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Stains and Flourescent lights

Started by Younger, November 05, 2011, 07:29:36 AM

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davidkilby

Sorry for the misspelling of "fluorescent".  My Windows 7 Spall Check misses things form time to time.

David

mad gerald

Quote from: davidkilby on November 08, 2011, 06:12:50 AM
Sorry for the misspelling of "fluorescent".  

Never mind, David - was just curious in case there would have been spelling differences ...

Quote from: marc_reusser on November 07, 2011, 01:34:13 PM
Isn't true color (or as close to natural light) somewhere around 5000-5300K?

... [nitpickingion]approx. 5500k (daylight forenoon/afternoon)[/nitpickingoff] ... ;)

Quote from: marc_reusser on November 07, 2011, 01:34:13 PM
When shooting photos in flouresc. you can get rid of any discoloration/tint, by manually pre-setting your "white balance" on the camera.

THX, I tried to avoid taking photos with fluorescent lights ... but had already a look in that bl**dy manual (which seems to be pretty incomplete) ...

finescalerr

I think fluorescents come in three basic color temperatures, around 5000 K, around 6500 K, and around 9300 K. I may have been mistaken about 9300 being "daylight"; instead 6500 may be a more typical color temperature for daylight. If I weren't in a hurry at the moment I'd look it up for you but I have to leave in just a minute and still need to get through the rest of today's posts.

Russ

mad gerald

#18
Russ,

the common compact fluorescent lights/bulbs available over here range between 2300k and 8000k, to match daylight it has to be >5000k, 6500k recommended ...  8)

The tricky bit is to find a suitable bulb with the favoured colour temperature, as over here they are going to establish these special energy saving fluorescent bulbs in many different shapes, so in some cases the whole range of colour temperatures is simply not available, i. e. regarding circular shaped fluorescent bulbs ... >:( ... and if you finally got lucky and find a matching one, they charge you up to EUR 50,00 for a single bulb ...  :o

marc_reusser

#19
I had a recent discussion with one of my lighting suppliers about this whole issue (as I wanted to get some bulbs for my workbench from him), and he brought up a couple of interesting points.

Though the 5300 -5500 K  ;)  range is the "daylight" range, ...apparently much more important is the CRI (color rendering index) ......pretty sure this is the term...having a brain-fart at the moment....regardless, this is the index that rates how accurately the color of the subject is being rendered (100 being the absolute/top end)...unfortunately very few mfrs actually note or list this anywhere on their boxes...they use meaningless generic terms like  "warm", "cool", "sunlight", "daylight" "tru-color" etc. .....so you not only want the K-range, but also the CRI.

He also noted that currently (at least with what we tend to get in the US)....the Flourescent bulb market is very poorly regulated, and there are only very "general" standards...so every mfr has a different description of say "daylight"....and to make things worse...there are no definite testing stamdards (in regards to color and light quality) that each bulb has to meet.....so you can get wildly varying hues from two of the same bulbs from the same mfr (I have personally noticed this just recently when I bought two GE from Home Despot....one went blue, and one went magenta....which does not work very well when using them both to light a model for photography)....this is because there are apparently also no exacting standards as to how, and how much gas and such is placed into the bulb, ...which can also often mean that despite saying a bulb will last 3000 (or whatever) hours....it may suddenly burn out on you in less than a week.


M
I am an unreliable witness to my own existence.

In the corners of my mind there is a circus....

M-Works

mad gerald

Quote from: marc_reusser on November 08, 2011, 02:30:55 PM
....it may suddenly burn out on you in less than a week.

... so even bulbs suffer from burn out ...  ;D ;D ;D
(sorry, but I could not resist punning on that one)

finescalerr

Gerald, go stand in the corner! -- ssuR

mad gerald

#22
Quote from: finescalerr on November 09, 2011, 12:17:21 AM
Gerald, go stand in the corner! -- ssuR

... will there be some company, comfy chairs and some booze today ... ? ... GD&RVVF ...  ;D

shropshire lad

Quote from: mad gerald on November 09, 2011, 12:30:36 AM
Quote from: finescalerr on November 09, 2011, 12:17:21 AM
Gerald, go stand in the corner! -- ssuR

... will there be some company, comfy chairs and some booze today ... ? ... GD&RVVF ...  ;D



  No . I took them with me when I finished my last sentence . Sorry .

    Nick

Wesleybeks

Some really interesting points made here. I was looking recently to improve the lighting over my workbench. What do you guys use and recommend as far as lighting fixtures, bulb colours(daylight, warm cool) etc go?
Kind Regards
Wesley

Modelling in sunny South Africa

james_coldicott

Hi All,

don't know if this is of any help but here goes... I have tried all manner of lighting options in my studio for painting and finally have a setup that works for me. Lighting becomes a real issue this time of year as I am doing a lot of detail work on my paintings and the winter light levels here require me to use the studio lights all day for the next few months.

My studio is 4.3m x 4.3m (about 14 feet square) and is primarily lit with 4 energy efficient 1500mm (5 foot) T8 58w 'cool white' Triphosphor Fluorescent tubes. I find the colour rendering on these excellent and the stated CRI is 85 (When I did the maths I reached a figure of 89) which is sufficient for me with occasional help from a halogen light. I am paying £30.00 for 10 tubes. As with all 'energy saving' bulbs they take a little while to come up to temperature but enable me to work an 8 hour day in comfort (the first time I haven't suffered from real eye fatigue)

Link to the lights I use is here...

http://www.sylvania.com/BusinessProducts/LightingForBusiness/Products/EnergyEfficientProducts/T8/default.htm

There are newer lighting technologies out there but for the time being I am sticking to the T8s as I am really happy with them.

BTW if you look at most of my photo's of models they have been taken under these lights with no additional lighting. A few examples here...

http://www.finescalerr.com/smf/index.php?topic=1321.30

hope this will add something to the discussion.

James






BKruger

#26
Quote from: marc_reusser on November 08, 2011, 02:30:55 PM
I had a recent discussion with one of my lighting suppliers about this whole issue (as I wanted to get some bulbs for my workbench from him), and he brought up a couple of interesting points.

Though the 5300 -5500 K  ;)  range is the "daylight" range, ...apparently much more important is the CRI (color rendering index) ......pretty sure this is the term...having a brain-fart at the moment....regardless, this is the index that rates how accurately the color of the subject is being rendered (100 being the absolute/top end)...unfortunately very few mfrs actually note or list this anywhere on their boxes...they use meaningless generic terms like  "warm", "cool", "sunlight", "daylight" "tru-color" etc. .....so you not only want the K-range, but also the CRI.

He also noted that currently (at least with what we tend to get in the US)....the Flourescent bulb market is very poorly regulated, and there are only very "general" standards...so every mfr has a different description of say "daylight"....and to make things worse...there are no definite testing stamdards (in regards to color and light quality) that each bulb has to meet.....so you can get wildly varying hues from two of the same bulbs from the same mfr (I have personally noticed this just recently when I bought two GE from Home Despot....one went blue, and one went magenta....which does not work very well when using them both to light a model for photography)....this is because there are apparently also no exacting standards as to how, and how much gas and such is placed into the bulb, ...which can also often mean that despite saying a bulb will last 3000 (or whatever) hours....it may suddenly burn out on you in less than a week.


M

Interesting you say that Marc, as I've been wondering how to accurately replicate true sunlight with flourescents. Too many layouts I have seen just plop in a generic flourescent they bought at Home Depot, and it throws the whole mood of the scenery off. Everything is too blue or white, causing the balance of the colors to be off the mark.

I tend to model central California logging. As you are a California resident, you know the sun behaves bit differently then a setting in the east or midwest. In that particularly dry region, everything is accentuated by the warmness of the sun...the rotting wood, the yellows of the grass and even the dirt is a much more lighter and drier than any other area you find. This is very difficult to model realistically with commercial lights, and I trying to comprehend how this can be done. I think one of the reasons Chuck's models look so good is because he shoots in real sunlight, and all the details are much emphasized in different texture and matter than they would if it was done with studio lighting. To me it gives a much more realistic feel to the overall scene.

-Brandon

mad gerald

James,

thanks for your additional input ...

Quote from: james_coldicott on November 09, 2011, 05:07:50 AM
Link to the lights I use is here...

http://www.sylvania.com/BusinessProducts/LightingForBusiness/Products/EnergyEfficientProducts/T8/default.htm

... these things look the part, regarding their specifications (and your photos) ... I started already researching, if this kind of illuminant is available in more kinda bulb form too ...

mabloodhound

Marc,

You are completely correct.   The CRI (color rendition index) is the deciding factor and the closer to 100, the better, however it must be combined with the higher temperature to get the desired effect.   I photograph all of my wife's handmade jewelry for the website and brochures and did considerable research on the subject of lighting for photography.
You're lighting supplier was right on point as most professional photographers will tell you the same.
I have found some good on line bulb stores that list ALL the factors, including CRI.   I suggest one might go to these sites and either buy from them or try to find the same product locally.   Take a look at this page and you'll see the CRI listed (as they do for most of their bulbs) but again the higher K is also required.
http://www.bulbs.com/Spirals_&_Bent_Tubes/results.aspx
Dave Mason
D&GRR (Dunstead & Granford) in On30
"A people that values its privileges above its principles will soon lose both."~Dwight D. Eisenhower

finescalerr

Regarding fluorescent layout lighting: It's okay if you want the diffuse light typical of a hazy or overcast day. If you want clean shadows and the contrast typical of sunlight, though, you'll need incandescent bulbs (including halogen) unless there's something else out there I'm unaware of. -- Russ