This is a nice image addressin the pi challenge. I concur with all of the compliments below!
I like the scientific tone this photo, created with the calculations and instruments, as well as the excellent lighting. I mentioned below that I thought the yellow tape measure took away from this slightly, perhaps because the tape measure is not a very accurate instrument relative to pi or the other objects selected for your photo.
As someone else noted, the arrangement is loose, perhaps a tighter arrangement with a closer point of view would enhance the feeling of precision and intricacy. I hope you realize that these suggestions can come because it is a strong image already. The composition and focus are superb, and the little touches like the tape going around the round object make this an intriguing and engaging image to begin with.
The lighting is also appropriately cool and scientific. I like how the calculations were done in a fine point pen.
I look forward to seeing more of your work! Good luck!
The photo is good on addressing the subject matter, but not very attractive. There is too much in it, and the arrangement of objects is very loose. The lines and curves could have been arranged with more attention to leading lines, etc.
The tape measure is a jarring yellow to me takes away from your cool, scientific mood by reminding me of carpentry, but I love the other tools, implements and calculations. Still, this image works and I give it high marks. 8