I think that you can do without the RED filter, it has not done much for your sky and you have lost all detail in the centre of your photo. But then again this is perhaps what you were aiming for. Just my opinion.
Thanks for the advice Vincent, I was trying to avoid a blown out sky, any idea on what I could have done to preserve the sky and preserve the detail in the center?
Joe did you expose for the area in the centre or take an overall reading ? Like Thomas I would advise a yellow ( my favourite is orange) or ND Grad filter. Your f2.8 is also giving you a very shallow depth of field, with a yellow or orange you should be able to increase that so all the foreground area is in focus.
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Vincent
Thanks for the advice, I will almost surely be getting a graduated ND filter soon. Sorry for the confusion but the f/2.8 is in the equipment part, I just inteded to indicate the exact lens I used. If I recall correctly I had this arounf f/22 when I shot it.