I would like to step into semi-pro food photography and I am wondering if i should upgrade my camera Canon 100D to something else. Currently I am using it with the Canon EF 50mm f/1.8 STM lens which i find it not as great as i would like it. Can someone advice me if i should upgrade my current kit or just pick a better lens to go with it.
Though I'm not familiar with the IQ of your current camera, I believe you'd be better served by a lens or two. The 50mm simply isn't enough. It doesn't focus close enough, and the focal length is limiting. I suggest you look into a longer macro lens, maybe 100mm or so. You'll also need to budget for lighting. A "better" camera body might give you somewhat cleaner images and higher resolution, but without the flexibility of a good selection of lenses, it won't take you very far.
If you can afford a macro lens, consider attaching macro tubes between the camera body and your 50mm for closer focusing distances and greater magnification. Macro tubes can compromise edge sharpness somewhat, but if your edges are out of focus, that may not matter. You'll need macro tubes with electronic contacts to enable the AF and aperture control of your Canon lens(es).
I assume you're shooting on a tripod. If not, budget for one.
Finally, color accuracy is largely a matter of properly processing your RAW files. Consider getting an X-rite ColorChecker Passport ($99) and Lightroom, and use the CCP to generate custom color profiles for your camera and lighting.
Finally, educate yourself on focus stacking techniques. In macro photography, it's often difficult to get DoF deep enough without stopping the lens all the way down and suffering image softening due to diffraction. Focus stacking involves taking multiple frames with focus set at different points, then merging the frames to create a final image with deeper DoF. Some cameras (including recent Panasonic Micro Four Thirds models) have focus stacking built-in, but you can do it manually in Photoshop with a camera that lacks this feature.
