Theories of Colour Vision

Theories of Colour Vision Kishan Lakhani How does colour vision work? It is difficult to imagine a world without colour perception as it is constantly in action by a whole spectrum of living organisms and for a range of purposes, it â€Å"not only allows us to detect objects that might otherwise be obscured by their surroundings; it also helps us to recognize and identify things we can see easily† (Goldstein, 2000, p.203), thus making it an essential component of vision. Colour dictates survival in many environments; the artic fox boasts a white pelt allowing effective camouflage over its prey and a significant factor in its ability to hunt (Sekuler Blake, 2006). I will explore the mechanisms that are said to explain colour vision at the photoreceptor level and beyond, but first of all we must understand what colour actually is. The electromagnetic spectrum ranges from cosmic rays to radio waves, as wavelength increases. Between UV and Infrared lies a strip, visible light, this is what we are interested in with regard to colour (Snowden et al., 2006). Colour arises when light rays from this visible spectrum (390nm-750nm) are reflected off objects and into our eyes. Differing wavelengths of light from this spectrum subsequently determine the colour perceived, as short wavelengths produce the colour violet (350nm), medium and long wavelengths produce green and red respectively. Sir Isaac Newton famously wrote â€Å"The rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that colour† (Sekuler Blake, 2006, p.236) So colour doesn’t really exist in the physical world at all, it is our own psychology that creates the concept of colour. Semi Zeki (1983) refined Newton’s words further saying that colour vis ion is a â€Å"property of the brain, not the world outside.†( Sekuler Blake, 2006, p.236) Hence we can sum up that colour vision lies in the eyes and brain – and not in the physics of light itself (Anderson 2012). So to answer the question ‘How does colour vision work’ we must explore the visual systems of the organisms further. Figure 1 The Electromagnetic spectrum (2012), Diagram showing the visible spectrum within the electromagnetic spectrum Photoreceptors are light sensitive cells found at the back of the eye in the retina. They contain visual pigments that absorb photons of light and convert this light energy into chemical energy, this process is called phototransduction. Within the pigment is a protein which determines the wavelength of light absorbed by the pigment and also a chromophore which is responsible for absorbing photons of light. (Wolfe et al., 2009) There are 2 types of photoreceptors, rods and cones. Cones are mainly concentrated in the fovea in the centre of the retina whereas Rods are completely absent in the fovea and more prevalent in the periphery of the retina (Snowdon et al,. 2006). Rods are adapted so they can operate in low light levels due to spatial pooling allowing scoptic vision, whilst sacrificing visual acuity. They contain just one pigment rhodopsin – denying colour vision due to the univariance principle. Cones however contain 3 photo pigments, which are sensitive to various wavele ngths of light and can therefore let us see colour. In comparison to the physical description of light, colour is much easier to describe as it is experienced psychologically not physically – such is the nature of light. It can be specified by just three values; hue, saturation and lightness.(Palmer, 1999) This is very important with reference to colour vision as it implies that many different lights will produce the same colour experience (Palmer, 1999). The three perceptual dimensions of colour can be summarised in what is known as the colour spindle. Hue is referred to as â€Å"the chromatic aspect of light† (Wolfe et al., 2009) and is dictated by its wavelength. Saturation corresponds purity and how vivid the colour is (Palmer 1999), and brightness involves the intensity of the colour (physically). The Young/Helmhotz trichromatic theory of colour vision works on the photoreceptor level, and ultimately was sprouted through the results of Helmhotz’s colour matching experiment. Observers were allowed to vary the intensities of 3 primary lights and mix them (in a comparison field) to match the colour of a single wavelength in a test field. They had to find a psychological match between the mixture of primary lights and the test light, simply by varying the intensities of the primary lights. This match is known as a metameric one, as the light in the comparison field is physically different yet psychologically identical to that in the test field. Results showed that by varying intensities in the comparison field, the observer could find a metameric match using just three primary lights. Dichromatic observers were unable to find matches for every colour in the test field. In summary, â€Å"with 3 primaries, you can get any combination of responses in the 3 cone types, so you can match the appearance of any test light.† (Anderson 2012) It is therefore clear to us that colour vision heavily relies on three different receptor mechanisms or cone photopigments, each with different spectral sensitivities (Goldstein, 2010). This is the basis of the trichromatic theory I will now elaborate on. Monochromats possess only one type of pigment in their cones. In this case, the ability to see colour is not possible. The same chain of events is initiated in the visual receptor despite there being a variety of wavelengths in the light absorbed by the pigment. The receptors response conveys information about how much light has been absorbed, but this response provides no information about the wavelength of this absorbed light. (Sekuler Blake, 2006) It is therefore impossible to discriminate wavelength when there is only one photopignment, which has uniform spectral sensitivity. The response could have altered due to a change in wavelength or light intensity, and monochromats are none the wiser – this is known as the principle of univariance. This situation is not unique to monochromats, as in low light levels rods are the only photoreceptors in action. They have one photopigment, rhodopsin resulting in the same dilemma. Consequently we â€Å"disregard the wavelength inform ation and see an image that appears in shades of grey† (Snowden et al., 2006) explaining why we can’t monochromats can’t see colour and why none of us have colour vision in low light levels. Dichromats possess two photopigments, which is very useful in terms of colour vision. The two pigment types have different absorption spectra, extracting some usable wavelength information about light (Sekuler Blake, 2006) It is now possible to separate and disentangle wavelength and intensity, allowing colour to be visible to a certain extent. Certain wavelengths are confused and constitute failures of discrimination (Sekuler Blake, 2006). A key reason that leads to the idea humans aren’t dichromats revolves around what is known as the neutral point. All dichromats possess this neutral point in which a single wavelength is always confused, and â€Å"the existence of a single neutral point is the hallmark of a two-pigment eye.† (Sekuler Blake, 2006, p.249) As humans do not show any traits of having the neutral point, there is a strong belief that humans have more than two cone photopigments. Trichromats hold three cone photopigments, enabling total discrimination of wavelengths throughout the visible spectrum. Trichromacy also ties in with Helmhotz’s colour matching experiment, indicating three not two photoreceptors are required for complete colour vision across the entire visible spectrum. The three pigments are most sensitive to light of a particular wavelength – approximately 430, 530 and 560 nanometres respectively. (Sekuler Blake, 2006) Figure 4 shows the each cone pigment absorbs a very wide range of wavelengths. So between 400nm and 650nm there are at least two types of cone photopigments absorbing light. In the region of 475nm, all three types of pigments are affected and stimulated. (Sekuler Blake, 2006) Hence we can conclude that the absorbance range is tremendously increased with three photopigments, and as light is reflected onto the retina every wavelength of light in the visible spectrum can be perceived in the form of colours by our brain. Trichromatic theory may explain how the existence of just three cone photopigments allows colour matching for any wavelength of light in the visible spectrum, using just three primary lights. However, it still leaves many unanswered questions when it comes to having a full understanding of how colour vision works – as Hering highlighted. Negative afterimages, the visibility of four psychologically pure hues (blue, red, green and yellow) and the absence of complementary hues such as blueish – yellow all indicate that trichromatic theory alone is inadequate in explaining how colour vision works. Hering made an important discovery with regard to afterimages. If we stare at the black dot in Figure 5 for around 30 seconds, and then look at a blank piece of paper we notice the colour of each square changes. The green changes to red and red to green, whilst the blue changes to yellow and the yellow to blue. Based on results like these, Hering proposed the concept that red and green are paired and blue and yellow are likewise paired. (Goldstein, 2010) An experiment where observers were shown patches of colour, and then asked to estimate the ratios of blue, green, red and yellow from each patch they received. Results showed that observers very rarely saw blue and yellow, or red and green together. (Abraham Gordon, 1994 cited in Goldstein, 2010) Sekuler and Blake (2006, p.255) also support this view that these complementary hues do not coexist, as â€Å"an object never appears both blue and yellow at the same time.† Hurvich and Jameson’s hue cancellation experiment st rengthens the case further, as any redness was eliminated when a green light was added to the red light. Hering also observed that those who are colour blind to red, are also colour blind to green; which ultimately led him to declare the opponent-process theory of colour vision. (Goldstein, 2010) So we can deduce from this evidence that blue is paired with yellow and red with green; the basis of the opponent-process theory. The opponent-process theory of colour vision follows the trichromatic theory, rather than replacing it, the two work hand in hand to explain how colour vision works. In fact it is the responses from the cones of the retina that form the basis of the opponent channels. (Anderson 2012) There are three opponent channels, two chromatic and one achromatic, and are formed by combining the responses from the three cone types. (Sekuler Blake, 2006) Figure 6 displays the red-green chromatic channel is comprised from the outputs of the M and L cones. It is also known as the M – L channel, as it signals the difference between the outputs of the M cones and of the L cones. (Sekuler Blake, 2006) The second chromatic channel is the blue-yellow channel, and it represents the difference between the S cone outputs and the sum of the M and L cone outputs. (Sekuler Blake, 2006) It is therefore also referred to as the S – (M + L) channel. The achromatic channel is known as the luminance channel, and combines the output of the M and L cones so we can also label it the M + L channel. The activity in this luminance channel hinges on the sum of excitation of both M and L cones (Sekuler Blake, 2006). This addition can lead determine an object’s visibility, â€Å"The shape of the photopic sensitivity curve (closely related to visibility) can be predicted by taking a sum of M and L cone responses.† (Smith and Porkorny, 1975 cited in Werner et al., 1984). Russel DeValois was responsible for the finding of opponent neurons in the retina and lateral geniculate nucleus (LGN), which could provide physiological evidence to back up Hering’s propositions. (Goldstein, 2010) The LGN is the station responsible for receiving input from the retina and transmitting it to the visual cortex. Devalois conducted experiments on LGN cells of monkeys (who have the same trichromatic vision as ours), and discovered opponent cells which behaved as if subtracting outputs from different cones and also nonopponent cells which behaved as if adding outputs from different cones. Devalois discovered opponent cells reproduced an ON or OFF response determined by the wavelength of light. (Sekuler Blake, 2006) This can explain the first chromatic channel Hering proposed (M – L) channel. Long wavelength cone excitation results in a positive or ON response, whilst medium wavelength cone excitation results in a negative or OFF response. Hence if the net re sponse is positive then a red colour is visualised (long wavelength of light), and similarly a blue colour is perceived if the net response is negative. This supports Hering’s initial observation that the hues red and green cannot coexist. Opponent cells were also responsible in explaining the S – (M + L) channel. Short wavelength cone excitation results in a positive or ON response, whilst wavelengths around 580nm (M+L) cone excitation results in a negative or OFF response. Further findings included the fact that nonopponent ON cells produced ON responses for every wavelength, although some wavelengths produced stronger responses than others and OFF cells produced OFF responses for every wavelength again with varying strengths. It is these nonopponent cells which form the achromatic channel outlined by Hering. (Sekuler Blake, 2006) All in all, colour vision begins at the photoreceptor level as explained by trichromatic theory. The outputs of the three cone photopigments have been redistributed into the achromatic and chromatic channels at the LGN, as trichromacy progresses to opponent-process theory. Palmer (1999) concludes by describing the dual process theory; in which the products from the trichromatic stage are used as the inputs for the secondary opponent-process stage. As we venture from the LGN, further into the visual system, the information is perceived by the visual cortex of the brain facilitating us with colour vision. Bibliography Anderson, S (2012). Colour vision, Vision and visual perception, Optometry. Aston University Dimitri Poumidis, (2008), Spectral Sensetivities [ONLINE]. Available at: http://www.gravurexchange.com/gravurezine/0805-ezine/ploumidis.htm [Accessed 25 January 13]. Goldstein, E. B. (2010). Sensation and perception (8th ed.) Chapter 9. Wadsworth Cengage Learning Joshua Stevens, Jennifer M. Smith, and Raechel A. Bianchetti , (2012), The Electromagnetic Spectrum [ONLINE]. Available at: https://www.e-education.psu.edu/geog160/node/1958 [Accessed 03 January 13]. Marc green, (2004), Opponent process theory [ONLINE]. Available at: http://www.visualexpert.com/FAQ/Part1/cfaqPart1.html [Accessed 09 February 13].Paul Schils , (2012), Chromatic adaptation [ONLINE]. Available at: http://www.color-theory-phenomena.nl/12.00.htm [Accessed 08 February 13]. Palmer, S. E. (1999). Vision science: photons to phenomenology, Chapter3. Massachusetts Institute of Technology Sekuler R. Blake R. (2005). Perception (5th ed.) Chapter 2. McGraw-Hill Sekuler R. Blake R. (2005). Perception (5th ed.) Chapter 7. McGraw-Hill Snowden R., Thompson P. Troscianko T. (2006). Basic Vision, Chapter 1. Oxford University Press Snowden R., Thompson P. Troscianko T. (2006). Basic Vision, Chapter 5. Oxford University Press Tom Jewett, (2009), Hue, Saturation, Brightness [ONLINE]. Available at: http://www.tomjewett.com/colors/hsb.html [Accessed 10 January 13]. Wolfe, J.M., Kleunder, K.R., Levi D.M., et al (2009). Sensation and perception (2nd ed.), Chapter 5. Sinauer Associates Inc

The Mayflower Compact

Morison’s quote does not diminish the importance of early documents such as The Mayflower Compact. It only puts it in context of part of a larger process that began with the English settlement of North America. The compact did not create a plan for Democracy. It did, however, establish a theoretical framework that would grow over the succeeding centuries. In 1620 the Pilgrims created a document of self-governance. It was meant to foster a better society, if only within their small colony. It was a combination of religious ideals and ideals of freedom. The Mayflower Compact was not a constitution. It did, however, implant ideas that would be central to the creation of a new and prosperous nation The Origins When the Pilgrims sailed for North America, nothing was assured. They were taking a tremendous risk with their lives. Past settlements had been decimated by weather, disease and Indian attacks. Despite the hardships, the settlers saw the new world as a great opportunity. Many were fleeing from religious persecution in Europe. While they remained loyal to the King of England, the fact was that the new settlers were far from his direct control. Some on board the Mayflower saw this as a chance to form a better and more just government. The Mayflower had landed far north of Virginia, its original destination. The settlers knew they were beyond the control of the Virginia Company. They would have to make do on their own. Knowing that past settlements had failed because of a lack of coherent government, the settlers took steps to remedy the problem. In 1620, they wrote the Mayflower compact. It was a basic theory of government. The settlers past experiences with religion and various forms of persecution influenced the document. The theory of government stated in the Mayflower Compact would, in time, become the prevailing model for a democratic society. The compact begins by paying homage to the King, but goes on to spell out the ideas of freedom that form the bedrock of American culture. The Ideals The signers of the Mayflower compact were Puritan separatists. For pragmatic reasons they recognized the King of England. They were primarily concerned, however, with staying in the good graces of God. They brought with them a unique combination of experiences and motives. The Puritans wanted a society more in accordance with their religion. However, they also had experienced the pain of religious persecution. They innately understood the danger of an all-powerful government. While they were firm in their religious beliefs, they wanted to limit how much those beliefs were written into future laws. The result was a local government based on social contract. It was pragmatic, given the small size of the colony. Everyone had to work together for survival. It was also idealistic in its aims. The social contract was not a new idea, but the settlement of America gave the first opportunity to use it on a large scale. The social contract was necessary to encourage further settlements that could survive away from a central government. The Mayflower Compact created a theoretical template to do this. The Pilgrims called their creation a â€Å"civil body politik† (Dahl, 2000). Its purpose was to enact just laws that would benefit the colony as a whole. The Plymouth colony eventually succeeded. Other colonies adopted the ideas of the Mayflower Compact, and the social contract became the primary form of government in America. The Lasting Impact Here was a unanimous and personal assent by all the individuals of the community to the association by which they became a nation. John Adams, 1802 (from The Pilgrim Hall Museum, 1998) The Mayflower Compact started a process by which democracy took root in America. Success breeds success. The Plymouth colony provided an example that people can thrive by essentially ruling themselves. The feeling that the colonists didn’t need an all-powerful king set in over the first hundred years of European colonization. The eventual products of this feeling were the Declaration of Independence and the new United States Constitution. The society that sprung from the Mayflower Compact made room for the wide variety of people that would come to America in future years. Freedom encouraged ever more immigration, and democracy was strengthened. The Mayflower Compact itself was not a blueprint for democracy. It did, however, plant the seeds of freedom with self-restraint. That idea is central to American democracy. Sources Dahl, Robert A. (2000). On democracy. New Haven: Yale University Press. Eldredge, Laurence H. (1968). Men, laws and government: some reflections on the Mayflower Compact. Philadelphia: Society of Colonial Wars in the Commonwealth of Pennsylvania. Pilgrim Hall Museum. (1998). Later Significance of the Mayflower Compact. Retrieved 2/6/2006 from: http://www.pilgrimhall.org/compcon.htm The Society of Mayflower Descendents. (2002). The Mayflower Compact. Retrieved 2/6/2006 from: http://www.ctmayflower.org/mayflower_compact.php Wishing, Lee. (2004). Thankful for a Fourth Grade Play. Retrieved 2/6/2006 from: http://gccsavvior.com/VISION_&_VALUES_CONCISE_Thankful _for_a_Fourth_Grade_Play.php?view_all=            

Un-Answered Problems With Samples of a Personal Narrative Essay Disclosed

Un-Answered Problems With Samples of a Personal Narrative Essay Disclosed Every precise detail matters if you would like to assemble an excellent narrative essay. There were pages strewn all over the ground alongside pictures I could no longer identify. Bear in mind that a high degree of detailing is a feature of all great narrative essay examples. Contrary to other objective essays it not only provides the huge picture but in addition provides the inside specifics of the situation. In any event, it's always a great idea to concentrate on an event that played a pivotal part in your life. You don't necessarily have to concentrate on an important life event provided that you're ready to convince the readers why the event was important and the way that it changed your life. Add everything briefly and tell about what you're going to go over in the primary body. The only means to do it is to grab their attention from the start. Narrative essay Universe start writing narrative essay like Here you can discover a very good narrative essay sample and utilize it for your goal. Without any of them, you can't compose an excellent narrative essay. Narrative essays includes a thesis statement, however personal they are. Regardless of the very first impression, a narrative essay isn't the simplest of all assignments. Rare or exclusive occasions of your life has to be cited in your essay as it is the heart of a personal narrative essay. When it has to do with narrative essay topics, there are a number of things you should take into consideration. Here are a few useful tips that it is possible to follow in your essay. The main issue to be cautious about in personal descriptive essay is that there shouldn't be any over-exaggeration. Writing events in a chronological manner is the most essential element to bear in mind when writing a narrative essay. The revisions are unquestionably free! Even in the event the deadline is truly tight, feel free to get hold of our managers. In some instances it represents a quarter of your entire grade. The most frequently encountered paper writing service that the bulk of our clients require is essay writing. Therefore, many students and employees decide to get inexpensive essay rather than writing it themselves. Most people today find it one of the simplest papers to write. Getting the Best Samples of a Personal Narrative Essay There's, clearly, a limit on the variety of pages even our very best writers can produce with a pressing deadline, but generally, we can satisfy all the clients seeking urgent assistance. Finally utilize outside sources to help you acquire the very best result possible. You can also get in touch with your writer to supply some additional recommendations or request information regarding the order's progress. If it's the first time you're likely to use our article writing service, you most likely have a lot of questions. If you've always experienced difficulties with this kind of assignment or couldn't find relevant data to present solid arguments, our experts are at your services. If you're creating a database driven site you must be mindful. Use the aid of true academic experts and receive the service you have earned! To make certain you will see a complete answer to every question, we've got a support team that's always online. Samples of a Personal Narrative Essay: No Longer a Mystery Your narrative paper is going to be crafted in a manner that allows it to come live and precisely recreate its story for those readers. From time to time, however, a narrative isn't about such essential topics. In case it's a personal narrative, it has to have details linked to personal experiences and their outcome. Irrelevant details will shift the focus of your readers and they won't be able to comprehend the story. The majority of individuals are placed into a dilemma in regards to writing a narrative essay. By these means, your points are easily inculcated to your audience. The stories of individuals who've overcome disorders or individuals who managed to get from a really tough crisis are extremely much like narrative essays. There are students who dread the concept of narrative essays, not because they thinks it isn't cool but because they may be very personal and so tough to write, in the meaning that simply recalling some undesirable experiences can be quite painful.

GDI Graphics in Visual Basic .NET Tutorial

GDI is the way to draw shapes, fonts, images or generally anything graphic in Visual Basic .NET. This article is the first part of a complete introduction to using GDI in Visual Basic .NET. GDI is an unusual part of .NET. It was here before .NET (GDI was released with Windows XP) and it doesnt share the same update cycles as the .NET Framework. Microsofts documentation usually states that Microsoft Windows GDI is an API for C/C programmers into the Windows OS. But GDI also includes the namespaces used in VB.NET for software-based graphics programming. WPF But its not the only graphics software provided by Microsoft, especially since Framework 3.0. When Vista and 3.0 were introduced, the totally new WPF was introduced with it. WPF is a high-level, hardware accelerated approach to graphics. As Tim Cahill, Microsoft WPF software team member, puts it, with WPF you describe your scene using high-level constructs, and we’ll worry about the rest. And the fact that its hardware accelerated means that you dont have to drag down the operation of your PC processor drawing shapes on the screen. Much of the real work is done by your graphics card. Weve been here before, however. Every great leap forward is usually accompanied by a few stumbles backward, and besides, it will take years for WPF to work its way through the zillions of bytes of GDI code. Thats especially true since WPF just about assumes that youre working with a high-powered system with lots of memory and a hot graphics card. Thats why many PCs couldnt run Vista (or at least, use the Vista Aero graphics) when it was first introduced. So this series continues to be available on the site for any and all who continue to need to use it. Good Ol Code GDI isnt something that you can drag onto a form like other components in VB.NET. Instead, GDI objects generally have to be added the old way -- by coding them from scratch! (Although, VB .NET does include a number of very handy code snippets that can really help you.) To code GDI, you use objects and their members from a number of .NET namespaces. (At the present time, these are actually just wrapper code for Windows OS objects which actually do the work.) Namespaces The namespaces in GDI are: System.Drawing This is the core GDI namespace. It defines objects for basic rendering (fonts, pens, basic brushes, etc.) and the most important object: Graphics. Well see more of this in just a few paragraphs. System.Drawing.Drawing2D This gives you objects for more advanced two-dimensional vector graphics. Some of them are gradient brushes, pen caps, and geometric transforms. System.Drawing.Imaging If you want to change graphical images - that is, change the palette, extract image metadata, manipulate metafiles, and so forth - this is the one you need. System.Drawing.Printing To render images to the printed page, interact with the printer itself, and format the overall appearance of a print job, use the objects here. System.Drawing.Text You can use collections of fonts with this namespace. Graphics Object The place to start with GDI is the  Graphics  object. Although the things you draw show up on your monitor or a printer, the Graphics object is the canvas that you draw on. But the Graphics object is also one of the first sources of confusion when using GDI. The Graphics object is always associated with a particular  device context. So the first problem that virtually every new student of GDI confronts is, How do I  get a Graphics object? There are basically two ways: You can use the  e  event parameter that is passed to the  OnPaint  event with the  PaintEventArgs  object. Several events pass the  PaintEventArgs  and you can use the to refer to the Graphics object that is already being used by the device context.You can use the  CreateGraphics  method for a device context to create a Graphics object. Heres an example of the first method: Protected Overrides Sub OnPaint( _   Ã‚  Ã‚  ByVal e As System.Windows.Forms.PaintEventArgs)   Ã‚  Ã‚  Dim g As Graphics e.Graphics   Ã‚  Ã‚  g.DrawString(About Visual Basic vbCrLf _   Ã‚  Ã‚   and GDI vbCrLf A Great Team, _   Ã‚  Ã‚  New Font(Times New Roman, 20), _   Ã‚  Ã‚  Brushes.Firebrick, 0, 0)   Ã‚  Ã‚  MyBase.OnPaint(e) End Sub Click Here to display the illustration Add this into the Form1 class for a standard Windows Application to code it yourself. In this example, a Graphics object is already created for the form  Form1. All your code has to do is create a local instance of that object and use it to draw on the same form. Notice that your code  Overrides  the  OnPaint  method. Thats why  MyBase.OnPaint(e)  is executed at the end. You need to make sure that if the base object (the one youre overriding) is doing something else, it gets a chance to do it. Often, your code works without this, but its a good idea. PaintEventArgs You can also get a Graphics object using the  PaintEventArgs  object handed to your code in the  OnPaint  and  OnPaintBackground methods  of a Form. The  PrintPageEventArgs  passed in a  PrintPage  event will contain a Graphics object for printing. Its even possible to get a Graphics object for some images. This can let you paint right on the image the same way you would paint on a Form or component. Event Handler Another variation of method one is to add an event handler for the  Paint  event for the form. Heres what that code looks like: Private Sub Form1_Paint( _   Ã‚  Ã‚  ByVal sender As Object, _   Ã‚  Ã‚  ByVal e As System.Windows.Forms.PaintEventArgs) _   Ã‚  Ã‚  Handles Me.Paint   Ã‚  Ã‚  Dim g As Graphics e.Graphics   Ã‚  Ã‚  g.DrawString(About Visual Basic vbCrLf _   Ã‚  Ã‚   and GDI vbCrLf A Great Team, _   Ã‚  Ã‚  New Font(Times New Roman, 20), _   Ã‚  Ã‚  Brushes.Firebrick, 0, 0) End Sub CreateGraphics The second method to get a Graphics object for your code uses a  CreateGraphics  method that is available with many components. The code looks like this: Private Sub Button1_Click( _   Ã‚  Ã‚  ByVal sender As System.Object, _   Ã‚  Ã‚  ByVal e As System.EventArgs) _   Ã‚  Ã‚  Handles Button1.Click   Ã‚  Ã‚  Dim g Me.CreateGraphics   Ã‚  Ã‚  g.DrawString(About Visual Basic vbCrLf _   Ã‚  Ã‚   and GDI vbCrLf A Great Team, _   Ã‚  Ã‚  New Font(Times New Roman, 20), _   Ã‚  Ã‚  Brushes.Firebrick, 0, 0) End Sub There are a couple of differences here. This is in the  Button1.Click  event because when  Form1  repaints itself in the  Load  event, our graphics are lost. So we have to add them in a later event. If you code this, youll notice that the graphics are lost when  Form1  has to be redrawn. (Mimimize and maximize again to see this.) Thats a big advantage to using the first method. Most references recommend using the first method since your graphics will be repainted automatically. GDI can be tricky!