Starting with your cylinders around arbitrary minor axes, you're doing a good job in executing your ellipses with confidence and keeping them smooth and consistent, as well as in checking your minor axis alignment afterwards. I'm pleased to see that you're quite attentive when doing this alignment check - you're identifying cases with both more significant discrepancies, as well as those that are much more minor. While the obvious ones are, well, obvious, it's easy to let the minor ones go, which can result in our growth plateauing when get into the realm of being "good enough".

There are a few points I want to call to your attention, however.

• Firstly, there are a number of cases where you drew your cylinders without any convergence to the side edges - basically making them parallel on the page, and forcing the vanishing point itself to infinity. I explain why this is incorrect in the second point of these reminders from the challenge notes.

• Secondly, I noticed quite a few cases where your cylinders appeared inverted - we can see this in 143 and 145 on this page for example, where the end with the hatching (which generally represents the end closest to the viewer) is considerably smaller than the opposite end. This is very incorrect, but I do wonder if you ended up adding hatching to the wrong side somehow. Might want to reflect upon how that occurred, and if it was the result of confusion or not understanding, feel free to ask for clarification.

• Thirdly - and this isn't something I necessarily expect students to grasp on their own, but I find that when students do pick this up themselves throughout the challenge it has a better chance of sticking, so I like to leave them that opportunity. Basically, the change in overall scale and the change in degree from one end's ellipse to the other is what tells the viewer how much foreshortening is being applied to the form. Or another way to think about it is how much of the cylinder's length is visible right there on the page, and how much of it exists in the "unseen" dimension of depth. Because they both represent the same thing, they have to operate in tandem. Meaning, if we have a significant, dramatic shift in scale (where the far end is way smaller), we should also have a similarly dramatic shift in the degree (meaning the far end should also be proportionally wider). Number 136 on this page is an example where there is a dramatic shift in scale, but virtually no shift in degree. Generally the viewer will notice something looks "off" as a result, though they won't specifically know why.

Continuing onto your cylinders in boxes, your work here is somewhat mixed. There are plenty of cases that are fine, but there are also a number of cases of the following:

• Spots where you drew the boxes with edges that are parallel on the page (basically the same as the first issue I pointed out for the previous section) - 179 on this page for example, though this was not at all uncommon across the set

• Spots where you extended a set of lines in the wrong direction (196 on this page, though this one was less common)

• Spots where you'd forget to extend some sets of lines (241 on this page - though again, not a common issue)

This exercise is really all about helping develop students' understanding of how to construct boxes which feature two opposite faces which are proportionally square, regardless of how the form is oriented in space. We do this not by memorizing every possible configuration, but rather by continuing to develop your subconscious understanding of space through repetition, and through analysis (by way of the line extensions).

Where the box challenge's line extensions helped to develop a stronger sense of how to achieve more consistent convergences in our lines, here we add three more lines for each ellipse: the minor axis, and the two contact point lines. In checking how far off these are from converging towards the box's own vanishing points, we can see how far off we were from having the ellipse represent a circle in 3D space, and in turn how far off we were from having the plane that encloses it from representing a square.

In order for this to work, however, we need to be extremely mindful of everything we're doing, and bring to bear all of the relevant concepts from throughout the course - not least of all, those involving boxes, line extensions, and so on. We'd also be bringing to bear the continuous practice of those past exercises (box challenge boxes + line extensions included) that we've been doing as part of our warmups thus far.

Before I'm comfortable marking this challenge as complete, I think it's best to give you the opportunity to apply what I've explained here and demonstrate your understanding of those points I've raised. Be sure to take your time with every step, so that you can execute the work to the best of your current ability. You'll find your revisions assigned below.