Starting with the cylinders around an arbitrary minor axis, there are some issues concerning the exercise although the cylinders themselves look good. Your side edges and ellipses are drawn confidently and smoothly, you've experimented with the rate of foreshortening (something that a lot of people seem to neglect, despite it being in bold in the instructions).

The reason why we ask for varied foreshortening comes down do the ways in which foreshortening manifests itself on the forms we create. It does so through the shift in scale (where the back end is smaller than the end closer to the viewer) and the shift in degree where the farther end is relatively wider. This is something students seem to understand not consciously but on a gut-feeling level, and others have trouble grasping the concept that these shifts occur in conjunction with each other.

A dramatic shift in degree with minimal shift in scale tells the viewer two contradictory things: that the length of the cylinder exists in the unseen dimension of depth, and the the length visible on the page is all there is. Similarly, a cylinder with a narrow front face but had dramatic side edges tells us that the front is facing away from us and the side is also facing away from us. Both can't be true, so we must ensure that both shifts exist together. Here is an illustration of what I mean.

You seem to understand this for the most part - if not consciously, then subconsciously. Hopefully this explanation helps push this further into you conscious mind.

There is one matter I want to address and that has to do with your error checking. See, you're not cutting your ellipses all the way through as laid out in the instructions. Whether or not that's been affecting your cylinders in this part I can't really tell since they already look decent and the lines themselves do cut the ellipses into two symmetrical halves so they're not just lines floating arbitrarily. However, this is something that's definitely been affecting your cylinders in boxes. So let's talk about that.

Moving onto your cylinders in boxes, overall I noticed that on the majority of your these, you skipped the minor axis error checking altogether. What we're trying to do here is develop our understanding on how we construct our boxes to have proportionately square faces regardless of the box orientation. To do this, we don't actively memorize every single configuration but instead we subconsciously develop that understanding through repetition and analysis.

The box challenge was all about developing a stronger sense of how to achieve more consistent convergences by analyzing the line extensions. Here, we're just adding three more sets of line extensions: the minor axis lines (which also happen to be one of the vanishing points), and the two contact points. We can check how far off these are from the box's vanishing points and this helps us determine whether the ellipse represents a circle in 3d space, and in turn how far off the plane was from representing a square.

As you can see in this diagram, each set has the box's own extensions but for the cylinder part:

• The minor axis lines are drawn separately for each ellipse marked in red

• In blue, there's another pair of extension lines which are the contact points that exist for each ellipse.

• The same applies for the contact points in green.

Looking through this section again I am noticing that you haven't included the minor axis lines and that might be what's throwing you off (ellipses not being cut into two symmetrical halves by those minor axis points for example). As a whole, I feel like you're struggling to follow the instructions so Ill ask to redo this part as well as the cylinders around an arbitrary minor axis.

50 cylinders around the minor axis

25 cylinders in boxes