Tuesday, November 29, 2011

Salt Printing Experiment - Part One

As this was my first foray into salt printing the initial starting point is to obtain all the chemicals, and there are quite a few!! Its not just the chemicals, there are other specialist bits and pieces required, syringes, coating rods and specialist paper.










With any new photographic discipline knowledge is sort. This came by way of an excellent book by Christopher James 'The Book of Alternative Photographic Processes" pages 34 to 59.
The first part of the process is to size the paper that will be contact printed. Most bought water colour paper is already sized, however James always recommends a sizing stage of the process to ensure consistent results.




The sizing process consists of coating water colour paper, or any other paper that you are using for that matter, with a solution of gelatin and salt. To make 1 litre of sizing solution you will require 8g gelatin, 18g of sodium citrate, 20g of ammonium chloride and 1 litre of distilled water.



8g of photographic gelatin



Gelatin bloom

The first step is to soak the gelatin in 500ml of the distilled water. This takes approx 15 to 20 minutes. This is known as the bloom stage. Add the remaining water and heat to 100 f. When the mixture reaches the required temperature mix in the other chemicals.




Prepare a double boiler bath - a smaller tray that fits into a larger tray. This is to maintain temperature while the paper soaks in the sizing solution. Gelatin will revert to a hardened state if allowed to cool. Feed the paper in one sheet at a time allowing to soak for between 3 and 5 minutes.



Hang the paper in a  dry dust free environment allowing to dry fully before using - approx 24 hours.

Friday, November 25, 2011

Professional Practice - Silverbased Test 5

For the  final experiment for this assignment  I wanted to try Adox film. This film was first produced in the 1950's and is an old school type. The emulsion  has a certain special sensitivity "partial panchromatic'  halfway between ortho and true panchromatic.




 Adox film has to be treated slightly differently form the modern day film. The emulsion is quite delicate and has to be handled with a little more care.  When developing, the sheet film has to be pre-soaked for 5 minutes in water which softens the emulsion.





The developer used was Rodinal 09 which is more suited to this film than the Ilford developer I normally use. I used the Paterson Orbital Processor as with the other test previously carried out. I did have a slight moment when the developer came out deep rose colour.




Pre soak 5 mins 20c water temp
10 mins developing 20c
60 Sec just water 20c
5 mins Ilford Rapid Fix 20c
20 mins wash 20c



The samples of this film are below:



Thursday, November 24, 2011

Profesional Practice - Silver based test 4


As part of the experiments I have been conducting I wanted to see what would happen if I used an old petzval lens and film. The lens I used is quite fast at f2.8, and with out a shutter an exposure of around 1 to 2 seconds is sort. The only film I had was ISO 400. This means controlling light becomes an issue. The light for this test was daylight mixed with an ordinary ceiling light behind the camera. For this test I was not overly concerned with any particularly lighting set up, I just wanted enough light so that I could use a  combination of film speed, aperture (fixed at 2.8 as I don't own stops for this lens) and time.























The first image was a 2 seconds exposure. The light to the models face is slightly under exposed, plus the camera is casting a shadow over the bottom of the face. At the top of the image is the swirly bokeh that is the signature effect of the petzval lens. The second image was still a 2 second exposure but with the light turned up (dimmer switch controlling ceiling light). Also the model was taller, so the shadow of the camera was cast in the neck area.

Conclusion

This test has proved that I could use this lens in combination with a faster film speed (ISO100 or below) and use the fauna subject mater in previous test to create a distinctive salt prints.