is it possible to record gameplay from my ps2 by using a recording software like camstudio but still with the use of a capture card because I really want to record my videos with camstudio?
Nope. Some programs that you can use are Debut Video Capture (that's the one I used), VirtualDub or DScaler.
Actually, yes, you can. Most video capturing programs offer a preview window; if you set CamStudio up to record that, you can technically do it. But this is very intensive and won't work well unless you have a very powerful computer. Even then the recording will most likely be laggy and the audio will be out of sync. It's more trouble than it's worth. If you're looking for a program to record with, first check the software that your capture card came with. If it's poor or it didn't come with any, there are a myriad of programs you can use. VirtualDub produces great quality but outputs in AVI only, which you'll have to edit & render in another program to get it to a reasonable file size. If you have Sony Vegas, it has a capture application too, though I've never had much luck with it. Windows Movie Maker has one too, but I've never used it personally. Those are some of the more popular ones.