\pm 0.67$ & $2.38 \pm 1.48$ & 167 & $1416^{+1877}_{-1127}$\
Abell 370 & $0.375$ & 02:39:52.94 & $-$01:34:37.00 & $3.16 \pm 0.38$ & $2.66 \pm 0.11$ & 65 & $711^{+213}_{-210}$\
MACSJ0416.1$-$2403 & $0.396$ & 04:16:08.38 & $-$24:04:20.80 & $1.07 \pm 0.26$ & $1.88 \pm 0.69$ & 66 & $219^{+230}_{-164}$\
MACSJ1149.5$+$2223 & $0.543$ & 11:49:35.70 & $+$22:23:54.73 & $2.50 \pm 0.54$ & $2.35 \pm 1.00$ & 109 & $582^{+397}_{-364}$\
MACSJ0717.5$+$3745 & $0.545$ & 07:17:32.63 & $+$37:44:59.70 & $2.68 \pm 0.55$ & $2.36 \pm 0.77$ & 91 & $609^{+438}_{-359}$ \[tab:clusters\]

Methodology {#sec:methodology}
===========

Source detection
----------------

For each of the six FF clusters, <span style="font-variant:small-caps;">SExtractor</span> [@bertin1996] was run in dual image mode on the 30 mas images of both the cluster core and parallel fields. The $F814W$ image was used as the detection image for all bands. A `WEIGHT_THRESH` of 0.002 was used to remove sources detected in the low exposure time regions along the edges of the fields. The XDF was treated similarly. In [@janssens2017], we used the $F775W$ image as the XDF detection image since it is much deeper than the XDF $F814W$ image. However, the XDF $F814W$ image is of comparable depth to the FF $F814W$ images, and its 