Choosing a subject really is a matter of personal preference. But it is good to think through the "Why?" before you begin painting.
Limitations of photography
Disclaimer - Unfortunately the reason for plein air painting has a lot to do with the inherent lack in photography to capture the colors out there. The human eye can take in so much more! But I must use photography here to illustrate the point. So there is a bit of a disconnect.... of which I am hoping the points can still be made well enough.
Which view to choose?
So... from the spot I chose to paint, these were 2 views that I could use as my subject matter.
This first view has a road leading into the gorgeous snow capped mountains with some shadows across the road and a variety of trees in the middle ground.... hmmm...
This next view has nicely shaped and beautifully colored mountains in the distance along with an interesting colored barn structure and great old trees in the foreground.
Hard to choose....
My decision = View #2. Why?
Color & Shape
Well I love color and shape. That usually wins out for me. Here, the interesting barn against the other colors intrigued me. (The colors in the barn - in both the scene as well as my painting - look VERY different in real life than in these photos. The building has a rusty colored roof. A nice touch in the otherwise blue/green landscape.)
Being Spring, it's the time to paint Spring colors in their glory. And the second view, spoke Spring louder to me. The green field and trees in their strong Spring colors with a touch of snow on the mountain. Overall, a quintessential Montana Spring scene with shapes that flowed and sat well together.
Problems in the first scene
To my eye, the first photograph had too much road - and I would want my painting to be more about those beautiful mountains than the road! The bottom half on the canvas would be dominated by road. Plus, the flat color of the road was not all that interesting to me. Even the shadow shapes across the road didn't have much variety. I found that very dominant road shape was too plain and harsh - not elegant, soft or interesting which I like in a painting. The road also cut the scene into not such pleasing shapes, leaving that bottom right hand corner WAY to boring and an oddly isolated shape. Even though the road does lead you into those mountains, you get 'caught' by the tree shapes in the middle ground. They don't set off the distance mountains in a pleasing way. The trees feel more like a barrier to the mountains than a lead in.
I would need to adjust the composition somewhat dramatically here. It would require some real planning to pull it off. Downsizing the road, adding variety and interesting shapes and adjusting the way those middle ground trees sat in front of the mountains. Overall, I just felt the composition was too awkward. If my focus was the gorgeous background mountains, the other elements of the painting (road and trees) distracted from it. They weren't good supportive players in my scene.
Good compositional elements in the second scene
Of course, as the artist I can always move elements around a bit. But the second photo, to me, just had the compositional elements set up already. Where the barn landed is a good spot - a little off center with the trees to the right against the backdrop of distant mountains. The shape of the distant mountains 'pointing' to the barn and trees. A good focal point for the painting, a little off center - (almost always more pleasing than smack in the middle of a canvas). With the trees on the right lending to the yellow side and the mountain behind them leaning to the purple side, it makes for a nice 'opposite' color combination (You need to know the color wheel for that comment) - accentuating those Spring colors that would be important to capture today.
Painting Spring In the Valley!
I liked the design elements more in View #2. The juxtaposition of scale with the small barn set against those massive mountains with elements of the overall design taking you down to that focal area... Good secondary players here, helping to support my visual statement of "Spring In The Valley"! So I went with View #2.