Cree A19 9.5w 60w 800lm 2700K for $13.97

[electronupdate]

I just tried to get a picture of the bald spot and it's not visible enough for the camera to pick it up when it's off, and when I turn it on the camera is swamped. I might have to wait for it to get worse before getting a good picture of the phenomenon.

Two polarizing filters can sometimes be used to overcome a light source which is too bright. Most simply done by snapping a pair of 3D glasses in half and rotating the individual lens, commercially I think they are called 'neutral density filters'

 

[PhotoWiz]

Two polarizing filters can sometimes be used to overcome a light source which is too bright. Most simply done by snapping a pair of 3D glasses in half and rotating the individual lens, commercially I think they are called 'neutral density filters'

I suggest photographing with the light off. You can adjust the exposure, but I think light coming through the bulb will overwhelm the subtle effect on the surface. Use a continuous light source such as a table lamp or outdoors in shade and try adjusting the angle of the lighting. Flash on camera would probably cause glare and that would overwhelm the surface effect too.

If you do decide to photograph with the light on, I'm guessing you can get the proper exposure without using a neutral density filter. Turn the ISO to minimum, stop down to f16 and set the shutter speed really high, say 1/2000th or so. Adjusting those three items should give you a good exposure. A neutral density filter is almost never used with digital cameras. When film was used, you only had a single ISO film in your camera, so using a neutral density filter allowed you to effectively change the ISO mid-roll.

Most neutral density filters have a single layer and do not filter polarized light. They are like unpolarized sunglasses. I seem to recall in the very distant past, having a filter with two polaroid layers that could be rotated as suggested. Perhaps that was called a "variable density filter" — can't recall.

 

[PhotonWrangler]

Thanks for the tips, PhotoWiz. I might give it another try.

Maybe it's my imagination but the bald spot seemed to become a little less prominent after the bulb cooled down. I'm wondering if the silicone coating flows a little bit when it warms up.

 

[PhotoWiz]

Thanks for the tips, PhotoWiz. I might give it another try.

Maybe it's my imagination but the bald spot seemed to become a little less prominent after the bulb cooled down. I'm wondering if the silicone coating flows a little bit when it warms up.

I just looked at one of my 800 lumen Cree bulbs, running in a base down, open shade fixture and the bald spot is quite noticeable. Surprisingly, the spot is not centered about the top, but more off to one side. Looking through this spot with the bulb off, the individual leds are quite sharp and clear. In other areas, the haze is strong enough that you can barely make out anything.

One problem with photographing this is that the transition from clear to hazy is gradual. What would really show the difference is two photos, one in the clear area and another in the hazy area.

 

[idleprocess]

Cree has been the title sponsor for a number of college football games, but never ran commercials - until this week:



I found it amusing - as did the friend I was watching the game with, who is not exactly a ... lighting enthusiast.

 

[PhotonWrangler]

That was a cute series of ads. The slam on the Philips paddle shaped bulb was unfair though. Saying that it's "not very good at being a light bulb" is clearly untrue.

 

[Marcturus]

Cree has been the title sponsor for a number of college football games, but never ran commercials - until this week

I don't like the dull, gray setting of the "enlightenment" series. And forget the authoritative accent, the guy runs ouf of breath before the last syllable of his sentence is finished. Is this really an improvement over the stereotypical female voice they used in the earlier spots that included cheerful colors and an uplifting melody? Cree seems to be targeting the conformist majority, also shown by making fun of differently shaped bulbs and of incandescence nostalgics. This means that LED bulbs have definitely left early adopter territory.
Btw, they will move out of the house or into the basement. Why? Because 80 CRI, 2700K *is* planned obsolescence.

 

[martinaee]

That was a cute series of ads. The slam on the Philips paddle shaped bulb was unfair though. Saying that it's "not very good at being a light bulb" is clearly untrue.

I did laugh though. Honestly though what is the reasoning for the new paddle shaped bulbs other than probably obvious cost saving to manufacture. I don't own any but is that base that seems to be one unbroken piece up into the diffusion all plastic? How are those at dispersing heat? I am kind of sad Phillips is doing away with the style they had that looked like a "normal" bulb from last year. These paddle bulbs are heavily pushed on sites like Amazon.

 

[martinaee]

small update: Had a nearby lightning strike yesterday.

Summary:

1 circuit breaker tripped
1 router internet LAN port fried
2 CREE 6W lamps dead
100's of other electronic doo-dads survived

So, it was a significant surge, as evidenced by the tripped breaker, but the Cree lamps seemed to be among the most susceptible things in the house...

Grr.

I was going to say I'm actually shocked (pun intended) they are damaged that easily by lightening, but it must have been quite close if it fried a router and tripped breakers in your domicile too. I can't really blame sensitive electronics on that.

It does however highlight one thing that older lighting techs probably did have going for them over new led light bulb tech that have onboard electronics.

 

[Bright+]

I have a recently purchased Cree 100w equivalent bulb that I've used for about 2 hours, running in a base-down position in a small open reflector. In this relatively short runtime I've noticed a drastic thinning of the diffused silicone coating around the top of the lamp. Others have noticed a thinning of this coating on the smaller Cree lamps after a longer runtime. Apparently the 100W equivalent lamps get warm enough to burn off this coating pretty quickly.

I can't imagine that Cree doesn't know about this issue; they must have observed it in their own labs. I'm not sure whether I should mention this to them.

You're not alone in this. With the exception of TW bulbs, it is the internally etched glass that makes it look frosty. There is some semi-volatile residues that gas out and condense out oily film on the inside which makes the glass turn clear.

The heat sink and driver gets up to 200*F. The glass surface is relatively cool, so that is where the oily vapor condenses out.

 

[markr6]

I had a few of these 40w bulbs outside, so I bought a 4-pack to put in my hallway. Aahhhhhh it's BAD! Horrible dull greenish tint. You don't notice it so much in a lamp, but when you put 4 bulbs in two ceiling lights...yuk!

My wife didn't complain yet and I'm sure I'll get used to it after awhile. At least that's what I'm telling myself so I don't feel like I just wasted $38.