Thursday, April 28, 2016

Proportional dividers

For people starting out in drawing who aren't confident in their drawing skills, there are several ways of transferring a subject onto a piece of paper.  Tracing, projecting, gridding are all used in varying degrees and a proportional divider is another option.


This is a simple tool that  provides accuracy for drawing and can be used to increase or decrease size. It can also be used as a check for measurement after freehand drawing if something doesn't look quite right.

Once the scale size is decided on, the central screw can be fixed in place. The closer to the smaller end of the divider that the screw is placed, the larger the proportion of the drawing will be and vice versa.  This setting should not be changed during measurements for the drawing. The small ends of the divider are used to measure the height or width of the subject.  The larger end is used against the drawing surface and small dots or lines are made to indicate the measurement.  These measurements are made throughout the drawing, depending on the number of objects in the piece.

Of course, the usual plumb lines for proportion and measurement are needed to ensure objects align as required.  Angles are usually determined by confirming an angle with a pencil then moving that same angle to the drawing.  Where points intersect will be the measurement test and can be adjusted as needed.

If drawing from life, it is crucial that your view point never changes and that your arm is locked at the elbow for each measurement.  If either of these change, the drawing will be not be accurate.  If using a photograph or drawing from a computer or tablet screen, you can measure direct from the image, scaling up or down as required.  Note if you use a computer screen: make sure that the photograph size is not enlarged or reduced if you draw over several sessions.

While tools can make life easier in setting up drawings, they shouldn't be relied on for daily use and can never replace the hand/eye drawing skills that develop over time.  It is well worth learning to use the classical techniques for drawing, proportion and measurement and use tools such as the proportional divider for complex pieces or to check for accuracy in line placement in freehand drawing.

The divider I used here is from Accurasee in the USA and can be ordered online.


Gary L. Everest said...

Hi Jeanette,
What a great post! I never knew such a device existed! I thought I knew my way around an art supply shop, but I guess not so much.
The tutorial was excellent, too.
Glad to see you're still so giving and sharing so much your visitors.
Stay well and enjoy a well-deserved spring!!

Jeanette Jobson said...

Hi Gary

Yes, there are gadgets for everything it seems. I don't think proportional dividers are often used as people find them a bit clumsy to work with perhaps.

I'll try a video tutorial for them that may explain a bit more clearly how they are used.

Ah spring...doesn't seem to want to come this year but eventually.

Be well and enjoy the sun and surf.

Jennifer Rose Phillip said...

I have one but never use it lol too fiddly just easier to grip something if I really need to

Jeanette Jobson said...

Jen, I rarely use one as I find its easier for me to draw freehand than take all those measurements, but the dividers are great for those starting out or for checking.

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