I’ve very glad you submitted this assignment.
I think a lot of people will be able to learn from this example. For starters, both photographs are great and your improvisational capabilities are spectacular. However, please don’t feel that you are limited by natural light. It’s great to experiment with what’s available and shape your photographs around your lighting situations. That being said, 1 or 2 small studio lights to allow you to create whatever lighting condition you wish so it does provide more flexibility.
In this example I see that you wanted to full expose the strong saturation of the colors and bring out the textures. I think the issue with both of these images is 1. color brightness 2. incorrect white balancing with the wrong color temperature.
There is a yellow / orange hue to both of your photographs. That seems to be caused by the lighting source you used. I can see it most visibly in the kiwi photograph as the extra orange really stripped the vibrancy out the green in the kiwi.
Very simply put, this is a white balancing issue. If you take the time to learn about white balance, your photograph will improve greatly. For some reason photographer ignore white balance (beyond the auto settings in their camera’s digital menu), because they feel it’s too complicated. It’s simply not the case.
White balance has to do with helping your camera find the “color” of white. The human eye always adjusts to proper white balance, but cameras don’t’ have this same ability.
The second part of the equation is knowing about the “color temperature of light”. Simply put, indoor lighting is 3200K (Kelvin) is stronger in orange and yellow hues. Outdoor lighting is 5600K and has a stronger blue hue to it. The higher the number goes, the closer to pure white you get.
You shot these photographs under 3200K which is why they look orange and stripped of their color vibrancy. If you shot under 5600K (daylight) these images would look closer to how I expect you wanted them to look. However, you don’t need to shoot during the day to get 5600K. Certain bulbs are balanced towards 3200K and other bulbs are balanced to 5600K.
Please watch this video. It will explain all of this in more detail and provide great examples.
http://www.youtube.com/watch?v=mwqNRqDx680
I think you’ll find this example very helpful.