Both Captcha and Recaptcha failed terribly on a forum that I run. I run a photography forum and what worked great for me was asking the user signing up to answe

Both Captcha and Recaptcha failed terribly on a forum that I run. I run a photography forum and what worked great for me was asking the user signing up to answer a pretty simple question related to this fairly specific (large format) kind of photography. I get no spammers or spambots at all now. Turning on recaptcha only briefly to test resulted in a mass of spammers.