The image at the very top of the article is the intrapositive. It’s a shot of my negative taken on film — specifically, the lower part of the image (the slice in the middle is a piece that I processed with histogram stretching, and the top is an inverted intrapositive). As you can see, it’s dim and has low contrast, but it is a positive; that contrast can be restored with histogram stretching (see this post: analog.cafe/r/how-to-inver…).
Unfortunately, this article doesn’t have fantastic examples of intrapositives. That image is an approximation—if I were to enlarge it, you’d see a fair amount of quality loss. A proper way to do this would be to either create contact prints on film (which can be quite challenging given that you’ll need to be in complete darkness) or you’ll need a similar setup to how people scan their film nowadays — with a stand and a macro lens (but instead of a digital camera, you’d use a film camera).
TBH, I think it would be easier, cheaper, and faster for you to select scenes with less contrast for your slide film (i.e., avoid harsh light and shadows). You can also push your Ektachrome E100 up to EI 400; it’s probably the most forgiving slide film you can get fresh today. Alternatively, you can look for Provia 400 film. It’s discontinued and expired, but most stocks I tried still work great: analog.cafe/search?for=%22…
Sam Bates
Dmitri