Versions with expensive filter wheels are probably not worth the extra cost, as one can easily rig something in front of the lens. The 120N has a working hot shoe, so flashes can be attached.

Must have book on photographic lighting.

Can be strapped onto the Vivitar (or other manual flash or light sources) with velcro straps (sold separately). Folds flat, so easy to transport. Handy when one needs a quick soft box.

Connects Sekonic L-358 to Vivitar for cord-based metering.

ISO 400 works on cloudy days in Seattle. Loading film is a bit tricky, I've taken to first wrapping the film a few times around the receiving spool, then inserting the spools into the camera, as 120 film has plenty of paper protecting the film from accidental exposure.

I have my film developed at a local lab, then scan it with this scanner. I also use other medium and large format cameras, so wanted a nice scanner. For a Holga, a cheaper film scanner or even print scanner should suffice to digitize the images. Have not experimented with a darkroom-in-my-bathroom, so have no chemical recommendations.

Use tracing paper to create soft-box light effects on the cheap. Or, spool it across the film plane and mark in your own focus distance readings by pointing the Holga at a candle or similar bright light source.