All bulbs not created equal

[HKzForDayz]

This is more a "thinking out loud" kind of post , but has anyone else noticed how different temps can be with same wattage bulb from competing brands? my two hatchlings are in 40 gals on the same table, and ive got their basking spots next to each other, so it is really easy to compare heights.

In Drogons Enclosure on the left, Its being heated by a 75w intense basking bulb by exoterra. On the right, Viserion has a ZooMed 75w basking spot bulb . Drogons basking spot sits higher in the enclosure, and the lamp sits closer to the top, while Viserions Basking spot is lower, and her lamp sits higher.

heres the kicker...Viserions basking temps are still higher. Its not really an issue because I can just adjust my distances until temps are correct, but it just seems crazy that there can be that big of a difference in the two bulbs.

 

[CooperDragon]

I think that may have a bit to do with the reflectors each bulb is using. While there are different sizes and shapes of reflectors, I'd imagine that they may vary depending on brand as well. The tough part is when different bulbs from the same brand act differently due to manufacturing inconsistencies. This seems to happen a lot with cheaper MVBs and UVB tubes.

 

[HKzForDayz]

Like the reflector inside the bulb itself? or are you referring to the dome/fixture they are in?

also, here is a shot of the two basking spots in question for reference

 

[CooperDragon]

I'm talking about the reflector inside the bulb itself, behind the element. If they have a different shape or even a different texture (one didn't get polished as much as another, one has a dent, etc) I'd imagine they would have a slightly different output in the end because the light would be directed differently.