Leaving emotional issues aside ("I just want to buy a new 'toy' so badly"), there are some very logical steps which show the way to a reasonable and informed decision. Consider the following list a "buyer's cheat sheet"; a list of questions and statements that you should ponder on before you buy anything, whether a camera, or a lens
- What is it that I am missing? Why am I unhappy with my current equipment?
If your answer is something generic, such as "my current camera/lens does not allow me to take good photos", that's still not good enough. It simply is impossible for any camera and any lens today, no matter what their brand or their quality, to not allow you to take good photos. If you are unhappy with your photos in general, I am sorry to tell you that it's not the camera that is to blame. It means you have not developed your technique yet, or you are a bit inexperienced. Work on recognizing why you don't like your photos, then work to solve the problem in your technique.
- Is it so that my current equipment makes it very hard for me to take successful photos of a certain kind?
- My camera is very noisy in low light. Should I buy a newer one?
If you believe your camera doesn't let you take good photos in low light, let me remind you that multi-awarded photographers have been using films to capture grainy but truly memorable masterpieces. Don't make the mistake to think that technicalities such as noise have much - if anything - to do with capturing a great photo. If all else is spectacular, it can be grainy. The less you focus on diagrams and charts, the more you will focus on learning how to take great photos.
- But some things are just impossible with certain cameras or lenses. Isn't that right?
The inner dialogue could've been something like this:
- I am unhappy with the D40 and 50mm f/2 combo for indoor sports
- Why? In which way it failed you?
- The manual focus lens is very difficult to use for sports.
- Do you have another lens, an autofocus lens which you can use?
- I don't. My kit lens is too slow, it's only f/5.6 at the long end. In theory I could use it, if I could buy a new camera, with better high ISO capabilities.
- Which would give you the most benefit for the least money?
- A new lens. I could get a 50mm f/1.8 or an 85mm f/1.8. That would give me over 3 stops advantage over the kit lens.
- That's a lot. It can't even be compared, no new camera could cover that difference, no matter how much better high ISO capabilities it would have
And that's how all decisions should be made. Would I want a Nikon D4 and the new Nikkor AF-S 85mm f/1.4? Well, of course I would want that. Can I afford them? No. But I don't let that paralyze me or interfere with my photography. Photography should be about going around problems to reach to the shot. Not keep complaining about what our current equipment can't do.
If you absolutely need new equipment, having identified your needs like in the example above, go ahead and get what you need. Just remember, new cameras and new lenses are not supposed to make us take better photos. They make us take the photos we would've taken anyway, with a bit more ease!