Delkin Devices Black CFexpress Type B

£136-£699 / $129-$699 www.delkindevices.com

Delkin has been serious about memory cards for years now and, in addition to a lifetime warranty, it offers a 48-hour replacement guarantee, meaning the company will replace any non-working card within 48 hours or less.

There are two lines of Delkin Devices CFexpress card, the Power cards which are designed for use in high-end cinema cameras for 6K and 4K raw video recording, and the Black cards that are designed to support 8K raw video recording. We’re looking at the 512GB Black card here.

As with some other cards, the max read and write speeds vary between the different capacity cards, but even the slowest (256GB card) offers speeds of 1645MB/s and 1400MB/s.

The rear metal casing of the Delkin Devices Black CFexpress Type B card extends around the edges to give a very robust feel.

We tested the Delkin Devices card in the Nikon Z 7II, and it slips in easily to the card slot with just a little wriggle room before it snaps home fully. Depressing the card makes it pop-up ready for removal, but the fit is snug enough that it doesn’t drop out.

To test the burst depth and max continuous shooting rate of the Z 7II with the Delkin Devices Black CFexpress Type B card, we followed Nikon’s guidance and set the camera to ISO100, manual focusing and Continuous High (extended) shooting.

With the Z 7II set for fine-quality JPEGs, we were able to shoot 130 files in around 13 seconds. Then with the camera switched to capture 14-bit uncompressed raws, we were able to record 44 files in under five seconds, not quite matching the claimed 48-file burst depth, but this could be explained by variations in the file size in comparison with Nikon’s tests.

When bench-testing the read and write speeds, we returned values of 915GB/s for the read speed and 921GB/s for the write speed, below the claimed maximums.

PROS Good range of capacities; 48-hour replacement guarantee

CONS More expensive than some; speed varies with card capacity