Re: Phantom OTRS Leuchars 87
With regards to perspective; they are some elements of your composition that are made for you - one being the horizon line and its associated vanishing point.
If I am allowed to assume that the bomb trolley is on level ground; and that both its wheels are the same circumference: Then a line out to infinity that touches the base of both wheels, and a similar line that touches the tops of both wheels, will eventually merge together. This is your horizon line (& vanishing point for the trolley).
Carry that nominal horizon line across the canvas, and there will be a tangent that merges with the under-belly of the Phantom fuselage. If you look at your reference photograph for the Phantom, hopefully it will include the actual horizon for that particular image.
It does not matter how well you paint the composition - if the rules of perspective are not obeyed, it will always look odd even to an inexperienced art critic.
I would use string to confirm this information as the vanishing point of the trolley is off canvas. You can have multiple vanishing points for the different elements of the composition - but all will (or should) share the same horizon - even if only a nominal horizon. It maybe that you need a different Phantom reference photograph with one that has the correct horizon - that is for you to assess. For sure when the preparation for a painting is accurate - you stand ready to achieve an awesome painting.
Hope that helps. Another good top-tip is that whatever part of the human body touches the horizon (*usually the eyes) - keep that as a constant for all standing persons. *The reason that it is usually the eyes is due to reference photographs being taken by photographers standing up. (Notwithstanding that you do get both tall and short people)