Thank you, all you for comments.
Yes, it is very tiny. (The Hubble's photo of this nebula is very very beautiful !)
I am glad for the quality of image.
Where's Wally - Double sense: yes and not so much. I was trying CRW 102, a very faint nebula only captured with halfa. Using Carte du Ciel and Google Earth. The Google Earth was showing the Ant Nebula in the area. The CDC, no. I increase de zoom in CDC, and the Ant Nebula appeared. Because this the nebula isn't in the center of FOV.
With live view from Canon - 20 seconds ISO 6400 the nebula was present.
The first photo with 2 minutes and ISO 400 showed the nebula, tiny and very red. Nothing about CRW 102. As the nubula was inside the FOV I didn't change nothing.
I did 30 x 2 minutes ISO 3200 of Halfa. I am trying something with DSS for CRW 102, but up to now ... nothing. Normal, because CRW 102 is very faint.
The sky was very very well. It was the same day that I did M 8. Undoubtly, this was very important to the result.
As the nebula already was very red, I didn't use the Halfa. I used only the 30 light.
note: many people say that I am wrong, but ... to my set of equipment the best configuration is high amount of photos, low ISO and low time of exposition. If I need some faint area of nebulas, I need two groups: one with low ISO and other with higher ISO and/or time of exposition. And mix them in Photosop with layer mask ressource.