The Clifton Gorge Camera Obscura

While in Bristol recently I had to take the opportunity to visit the Clifton Observatory. Perched on the hill beside the Clifton suspension bridge the building is a former windmill, converted into a studio by an artist, William West in 1828. The following year he installed various optical instruments including a camera obscura.  For £2.50 the discerning member of the public can climb the tower and operate the camera obscura.

The lens is mounted in a rotating housing along with a 45-degree mirror on top of the tower. This means the horizontal view is projected vertically onto a 5 foot diameter table. The table is round and slightly dished to provide the sharpest image (simple lenses like this tend to have a rather curved plane of focus). There's a large handle to pull the mechanism around a track to alter the direction of view.

Viewing the image: I'm holding the direction handle to pan the camera. (Picture: catherine Roberts)

- and it's all utterly magical.  The view of the gorge and the bridge is the most impressive of course, with every change in the weather from sunshine to cloud accorded a drama and significance out of all proportion. Watching traffic and pedestrians crossing the bridge was fun, especially as there's a sense of clandestine spying.

The image on the viewing table. Lumps and bumps on the surface show it's hand made and has probably been repaired and repainted countless times.

Looking up: the lens assembly, guide rod and rotating track can all be seen inside the black wood panelled ceiling. - plus a modern smoke detector. 

Some strong gusts of wind made the lens housing shake, wobbling the image and reminding us that this was a live, real thing happening constantly, whether or not anyone was there to witness it. Other visitors remarked on how "clever" it is.  I think it's beyond that: A machine which is a combination of great simplicity and inspired design. - more of a definition of a work of genius.

 I adore camerae obscurae and this one is a gem. There are quite a few errors on the information board (it states that there are only three publicly accessible camerae obscurae in the UK* for example) but it's well worth a visit.

*Others include:
Eden Cloud Chamber. Eden Project, Cornwall.  Land artist Chris Drury has built a camera obscura from 120 tons of slate. The lens looks straight up to project the sky onto the floor.
http://chrisdrury.co.uk/eden-cloud-chamber/

Foredown Tower, Portslade, near Brighton/Hove. An old water tower housing a camera obscura.
http://www.brighton-hove.gov.uk/content/leisure-and-libraries/museums-and-attractions/foredown-tower-learning-and-visitor-centre

National Media Museum, Bradford (I can find very little about this on their own website bar a passing reference to it in one of their children's galleries but I have found accounts and pictures from visitors so it does seem to exist! do let me know if you have more info)
http://www.nationalmediamuseum.org.uk/planavisit/exploreourgalleries/magicfactory

Barrie Pavilion, Forfar, Scotland.   Situated in a cricket pavilion and run by volunteers.
http://www.kirriemuircameraobscura.com

Constitution Hill, Aberystwyth.  Allegedly the largest camera obscura in the world though I'm not sure what the measurement standard. They have a 14" diameter lens which is pretty big.
http://www.cardigan-bay.com/cliff-railway-camera-obscura-aberystwyth.php

Castle Hill, Edinburgh.  The first one I remember visiting as a child. Great views and a good guided tour as I remember.
http://www.camera-obscura.co.uk/camera_obscura/camera_obscura.asp

The Water Tower, City Walls, Chester.  Small and quirky by the looks of it.
http://www.grosvenorconstruction.co.uk/2013/01/23/camera-obscura/

Dumfries Observatory  Similar to Clifton in design and history
http://www.dumfriesmuseum.demon.co.uk/dumfmuse.html

Great Union Camera Obscura, Douglas, Isle of Man
http://www.iomguide.com/douglas/camera-obscura.php

Lacock Abbey, Wiltshire (while technically a camera obscura it's not room-sized, but a small box set into the window at the Talbot Museum) https://www.nationaltrust.org.uk/lacock-abbey-fox-talbot-museum-and-village/features/learn-about-the-history-of-photography

The Photographer's Gallery (a bit of a weird one as it's in a tube sticking out of the wall. The view rotates around a horizontal axis instead of the usual vertical axis)
http://thephotographersgallery.org.uk/camera-obscura-2

Portmerion Village. Wales  (NB: not advertised as open to the public but it does exist)
http://www.portmeirion-village.com

Greenwich Observatory
http://www.rmg.co.uk/see-do/we-recommend/attractions/camera-obscura

Lastly, take a look at a fictional one in one of my favourite films: A Matter of Life and Death starring David Niven.  One character has his own private camera obscura in his house. - see:

http://www.tcm.com/mediaroom/video/1075290/Matter-Of-Life-And-Death-A-Movie-Clip-Camera-Obscura.html