UCA collodion sessions for 2018. Best Hats Yet!

I've just finished the third day of workshop/demos for UCA students. We made some great plates, thanks to a wonderful new (actually 100 year old) portrait lens, good weather and most importantly some creative, enthusiastic and inventive people who really got into the spirit of things. Thanks to everyone for making these: a real team effort as always.

The first day was for year 2 BA Photography. Here are the plates. Mostly half-plate ambrotypes:

Sadly Emily's last plate, a whole plate tintype fell victim to the old collodion shrinking as it dried. The odd thing was that we made a couple of other whole plates and they didn't peel. Maybe too long 'setting up' between the pour and the silver nitrate? I'm not sure but it's a reminder of how fickle this process can be. The learning curve is endless.


The next session was for MFA students. Corinne brought some great dressing up stuff and everyone made a real effort to transform themselves for the camera:

The set-up in the finishing room: Note the head brace to help the sitter keep still. (photo: Hayden Wilde)

Corinne has a go at pouring a plate. I was impressed with everyone's skill at this tricky operation. (photo: Hayden Wilde)

The hat needed a little adjustment! (photo: Hayden Wilde) 

Su Ji posing for the 12"x15" plate camera. Note how the orange feathers record as black in the Ambrotype. (photo: Hayden Wilde)

Hayden was the super-assistant for these shoots. We made this whole plate tintype as a small token of thanks.

The following day, the remainder of the MFA people came for their session. Again, some great hats, inventive use of props and original styling and poses:

The mirror Danielle is holding has solarised: - a beautiful effect.

Thanks to everyone who took part. Looking at the smiles in all the production shots it's clear you all enjoyed it as much as I did.

Thanks once again to Hayden. His hard work and super-efficiency were very much appreciated.

A Cure for Old Age! - (for collodion at least).

Collodion doesn't have a great shelf life. Even if kept in the fridge it deteriorates over time.  As the solution ages, it darkens in the bottle from a light straw colour to a deeper orange, almost red.  Old 'red' collodion can still be useable but the sensitivity is generally much reduced and the contrast is higher.  Some people use it to their advantage, using red collodion when they need more contrast or mix it with fresher solution for a custom coating but most of us accept that like conventional photo chemicals it is best to use the stuff up before it goes 'off'.

Recently however I've come across a couple of references to the use of acetone to resurrect old collodion. Quinn Jacobson mentions it and there's a great account on the Collodion User's forum by Tara Oliphant (www.derivedlogic.com)  which recommends using 0.5ml of acetone per 75ml of collodion to restore it. This works out as 6.66ml per litre or 0.0066%. - say .007% for the real world.

As I've got various bottles of elderly stuff lurking in the fridge I tried it. 

The old, red collodion I tested is some of John Brewer's own-recipe positive stuff which must be at least a year if not two years old. (dating the bottles when they are new is a good idea) It's been stored in a fridge at approx. +5deg. C and it still works, though it tends to crack and flake sometimes on larger plates (it's noticeably thicker when pouring).

As per the recipe I added 1.7ml (should be 1.66ml but that's hard to measure accurately!) of acetone to 250ml of collodion. This is a tiny amount: less than 1%of the volume. I doubted anything much would happen but after only an hour the colour had already improved!

After 1 hour the acetone has already lightened the collodion...

Another 9 days in the fridge and it looked almost brand new.  I'd expect the conversion to be quicker if the stuff is left at room temperature but I prefer to keep it safely stored in the airtight fridge.

After 9 days (in the fridge) the treated collodion has reverted to its original colour

Testing.

Side by side tests made under the same lighting conditions - or as best I could in daylight. flash is more consistent but I seldom use it in my wet plate work and I wanted a relevant test result.
For the record these are quarter plates and the lens is my 5" magic lantern petzval.

I established the best exposure for the old red collodion as 6 seconds at f/3.  I kept the exposure the same for the treated collodion (it was a dull day and the light was pretty stable) Here are both plates:

untreated old 'red' collodion. 6 sec f3

same collodion treated with acetone. 6 seconds f3

Interestingly, even though older collodion is supposedly more contrasty the treated stuff has better range. The highlight and shadow are fairly similar (slightly brighter highlights on the acetone one) but the mid tone separation is much improved.
I'm surprised there isn't a greater difference in speed. the light level may have dropped a bit on the second exposure so it's actually brighter than it appears. (another way to test would be to pour both pools of collodion on the same plate so exposure and processing are identical). Anyway, there IS a definite improvement. The 'restored' collodion flows more freely onto the plate - though I think the more obvious crepe lines are a result of inconsistent pouring on my part.
I would expect it to have fewer problems with peeling, though that tends to affect bigger plates so we shall have to see.
(UPDATE:  No, unfortunately  peeling is still a big problem on larger plates. We made this whole plate tintype the other day and it was fine until it came out of the wash and started to dry. The peel started in one corner and spread across the whole image in about 20 minutes. - Heartbreaking!

The general wisdom is to add some alcohol to the collodion - that's IDA (industrial denatured alcohol) for those of us in the UK. - I'll try that next...

At some point I'll try a side by side test of some different collodion recipes as I have a variety in stock. See the excellent wetplatesupplies blog for a very detailed comparison test.

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