Starting with your cylinders around arbitrary minor axes, your work is nicely done! Your marks are confidently executed, leading to evenly shaped ellipses and smooth, straight side edges. You're also quite fastidious in checking your ellipse alignments, capturing both the more obvious issues as well as some of the subtler misalignments. This is important, because it helps us avoid plateauing as we get into that territory of being "close enough" for others not to easily tell that anything's off at a glance.

The only thing I want to draw to your attention is something that I noticed you were doing correctly sometimes, but not entirely consistently - which suggests that you're still developing that subconscious understanding of the concept I'm about to explain, but that it hasn't quite reached the fully conscious level. I don't actually explain this in the notes because I find that many students figure this out on their own (as you appear to have started to), and the kinds of things we pick up ourselves tend to stick more strongly in our minds going forward.

So the issue is this: foreshortening, which is the visual manifestation that tells us just how much of the length of a given form is represented there on the flat page, and how much of it exists in the "unseen" dimension of depth, comes up in two ways. There's the shift in the scale from one ellipse to the other, where the far ellipse is smaller than the one closest to us, and there's the shift in degree where the far end is always wider than the end that is closer. Sometimes these shifts are very subtle, but in other cases they're dramatic - but the key point to keep in mind is that they work in tandem, at roughly the same rate, because they represent the same thing.

There are some cases where, like in 134 on this page you'd have a much more significant shift in scale, with not quite the shift in degree to match. There were also plenty of places where your degree shift roughly matched the scale shift, so this is simply something to keep in mind as you go forwards.

Continuing onto your cylinders in boxes, your work here is very close to being well done, with one key shortcoming. 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.

The shortcoming is this - while you've done a great job of extending all of the lines of two out of the three sets, you pretty frequently (though not always) neglected to extend the boxes' edges that align towards the same vanishing point as your cylinder's minor axis. As a result, your ability to actually gauge the convergences of those lines and compare them with the orientation of the ellipses' minor axis lines was diminished. While you did well with the other two dimensions, leaving one set like this leaves us vulnerable to accumulating errors in that area, without being aware of them.

Now, I'm not going to hold you back over this, as it's a very easy issue to address once you're aware of it - but going forward when you practice this exercise in your warmups, be sure to extend all of the important lines. I'll go ahead and mark this challenge as complete.