If you own an interchangeable lens camera, then you may be faced with a dilemma if you decide to upgrade your kit. Should you prioritize upgrading the camera body, or purchasing a new lens?
To answer this question you need to look carefully at what your current gear doesn't do satisfactorily. By looking at the main problems you have with your current gear, you can better understand whether it is a new camera or new lens that will best resolve those problems for you.
If your main problem is that you want to operate your camera from positions where you can't look through the viewfinder or see the screen, then a new lens won't help at all. In this instance you'd be much better off with a camera that offers an adjustable rear screen, or one with WiFi and a remote control app for your phone.
Maybe you want to take a series of photos of crowds, with the camera held up above your head on a pole, to get a better view of the crowds. Or maybe you want to take low angle shots of subjects without having to lie on the ground to see through the viewfinder. A variable angle screen on your camera can come in very useful for this type of photography.
Or maybe you're shooting athletics and want to get some track side shots, without actually being able to stand at the track side during a race. Or want to get close-up shots of birds on your garden feeders without standing nearby where you'd scare them away. A camera that can be controlled remotely can allow you to do this, letting you see what the camera sees and take photos using the camera from your smartphone or tablet.
If you're having trouble with your current camera / lens combination not focusing fast enough or accurately enough, then deciding which to upgrade can be quite tricky. Both choice of lens and choice of camera body can have an effect on autofocus.
I would suggest reading reviews of your current camera and lens(es) to see if any mention is made of autofocus being particularly good or bad. If reviews indicate your camera has a particularly good autofocus system, then it's likely any autofocus issues stem from the lens you're using, and so upgrading your lens would provide the greatest benefit.
If reviews indicate that both your current camera and lens have very good autofocus capabilities, then it may well be there is no problem with them. The problem may instead be with your autofocus settings. Make sure you investigate the best autofocus settings for your camera for the type of subjects you like to shoot before deciding there is a problem or not.
One thing to bear in mind if you own several lenses is that upgrading your camera body means that the improved focus abilities of the new body are available with all your lenses. Whereas if you buy a new lens with better AF, it is only that single lens that is 'upgraded'.
For candid photography, such as most street photography, the main aim of the photographer is to capture the subject without being noticed. If someone notices they are being photographed, they are likely to act differently, and a true candid photograph can no longer be made.
Both a camera upgrade and a lens upgrade can help here. You may decide to upgrade your camera to a model that is smaller, and so less noticeable, than your current model. Or you might decide to do the same with your lens.
You might decide to purchase a camera with a quieter shutter, or even one that offers a silent electronic shutter option. Or you might decide to upgrade to a lens with a quieter focusing motor.
Making a decision here can be quite difficult, since both upgrading the camera body and the lens can be beneficial. If you're mainly concerned about the size, I'd suggest looking at camerasize.com. There you can make a comparison between your current camera with a smaller lens against a smaller camera with your current lens, and see how they compare.
If you're after a shallow depth of field to create blurry out of focus backgrounds, then a new lens can definitely help. Depending on your current camera, a new camera body may be able to help too though.
If your current lens(es) are slow zoom lenses, with maximum apertures in the f/3.5 - 5.6 range, then the purchase of a fast lens can make a big difference as to how shallow a depth of field you can achieve. For example, a 50mm f/1.8 lens gives around 3½ stops less depth of field when shot wide open at f/1.8 than a standard 18-50mm kit lens when shot wide open at 50mm f/5.6.
- Already have one or more fairly fast lenses
- And use a camera with an APS-C sized sensor
- And are using a camera system that has cameras available with 'full frame' 35mm sized sensors
- And are using lenses that are designed to work with the full frame model cameras
Then upgrading your camera body to a full frame model may make more sense than a new lens. A full frame body offers a stop less depth of field than an APS-C sensor camera at any given aperture value. And this will effect all your lenses that work fully with the new camera.
For example, if you have Canon's 50mm f/1.8 lens and an APS-C sensor camera, and want 1 stop less DoF, then you could upgrade your lens to the $1449 50mm f/1.2 lens. Or you could upgrade your camera body to the full frame 6D for $1399, which would give you a stop less DoF with your current f/1.8 lens.
Note that the 50mm lens when used on a full frame camera would give you a wider field of view though. The $349 85mm f/1.8 lens used on a full frame camera would give a similar field of view (slightly narrower) and same depth of field as the $1449 50mm f/1.2 lens used on an APS-C camera.
Yet again, this is something that upgrading your lens or camera can both help with. A camera that offers more megapixels or no anti-aliasing filter can capture greater detail in your images. A sharper lens that better resolves fine detail also helps you capture greater detail.
I would suggest trying to determine whether your dissatisfaction with the current level of detail your kit is capturing is down to the camera or the lens. (After first ensuring that the problem is not you, for example if your images are blurry from camera shake, then a sharper lens or higher pixel count camera won't help - you just need to use a faster shutter speed).
If you can zoom into your images at 100% and the images are sharp, but you want to be able to zoom in further, then a better camera will be the solution. If the image is not sharp at 100%, and you're sure the problem is not your shooting technique, then a better lens will be the solution.
If you do decide that you want a higher pixel count camera, bear in mind that the higher the pixel count, the more difficult it is to achieve an image that is sharp at the pixel level. Shake from hand-holding the camera can become more visible due to the increased resolution, meaning you need to use a faster shutter speed or use a tripod to make use of the extra resolution.
If you shoot subjects where you use a very small aperture (such as macro photography) then a higher pixel count sensor doesn't really capture much more image detail. It just provides an enlarged view of the softening caused by diffraction from shooting at such small apertures.
If you want images that capture a wider field of view (e.g. for landscapes) or a narrower field of view (e.g. for wildlife) then your best bet is purchasing a suitable lens.
It is possible to get a wider field of view or narrower field of view by purchasing a new camera body. If you currently have an APS-C sensor camera, then upgrading to a full frame camera would give all your lenses a 1.5x wider field of view. Or the opposite would happen if you upgraded from a full frame camera to an APS-C sensor camera, giving all your lenses a 1.5x narrower field of view.
A higher megapixel camera can also allow you to crop your images more, which gives a narrower field of view. But in general, you are much better off purchasing a lens that gives the field of view you are looking for than changing your camera body. Changing the camera body is often more expensive, plus it affects the field of view of all your existing lenses, assuming they are compatible with the new body. A new lens lets you continue using any existing lenses as you're used to, plus covers the field of view you were missing with your new lens.
If your current camera doesn't feature video at all, but you want to be able to shoot video, then a new camera that offers video capability is the obvious choice. If your current camera offers video but the quality isn't good enough, then again, upgrading to a camera with better video specs makes the most sense.
If you're happy with your current camera's video quality, but find that the focusing during the video can be a bit hit and miss, then a new lens may help (though a better camera may too). Lenses featuring stepping motors are designed to work better when focusing for video.
As I mentioned earlier in the section on autofocus, if you're not sure whether it's the camera body or the lens that's currently letting you down, it can be a good idea to see what other people say about them. If others are finding autofocus during video problematic with the same lens that you have and a more up to date camera model, then it's likely the lens that needs upgrading.
If your camera is 6 years old or older, then I would definitely recommend updating your camera body for better low light performance. Cameras are constantly improving in both the levels of light they can capture usable images in, and the reduction in noise at high ISO settings.
If you have a camera that is only 3 years old or less, and don't own any fast lenses for it, then I'd suggest upgrading your lens. A fast prime lens can give you around 3 stops more light gathering power than a slow zoom lens. While upgrading your camera might only give you a one stop better performance at high ISO.
It's also worth looking at cameras / lenses with image stabilization. If you shoot slow moving (or static) subjects in low light, and you have the possibility of upgrading to a camera that features in-body image stabilization, then go for it. In-body image stabilization means the camera performs stabilization by physically moving the image sensor to compensate for camera shake. This means that you get this benefit with any lens you use with the camera. Great if you shoot in low light a lot.
Note that if you currently have a slow lens that features image stabilization, then upgrading to a fast lens that doesn't feature image stabilization may not have much benefit (unless your camera also features in-body stabilization). Image stabilization allows you to shoot at shutter speeds 3-4 stops slower than you could normally without getting blurry images from camera shake. If you're shooting static or slow moving subjects, then a lens without stabilization would need to be at least 3-4 stops faster for you to get any benefit.
However, if you're photographing moving subjects in low light (such as sports games at night), then image stabilization is less of a benefit. It can only compensate for blurriness from movement of the camera, not the subject. For this type of low light photography, then upgrading to faster lens will be a better choice.
Both lenses and camera bodies can be quite expensive, so you do need think carefully about which will provide you with the most benefit before deciding to upgrade. Hopefully by following the tips above you'll find it a little easier to decide which will make the biggest impact in improving your photography.