I originally had a dimmer but I noticed that the bulbs give off an annoying buzz when they are not set to 100%. I personally would only use the dimmer for fine tuning (e.g. going from 87F to 85F) and not use it to reduce a bulb from say 100W down to what a 75W outputs. I did away with the dimmer all together and am (was) now using a 60W household bulb at 100%.
2 weeks ago I bought one of the below which is going to replace my incandescent bulb since my plants are responding well to it and my chameleon prefers to bask under it over the incandescent. It is a little too warm directly under it and am working on building a frame to sit on top of the cage to elevate it a bit. Another bonus for my setup is the fact that the LED bulb has a cooling fan which blows warm air into the enclosure which helps to increase the gradient temp a bit.
This LED came as a recommendation from another forum member when I was looking for advice on keeping my umbrella plant alive. It was losing leaves like crazy and getting bare on one side. Since putting this in it stopped dropping leaves and there is new growth already appearing. Here's a link to the
thread if you are interested.
https://www.amazon.com/gp/product/B07C7L31K8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1