It’s an exciting time to be a photographer. It seems like new cameras and lenses are being announced every few months. Every new camera has something new and exciting to offer. With new lenses, there are a lot of available focal lengths at various qualities, build and price levels. Helpful reviews, articles and sample photos make a very convincing argument for wanting to own the newest gear. But do you really need that new camera or lens? Let’s see!
I like tracking and watching reviews of the latest gear. It’s fun to see which new technology is out there and how it can change photography. Some of the exciting advancements have been frame-per-second specs, ISO sensitivity, bigger and better batteries for mirrorless, dual card slots and so much more. Sony and Canon are the two systems that I follow as I use both systems. 
I own two systems for a few reasons: 
  • Sometimes I need two camera bodies during shoots. 
  • I like experimenting with time-lapse and long exposures. Having two bodies allows me to continue shooting while one camera is doing its thing.
  • I like the optical viewfinders when working with external flashes.
  • I like the look of the photos out of Canon cameras. I like the camera size and technology of a Sony camera.
Because I spend so much time behind a camera, it’s only natural to wonder what the newest camera can do or how a new lens will perform. This is because I am shooting with mostly older gear. I take my Canon 5D Mark II and Sony a7 II with me during most shoots for clients. I bring a small variety of lenses with me as well. Typically, I’ll bring my Zeiss 55mm f1.8, Sony 28mm f2, and a nice vintage portrait lens for fun with my Sony kit. For my Canon kit, I’ll bring the Canon 50mm f1.8 and Canon 24-105mm f4 L.
When you look at everything all together, you can see that almost every camera and lens that I have is upgradable in some sense.

Sony Kit

 Canon Kit

Basically, to make a long story short, most manufacturers offer a specific lens or camera body in a number of different options. A few questions that I always ask myself are, Do I really need something else? If I replaced something, how much value would it provide? How do I make my selection?”
I think it all comes down to quality vs. affordability when deciding how to upgrade something or buy your first camera. In a perfect world, you buy an affordable camera or lens, it lasts forever and it always produces great results. I wish it was like this. Really, I do! 
I take image quality and build quality into consideration. With image quality, I always check that corners look good and try and determine the combination to get the sharpest image. I also try and check the chromatic aberration, fringing and lens flare results. If the images look like they have bad chromatic aberration or fringing symptoms, it’s usually fixable in post-processing. With build quality, I really prefer a solid-feeling metal construction with some level of weather/dust sealing. 
I always start looking for something used. Most photographers who are buying expensive gear take good care of their gear. You can easily see if what you’re picking up is scuffed on the outside and you should totally try out what you’re buying. You always want to confirm that the quality matches your expectations. With used gear, affordability is often related to quality. I’ve had no problems with the lowest level of quality with a number of different used sites.
If I can’t find exactly what I’m looking for, used, I’ll see if the second-best option is available. Sony, for example, recently announced their a7r III. If I was originally looking for a new camera that was high in megapixels for studio use, maybe the Sony a7r II or even the original Sony a7r would be okay

My magic formula (takeaways)

As an example, let’s talk about possibly upgrading my Sony a7 ii
For me, this would mean that I get better battery life, redundant memory card shooting, faster image bursts and better autofocusing. Based on those answers, I’ll look at the cost to switch. I’ll see what a new camera goes for used vs. new. Based on how much I can get it for, I put a value at the gaps that I am trying to fill. If they’re not worth it, then the timing isn’t right. For now, I won’t be upgrading. If I started shooting more sports or started missing focus with my family portrait work, I would start to reconsider.  
The most expensive camera isn’t always the best camera. The best piece of gear that you can own is one that fills a gap, helps you solve a problem and is in your price range.
This general formula helps me make decisions on when to replace something in my kit or when to make a new addition.