Pinhole Camera Conversion

To keep with the fine art theme of my graded unit I thought that it would be nice to try my hand at some pinhole photography, so I decided to convert an old folding camera that I have as it uses 120 roll film and gives a 6x9 negative.

Wirgin 6x9" folding camera

The first thing I did was a bit of research on the internet to find out about focal length and optimum pinhole size when I happened upon a wonderful resource for designing and building pinhole cameras at http://www.mrpinhole.com/index.php which did the calculations for me and worked out that for the focal length of the camera which was 4.5” I needed a pinhole with a 0.018 dia. I have decided that for the moment I don’t want to make any modifications that are not reversible but this may change at a later date.

The first job was to unscrew the rear lens element which gives you access to the shutter blades, I then cut down apiece of felt and placed it on the shutter blades as this will protect them from jamming when the pinhole disc is placed in there.

Rear lens element

Shutter Blades

Felt disc inserted to protect shutter

The next problem to address was the pinhole itself, further research has led me to the discovery that a size 10 sewing needle will produce a 0.018 Dia hole so as I didn’t have one to hand I bought one from a specialist sewing place as the packets numbers don’t seem to correspond with the needle sizes. There are numerous materials that the pinhole disc can be made from, drinks can, brass shim, tin foil (but these can tear easily) or as I chose a tee tree light tray. I started by finding the centre and then marked a dimple with a ball point pen which I then sanded slightly to thin the metal, the next job was to place the pin in the centre and work it gently drilling the hole through the aluminium and then it was on to check the size.

My pinhole disc

To check the diameter of the hole I scanned it and then opened it up in Photoshop and used the ruler tool to measure it, I fluffed it and have made it too big! It measures 0.031” which works out at F145 so it’ twice the size of the optimal 0.018” F254 that I was aiming for but I want to try it out of curiosity’s sake more than anything but I am going to measure the needles I bought with a micrometer and make another disc hopefully with the right size hole this time.

All that was needed to finish the job was the disc was placed onto the felt washer and the rear of the lens screwed back in place, the beauty of this conversion is that I still have a working shutter that I can use with a standard cable release I can’t wait to try it now when the weather gives me a break I will be out shooting a few shots that I have in mind to do in an old church yard.

Cyanotypes Part 2

Following on from my first cyanotype post I have now had the chance to test the process with the digital negative I had. The first test I did I exposed a sheet of parer for fifteen minutes under the U.V lamps that we have a college, lthough there was an out line of an image I could tell that we was going to need a much longer exposure time so I doubled the exposure time and then doubled it again, at an hour I was getting a good exposure but lacked any sky detail so I exposed the next sheet for an hour and a half this didn't overpower the main image and also put detail in to the sky area. After each exposure I washed the prints of with water, I have since learn't that I haven't been washing them for long enough and you can tell this in the two photographs that there is a bit of yellow staining from unwashed off sensitiser. T he prints require a good five mintes rinsing to ensure they are clean.

I have also found out by trial and error that differnt papers using the same negative require quite different exposure times, this is similar to the way different paper's behave in traditional B&W photography and I have got some really good results on some parchment paper that I purchased as single sheets from an art store.

The next step is going to be making some tea toner and toning some images, it will be intresting to see how the toner changes the images.

 The above image has been exposed for 1 hr

This is the image that was exposed for 1.30 mins as you can see there is detail in the sky area

The sensitiser I have made up from the formula gives a lovely china blue when it has fully dried, these images are just as they have dried.

Sheet Film Processing

The time has come for me to develop my own 4x5 sheet film, lately I have been getting varying results back from the lab I use and I can't be sure whether its me or them that's producing them so if I keep everything in house I should be able exact some control over the process.

I have acquired a Paterson orbital processor that I have modified to process the film in. I have seen some articles on the net about doing this and some seem to be of the opinion that you need to scuff the bottom of the processor to stop the film sticking to it or you need to apply some resin to lift the film slightly of the bottom, I have gone for both methods, erring on the side that maybe there is merit in both techniques and a mix of the two will be the best option.

 The Above image shows the complete unit and base

As you can see from this image I have scuffed up the bottom using a Dremel multi tool then added resin in the base to slightly lift the film off the surface, I went for a combination of spots and lines to see if either was better than the other and have found out that either work as long as the film is supported all the way round IE the top r/h one in the image needs some additional blobs of resin added to it to support the outside of the film and the one below it could do with a blob in the middle.

The advantage of this system is that you use far less chemical stock than the traditional tanks and it can be loaded in a changing bag and processed in daylight. I am using 200ml of solution which I think is plenty although I have heard of people using 150ml or less. I am still in the testing stage at the moment but so far I am impressed with the results, the tank just needs a few tweaks and it will be there.

Rudman Bleach and Redevelopment

Really good instructional piece from the master Lith printer Tim Rudman

Cyanotypes part1

A fellow student, Julie and myself have been making up the solution and coating paper to make Cyanotype prints this morning.


The Ingredient's required are :

• Ferric ammonium citrate (green)
• Potassium ferricyanide
• Water (distilled but I think they call it ionised now)

Plus the following equipment:

• set of scales
• 3 x  containers for mixing ingredients
• Syringe to measure out water
• Plastic spoons
• Face mask
• Goggles
• Rubber gloves
• Cleaning cloth
• Brush or something to coat paper.

Method: First take 100ml of distilled water and place in one of the mixing containers, then weigh out 25 grams of Ferric ammonium citrate and mix them together, Measure out another 100ml of distilled water and weigh out 10 grams of pottasium ferrycyanide and mix these together. When you have done that you have to mix the two components together in the third mixing jar, this does not need to be carried out under safe light conditions but can be done under a low level tungsten bulb.
Once you have the two solutions it is then just a matter of applying it to your chosen media, for this project I have chosen some linen paper I got from an art store; then store in a dark place to dry.

Glen Ogle Viaduct

Glen Ogle Viaduct : Captured with a 4x5 Arca swiss model B on Fuji Provia 100.
I took this on the way back from Glencoe where I was shooting an assignment for an environmental unit at he beginning of 2011.

Beginnings

My intention is to use this blog to share my photographic journey. I aim to post at least twice a month a mixture of my work and technical articles that I hope will be of use to fellow photographers and also use the blog as a diary for my own purposes, it will be nice to collate all my info in one place rather than all over the house. Please feel free to comment both good and bad but please keep it constructive and if you have any links you would like to share please send them to me and I will add them to the site.

TTFN
Barrie