Congratulations on getting through the cylinder challenge. While you've done some decent work here, there are a number of things I do want to draw your attention to:

  • While you are showing a good deal of growth in your cylinders around arbitrary minor axes, I do get the feeling that you're not necessarily investing as much time into each individual mark as you could be. Specifically when it comes to drawing the side edges of your cylinders, your accuracy tends to be off enough that makes me wonder whether you're actually employing all of the steps of the ghosting method, and whether you're truly doing them to the best of your ability. I'm not actually seeing some of the tell-tale signs that you're using the ghosting method as thoroughly and consistently as you should be, which certainly would explain the lack of accuracy. Remember that regardless of what task you're performing, how complex, simple, or repetitive it might be, you should be investing as much time as you require to draw each line to the best of your ability.

  • While I'm pleased that you attempted to identify the 'true' minor axis of your ellipses throughout the entire exercise, and you were rather fastidious in doing so, there were a number of places where your estimation was incorrect. I picked one of your later pages and marked out the ones that were notably incorrect. I don't expect the ellipses to be drawn to the correct alignment each time, but it is important that you take more time in identifying the true alignments after the fact in order to identify how far off your estimation ultimately was.

  • As a whole, I think you're drawing too small. In drawing smaller, we are less able to make use of our brain's spatial reasoning skills, and are also less likely to engage our whole arm when drawing (especially with ellipses). This can cause problems that would otherwise not be a concern due to the simple way in which we approach things more seriously and with greater focus when drawing bigger. It's just that much easier to whip off a bunch of tiny, cramped ellipses and lines without realizing that we're not putting our all into it.

The same issues apply to your cylinders in boxes, and I do think they impede just how much you've actually gained from the challenge. That said, I can see that your proportions - specifically for the boxes themselves - have improved. That is ultimately what this part of the challenge is about. Similarly to how adding line extensions to the boxes helps us identify where our lines aren't converging consistently, and by being made aware of this we can continue to improve upon them and bring them more into line in later attempts, the addition of cylinders works much in the same way. In this case, the cylinders (specifically the ellipses) and their own line extensions helps us identify where the opposite sides of the box aren't quite proportionally square, and as we try to bring those line extensions into place with subsequent attempts, we gradually get better at constructing boxes with opposite faces that are proportionally square.

Now, all that said, I really cannot stress this enough: these exercises and challenges only work effectively if you aren't focused on just getting the task done. Completion is irrelevant - if you rush through just to get it done, but don't take your time to really execute it to the best of your ability, then you won't be pushing your limits. Pace yourself, and if that means completing just one page of cylinders a day, but doing them at your absolute best, taking as much time with each individual line and ellipse as you require, then that will gain you far more in the long run.

Now, I am going to mark this challenge as complete, but I strongly urge you to continue incorporating these exercises into your regular warmups, so as to continue growing from them.