I get asked this question a lot, with respect to camera equipment, lenses, lighting equipment, etc.
This is a really complex question and an even more complex answer.
The short answer is based around the principle that only you know what you will need.
My pat starting point for advice is to use what you have until you reach a limitation. But make sure you understand that limitation.
If you are shooting a dancer, for example, in a stage performance, you are encountering challenges of low light and fast action. In general you need a fast shutter speed to catch the action, but getting enough light to reach that shutter speed may be a problem. There are 2 ways to solve this problem: increase your camera sensor’s sensitivity to light (ISO), or use a lens that collects more light. Or both.
The easiest approach obviously is to increase ISO. Most if not all cameras have a ceiling where noise starts to degrade image quality. You can address this to some extent by using software. Once you’ve tried both, and still can’t get the speed you need, perhaps then it is time to look at investing in a faster lens.
Another example: if you are shooting with a single strobe, and need more control of the light, you may wish to invest in another modifier. Or if you are using a single strobe and really wish you could separate your subject from the background more, perhaps it’s time to invest in a second strobe.
And so on.
Need and limitations on your work should dictate what and when you purchase. There are other limitations – such as time – that can also be solved with equipment.
Some excellent photographers use minimal gear, while others use a bewildering amount (are you listening Joe McNally?)
Photography is a journey. Part of the experience of that journey is learning and growing in the craft. How you make the picture will definitely influence your ability to artistically define yourself and your work. The catch I was referring to above is that like with most tools, the higher quality the tools are the easier and more enjoyable the task often is. The trick is knowing where to invest your limited resources. This is why I suggest moving slowly and let need dictate. Try to use what you already have; if that isn’t satisfying, then go ahead and make the investment to fill a compelling need that you have.
An oft quoted piece of guidance is to buy the best that you can afford. While I personally have paid “the poor man’s tax” many times, I would proceed cautiously. Good lenses are almost always a great investment, but sometimes you can save extraordinary amounts of money making compromises. There are a couple of good examples that come to mind.
For my AC powered studio strobes, I use Paul Buff products – White Lightening and Alien Bees. Alien Bees especially have the reputation of being a “weekend warrior” solution. But they are affordable, rugged, well supported, and have many affordable light modifiers of excellent design available. They have always been criticized for wide fluctuations in color temperature as you vary the power output. But this criticism – and your buying decision – needs to be made from a realistic, not an emotional – standpoint. It turns out that Alien Bees light quality isn’t much different than other, higher priced units (some many times as expensive). And, unless you are shooting for a demanding advertising client, may not be a very big factor anyway.
There are many other, important, reasons for choosing a lighting systems (which I haven’t even begun to cover), and I’m not endorsing Alien Bees. My point is that you can fill a need with a relatively high quality light for a significant cost savings if you have done your homework and fully evaluated what your needs really are. This is a situation where you can get by with less than the best and still never hit a limiting factor. Do your research ahead of time. Systems such as this command a good price on the secondary market, so your risk is also minimized by the ability to sell the equipment if you ever do decide to move up.
The other example I want to use is 70-200mm f/2.8 lenses. Most camera manufacturers sell these lenses for around $2000. Third party lens makers offer these same lenses for roughly half this cost (and in one case, about 40% of the cost). Such a deal. For a lot of people, this may be the sensible solution. But hold on. It turns out that for this price point, you can chose either high optical quality or fast focusing. Not both. You want both? Well, my friend, time to pony up that extra $1K.
So if you are shooting, say, dance, where you have to track a fast moving subject and where you want great optics, and you don’t want people staring at you with open mouth as you utter a steady stream of expletives because your lens can’t keep up, then it would probably make sense to make that additional investment. It’s also true that manufacturer’s lenses tend to hold their value more than third party lenses.
Finally, remember that there are two primary variables affecting any type of photography: capture and post processing. It’s senseless in my opinion to ignore one at the expense of the other. You need to plan your purchases so that both sides are well represented.