In , Crackles McFarly wrote:
On Fri, 26 Oct 2007 10:59:19 -0500, bud--
sayd the following:

Crackles McFarly wrote:
Maybe the server lost this post on some other servers.
Here is my question again....

Your first post made it. Not obvious what you are doing and what the
problem is from your post.

Lumens=1200 on first 2 lights I bought and they were really dim.
LOWES,HOME DEPOT I couldn't find one higher than 1250 Lumens?

I decided to pick one based on CRI. The higher number was suppose to
be the most bright...

I picked two lights that had LOWER Lumens but HIGHER CRI.

Did I make the right choice, if NO please tell me how to identify these.

CRI is color rendering index and indicates how the lamp compares to
natural light (not an exact definition). 100 is maximum. If the light
was very green the CRI would be low. CRI measures color 'quality'.

Brightness is measured by Lumens.

All I find at Homedepot and lowes are 1200 lumens?

Where do you find lumens above 1200?

p.s. It's a 2-foot piece.

1200 lumens is good for a 2-footer single-bulb. Please be aware that
most single-bulb ballasts and many 2-bulb ballasts for 20 watt 2-footers
only deliver about 16, maybe 17 watts per 2-foot bulb even when intended
to be used with 20-watt 2-footers.

One reason is that there is a common size of "E-I" core (5/8 inch square
center leg), overall length 3 times that at 1.875 inches plus maybe 1/8
inch when thickness of a mounting bracket is added in, 1.5625 inches
overall width (mounting bracket may add 1/16 inch to that), and 1.25
inches or a litle less thick not including housing/bracket - thickness
will often be close to 1.25 inches.
Such a long-established size of 110-120 volt ballast for
long-established 20 watt 2-footer has traditionally needed to underpower a
20 watt 2-footer by 15-20%. Many of these ballasts are also rated
for 15 watt "bulbs" and deliver close to 15-16 watts to those. A few of
these are also rated for 14 watt "bulbs" and a few subset of these are
even rated for use with 13 watt T8 (1.8 inch diameter) "bulbs" that have
length close to 1 foot.
This means that even with efficiency increasing slightly with
underpowering, a 20 watt 2-footer rated to produce 1200 lumens has a good
chance with many common ballasts producing about 85% of that - about 1050,
and that assumes optimum temperature (fluorescent "bulbs" are dimmed by
temperature being non-optimum in either direction). Expect less if color
rendering index exceeds 86 or color temperature exceeds 5000 Kelvin.

17 watt T8 (1 inch diameter) 2-footer tends to achieve at least that
much, probably 1200-1300 lumens for slightly optimistic figure for typical
usage (assuming underpowering to extent for such "bulbs" that I find to be
"typical" in my experience, along with the ballasts dfor those being
"electronic" while such size "bulbs" have performance rated on a
more-old-fashioned "magnetic" "standard-for-that-bulb ballast".

- Don Klipstein )