ExpoImaging ExpoAperture2 Depth-of-Field Guide Metric 2 Disc Kit, Includes Standard Dial and Telephoto Dial

What can I say quality is great and easy to use, will be a great help to determine DOF.Great buy

Nice product. Extremely useful in the field. The booklet comes with all the instructions needed, but if you need to know how to determine the hyperfocal distance, you can easily figure out how to do it after downloading the files in the 'Support' section available on their website. All in all, strongly recommended for a full creative control of your photography.

Does what it says on the packet and saves the mental calculations of the past

The instructions could be more helpful and less technical. I purchased the Metric edition, when one goes on line the instructions are much more explicit running into several pages. In documentation provided with the purchase it states there should be a DVD with the product, on enquiring with the manufacturer this has now been excluded from the package. However one is directed to the online manual which is for imperial dimensions and measurements and not metric. They could do better. It is possible to decipher the instructions but I'm sure they could be made easier to understand particularly when has to keep revercing the disc to get the final result.