do so. I tend to take only one or possibly two photos of the same subject, which makes me carefully consider everything.

This can only be a good thing!

The downside is that it can take a while to fill a roll of film, as I have to have up to  36 pieces of inspiration before I can get the film processed When I get my current film done, I’m looking forward to seeing some of the shots I’ve taken over the last few days.