Some core ideas demonstrated

The purpose of this “Post” is to provide the link (below) to my introduction to “Chapter 15 : The core ideas“, the third chapter of “Drawing with Knowledge” (the second BOOK in the two book volume).  The main subject dealt with is how to use the core ideas of Linear Perspective as a guides to looking, when drawing from observation. As far as I know, this is the the only place you will find it discussed at length. A preliminary idea of what this means can be found in first paragraph of the “Introductory” to this chapter (you will find a slightly edited version next, under the title of “Some core ideas introduced“). Further below, you will find links both to all published chapters from “Drawing with Feeling” (the first BOOK in the two book volume) and to earlier chapters of  BOOK 2.


Some core ideas introduced

As already explained, the rules of linear perspective were developed by Renaissance artists as aids to image-construction. This chapter starts the process of showing ways in which they can be used as a guide to looking. For this purpose a sound understanding of the core ideas that underpin them is necessary. Although many books attempt to provide this by referring to different examples of perspective constructions, using a variety of diagrams, they never really show how these relate (or fail to relate) how we see in the real world. My approach is very different. Eschewing diagrams, it makes use of  participatory demonstrations, using real world props. In addition to revealing the core ideas behind the standard rules, these provide a fascinating introduction to some of the seeming anomalies of visual experience.

Few people would disagree with anyone who tells them that objects appear to get smaller as they recede into the distance. This phenomenon is one of two core ideas behind of the laws of linear perspective, as taught in art schools. The other is the influence of the eye-line. If these were all that mattered, there would be a great deal less to write about in this chapter. However they are far from being so. The reason is not only that the crucial role of the picture plane, as the third variable, is too often neglected, in the interests of simplicity. Even more important, from the point of view of the ideas presented in this chapter, is the fact that appearances can be dramatically influenced by the constancies of size, orientation and shape, as well as by the context in which they occur. This is because the constancy phenomena, which are context dependent, push appearances in different, often opposite directions to those predicted by the laws of linear perspective as conventionally taught. The resulting confusion can cause all sorts of problems for those who seek to use them as an aid when attempting to make accurate drawings from observation. This chapter shows how interactive demonstrations can be used to help people understand the reasons why. Subsequent chapters both continue this process and suggest many practical ways of using the knowledge that will be made available.


Two views of the Chateau Corduries, followed by a question,

core ideas
1 :  Château de Corduries seen from the studio window


core ideas
2 : The image of the Château de Corduries enlarged


A question: How do you change the size of the château as seen from the studio, without leaving the studio or without using a magnifying glass?


core ideas
William Stots : Anamorphic portrait of Edward VI  (top as  seen from front and  bottom as seen from side)


core ideas
Painting School of Montmiral studio fireplace as seen from side – chalk pastel



Chapters from BOOK 1 and BOOK 2 of  “Drawing on Both Sides of the Brain” (Volume 1 of the series of four volumes)


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7 thoughts on “CHAPTER 15 : CORE IDEAS”

  1. This post is so full of insights. You give students learning about linear perspective much to consider. It is an original approach and also practical. It makes common sense to both use knowledge and yet, also respond to the unique characteristics of what you are trying to draw and the viewers experience of the image. Once again, you heighten awareness of the many variables that are often neglected. Thank you Francis!

    1. Thanks Sarah for your enthusiasm. I do believe that using linear perspective as a tool for finding out about appearances has been badly neglected, and not only for the for the reasons explained in Chapter 15. The are three more chapters to come, all full of useful things that appeared to be new to all the hundreds of students who have come to the Painting School of Montmiral over the last 34 years.

  2. Thank you for posting this. It’s interesting to see how you have used your studio and the specific surroundings of the School to demonstrate these ideas.

    Despite being an experienced painter there is information here which I hadn’t considered. What I mean by that is I hadn’t consciously considered them, I’ve painted that Chateau from the window, [ and similar] and actually the extreme shallowness of the perspective angles hadn’t occurred to me, but I probably wasn’t relying on a linear perspective approach. Although I’m familiar with the basics around the tracing glass, this chapter throws up lots of more complex points that I’ll need to re-read.

    The ‘experimental set-up’ is well explained, and the diagrams very helpful [ probably vital] but it is quite complex and even when well explained it’s not always easy to visualise what’s happening. I guess an experiment isn’t supposed to be a leisure read! A book has to use words and pictures, but I wonder whether the exploration of some of these ideas would be best supported through video clips. I know cameras and eyes are different, and the viewer won’t get the exact effect, but I think they could get a quicker handle on some of the more complex subtle experimental findings that the tracing glass reveals. Of course, it would require significant time and resources to set this up.

    1. Thanks Mark for your input. Better than a video clip would be for people to come as students. Maybe in the Autumn, when when a film maker is coming to complete a film of me, I could persuade him to help.

  3. Of the two fireplace drawings ‘Figure 7 and ‘Figure 8, I fail to see how you could achieve Figure 8 from position B. When sitting in the same position, the fireplace and chair have not moved; therefore the same surfaces remain visible; and only those surfaces. As you cannot see the closest inner fireplace wall in Figure 7, you will still not see it having turned the viewing pane. From Figure 9, it is clear the fireplace and both inner walls are at right-angles. Looking at Figure 8, both inner walls of the fireplace are visible and the closest outer wall is missing. To draw Figure 8, after placing the dots, which will create a rectangle, you then have to construct a fireplace from what you know, rather than what you see. If that is the case, when you know both inner walls of the fireplace are the same depth, why were they not drawn equally? I understand how making the viewing plane parallel with the fireplace, will eliminate the effects of perspective; but it does create other issues, as you cannot see around corners. Figure 8 does not make any sense.

  4. The ‘open window’ ‘closed window’ metaphor is a simplistic one. Linear perspective clearly demonstrated when the window is open, seems to have been eliminated when the window is closed. But not quite! When closed, some perspective remains. In standing before the closed window, its top is 1.5m above eye-level, with the bottom 1.5m below eye level. Of the wooden window bars and surround, those higher than eye level, you can see their beneath surfaces, and those below eye-level, you can see their upper surfaces. Only a window bar at eye-level, will you see neither its top or bottom. When standing directly in front, that is vanishing point, not off to the left or right. Because the window is also 1.5-2m wide, the perspective is still there, but very subtle. Every recessed pane of glass has perspective elements in the joints; with each being a different angle that correspond to the laws of linear perspective. Yes, the clues are small, but they exist. When we talk artistically about looking deeper and deeper, they are the nuances that should be noticed. Factual drawing is not simplistic.

  5. Thanks Keith. All you say is very true and I hope interesting to readers of the the chapter. However, it is a bit detailed for the context. It’s the kind of thing I mention to students I think would be interested. I would be very disappointed if any reader of my books disagreed with your closing sentence.

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