Solargraph photography - my first effort 2011 - 2012

Solargraphs are different from a the usual pinhole photograph.


Firstly the exposure times are much longer than we are used to do. The short exposure time of the latent photograph in pinhole photogaphy will be visible as normal in developing it. 


Secondly after a long exposure all the tracks of the Sun are already visible on the emulsion. 


A solargraph is made using a piece of normal black and white photosensitive paper such as is used inside a pinhole camera but be amazed the result will be in colour.

The image shows the actual track of the sun and you can see that in December (low down) it passes behind the near by properties but then rose progressively.

The solargraph was scanned and then mirror imaged and colour reversed, so that it is a positive image and also a representation of the scene observed by the pin hole empty "coke can".

All the tracks of the Sun are visible some broken indicating the sun went behind cloud. 


The exposure started on 21st December 2011 ( the low traces in winter) and it was removed on 17th April 2012  ( the progressively higher in the Spring traces).

Some water did ingress into the can and hence the damage noted at the bottom which surprisingly was at the top of the can when in position as of course one obtains an inverted image as expected in a camera.


A new set up will be established ASAP but I need two beer cans (empty)  that can be used and provide greater vertical height. The pin hole will also be moved from a central position on the can to a higher one, as it is hoped capture the sun's full summer transit.

Here is the mirror image but as original colouration.

Storage

I have learned that silver halides remain on the B & W paper where full conversion to exposed silver has not taken place. 

Had I been using normal darkroom processes these remaining halides would be removed using a fix chemical solution but to do this with solargraphs could result in the image being bleached to a very thin image.

So this means that further exposure to light could completely blacken my solargraph image so it must be stored in complete darkness and may be best to make only a limited number of scans of the image.

Am I pushing the limits of Macro

In another of my hobbies Amateur Radio I am having to use what is called a Surface Mount component.
The leg spacing centre to centre is 0.65mm making the overall length of the component about 5mm.

The photo was taken with a Nikon D80 with a a Nikon AF 24-85mm Macro lens at f22

500mm pinhole camera "lens"

The focal length or projection length is determined by how far the pinhole is from the negative. In this case I have built a "tube" to have  the pinhole at 500mm from the negative.


The photographs are of Kingsnorth Power station taken from the shore line 3kms away the other side of the river.

As with pinhole camera the focus is soft but the depth of field is from in front of the camera to infinity.

A different view with closer foreground

The exposure was 6 minutes with a pinhole of 0.89mm giving an aperture of f/561.

The Calculation

I established the size of lens needed by measuring the width of the power station and the distance away on an Ordnance Survey map.  Then by the use of simple trigonometry I established the Tangent of the angle for half the width of the station. Knowing the half width of the image and now the Tangent of the angle I calculated the distance of  the lens to negative and made the necessary tube accordingly.  It created a photo exactly as expected.