Digital Light & Color

Long story, but it's about illustrating different knot structures. The attached images are not mine, but I like them a lot for their clarity and simplicity.

I can think of how this can be done with diffused flashes and black background in a studio. But, how about trying to do that without flashes or a studio (or the appropriate background)?

I have some ideas on how to simulate such lighting by using a 'green screen' kind of idea, masking it, bringing it to black, and then dealing with the rope contrast, but I was hoping to get some practical advice from people more familiar with studio photography before I actually dive into it too deeply. What's the easiest way to do something like this using only natural light and a limited choice of backgrounds (I do have a blue towel...)?

p.s. I do realize that this is a strange request.

I use black velvet as a background. You can buy small quantities very inexpensively. If you use a colored background, some of the color of the background will reflect back on the subject, and this requires special software to remove completely.

One option is to use a flatbed scanner instead of a camera. This is how I produced the image below.

Otherwise try to light the subject from both sides -- a copy stand with two or more lights works well. Or maybe a ring light for macro subjects.

Another option is to photograph the same subject first with the light on one side and then the other. Then blend using Stack Images.

Thanks. I also asked the author and to my surprise a flatbed scanner was used. I thought that the DoF would be way too shallow for projects like these. Is DoF even applicable for scanners? They need to focus somehow on the surface of the page being scanned I imagine?

Scanner DoF varies from model to model. Some DoF is necessary because originals are not always totally flat.

Even when scanning with a black velvet background, there will still be a few highlights that show through. I first use the Mask Curve tool to mask the very dark areas. Then I use the Mask Brush tool to do a quick cleanup and then the Mask Pinhole or Median tools to remove any remaining small holes in the mask and then use Composite to overlay pure black where the mask is.

I purchased but have not yet tried some Japanese black flocked paper that is supposed to be super black:

https://www.ko-pro.black/flocksheet/