Nail lamps can be very complicated and expensive to make. That is why, im assuming, that most lamps are not made properly.
There is a nail scientist that I speak with often about nail technology. He is the best in the industry. That is why I know about this topic.
Even if the lamps are poorly made, its recommended that you use the same brand gel as the lamp. Because there may be brands out there that do things correctly but haven't had a chance to provide convincing evidence. That said, there are alot of nail techs that does not follow this general rule because they think that because the gel hardens under the lamp, that all is good. But doing this leads to service break down and allergies.
That is why I always recommend CND products, from the lamps to the gels, CND all the way. They have proven to me that their products are well engineered and thought out.
Again, the problems from using poorly made lamps and gels are premature service breakdowns, nail damage, allergic reactions. Those are serious problems and are not to be taken lightly(which alot of techs do)
Copied from a previous post written by @BobSweden An excellent, clear and comprehensive explanation. UV LAMPS EXPLAINED Chemists recommend that you use the UV lamp supplied by the gel manufacturer. If you don't, there is a risk of heat spikes or there is also a greater risk that you can...
Read this thread for a detailed explanation and to help you understand how lamps work.