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Lighting decision. Need help :)

Hi guys, so i managed to make a space just for enjoy painting (and drawing)
I have 30m2 of space and i would like to loghtning my easel for work good, ive tought a roof ceiling of 120cm of t8 tubes like this one 
I am searching for good light tubes t8 and with high cri! I cant found anything on amazon. it .. only somethingg around 80 or 85 cri!
Also do you have any other suggestion for loghtning maybe without using thoose ceilinfs you have any other setup or idea in mind? 
Also i would setup a wall with a box for painting still lifes and also do photos/live painting a model! Thanks

Comments

  • What is the height of your ceiling?
  • dencal said:
    Thankx for reply 
    Could i buy from amazon or ebay it? Because i prefer they would ship in italy :) 
  • lillo9546


    There are dozens of T8 varieties available on Amazon and EBay Australia. We are special with remote location and our own taxes. I expect there would be the same on the Italian equivalents. But I would struggle trying to read Italian. Have a look, you will find them in ten seconds.

    Denis



  • dencal said:

    lillo9546


    There are dozens of T8 varieties available on Amazon and EBay Australia. We are special with remote location and our own taxes. I expect there would be the same on the Italian equivalents. But I would struggle trying to read Italian. Have a look, you will find them in ten seconds.

    Denis



    Yup i can find a variety.
    The problem is that they are only below 85 cri so i cannot find any 95+ cri t8 lamp.
    Ive searched on ebay too
  • dencaldencal -
    edited March 19
    lillo9546

    What about self adhesive strips. 95CRI

    Stick em me on the ceiling, or buy some used T8 housings.


  • dencal said:
    lillo9546



    Denis
    Thanks i tried search it on amazon italy and could not find. I will buy a 120cm or 150cm , beside the cri fact, how many lumens, watts do i need ? The height of the room its 2 meters 
  • lillo9546

    If the centre of the easel is 1.2m from the ceiling, you will get 6% of the lumen output. So let’s start with aiming for 800 lm at the canvas. 3200 lumens in each led tube, 6% is 192 lm per tube. You need 4 tubes or two pairs.

    If the centre of the easel is 1.83m from the ceiling, you will get 3% of the lumen output. Aiming for 800 lm at the canvas. 3% is 96 lm per tube. You will need 8 tubes or four pairs.

    Light falls away with increasing distance from the source according to the inverse square law.

    Denis

  • edited March 20
    Thanks so i need 3200 lumens 2 tubes?
    In italy i found a shop that sells 2400 lumens 4000k and 6500k tubes at good price. The only thing is that they are 85 CRI  
    How much is important to get the 95CRI over thoose 85 ones? Is there a huge dofference?
  • dencal said:
    lillo9546

    If the centre of the easel is 1.2m from the ceiling, you will get 6% of the lumen output. So let’s start with aiming for 800 lm at the canvas. 3200 lumens in each led tube, 6% is 192 lm per tube. You need 4 tubes or two pairs.
    dencal said:
    lillo9546

    If the centre of the easel is 1.2m from the ceiling, you will get 6% of the lumen output. So let’s start with aiming for 800 lm at the canvas. 3200 lumens in each led tube, 6% is 192 lm per tube. You need 4 tubes or two pairs.

    If the centre of the easel is 1.83m from the ceiling, you will get 3% of the lumen output. Aiming for 800 lm at the canvas. 3% is 96 lm per tube. You will need 8 tubes or four pairs.

    Light falls away with increasing distance from the source according to the inverse square law.

    Denis


    If the centre of the easel is 1.83m from the ceiling, you will get 3% of the lumen output. Aiming for 800 lm at the canvas. 3% is 96 lm per tube. You will need 8 tubes or four pairs.

    Light falls away with increasing distance from the source according to the inverse square law.

    Denis

    Ive done some exact calcs
    My ceiling height from the floor is 2,20m
    Im with my easel center, at 1m distance from the ceiling above. 
    Ive found in Italy philips graphica 90 tubes! 
    Its a 150cm, 98 CRI and about 3750 lumens. (It comes in different temperatures)
    As i have 2 bulbs of 3750 lumens, how much im getting at 1m distance?
    Another thing is temperature. I would buy one 4000k and one 6500k to have 5250k temperature. Or its better to buy the 5500k x2 times? 
  • PaulBPaulB mod
    Combining a 4000k and a 6500k to try and get an average 5250k is wrong.  It just simulates a very low CRI.
  • lillo9546

    At one metre 11% of the ceiling light will fall on the canvas.
    A 3750 lm unit will deliver 412 lm so you will need 2 tubes.
    Keep looking until you find 5000k, sometimes referred to as “Daylight”.

    Denis
  • PaulB said:
    Combining a 4000k and a 6500k to try and get an average 5250k is wrong.  It just simulates a very low CRI.
    I dont wanna say name, but cesar santos use one warm one cold, so he is doing it wrong ,(he told in one video) 
  • PaulBPaulB mod
    lillo9546 said:
    PaulB said:
    Combining a 4000k and a 6500k to try and get an average 5250k is wrong.  It just simulates a very low CRI.
    I dont wanna say name, but cesar santos use one warm one cold, so he is doing it wrong ,(he told in one video) 
    You are contradicting yourself.  You want high CRI, that's how your question began, but then you suggest throwing that away by mixing different light temperatures.
  • PaulB said:
    lillo9546 said:
    PaulB said:
    Combining a 4000k and a 6500k to try and get an average 5250k is wrong.  It just simulates a very low CRI.
    I dont wanna say name, but cesar santos use one warm one cold, so he is doing it wrong ,(he told in one video) 
    You are contradicting yourself.  You want high CRI, that's how your question began, but then you suggest throwing that away by mixing different light temperatures.
    I found this. Its a 95 cri with 5300k. The 98cri version is at 6500k.  http://www.lighting.philips.it/prof/lampade-e-tubi-convenzionali/lampade-fluorescenti-e-starter/tl-d/master-tl-d-90-graphica/928045295081_EU/product
    I dont know how much CRI i need for a good painting room lightning setup, i wanna say thay if i can do good with 80/85 CRI, i would go for a eco line, but instead if the difference is very noticeable, i need for a 95+.
    Tell me ypur experience i never saw the diff from real Life, but u saw :) 
  • lillo9546

    COLOR RENDERING INDEX (CRI) - a CRI of 80 to 90 is good for artwork - a CRI of 90 to 100 is excellent for artwork. A reading of 100 means the light allows you to see the color of things as it would be seen in the sunlight.

    TEMPERATURE IN KELVIN UNITS - measures how warm (yellow) or cool (blue) the emitted light.
    Any deviation from 5000k (daylight) will distort how you perceive, mix and apply color. A good example of the distortion is how a red shirt appears under a bluish fluoro light compared with the same shirt in daylight.

    Denis

  • dencal said:
    lillo9546

    COLOR RENDERING INDEX (CRI) - a CRI of 80 to 90 is good for artwork - a CRI of 90 to 100 is excellent for artwork. A reading of 100 means the light allows you to see the color of things as it would be seen in the sunlight.

    TEMPERATURE IN KELVIN UNITS - measures how warm (yellow) or cool (blue) the emitted light.
    Any deviation from 5000k (daylight) will distort how you perceive, mix and apply color. A good example of the distortion is how a red shirt appears under a bluish fluoro light compared with the same shirt in daylight.

    Denis

    Thanks okay i understand!
    Just wondering how much lumens should i get on the canvas? 800 lumen is fine? 
    Other question, a 70w led yube (so in this case are 2 so 140w), 6/7 hours a day x 30 days, 1 kw cost 0.20€ in italy, its like 8€ per month right? 

    If my calcs are correct i would buy  the 70w version that is 98 cri over the 35w that has 85 CRI. For 5€ more per month i dont really care if i can get a better quality i will get so :)
    150 cm is better than 120cm? 
  • lillo9546

    Yes 800 lumens is adequate. 



    Yes. A brighter and color accurate light source is preferable.

    Denis



  • edited March 21
    dencal said:
    lillo9546

    Yes 800 lumens is adequate. 



    Yes. A brighter and color accurate light source is preferable.

    Denis



    Im gonna go for the
    Philips 58w (69kw/h) 95cri 5300k 3750lm (so its 3750x2=7500x11=82500/100=825lm to my easel) 
    The 98 cri is 6500k is too much i think. 
    I have to care something o take a special ceiling? Because i can buy a cheap ceiling with the correct measures and just put the bulbs inside right? 
    120 or 150 cm :)

    Also for a shadow box, how much lumens do i get? I think i will.get a normal lamp or do i need also a cri lamp there :)
  • lillo9546

    The CRI level and the color temperature of the bulb/tube will not influence the running cost.
    The rated output in lumens will influence the running cost.

    In practice it is unlikely that you will need the studio lights on for seven hours a day 365 days a year. Half both these figures sounds more realistic. There is much more to life than painting.

    If you are using adhesive LEDs this is a cost effective and neat diffuser.


    or if using T8 tubes buy second hand and rewire without the ballast.

    Shadow box:  the light source is about 60cm from the subject. 25% of the light will be useful. Aim for equality with the studio - color checker- and studio - easel light level. Filter or use dimmer.

    Match the SB light with the studio light for temperature, CRI and strength, otherwise you will drive yourself mad when things don’t match.

    I have about 600 lm in the SB and looking for a bulb to bring it up to 800 lm.

    Denis




  • dencal said:
    lillo9546

    The CRI level and the color temperature of the bulb/tube will not influence the running cost.
    The rated output in lumens will influence the running cost.

    In practice it is unlikely that you will need the studio lights on for seven hours a day 365 days a year. Half both these figures sounds more realistic. There is much more to life than painting.

    If you are using adhesive LEDs this is a cost effective and neat diffuser.


    or if using T8 tubes buy second hand and rewire without the ballast.

    Shadow box:  the light source is about 60cm from the subject. 25% of the light will be useful. Aim for equality with the studio - color checker- and studio - easel light level. Filter or use dimmer.

    Match the SB light with the studio light for temperature, CRI and strength, otherwise you will drive yourself mad when things don’t match.

    I have about 600 lm in the SB and looking for a bulb to bring it up to 800 lm.

    Denis




    Thanks! So having 600 lumens feel too low? 
    No i have a normal ceiling to fit bulb in it, it is wrong? 
    How much lumens lamp should i get for the Shadow box 
  • MichaelD said:
    I have found this thread very illuminating
     :) 
    There is too much lumens here
    PaulB
  • Folks

    Stop foolin around, this is serious. How can you make light of this situation?

    Denis
    BoudiccaMichaelDPaulB
  • dencal said:
    Folks

    Stop foolin around, this is serious. How can you make light of this situation?

    Denis
    I know darkness will take me.. A scattered dream its like a far off memory.. 
  • Look what I found at Home Depot yesterday!!


    dencal
  • Bancroft414

    Brilliant. Thanks for posting. 
    At 3ft you need 4 of these units. At 4ft need 8 units. At 5ft, 11 units to achieve 800 lumens on the canvas.

    Denis

  • edited March 24
    dencal said:
    Bancroft414

    Brilliant. Thanks for posting. 
    At 3ft you need 4 of these units. At 4ft need 8 units. At 5ft, 11 units to achieve 800 lumens on the canvas.

    Denis

    Denis I'm confused. The box says 1700 lumens. Help me understand your math.  

    I scrolled up and re-read previous posts... so I think I get it -- the further away the less of the light reaches the canvas.

    I am struggling to figure out how to create a light source fixture for 3 or 4 bulbs that doesn't overpower my still life set up. Currently have foil on one half of the bulb



  • dencaldencal -
    edited March 30
    @Bancroft414

    Still life setups should be well shielded from studio lights in a shadow box.

    Studio light should be about 800 lumens (Architectural standards suggest 1000 but hard to achieve and expensive).

    The inverse square law of light:
    The inverse-square law, in physics, is any physical law stating that a specified physical quantity or intensity is inversely proportional to the square of the distance from the source of that physical quantity. Wikipedia
    Square 3*3 = 9 
    Inverse 1/9 of 1750 = 194 lumens
    800/194 = 4 light units.

    Your current setup looks very underpowered.

    Use a light meter app 
    LuxMeterPlus by AM PowerSoftware
    https://itunes.apple.com/au/app/luxmeterplus/id482015593?mt=8

    To measure the light falling on the canvas and palette. 


    Denis
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