John Dillwyn Llewelyn FRS FRAS[1][2] (12 January 1810 – 24 August 1882) was a Welsh botanist and pioneer photographer.

Some thousand calotype and wet collodion negatives still exist together with albums in private and public collections and retained by the family.

[citation needed] In 1856 he announced his own oxymel process which allowed collodion negatives to be preserved over many days.

They wrote "We have heard of a new method of preserving collodion plates for a week or a fortnight discovered by Mr Llewelyn of Penllergare a gentleman to whom all photographers owe a world of thanks.

The plates may be prepared at home and a boxful taken out and think of this ye tourists, as you travel along and a fine prospect meets your eye you have nothing to do but to stop your carriage, get out your camera, and in a few minutes you may secure a picture, drawn by Nature herself, that would have taken you hours to sketch..."[citation needed] He also took a number of stereoscopic images by using a camera he bought for his daughter Thereza's birthday in 1856.

There are also a number taken in Cornwall over several years, many in Bristol including some pioneer animal and bird images in Clifton Zoo, Yorkshire, Derbyshire and a few in Scotland.

His circle of photographic friends included Philip Henry Delamotte, Robert Hunt, Hugh Welch Diamond and especially his distant relative Calvert Richard Jones.

Anecdotal diary references tell us that, in the 1840s, he was with his friend Antoine Claudet, conducting experiments on the daguerreotype process.

One book by Llewelyn that was scheduled for publication was Pictures of Welsh Scenery to be published by Joseph Cundall of Bond Street, in 1854.

Emma had died the previous year and both are buried at Penllergaer Church, originally built by Llewelyn for his family and estate workers.

Their eldest son John Talbot Dillwyn Llewellyn became High Sheriff of Glamorgan in 1878, mayor of Swansea in 1891, and M.P.

Guided by the unique archive of John Dillwyn Llewelyn's mid-nineteenth century photography, the upper lake will be de-silted, and steps, terraces, waterfalls and cascades will be repaired and restored to reinstate the picturesque and romantic design.