tag:blogger.com,1999:blog-7580430527071698103.post464668727579632175..comments2023-11-16T19:54:57.183-08:00Comments on Douglas Flynt: Accurate Ellipses Douglas Flynthttp://www.blogger.com/profile/03555979975038363353noreply@blogger.comBlogger16125tag:blogger.com,1999:blog-7580430527071698103.post-7067475151147469762020-06-26T09:35:03.587-07:002020-06-26T09:35:03.587-07:00Awesome! Never seen this before, and I have stud...Awesome! Never seen this before, and I have studied eclipses quite a bit, in the context of astronomy. I would love to figure out why this works.Chris Mc.https://www.blogger.com/profile/15635591814184736952noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-89935781878347279112019-09-09T14:10:58.769-07:002019-09-09T14:10:58.769-07:00I never visualized the axis rotation as the circle...I never visualized the axis rotation as the circle moves left or right. Amazing that basic concept I did not know and I've been drawing since 1972, when I was 2. :) Thank you for sharing this.Anonymoushttps://www.blogger.com/profile/11295903602719880257noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-21704539230752982682019-04-27T08:05:13.543-07:002019-04-27T08:05:13.543-07:00Thanks for the question. So, when viewing a circle...Thanks for the question. So, when viewing a circle in perspective the ellipse at the circle’s true midway point is not the widest point. The widest point will be slightly below it, corresponding to the major axis of the ellipse. This is why I mentioned earlier in this post, “it is interesting to note that if we take an ellipse and place it in perspective the resulting curvature we perceive is no different than if we were to construct an ellipse at the "picture plane" using the dimensions of the major and minor axes as they appear at this picture plane.” Hope that helps! Douglas Flynthttps://www.blogger.com/profile/03555979975038363353noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-14622139194830640462018-08-23T13:05:46.425-07:002018-08-23T13:05:46.425-07:00This is one awesome technique that I haven't f...This is one awesome technique that I haven't found anyplace else! Thank you!fotishttps://www.blogger.com/profile/03542214501535948130noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-11763662930898528552018-07-19T16:21:08.209-07:002018-07-19T16:21:08.209-07:00Thnx for sharing this handy method of construction...Thnx for sharing this handy method of construction! Hm what I've never quite understood about a circle in perspective being an ellipse: If we look at the grid with circle inside, drawn in perspective (this one:)<br /><br />http://douglasflynt.com/ellipses/circle_in_perspective.jpg<br /><br />then it is obvious (or not) that the size of the squares decreases as they recede into the distance. The circle is divided in half by the squares, so how then can the circle in perspective by symmetric with respect to the horizontal axis? (ie like the ellipse is.) Shouldn't the top half of the circle in perspective (the half farthest away) be narrower that the bottom half (the half closest to us)? Because the top half of the circle is enclosed in the squares that recede in the distance and the bottom half of the circle is enclosed in the squares that are closest to us...JVRhttps://www.blogger.com/profile/05650362716576043890noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-74882981331326609572016-07-04T10:36:58.817-07:002016-07-04T10:36:58.817-07:00Really great explanations here. One cheating metho...Really great explanations here. One cheating method one can do is if you have a photo reference of your subject, bring it into an editing program like photoshop or MS publisher, customize your page size to the same as your canvas, import your photo ref, then drag in your ellipse over top of the image until it matches, dont forget to rotate the ellipse to match a two point perspective. Once you have that exact match, copy and paste that ellipse shape into a standard 8.5x11" page and print it. Cut the shape out with scissors, now you have an ellipse template to trace. Seems like a lot of work but it's well worth knowing that your ellipse is exactly correct especially if you use this method in concert with a grid drawing method. As a semi professional artist It's worth knowing that that shape IS correct rather than freehanding it hoping it works out. I don't mind a little non traditional methods to make up for my drawing shortfalls.Anonymoushttps://www.blogger.com/profile/15515536520485087314noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-90699934454442031692016-01-18T10:07:05.961-08:002016-01-18T10:07:05.961-08:00This information is fantastic and is exactly what ...This information is fantastic and is exactly what I needed. My first few attempts didn't look great, then I tried the vanishing point further away - and it works a treat. Thanks so much! Now I just need some rules for drawing several related elipses (eg, top of a glass, bottom of glass and the surface of the liquid).Wendy Booth Arthttps://www.blogger.com/profile/16346635686257555724noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-36084540730312760182014-04-18T11:30:26.357-07:002014-04-18T11:30:26.357-07:00Glad you were able to make use of the information ...Glad you were able to make use of the information Ken. Thanks for the comment! Douglas Flynthttps://www.blogger.com/profile/03555979975038363353noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-82757625453410100862014-04-16T12:33:47.537-07:002014-04-16T12:33:47.537-07:00I teach plumbing. I have been searching for an eas...I teach plumbing. I have been searching for an easy way to teach how to make an elipse for the purpose of how to cut an eliptical shape from a sloping surface when passing a pipe through. Seems a bit complicated to start but once done 4 or 5 times it becomes quite natural. Many thanks for this clip.Anonymoushttps://www.blogger.com/profile/13022093849137365295noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-58159802115950410892013-07-08T06:50:58.765-07:002013-07-08T06:50:58.765-07:00Essayer, I'm still not sure why images are loa...Essayer, I'm still not sure why images are loading for some viewer and not for others. My apologies but I am glad you enjoyed the post.<br /><br />Judy, thanks for the comment. Glad you enjoyed the post. Perhaps I can do something related to brush handling at some point. <br /><br />M, please keep in mind that the for the last diagram the center of the ellipse is not the center of the ellipse in perspective, but the center of the ellipse as considered 2-dimensionally as it would appear at the picture plane. The main assertion is that the correct curvature for an ellipse in perspective can also be created 2-dmensionally (upon the picture plane). The construction at the picture plane will not have the some center as the ellipse being seen in perspective. You are correct that the knowledge isn't particularly valuable for 3d rendering, but it is when sketching in a 2d manner. Thanks for the comment.<br /> Douglas Flynthttps://www.blogger.com/profile/03555979975038363353noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-64486796845325717662013-07-02T01:02:52.351-07:002013-07-02T01:02:52.351-07:00Cool post I' currently programming 3D renderin...Cool post I' currently programming 3D renderings for charts. What was confusing to me and also seems to be wrong on the last pictures, is that in perspective, the center of the ellipse is not at the 3D center of the surrounding square. So when trying to calculate the ellipse in a computer program for perspective drawing, one have to be carful to determine the real center of the ellipse.<br />But for hand sketching this approach is very great. Thank you!<br />MarcoMhttps://www.blogger.com/profile/11547531187356331729noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-42202780329793277772011-10-29T03:34:29.807-07:002011-10-29T03:34:29.807-07:00I so wish I could see the images. I have read how...I so wish I could see the images. I have read how to draw the ellipse--but I wish I could see a demo or read about how to paint them. Even when I've drawn accurately, I can't paint them accurately. There must be some tips on brush handling that would help! --like, which part do you paint first, etc. Thanks for your wonderful blog. JudyAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-29602839588041016722011-09-19T12:06:47.462-07:002011-09-19T12:06:47.462-07:00I have been trying to draw a still life subject fo...I have been trying to draw a still life subject for the first time and I have struggled with the ellipses for the last week. I was at the point of giving up totally. This has been extremely helpful, thank you!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-78273976471007046952011-09-12T11:10:32.654-07:002011-09-12T11:10:32.654-07:00Hey thanks, this has been really helpful (though s...Hey thanks, this has been really helpful (though some images didn't load for me too, I got the gist with your explanation). An important aspect of perspective drawing I've always wanted to learn.. thanks again!.. :)Jacqueline Katherine Gomezhttps://www.blogger.com/profile/10367611708624473376noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-67860447126291329302011-08-18T12:12:46.147-07:002011-08-18T12:12:46.147-07:00Some people have had problems viewing this post. ...Some people have had problems viewing this post. I believe it was because of the number of images and their file size. I have reduced the file size of the images so hopefully you will now be able to view it without problems. Douglas Flynthttps://www.blogger.com/profile/03555979975038363353noreply@blogger.comtag:blogger.com,1999:blog-7580430527071698103.post-51816168475809151162011-08-16T05:23:10.486-07:002011-08-16T05:23:10.486-07:00I'm affraid that there is some problem with th...I'm affraid that there is some problem with the images in this post. I cannot see them.Anonymousnoreply@blogger.com