I want to buy a SLR as jewelry. What should I choose?

In view of your budget, it is important to buy a cheap lens that supports macro. As for the fuselage, it doesn't really matter. Now no matter which one is the cheapest entry-level SLR, the picture quality is very good, and because the price has been castrated, it is all mechanical properties and materials, which are not very important to you. And good picture quality and excellent macro shooting ability (because shooting close-ups of jewelry requires very detailed performance) are very important. My personal suggestions are as follows:

The most ideal combination:

On the fuselage, I recommend you to consider Nikon's d3200. Although it is entry-level, it has excellent image quality of 2400w high pixels. High tolerance, good color performance, excellent and delicate picture quality, which is very suitable for still life shooting. As for the lens, in addition to the camera lens, it should be equipped with Nikon 40mm f/2.8 macro, which is a special macro lens for Nikon semi-cameras, and is a fixed-focus lens for shooting still life and macro close-ups. With the ultra-high resolution of the d3200, you will get professional-grade image quality. Moreover, the combined total price of d3200 sets of machines +40mmf2.8 is not counted, and it can be won around 4000. It is a relatively balanced macro combination in the current half-width machine.

The most special combination:

In fact, there is no need to shoot jewelry with a macro lens. If the requirements are not very precise and professional, then a set of close-ups with tens of dollars can also solve the problem of macro shooting. Pentax k-30 is recommended here, with excellent color, moderate pixels per inch, good durability and high overall cost performance. However, the main concern here is its excellent direct color, which can save you a lot of trouble in repairing the film. In addition, the quality of Pentax 18-55 is also good, basically one camera is enough, and a lens with several times magnification (generally x4 x6 is enough) can get the effect of shooting close to the macro lens.

Cost-effective combination:

If you want to make the budget lower, the combination of Nikon d3 100+ Sigma 70-300mm f/4-5.6 DG macro is also a good combination for jewelry shooting. Sigma 70-300 is a bit fleshy in the head, but the image quality is not bad after the aperture is reduced to f8. Nikon d3 100 is not a high pixel per inch, but also has a very good performance, and it is also a good cheap macro shooting combination. It's just that this combination needs attention, that is, the equivalent focal length of 70-300 is longer after being placed on a half-frame machine, and it is easy to shake hands when shooting at ordinary times, so try to shoot with a tripod (a stable tripod of about 200 is enough). The angle of view is also relatively narrow, which requires more practice to adapt.

Of course, in addition to excellent equipment with close-up ability, it is also important to arrange auxiliary light when shooting ornaments. Flash the light if you can. If there are no conditions, you can consider using light to enter the room during the day to shoot ~ ~