For Every Airbrush Artist!

Ready to get involved? Register for free and you won't see any google advertising!

Register

Greyscales the basics

Discussion in 'General Airbrush Tutorials' started by haasje dutchairbrush, May 11, 2014.


  1. haasje dutchairbrush

    haasje dutchairbrush Air-Valve Autobot! Very Likeable!

    Joined:
    Oct 17, 2013
    Messages:
    2,875
    Likes Received:
    5,372
    Trophy Points:
    126
    Location:
    Netherlands
    As I seem to refer to greyscales a lot in replies I thought I'd make my life a tad easier by making a post I can refer to :witless:. This is by no means the ultimate/sientific write up but should explain the basics.


    Greyscales the basics.


    When copying a painting, whether in color or monochrome it is important to keep the greyscales (transitions from light to dark) in mind. The light and dark determine how we perceive an image.
    When for instance we have a nose the light and dark areas fools our mind that we see a 3d object on a 2d surface. As we are basically fooling our mind this also means that if we don’t get the light dark values correct our mind will perceive it differently. A shadow on the side of the nose that is too dark for instance will in our minds look like it stands further out.
    When trying to achieve a realistic look (portraits for example) we need to keep the grey scales in mind.

    Basic grey scales.
    The basic greyscale (img 1) runs from dark to light, where 1 is black and 10 is white. Now one may think “yup that’s nice but when I see a black and white image that’s obvious”. The way we perceive a value in an image is however influenced by the scales surrounding it. If we take a chess board, a square surrounded by darker squares will be perceived as lighter than a square surrounded by lighter squares.
    In img 2 we have a square A and B. Although B looks a lot lighter it is actually the same color (grey value) as A. The difference in perception is caused by the light/dark values of the squares surrounding them.
    This means that even when one is doing a straight forward copy of a black and white image it is important to check the value of an area before painting it as one doesn’t want to be fooled by the values surrounding it.

    A nice trick to do this is by isolating the part of the reference you are about to do. Cut out a small square in a piece of white paper and keep it on the area you want to paint as you now don’t have any values surrounding it to fool you one can see exactly what value the area has.

    Img1:
    [​IMG]

    img2:
    [​IMG]


    Translating a greyscale.

    As an airbrusher we will often want to “translate” an image to another color (sepia is often used in monochrome portraits for instance).

    One is than faced with the problem that the black in the reference is actually darker than the darkest the sepia can get.
    To solve this we paint a transition from the darkest to the lightest we can get with our paint (carefully layer a transition). We than can add numbers to our transition from 1 to 10. We now have a translation strip (img3). If something on the reference is value 6 for instance you just have a look at your translation strip and find value 6 to know how dark you can go. This way you could even “translate” a black and white painting correctly to a very light color like yellow.

    img3:

    [​IMG]
    LovesArt, ko., Digitalflyer and 12 others like this.
  2. Squishy

    Squishy Queen Clown Slayer Mod

    Joined:
    May 8, 2012
    Messages:
    11,687
    Likes Received:
    8,704
    Trophy Points:
    126
    Location:
    Hampshire South Coast UK
    Thanks for sharing this haasje! Though I still can't make my brain believe those 2 squares are the same Lol, I understand what you're saying. This kind of thing is the underpinning knowledge I need, I usually just go by instinct and wing it, but this kind of info is invaluable to someone like me with no art training. So thanks again, you're a legend :)
  3. AndreZA

    AndreZA Elite Member! Elite Member! Very Likeable!

    Joined:
    Feb 28, 2012
    Messages:
    5,773
    Likes Received:
    6,152
    Trophy Points:
    126
    Location:
    Johannesburg, South Africa
    Kat Wolffpack and CALz AyrWKz like this.
  4. beanpoleuk

    beanpoleuk Elite Member! Elite Member! Artist of the Month! Very Likeable!

    Joined:
    Jan 8, 2013
    Messages:
    2,737
    Likes Received:
    5,182
    Trophy Points:
    126
    Location:
    Somerset UK
    To true, very useful info haasje thanks for sharing.

    Sent from my GT-I8190N using Tapatalk
  5. matty171

    matty171 Air-Valve Autobot!

    Joined:
    Mar 9, 2014
    Messages:
    3,996
    Likes Received:
    3,269
    Trophy Points:
    126
    Location:
    Belfast
    just read this again, firstly Haasje thanks again for this, sorry to bother you but can i ask if you were to see, img 2 the chess board, could you tell by looking at squares A and B that they were the same or even close to each other?? suppose what im asking is have you trained your eyes to spot this over years or when you look at img 2 do they look really different to you aswel because to me they look worlds apart, in fact ive read the post several time because i thought i was reading it wrong were it said A and B were the same lol i feel like such an empty nut.
  6. haasje dutchairbrush

    haasje dutchairbrush Air-Valve Autobot! Very Likeable!

    Joined:
    Oct 17, 2013
    Messages:
    2,875
    Likes Received:
    5,372
    Trophy Points:
    126
    Location:
    Netherlands
    I by now am able to not being fooled by looking through my eyelashes when I look at a reference, it also helps that after a while you'll start to get a feel for the area's you need to look out for. This chessboard though is the most extreme example I could find and even looking through my eyelashes they look different (althtough the difference is reduced). When showing this to tudents I normaly use photoshop to coppy one square and place it on top of the other to prove it as I think even a verry well trained eye will still be fooled by it.
  7. matty171

    matty171 Air-Valve Autobot!

    Joined:
    Mar 9, 2014
    Messages:
    3,996
    Likes Received:
    3,269
    Trophy Points:
    126
    Location:
    Belfast
    Ahh ok, i was thinking you had some sort of super power lol im gonna download a grey scale once my ink for my printer comes and start using it more, thanks very much im going to learn a bit more about this then start my painting from scartch.
    Peace



    Ride the storm
    LovesArt likes this.
  8. airbrushtutor

    airbrushtutor Love Spreading Overseer Admin

    Joined:
    Feb 21, 2012
    Messages:
    1,952
    Likes Received:
    1,905
    Trophy Points:
    111
    Excellent advice :) :applause::triumphant:
    LovesArt likes this.
  9. Diegojavbau

    Diegojavbau Air-Valve Autobot!

    Joined:
    Jun 29, 2012
    Messages:
    5,550
    Likes Received:
    4,274
    Trophy Points:
    126
    Location:
    Berisso , Buenos Aires , Argentina
    Ecellent advice

    Demostration (look like magic)

  10. ferret

    ferret Needle-chuck Ninja

    Joined:
    Feb 29, 2012
    Messages:
    801
    Likes Received:
    333
    Trophy Points:
    61
    Thankyou very much for taking the time to give us this valuable and helpful information .
  11. matty171

    matty171 Air-Valve Autobot!

    Joined:
    Mar 9, 2014
    Messages:
    3,996
    Likes Received:
    3,269
    Trophy Points:
    126
    Location:
    Belfast
    That excrement blows my mind



    Ride the storm
    kronek67 likes this.
  12. grantmartin850

    grantmartin850 Detail Decepticon!

    Joined:
    Jan 29, 2014
    Messages:
    1,101
    Likes Received:
    590
    Trophy Points:
    111
    Location:
    Panhandle of Florida
    It's amazing how even knowing it doesn't change it

    Sent from my SCH-I500 using Tapatalk 2
  13. HCP-draggin

    HCP-draggin Gravity Guru

    Joined:
    May 13, 2013
    Messages:
    436
    Likes Received:
    215
    Trophy Points:
    41
    Location:
    Cold, WI
    Great post, great topic.

    "Let value lead" is an important point to remember when doing any realistic painting. A colors value (where it lands on the greyscale) is the most important factor our eyes look for to translate an image.

    Think of it this way, you can take a black and white photo, put in into Photoshop, and change the black values to any color, and you will still be able to tell what the photo is showing. Hell, some people do that and call it "art", but I digress.

    So, of the three factors that make up a color (value, hue, saturation), value is the main one to get right. Every other color can be a little off, but as long as the value is right, the brain will mostly see it as "normal".

    Also, using the "window" method (cutting a small square in a piece of white paper) of isolating colors is so effective, I'd consider it vital, at least to my normal painting process.
    LovesArt likes this.
  14. splasha

    splasha Detail Decepticon!

    Joined:
    Nov 8, 2013
    Messages:
    1,854
    Likes Received:
    1,049
    Trophy Points:
    111
    Location:
    Geelong ,Victoria,Australia
    Just a qiick question here about optical perception.
    As one with very limited 3D vision [actually almost none!} most of the images shown ,with the exception of the greyscale itself,
    appear to me to be very similar in colour [grey] but I can still see the gradient of the scale very well.Why is this?
    I guess this is how my brain has learned to cope with the defect in vision.
    They all thought I was just a clutz, as a kid, but it turns out that it was in fact my depth perception or lack thereof.
    I personally don't think it has caused me too many problems, but I still can't see those dang 3D images from the mazes!
    Even 3D movies at the cinemas are a no-go for me, but I guess that you never miss what you never had.
    Cheers,
    Splasha
    LovesArt and Kat Wolffpack like this.
  15. Oddball

    Oddball Detail Decepticon!

    Joined:
    Apr 6, 2014
    Messages:
    1,396
    Likes Received:
    1,125
    Trophy Points:
    111
    Location:
    North Wales, UK
    I can't believe that demo in the Utube clip! I just can't get my head arounfd the fact the the "Light" square in the shade is the same as the Dark" square in the light! Amazing!
    I don't know wether I should thank you or curse you lol, this has completely thrown all my lifes worth, of Infomation stored, in the bin! I keep looking at things and saying "are they the same grey scale? are they REALLY the same grey scale"!
    Of course I'm thanking you - but now I don't know where I am with this information, it has made me hesitant and I can no longer get in the grove because this information keeps getting in the way!
    Mr. Magoo likes this.
  16. Jar

    Jar Spider Splatterer

    Joined:
    Mar 24, 2014
    Messages:
    119
    Likes Received:
    56
    Trophy Points:
    26
    Location:
    Toronto
    I like the examples. I struggle with the subtleties of the gray scale that is I think my last frontier. Of course until the next frontier come.
  17. kronek67

    kronek67 Spider Splatterer

    Joined:
    Jan 12, 2014
    Messages:
    123
    Likes Received:
    64
    Trophy Points:
    26
    Location:
    Deland, Florida
    Is there a link to the Youtube clip?

    This is one of the best things I have learned and just in time. I'm starting my first challenge today and it is a black and white photo reference.
  18. kronek67

    kronek67 Spider Splatterer

    Joined:
    Jan 12, 2014
    Messages:
    123
    Likes Received:
    64
    Trophy Points:
    26
    Location:
    Deland, Florida
    WOW! I just put the checkered board into photo shop. It is almost unbelievable, but they are the same. Its all relative.
  19. JackEb

    JackEb The Dragon Hunter Staff Member Admin Very Likeable!

    Joined:
    Apr 21, 2012
    Messages:
    8,705
    Likes Received:
    8,750
    Trophy Points:
    126
    Location:
    Mt Barker, South Australia
    Don't know if you found the link but just type Brussup into YouTube there a heap of cool illusions
  20. CALz AyrWKz

    CALz AyrWKz Moderator Mod

    Joined:
    Nov 24, 2012
    Messages:
    8,523
    Likes Received:
    6,552
    Trophy Points:
    126
    Location:
    New York, USA
    I don't know how I missed this, but it explains greyscale perfectly.

Share This Page