“Murph, you’re an intelligent being… what are you trying to accomplish?”
Playing with light… or… trying to navigate through it…
well, here are some tips for trying to figure it out any way, regarding a lizard’s requirements of it…
This is one of Murph’s bulb’s boxes. Upon researching lighting for reptiles, it’s easy to get overwhelmed in the scientific aspects of it all, and reading reviews and opinions do not always help. You will see above, the chart shows if your reptile is 8 inches from the bulb, he or she is at about 95 ° fahrenheit in the basking location. There are dual receptacles, in which one can also place an infrared heat lamp for more warmth without too much full spectrum exposure, if the basking spot is too cool. The box shown above encased a full spectrum bulb.
Here, Lil’ Murph is sleepy in his hammock. I didn’t want him too cool, so I left electrified only the infrared heat lamp until it was cuddle time for us. Companies do make a heat-emitting night light.
Personally, I do not trust plastic in the lamps or their stated maximum wattage acceptance, so I purchase bulbs with an output just under that. I play with and place (sometimes with very fool-proof rigging for safety) bulb receptacles where it feels right. I then monitor the temperatures of the basking area and the cool-down area, adjustments may be needed. Basically, there is a small window of appropriate temps, for example, if the ideal basking temp is say, 105° for your reptile, and it is 115° at that spot, lower their basking area or raise the lights if you can. Also know that if your lizard is too hot for too long, she or he will move. Do your best.
As for brands of bulbs, a vet once told me some companies’ bulbs were believed to slowly burn the retinas of reptiles. Awful. I can’t say I have found evidence in that statement, and I shall not recommend one brand over another as of yet.
If you have a Beardie, I want to again recommend “The Bearded Dragon Manual.” It is important to research what the full spectrum bulbs, and seperately, but very importantly, the UVB bulbs do for reptiles. Not all reptiles have the same requirements. Please see this link for uvb requirements: http://www.joshsfrogs.com/catalog/blog/2016/01/what-uvb-bulb-do-i-need-for-my-pet-reptile-or-amphibian/
Where research is concerned, don’t rely on one thing you read, not even here. Research and compare your findings. Sometimes you may find yourself working in the middle of 2 opposing care-taking tips.
Lil’ Murph’s UVB receptacle requires an 18″, or nearly 46 cm fluorescent bulb. This one is Zoo Med Reptisun 10.0, high output, 15 watts. If ordered online, that skinny, yellow bulb-containing box comes in a shipping box that much larger! It’s silly. Murph (on his 2nd level, where he almost always hangs out) is 7 – 9 inches from the UVB, thus, making 10.0 ideal to replicate the sun exposure he would absorb in his ancestral origin among the sands and brush of Australia (based on what seems good over years of Beardie motherhood).
I want to point out here… If you reside in an area where flooding or snow may prohibit travel, it is a good idea to always have more bulbs in the event that one burns out because heat and light are vital to a reptile’s health. Also, if you are like me, and prefer to plan for the worst, such as a power outage, or an unforeseen catastophe, consider ways to safely keep your sweeties warm (in an animal carrier, perhaps) by a wood-burning fireplace or other means (carbon monoxide is a caution here). 
If they must go without sunlight, artificial, or not, it should not pose too much a health risk if this is very temporary, so long as they can stay warm for a few days or so, all should be well. If such a precaution is taken, check skin temperature and signs of overheating, such as a constant gaping mouth. If they are lethargic, they may be too cold or depressed from lack of liberty and/or their enclosure with which they are familiar. Move them nearer or further from the heat source as believed is best. Give her or him a just amount of time as is possible to walk around while you observe, but don’t let him or her get too chilled. Cuddling and/or petting is very important in the lizard/human relationship, so if the power goes out, don’t forget our lizards, amphibians, and all other animal friends need us.
