In article , jackiel@interport.net says...

>I just bought a used Nikon 2020 which lists the Nikon SB-20 flash as the
>only one which will permit TTL metering. In looking at these flashes, even
>second hand they seemed pretty pricey, around $175. Does anyone know of a
>flash I could substitute for the SB-20 which would cost less?

Any Nikon TTL flash will work well, but only the AF type will give a
low-light focus-assist beam for AF lens focus. The SB-15 is a wonderful,
compact, reasonably-priced (used) Nikon flash - and Vivitar, Sunpak, and
others make small inexpensive Nikon-TTL flashes that would work well.
The booklet is outdated.
Hope This Helps