The High-resolution Coronal Imager (Hi-C) has been launched three times from White Sands Missile Range. The first launch (Hi-C 1), occurred on 11 July 2012 and during the 345 seconds of data acquisition, Hi-C 1 obtained the highest spatial resolution and highest cadence images of the EUV (19.3 nm) solar corona ever achieved. Those few minutes of data have thus far generated >25 refereed publications and is arguably one of the most scientifically successful sounding rocket payloads ever launched by NASA. Unfortunately, the second launch (Hi-C 2) did not result in any science data.

On 29 May 2018, it was launched for a third time (Hi-C 2.1). On this occasion, 329 seconds of 17.2 nm data of target active region AR12712, was captured with a cadence of ~5.5s, and a plate scale of ~0.13x0.13 arcsec^2/pixel.

In this study we investigate coronal strands as seen from Hi-C 2.1 and SDO/AIA 17.1 nm observations. We search for evidence of substructure within the strands which is not detected by AIA, and whether they are fully resolved by Hi-C 2.1. With the aid of Multi-Scale Gaussian Normalisation (MGN), strands from a region of low-emission which can only be visualised against the contrast of the darker, underlying moss are studied. A comparison is made between these low-emission strands with those from regions of higher emission within the active region.