Why is the SLR not as good as the still life shot by LX7? Is it the lens or the camera itself, under the same light?

Simply put, it is the shooting method.

You said that you have been playing with the SLR for a long time, and you should start studying deeply. You can't shoot still life, especially small objects. First, the automatic exposure may not meet the requirements; second, the autofocus point may not be the required point; third, the depth of field may not be required.

You can use Av file or M file, and pay attention to manual focusing. Now SLR has the function of real-time framing and magnification in precise focusing. After using it, I know it's not the camera.

Don't think there is something wrong with the equipment just because there is something wrong with it. Change equipment.

Whether a photo is taken well has nothing to do with whether there is a reflector or not. Even those who sell micro-cameras dare not boast that they are better than SLR. Conversely, the effect of taking pictures with SLR is not necessarily good. The first is whether you have mastered the shooting method, and the second is to use appropriate equipment and auxiliary accessories. Let me say a few words briefly for your reference.