6:07 PM, Monday June 15th 2020
Starting with your cylinders around arbitrary minor axes, you've overall done a good job of pushing through the challenge, although I did notice some issues with some of your red "true minor axis" lines. As you can see here, a number of the ones that you drew in weren't the actual minor axis of the ellipses you'd drawn. This inevitably caused a bit of an issue in that if you're not consistently identifying the correct minor axis, you won't be able to identify the discrepancies between how an ellipse was drawn, and how it should have been aligned. In turn, this can result in less overall growth/progress over the course of the exercise.
When doing this sort of thing in the future, take a little more time to analyze your ellipses - remember that the minor axis line is the one that cuts an ellipse into two equal, symmetrical halves down its narrowest dimension. When you have the initial line you'd tried to align to present, it can make it more difficult to really see past it and notice where the alignment is off (especially when the errors are more subtle), so it's going to require that much more focus and attention from you.
In general, the funnels exercise from Lesson 1 can help when it comes to learning to more purposely align your ellipses to a central minor axis line, so be sure to incorporate that into your regular warmups if you haven't already.
Another point I noticed was that while you are showing some signs of using the ghosting method, it's important that you always remember that the ghosting method basically exists purely to allow us to execute our marks with confidence, free from hesitation and fear of making a mistake. The second our pen touches the page, any opportunity to avoid a mistake has passed, and all we can do is push through to ensure that the mark still comes out straight and true, even if it ends up being a little less accurate. Looking at your linework - specifically the side edges of your cylinders - there tends to be a bit of wavering. It's not that significant, but it's enough to suggest to me that you're not executing those marks with the kind of confidence they require. If you're unsure of how to think through the ghosting method, I strongly encourage you to read this explanation I gave to another student.
Lastly, I noticed that the foreshortening on your cylinders appears largely to be the same across all 150 of the first section's cylinders. When doing this kind of exercise in the future, be sure to vary the foreshortening to explore both cylinders with more dramatic foreshortening alongside those that are more shallow.
Moving onto your cylinders in boxes, while these are immediately feeling somewhat better overall (your identification of your minor axes is generally more accurate, for example, and I can see much more meaningful growth), it appears that only up to cylinder 174 was included in the album (you may have run up against the imgur album limit). Please submit the remaining 76 cylinders in boxes and I'll give you feedback on them as well.
Looks like your last 76 cylinders in boxes weren't included in the album. Upload them to a new album and I'll complete my critique.
7:18 PM, Monday June 15th 2020
So you are definitely showing progress throughout these cylinders in boxes, although I do think there is still room for improvement in getting your ellipses to fit more snugly within their enclosing planes, while still maintaining their smooth, even shapes. With the gaps between the ellipses and the edges they're meant to be touching, it definitely becomes a little harder to pinpoint the actual contact points, and to assume things are more correct than they are (and therefore overlook certain mistakes).
Still, overall these are going quite well, and you're making a fair bit of progress overall. This exercise at its core is actually more about the boxes themselves than the cylinders - similarly to how extending our boxes' edges allows us to determine whether or not those lines are converging consistently towards their shared vanishing points, and to gradually improve that consistency over the course of many pages, adding the cylinder serves as another form of error-checking. In this case, it allows us to test whether or not the opposite faces of the boxes are actually proportionally square, as this is a major factor of whether or not our minor axes/contact points are aligned (which in turn allows us to check if our ellipses in fact represent circles in 3D space). After all, if the ellipses represent circles in 3D space, then the plane enclosing them will be proportionally square.
Anyway, that's all a long roundabout way of explaining that you are indeed making progress in getting your boxes to be more suitable for containing cylinders (proportionally speaking), although improving the accuracy of your ellipses (without sacrificing their smooth, even shapes) will help you improve further.
All in all I think there are areas where you stand to improve a great deal, but you can do that with additional, focused practice, and taking more time to identify your minor axis alignments. Those are things you can do in your own warmups. As such, I'll go ahead and mark this challenge as complete.
Move onto lesson 6.