Thank you, allan. Much time ago I used this method, and with a dobsonian mounting. Since I received my equatorial, I never used it again. I don't know why.
How I used it at that time:
http://astronomia-e-astrofotos.10697...tes-td973.html and
http://astronomia-e-astrofotos.10697...oes-td972.html
Since I haven't a good barlow, they are very expensive, I will try it again.