Electric_Light

In commercial lighting, sometimes we get too absorbed in watts per sq.ft and lumens per watt.

I've had the chance to test the CREE CR6 LED can and like halogen track light, it's a very "hard" light that casts a strong shadow.

Top left: CREE CR6 in can light with my hand about a foot above the surface.
Bottom left: same setup, except this time with a textured lens R40 type CFL


Top right: comparing what a sheet of paper looks like in my office lit with a wrap-around type lighting (background) vs CREE CR6 LED (center). To each his own, but if I had to work in such a strong shadow, it would drive me nuts. Shadowing is particularly more pronounced when the light hitting the surface isn't blended from multiple fixtures from different angles.

Hard lighting has aesthetic appeals in accent lighting and have artistic applications, but for general lighting, its undesirable.

Here are some photos. I've used R40 textured lens CFL, standard T8 wrap around and a CREE CR6 LED can look a like.

Bottom light:
Even with a single fixture, fluorescent fixture with acrylic wrap-around lens produces very little shadow.

It's possible to achieve the same effect with LEDs using intricate optics inside a luminaire, but it comes at the expense of reduction in lumens per watt.

Even in a residential setup, fluorescent provides for very soft light comparable to frosted glass incandescent fixture, but at a much better efficacy.

Do you want to see a shadow of yourself on the surface or the surface itself with minimal shadow? well, that's up to you.

Attached Images

	CR6LED.jpg (19.9 KB, 134 views)
	wrap_around.jpg (30.6 KB, 128 views)
	BR40.jpg (18.4 KB, 130 views)
	fluorescent.jpg (20.1 KB, 133 views)

Dnkldorf

Shadows are caused by positioning of the light sources.

Not the light source...

Is that you're pitch now, shadows????????

(insert face palm jpeg)

Electric_Light

Actually, the light was positioned exactly the same.

Compare the LED vs textured CFL. Same exact socket and same exact photo shoot position.


LED lighting provides exceptional shadowing ability. It ensures you can see a razor sharp shadow of you doing face palm onto your desk.

Dnkldorf

I hope this isn't your best marketing strategy, showing pictures of your hand and pointing out shadows.


Your pictures suck, and there is no way to tell what your doing.

Give us apples to apples comparisons, with one pic showing both light sources. Then show us these "shadows" you speak of.

Electric_Light

The second picture shows exactly that. You'll see a very clear shadow of yourself on your work piece if you're doing typical office work. Especially with LED direct lighting like the CREE CR6. That picture provides side-by-side comparison.

Dnkldorf

Let me go slow.


Take a picture of the (2) or (3) bulbs you are going to compare.
You say these are track lights?

Take of picture of the track light on the heads.

Put the bulbs in, take a picture, so we can see the bulbs in.

Turn the on, take a picture of where you measuring. Let us see what your doing.

OK?

Electric_Light

No, it's a can light that points straight down. Sheet of paper about 7' below the light and my hand about a foot above the work surface.


You're expecting me to remake the demo setup again? Try for it yourself using what I've described above, so you can see for it with your own eyes.

Dnkldorf

I have no idea how you can put your hand a foot above a can light.

You'd be in the attic.

Electric_Light

That was a typo

Dnkldorf

You don't have 2 lights?

What kind of comparison is this?

You can manipulate too many variables, and prove one thing over another.


This experiment and results, is a FAIL, in my book.

chicken steve

Are the photometrics for each avialable from the manufacturer? ~CS~

Electric_Light

The LR6 should be available somewhere on the CREE site.

Many manufacturers make photometric available for fluorescent fixtures, but I do not have any data on the one I used in this experiment.

They're generic sheet metal white painted fixtures with two T8 lamps and an acrylic prismatic wrap-around cover.

mbednarik

all of the public input i get is pretty much the following: I hate the CFL, i like the halogen or LED product. I hear this more than once a week. I am not going to install a product people don't like, sure fire way to the unemployment line.

WmEricB

What reason,if any, do they give for their dislike of the CFLs? Just curious.

mbednarik

The slow start up time. They don't seem to last long because of request cycling. Those are the two main reasons.

Electric_Light

Who's the public? Resi, comm/industrial or a fairly even mix?

What CFLs are they talking about? Not all CFL systems are the same and not all LEDs are the same.

Do you mean built-in ballast CFLs that cost $2-3 and targeted towards residential users or $6-7/ea pin-type CFL that utilize high quality programmed start ballast?

CFLs shouldn't really be instant started like they often are in screw-in CFLs. The cathodes are smaller and aren't as tolerant as bigger T8 lamps.

Just because $2 screw-in cheapies suck doesn't mean they all do.