The tongfamily article references energy star rating as a point to purchase. I disagree. Energy Star rating is vastly over rated, IMO. Did you know that most manufacturer's ES their 2700K lamps, but not their 4100k? why? because it's virtually teh same lamp and they woudl have to PAY for teh ES rating when the only difference is kelvin/phosphors, which is not part of the ES checking.
New GE CFLs at Target
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blasterman
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About a year and a half ago I had to replace the recessed incans in a banquet room that is used mostly now for charity poker. Circuit they were on was at it's limit, they needed more light and I just couldn't use 100watt halogen PARs. Owner didn't want to spend the cash on doing a light/electrical upgrade. So anyways, I bought four different brand 23watt Reflector CFLs and let them decide.
We all agreed the Sylvania had the best color and brightness. My eyes put the Sylvania at 3200-3500k. They beat a 75watt Halogen PAR 38 easily in terms of perceived brightness.
I should note that recent bare Sylvania CFLs I've bought weren't as good as the ones above. Phosphor of the month in China I guess :whistle:
I do see a possible dilema here with CFLs makers and consumer testing. A phosphor mix that puts out more Lux per watt is likely not the one that looks the best, and vice-versa. I recall the Vita-light as having this issue.
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Just out of interest I bought a pack of two GE Daylight 6500K 10 watt CFLs
They are for use in a "task" lamp when I need to look at things under simulated "daylight" eg: photos.
Now I know these do not have great CRI -
GE claims CRI=82
Viewing the limited area lit under the lamp actually does look kind of like daylight - but looking at things under the light - did not look that great to me. But then again all my household lighting is Soft White incandescent or CFL (2700K)
For grins I took a photo of my home printed Macbeth color chart under these Daylight CFLs - allowing them over 10 minutes to properly warm up and used fixed daylight balance on my digicam.
I'm actually quite surprised at how well the photo turned out -
yes, indeed it's a bit cooler/bluer than I really wanted (I think I would prefer about 5500K) - but it's not bad when compared to the daylight control photo I have.
Using the key in this pic -
I can easily see the blue tint in patches D2 and D3 for the GE 6500K CFL - and the red in C3 is not as vibrant/rich
- but it's not bad at all IMHO.
But like I said under the light - things just don't look quite as "nice" - there's the feel of old fashioned fluorescent tubes - perhaps not as green - but things just are not that vibrant - this of course could just be me being used to 2700K lighting and anything cooler will look, well, cool.....
I am just surprised at how well the photo turned out
- and yes I am sure I used Fixed Daylight white balance
- that's why I included the one I took with AWB (Auto White Balance) just to compare (look closely at the patches D2 and D3 to see the difference in tint).
They are for use in a "task" lamp when I need to look at things under simulated "daylight" eg: photos.
Now I know these do not have great CRI -
GE claims CRI=82
Viewing the limited area lit under the lamp actually does look kind of like daylight - but looking at things under the light - did not look that great to me. But then again all my household lighting is Soft White incandescent or CFL (2700K)
For grins I took a photo of my home printed Macbeth color chart under these Daylight CFLs - allowing them over 10 minutes to properly warm up and used fixed daylight balance on my digicam.
I'm actually quite surprised at how well the photo turned out -
yes, indeed it's a bit cooler/bluer than I really wanted (I think I would prefer about 5500K) - but it's not bad when compared to the daylight control photo I have.
Using the key in this pic -
I can easily see the blue tint in patches D2 and D3 for the GE 6500K CFL - and the red in C3 is not as vibrant/rich
- but it's not bad at all IMHO.
But like I said under the light - things just don't look quite as "nice" - there's the feel of old fashioned fluorescent tubes - perhaps not as green - but things just are not that vibrant - this of course could just be me being used to 2700K lighting and anything cooler will look, well, cool.....
I am just surprised at how well the photo turned out
- and yes I am sure I used Fixed Daylight white balance
- that's why I included the one I took with AWB (Auto White Balance) just to compare (look closely at the patches D2 and D3 to see the difference in tint).
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I did something similar a few years ago with some linear tubes I use around the house:
I think the picture is self-explanatory. Color balance in all cases was set to sunlight (that's why the daylight picture looks slightly blue). Notice how there is practically no difference between the 5000K CRI 86 triphosphor tube (the Ushio 850), and the other two high-CRI 5000K tubes. The Ushio tube renders reds with a bit more orange, although it's not readily apparent in the picture. The Philips 741 tube is yellower and also desaturates colors a bit. The colors under the halogen incandescent are severely red-shifted relative to everything else. However, they can be corrected to something similar to the other light sources:
These kinds of tests are lots of fun to do. Next time I do such a test I'll use my light meter to make sure the intensity falling on the color chart is the same. And yes, my color chart is a printed copy also. Too cheap to spring for the real thing. ;)
I think the picture is self-explanatory. Color balance in all cases was set to sunlight (that's why the daylight picture looks slightly blue). Notice how there is practically no difference between the 5000K CRI 86 triphosphor tube (the Ushio 850), and the other two high-CRI 5000K tubes. The Ushio tube renders reds with a bit more orange, although it's not readily apparent in the picture. The Philips 741 tube is yellower and also desaturates colors a bit. The colors under the halogen incandescent are severely red-shifted relative to everything else. However, they can be corrected to something similar to the other light sources:
These kinds of tests are lots of fun to do. Next time I do such a test I'll use my light meter to make sure the intensity falling on the color chart is the same. And yes, my color chart is a printed copy also. Too cheap to spring for the real thing. ;)
I did something similar a few years ago with some linear tubes I use around the house:
I think the picture is self-explanatory. Color balance in all cases was set to sunlight (that's why the daylight picture looks slightly blue).
I do remember your pics and may have commented on them then -
Daylight/sunlight balance on a digital camera is supposed to be around 5500-6000 degK
and it's supposed to INCLUDE sunlight -
Your pic looks very blue because I think it was taken out of the sun.
when there is no direct sun - the light usually is very blue -
ie: basically reflecting the Blue sky.
Yes, I remember there was no sunlight when I took that picture, only skylight (which is about 7500K and up IIRC).
Many thanks for that confirmation.
Wikipedia on Color Temperature gives -
"5500–6000 K - Typical daylight "
I found in Google books - Perfect exposure: from theory to practice By Roger Hicks, Frances Schultz -
this extract -
interesting that average English daylight (SB) is 4800K
and American daylight (SC) is 6500K -
probably because of the "big sky" over here in the USA.
This is also in my old edition (1969) of The Focal Encyclopedia of Photography under color temperature.
Thanks! One of these days I may do something similar with different LEDs, and also redo the linears under more controlled conditions (I don't remember having a light meter so as to get the same intensity for all the tests above).
Me neither. My late father just happened to buy the 10-pack of TL741s at Home Depot because that's what they had on sale. We use them in utility areas but once they're gone, we'll be using the Ushio 850s (I bought a pack of 25 and still have 16 left). Personally, I like the Paralite Maxum 5000s the best although they're pricey compared to normal commodity tubes (i.e. about $6 each in 25s versus about $2 for something like the Ushio 850s). The GE Chroma 50s are a bit better than the Paralites but they cost just as much, have the T12 form factor, and have a lot less output ( a bit over 2000 initial lumens versus about 3200 for the Paralites).
In your opinion who makes the best linear T8 tubes? (just curious) I'm referring here to commodity tubes like 741s, 850s, etc, not high-CRI specialized tubes like the Paralites.
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Well - I didn't like those GE Daylight 6500K 10w CFL - I figured that they were probably too dim and since the Kruithof curve shows we lean toward warmer tones/yellow at lower light levels - I thought I'd give the 15w versions a try.
There's quite a gain in efficiency
so these are rated 900 (initial) lumens.
I had lowish expectations seeing that I didn't like the 10w versions - but I was actually very pleasantly surprised when I turned these on it has to be my eyes conforming to the Kruithof curve.
Anyway I did my test shots of the home printed Macbeth color charts again with fixed daylight white balance (as well as one with AWB) and compared these to my Daylight control shot.
Not much difference from the 10 w - but somehow it seems that there is more contrast/saturation on the 15w? - could be just the exposure on my digicam - but it is more pleasant - the 10w seemed grayish - but the 15w does seem more daylight-like.......
GE Daylight 6500K 15w CFL specs
Initial Lumens 900
Mean Lumens 738
Nominal Initial Lumens per Watt 60
Color Temperature 6500 K
Color Rendering Index (CRI) 82
There's quite a gain in efficiency
so these are rated 900 (initial) lumens.
I had lowish expectations seeing that I didn't like the 10w versions - but I was actually very pleasantly surprised when I turned these on it has to be my eyes conforming to the Kruithof curve.
Anyway I did my test shots of the home printed Macbeth color charts again with fixed daylight white balance (as well as one with AWB) and compared these to my Daylight control shot.
Not much difference from the 10 w - but somehow it seems that there is more contrast/saturation on the 15w? - could be just the exposure on my digicam - but it is more pleasant - the 10w seemed grayish - but the 15w does seem more daylight-like.......
GE Daylight 6500K 15w CFL specs
Initial Lumens 900
Mean Lumens 738
Nominal Initial Lumens per Watt 60
Color Temperature 6500 K
Color Rendering Index (CRI) 82
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Your assessment seems to match what others have said regarding high-CCT lighting. Basically, you need a lot of it in order for it to look pleasant. At lower light levels, the 6500K looks dreary bluish grey. But crank up the light levels and its looks much whiter and more "normal". That's just the Kruithof curve at work. So if you plan to only get by with a 10 watt CFL, then 3500K or 4100K might look better. But if you have the room much brighter, then 6500K can look pretty decent.
It's amazing also how yellow incands and soft white CFLs look when you shoot them under daylight color balance. And yet our eyes can eventually adjust to them so they look relatively normal (still yellow but not distractingly so).
blasterman
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I just went through this the other night and did a better round of tests. After years of testing film and shooting my own calibration targets I'll give you guys some advice.
1 - Ditch the MacBeth charts and use a box of Crayons instead. The Crayons have a much broader gamut / brightness/contrast range than MacBeth charts using more common commercial pigments, and have a translucency that looks a bit like human skin. MacBeth charts are about only good for calibrating TV's at an appliance store.
2 - Unless your camera has a full manual settings, comparison tests are subject to skepticism because you don't know what color balance and post processing the camera is doing. Much better off shoting RAW and applying corrections with a RAW converter.
I shot a bunch of CFLs the other night, and after nulling out CCT differences found there was no difference between daylight (5000-6000k) CFLs and 3500, so it's obvious the same phosphors are in play, just different levels of them. However, neutral white LEDs yielded a different color rendition than CFLs, especially with oranges.
GE Chroma 50's used to be one of my favorite tubes, but were actually closer to 4200k than 5000. Even though Vitalights at the time and had better lumen efficiency specs, the Chroma 50 wasn't nearly as green and much easier to live under.
1 - Ditch the MacBeth charts and use a box of Crayons instead. The Crayons have a much broader gamut / brightness/contrast range than MacBeth charts using more common commercial pigments, and have a translucency that looks a bit like human skin. MacBeth charts are about only good for calibrating TV's at an appliance store.
2 - Unless your camera has a full manual settings, comparison tests are subject to skepticism because you don't know what color balance and post processing the camera is doing. Much better off shoting RAW and applying corrections with a RAW converter.
I shot a bunch of CFLs the other night, and after nulling out CCT differences found there was no difference between daylight (5000-6000k) CFLs and 3500, so it's obvious the same phosphors are in play, just different levels of them. However, neutral white LEDs yielded a different color rendition than CFLs, especially with oranges.
GE Chroma 50's used to be one of my favorite tubes, but were actually closer to 4200k than 5000. Even though Vitalights at the time and had better lumen efficiency specs, the Chroma 50 wasn't nearly as green and much easier to live under.
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It seems you know pretty much what you are doing - so this is not in anyway negative comments about your methods.
1) Unfortunately the Macbeth Color Rendering chart is the standard that photography is using. I don't disagree with you that by eye it is hard to judge how one light source of the same CCT is better than another - other than in very subtle ways - and that is open to subjective interpretation. But Macbeth is the standard - and in a way I quite like the "subjective" aspect - which reflects real-life since I don't think there is any "universal" agreement to how accurate/pleasant any artificial light source is - those are always open to "subjective" interpretation anyway.....
The CRI (Color rendering index) chart is even less helpful, with its fewer and less intuitive colors -
" Note that the CRI by itself does not indicate what the color temperature of the reference light source is; therefore, it is customary to also cite the correlated color temperature (CCT).
According to (Schanda & Sandor 2005), CRI is being deprecated in favor of measures based on color appearance models, such as CIECAM02 and, for daylight simulators, the CIE Metamerism Index. (Guo & Houser 2004) and (CIE 1995) note that CRI is not a good indicator for use in visual assessment, especially for sources below 5000 K.
A newer version of the CRI has been developed (R96a), but it has not replaced the better-known Ra (general color rendering index). "
(my highlight in Red )
Out of interest what do you recommend as the box of crayons to use?
2) RAW processing probably begs even more questions - not many people have digicams with RAW - and not only that a lot of people including experienced photographers do not use RAW on a regular basis to have become well versed with RAW.
RAW actually requires even more Post-Processing by the user which means it is even more open to question. There is no such thing as a standard template conversion from RAW to a viewable format like JPG. The "default" conversion by most manufacturers is conforming to the camera's settings - which by-and-large basically means it receives the same processing as an in-camera JPG - so the user is no better off than if the picture was taken with jpg to begin with.
For illustrating color/tints the all important setting that anyone needs to know is basically the white balance. Auto White Balance (AWB) maybe useful for general photography - but it is not much good in illustrating colors from an artificial light source (other than perhaps trying to mimic the way our eyes "might" see).
The most commonly (but not always) useful setting for most of us here is the fixed daylight/sun white balance (equivalent to daylight white balanced film) this helps illustrate how a light source may deviate from average daylight (between 5500-6500 degK).
Color temperature or CCT seems to be more "important" than any CRI which is not very well understood - see quote above from the Wikipedia -
" note that CRI is not a good indicator for use in visual assessment, especially for sources below 5000 K. "
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PRobably:
G-E
OSI
Ushio
In that order. However, if you asked about T5s, I wouldn't have listed Ushio's. Their F54T5HO's are not quality lamps. I've had quite a few returned to premature failure. For T5HO's, I'd stick with G-E or OSI. WIth teh exception of CFL's, I will generally take G-E over anyone, but Sylvania is a close second.
FOr CFLs, I'd take Greenlite, Litronic's, and a company called Overdrive. I'm starting to stock Green Energy LIghting (formerly PEC-Phoenix) and am a fan of those too. Not that I dont' like G-E and OSI, it's just for the price v. quality I like the above companies.
Any opinion on
Eiko SP30/955K
it's a 5500K 30watt CFL that claims CRI=93....
(there's also a 50 watt version in E26 medium screw base)
and is supposed be for specifically ColorMaster Digital Imaging
specs -
Volts 120
Watts 30
MOL in/mm 6.3/160
MOD in/mm 2.76/70
Avg Life 10000
Bulb T-4
Base Medium Screw (E26)
CT deg K 5500
Replaces Std 150W Incandescent
CRI 93
Approx Initial Lumens 1500
Thanks,
Eiko SP30/955K
it's a 5500K 30watt CFL that claims CRI=93....
(there's also a 50 watt version in E26 medium screw base)
and is supposed be for specifically ColorMaster Digital Imaging
specs -
Volts 120
Watts 30
MOL in/mm 6.3/160
MOD in/mm 2.76/70
Avg Life 10000
Bulb T-4
Base Medium Screw (E26)
CT deg K 5500
Replaces Std 150W Incandescent
CRI 93
Approx Initial Lumens 1500
Thanks,
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Mixed lighting.
I left one of the GE Daylight 6500K 15w CFL in the room where I took the test shots of my home printed Macbeth color chart - but in the other light socket I thought I'd try a GE Soft White 2700K 13w CFL (this is one that was bought about 2 years ago rated at 825 (initial) lumens).
Although it's pretty obvious that one part of the room is warmer - the overall effect balance seems quite nice.
Just out of interest I took a photo of my home printed Macbeth color chart to see what it looked like -
the Daylight 6500K 15w CFL (900 lumens) was a measured 58" from the center of the chart - the Soft White 2700K 13w CFL (825 lumens) was to the right and 93".
A crude approximation of the intensity of each bulb on the chart is a ratio of
900/(58x58) 6500K to 825/(93x93) 2700K
= about 73.7% 6500K to 26.3% 2700K
- which averages out to be about 5500K?
Again the photo shows no dramatic difference - perhaps the grays on the bottom row are more neutral without too much tint shift/bias - it's certainly less blue than the daylight balanced shot when two GE Daylight 6500K 15w CFL's were used - the balance may be closer to that of the AWB version of 2x 6500K -
But I was surprised to see that the reds seemed no more vibrant than the 6500K only shots.
But these really are only look-see comparisons.
Overall having those two differing bulbs does seem to make the room look more pleasant and the area directly under the 6500K can be for "simulated" daylight examination
- I think I'll keep that ad-hoc mixed configuration for now.
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blasterman
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Box of Crayola (any size) work fine
Sorry, but you don't have good ceonceptual grasp of RAW processing, and shooting MacBeth charts with a digicam in 'Automode' just doesn't prove much because you have no idea what the camera is doing. With RAW you can at least remove color temp from the equation. Also, you're confusing post processing with color space conversion, and while sRGB doesn't have near enough gammut range to brag about, it gets more muddled up when digicam algorithms distort colors on the basis of trying make colors look good in JPEG.
Granted you have to make use of the gear you have, the MacBeth chart is still a near useless reference target - unless you're mixing paint. MacBeth charts are used to determine *consistency* between illumination sources at very specific and narrow points. Were trying to approximate visual and perceptual *differences* between light sources, and the best way top do this is with a real world subject. A human subject is the best reference, but Crayons are a good stand in because wax approximates human skin tone very well.
It's possible for instance for two different light sources to reproduce a MacBeth chart that looks pretty similiar, but our eyes under real world condition would tell us the lights are very different. It seems for this type of test you want to use subjects that best approximate what humans see and not how specific patches of color are rendered.
Proof of this is the fact most of us think the color of cheap, daylight CFLs above 5000k is horrid at the least. The MacBeth chart simply doesn't have enough range to show this, yet the 'oldschool' marketing reps are using MacBeth charts as a reference and hence why these bulbs are shoved on the public. "Well, the MacBeth chargt says it's neutral, so your eyes must be broke". Confusion here is our eyes see more colors than a MacBeth chart.
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....interesting comment
In the RAW processing software (I have Canon and Pentax) -
there is color temperature adjustment -
but that is setting the camera's balance for a particular color temperature
- so to make a pic cooler one sets a lower color temp and to make the shot warmer one sets a higher color temp.....
so unless one has an accurate color temperature meter -
the light source color temp is not known and to get the pic to "look like daylight" -
is a matter of trial and error -
of course we can guesstimate the color temp
such as 2700K for household incandescent and perhaps use whatever the CFL are spec'd at
- but that in itself is a variable .....
but my purpose is not necessarily trying to make the pic "look like daylight".
No not full auto mode but set white balance to Fixed Daylight white balance - this is akin to using daylight white balanced slidefilm - I don't think many experience or professional photographers specially ones who are experts in color reproduction say for the cloth industry can be critiqued for not understanding color slide processing - they just understand the light sources and the film stock used. Using Fixed Daylight White balance is liken to setting the color temperature in RAW processing to ~6000K.
Perhaps we may be talking cross purposes the whole point of presenting pics with fixed daylight white balance (like shooting with daylight balanced slide-film) is merely to show how the illumination diverges from "daylight" - whereas if I understand what you are saying - removing color temperature from the equation - kind of defeats that, as all pics are then corrected for the light sources and all balanced and look like daylight pictures -
and we already know for example regular incandescent light bulbs at about 2700K do not look like daylight.....
Our eyes may see it that way - but that's not what I was trying to illustrate.
I am not trying to use photos as any kind of quantitative measurement - but merely as an illustration of what a light source on a target looks like when compared to daylight - and RAW processing is not necessary to do that for me.
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PhotonWrangler
Flashaholic
Those reveal CFLs have just shown up at my local Wally World.
blasterman
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Nah, they just insisted on using the dullest slide stock, like EPN or EPP :D The result was Kodak following suite and engineering their main films to be only being able to handle low gamut ranges correctly. I'm still arguing with film heads about that.
That's fine with me - provided the camera in use is indeed locked into a specific setting, aka manual. My main grips is that digicams do an extreme amount of post processing automatically, and then dump the results to a JPG file based on color saturation algorithms that housewives consider in marketing tests makes their 4yr old have the best skin tones. RAW insures this crap is turned off, and the point of reference is decided by the shooter, not a doctored color chart in Sony engineering labs.
As long as the shots are taken at a fixed color temp, and you know it's fixed along with color enhancements turned off, then it's a fair shoot in my book.
Classic case of this are Fuji Digicams which are stroked to provide pleasing skin tones. DPreview shows all these little nuances with Macbeth charts as references. RAW is frequently the only way to insure totally neutrality because many digicams insist on cheating to provide the best skin tones with no user intervention.
As a side note, if you want to try an interesting experiment, shoot the Macbeth chart under open sunlight outdoors. Then, use this as a reference for CFL and LED tests. This eliminates any camera or processing variables because the grey patch on the Macbeth at a daylight setting should register darn close to grey. Using this as a reference shows CRI limits with artificial sources especially.
Using that 'sunshine' reference shows how goofy the color rendition of CFLs actually are.
