You have asked how much light there would have been at the cap and glove location under the agapanthus. This can be determined from the dimensions shown in the Bodziac diagram of the front porch and walk. I make the conservative guess that the porch light was at the center of the walk at about the location of footstep "M." (It was probably closer to the front door, at "R," but the first assumption gives more light at the agapanthus.)
VERTICAL SHADOW: From this, the porch light was 17.9 feet (horizontal) from the front gate. I measured my own front porch and found that steps are 12" wide and risers are 8" high. I also found that it is 7' 6" from the floor of the porch to its ceiling. I will assume that Nicole's porch light is 8' off the ground (also conservative.) From these considerations, I find that the beam from the porch light will first strike the ground east of the porch at 17.1 feet from the light, or about 9 inches from the gate. This is roughly at the location of the agapanthus stalk. According to the limitations of the vertical shadow, the objects under the agapanthus would be barley illuminated, if it were not for the leaves of the plant itself.
HORIZONTAL SHADOW: However, I also note that the north wall of the steps causes a horizontal shadow, and this would fall about 8 inches south of the stalk of the agapanthus. Most of the cap and glove would be in this shadow. Therefore, I conclude that most (but probably not completely all) of these two objects would be outside of the illumination of the porch light, even without the leaves of the plant.
AMOUNT OF ILLUMINATION: I also took a navy blue knit cap 18 feet from my own porch light and dropped it on dead leaves the color of tan dirt, and evaluated the adequacy of illumination. There was no trouble in recognizing that there was an object on the ground. However, it was not in the shadow of the wall, and not under the leaves of the agapanthus. But, the level of illumination is definitely not a problem.
EFFECT OF AGAPANTHUS LEAVES: Finally, I took the same knit cap into the backyard, and put it (at night) on the dirt under the leaves of my own agapanthus plant in about the same condition as photographs of the crime scene. The lighting in this case was quite bright; the location is about 8 feet (horizontal) from a 300 watt floodlight. I would guess that the light level is several times that at Nicole's agapanthus. It was very hard to recognize the cap under the leaves of the agapanthus, or to tell that there was an object there at all. Only by knowing that there was something to be seen, and looking closely could I see it.
CONCLUSION: On the basis of these several observations, I would have to say that Simpson (assuming he did not have a flashlight) would certainly not have noticed the left hand glove and cap if he were not specifically looking for them, and if he were looking for them would not have found them unless he moved the leaves of the plant with his hand or groped beneath the leaves for it. In either of these cases, he would have found it quickly.
SIGNIFICANCE: If Simpson had himself committed these murders, then he would have been in a position when the crime was finished to realize that the was missing three items he had brought with him: two gloves and a cap. Whether he actually would have realized at the very stressful moment we can not be sure. But, if he did realize that he had lost the cap and left hand glove, they would have been easy to find. One of the Bruno Magli footprints (Q68) is just two inches from the left hand glove. All Simpson would have had to do is reach down, spread the leaves of the agapanthus with his hands, and he would see both items.
On the other hand, if he was lured to the place by a phone call advising him that his own glove was on top of Nicole's corpse, he could easily see and recover that, but would not be aware that there were other items to be found. A quick look around the place under the circumstances of the lighting at that time, would not reveal that there was more. Simpson then would take away the right hand glove but leave the other two items. Since this is what did, in fact happen, the evidence suggests that Simpson's visit was after-the-fact, and not as a result of having committed the murders himself.
Dick Wagner Van Nuys, CA (12/29/98) NG_500a