The more you photograph, the more issues will potentially arise. It's kind of like a spiral. But, being aware of the issues and being capable of avoiding them, will be how you'll achieve better photographs and really enjoy photography.
Of course, you might be aware of some of these issues, but still, if one of the 4 points below helps you, it’s a win.
Different Contrast Levels With The Same Lens
You’ve probably noticed this, I've certainly noticed this and to be honest, there is no real way to fix this. Lenses sometimes provide bad results, it's a fact. However, if you understand why this is happening, you’ll be able to lessen the impact as much as possible.
Each lens is built from several lens elements, nothing new, however each of those glass elements inside of the lens has coatings to counteract different anomalies in order to provide a better picture. Depending on the quality of the lens, the coatings will be different, thus affecting the quality of the image.
Of course, the glass elements need to be of top quality in order to have the sharpest image possible, but coatings are the ones which are the most to blame for such varying contrast.
The Metering Is Often Incorrect
No meter is ever completely correct. That is basically a fact. However, the thing you need to understand about metering in-camera is that it behaves differently depending on the settings, the scene, and how you use them.
Firstly, you need to check if you are using the correct metering mode in your camera. Now the “correct” one is dependant on what you expect the metering system to do. If you want it to sample exposure from the middle point, then be sure that spot metering is checked.
Secondly, learn how each of the metering settings work, so you can use them according to your exact needs. If you know your camera like the back of your hand, it will do what you need it to do. Read the manual, try it in practice, get used to the way it operates and it will serve you perfectly.
Lens Flare Is All Scattered And Weird?
This is quite obvious really, but I have to admit that it had me wondering several times before I realized that the front or back element was dirty. Basically, when you have direct sunlight or any light for that matter hitting the lens, every speck of dust, dirt, and what not, gets lit up like a Christmas tree!
Add some optics on top of that and you get bokeh where you shouldn’t have bokeh, essentially creating odd lens flare.
Note. You can use this to your advantage in order to create some cool effects of course.
One thing that you should have in mind is that, if the front and back elements are nice and clean, and you are still getting specks like that, you might have a bigger issue. The same problem will occur if you have mold or dust creeping in between the lens elements inside of the lens.
That is not something you can clean by yourself, and you should take the lens to the service center before the damage becomes too extensive to repair.
Using Tripod But Pictures Are Still Blurry?
Usually, tripods don’t really work well for immediate camera stabilization. Meaning, they need some time for the oscillations to go away. The higher the tripod is set (meaning the thinner parts of the legs are being utilized) the rocking needs more time to settle.
Furthermore, additional vibrations will affect the picture quality too.
To counter this, you should first remove the camera strap; for one it is a hazard, and two, it will induce slight vibration. Straps are bound to 2 points on the camera, allowing them to twist the camera in basically every direction, effectively inducing vibration more than the camera itself due to bad aerodynamics.
Mirror lockup usually doesn’t change anything, but just in case, do that too.
Lastly, make sure you set your camera on a 10 second timer, or use remote trigger to release the shutter. The 10 seconds timer is usually enough for the rocking (which is just slight, but enough) to settle.
If the rocking doesn’t settle within that 10 seconds (even if it is near 10 seconds) then you need a better tripod because that one will eventually end up breaking your camera.