Following the success of the first mission , the High-Resolution Coronal Imager ( Hi-C ) was launched for a third time ( Hi-C 2.1 ) on 29 th May 2018 from the White Sands Missile Range , NM , USA .
On this occasion , 329 seconds of 17.2 nm data of target active region AR 12712 was captured with a cadence of \approx 4 s , and a plate scale of 0.129 ^ { \prime \prime } pixel .
Using data captured by Hi-C 2.1 and co-aligned observations from SDO/AIA 17.1 nm we investigate the widths of 49 coronal strands .
We search for evidence of substructure within the strands that is not detected by AIA , and further consider whether these strands are fully resolved by Hi-C 2.1 .
With the aid of Multi-Scale Gaussian Normalization ( MGN ) , strands from a region of low-emission that can only be visualized 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 target active region .
It is found that Hi-C 2.1 can resolve individual strands as small as \approx 202 km , though more typical strands widths seen are \approx 513 km .
For coronal strands within the region of low-emission , the most likely width is significantly narrower than the high-emission strands at \approx 388 km .
This places the low-emission coronal strands beneath the resolving capabilities of SDO/AIA , highlighting the need of a permanent solar observatory with the resolving power of Hi-C .