What I look for in a lens.
So what do you really need?
A good way of finding out what you really need, is to review your images. Look back at all your keeper images, filter out everything that you did not rate 4 or 5 out of 5. Now look at the focal lengths and apertures used. If you were using an 18-55mm lens and you find that most images are at 18mm, or some are stitches of 18mm images, then perhaps a wider lens would be of benefit. It could also be that 18mm is in fact what you need and you do not need another lens. On the other hand, if you constantly find yourself at the 55mm end and cropping a lot, then perhaps a 55-200mm or 24-70 will be beneficial. Perhaps you find that a lot of your images suffer from excessive noise, camera shake or motion blur and you simply need a bigger aperture. Or perhaps you’ll find that every keeper was shot with your 85mm F1.4 lens and images with any other lens was rejected. Get rid of the other lenses you do not use. Sell them or swap them for something different.
One thing that photographers can’t seem to get enough of, is detail. Most of us would not mind to get more detail from our existing gear. That detail comes from pixel count on our sensor, dynamic range of the sensor, the amount of light the lens was capable of providing and the overall sharpness of the lens used. Perhaps you have lenses that cover your desired aperture and focal ranges but they lack image quality or sharpness.
You’ll have to decide what matters most to you when you buy that lens. Sharpness, multi-purpose, weather seal, price, etc.
On the next page we’ll look at sharpness and pixel counts.