Starting with your form intersections, overall your work here is quite well done. I'm not really sure what you were doing with that second page, where the forms get blobby, and where you ended up working with a rough sketch and a clean-up pass which is expressly stated as something to avoid here, but if we ignore that page you're mostly doing great (although I am seeing the rough sketch approach in your third page to a lesser degree). Just... don't deviate from the instructions of the exercises here, as mentioned back in Lesson 0.

Oh, and one additional thing - you're using your minor axes for some of your cones, but be sure to employ them for every form that has an ellipse.

Continuing onto your object constructions, by and large you're knocking these out of the park. This lesson's work really focuses heavily on the concept of precision. Where Lessons 3-5 focus on organic subject matter, where we tend to work in a more reactionary, inside-out fashion - that is, we'll put down a mass, and depending on how that mass came out, we may adjust where we draw the next part, working towards a direction but not according to rigid specifications - here our approach gets turned on its head, constructing in an outside-in manner, where we establish our intentions ahead of time.

Precision is often conflated with accuracy, but they're actually two different things (at least insofar as I use the terms here). Where accuracy speaks to how close you were to executing the mark you intended to, precision actually has nothing to do with putting the mark down on the page. It's about the steps you take beforehand to declare those intentions.

So for example, if we look at the ghosting method, when going through the planning phase of a straight line, we can place a start/end point down. This increases the precision of our drawing, by declaring what we intend to do. From there the mark may miss those points, or it may nail them, it may overshoot, or whatever else - but prior to any of that, we have declared our intent, explaining our thought process, and in so doing, ensuring that we ourselves are acting on that clearly defined intent, rather than just putting marks down and then figuring things out as we go.

In our constructions here, we build up precision primarily through the use of the subdivisions. These allow us to meaningfully study the proportions of our intended object in two dimensions with an orthographic study, then apply those same proportions to the object in three dimensions.

For the most part, you've done a great job in laying out those intentions ahead of time, safe for a couple minor spots - for example, this little box along the top of your camera constructions, whose height was established more based on eyeballing/approximating, rather than specific intent. One thing to note is that while your initial bounding box for this camera was not wide enough to provide us with a lens that would be circular in 3D space, that's not actually a problem for this lesson, because while the proportions were incorrect, the approach in its implementation was still predecided, and thus precise. Precisely... disproportionate, but precise all the same.

I do have a couple other minor points to call out for you to keep in mind as you move forwards.

• So as I mentioned in regards to your form intersections, we definitely want to avoid situations where the student ends up tracing back over existing linework in order to reinforce it in its entirety. Line weight is an excellent tool, but it's one that we primarily reserve for clarifying how different forms overlap one another, specifically limiting it to the localized areas where those overlaps occur as explained here. So in your constructions here, though we no doubt end up with a lot of subdivision lines, we should still be drawing those with confidence, and allowing them to stand on their own where they can, adding line weight only to clarify those overlaps, rather than tracing over large chunks. Tracing tends to make us focus on how those lines actually sit on the flat page, rather than how they represent edges that exist in 3D space.

• Do not neglect objects with minimal thickness. A good example of this is your yogurt cup, where the top lip of it was drawn as a single edge, rather than as a very narrow plane. In doing so, you effectively made that edge appear paper-thin, which in most situations will feel off to the viewer, and may undermine the solidity of the construction to a point. Instead, giving it a little thickness helps the overall structure appear more solid. We can see a similar concern along the inside edge of the camera lens here. Always try to include even the small structural features, as they do make a notable difference. They certainly make things harder to be sure, but it's well worth it and paying attention to that sort of thing in your own drawings will have a significant impact.

Other than that, nice work. I'll go ahead and mark this lesson as complete.