pinhole – Camera Obscura

Pinhole polaroid porn and umigraphy portraits, by Arnoud Bakker

Arnoud Bakker — Wed, 08 Sep 2010 19:28:47 +0000

Text and photography by Arnoud Bakker.

A thousand words, thats what they told me, a thousand and otherwise they will not publish my thoughts and works. I think that’s fair. By telling and thinking, a thousand is just enough to explain what I think I’m doing.

As I was raised and educated as a photographer, that was like 12 years ago, when I finished Art academy, ARTez (the AKI) in Enschede (NL). I loved the darkroom that time, and I made myself a way, -by making kind of collage-like-big-paper-and-stuff-negatives- to create a world that was mine, without the -It just looks like- look… No, by being extreme with tape, cutting, and glueing, it went beyond that. It became a new reality for me.

While considering the fact that photography was still analogue in that time. A couple of years later the digital revolution was a fact, and everything became possible. With a digicam, a CF, photoshop and some patience.

Although I’m not a purist, I noticed that I didn’t felt comfortable with the new situation. I had the feeling that I was pulled in this digi-race in order to survive. But the uniqueness of an image had been degraded to zero. Nowadays every file can be copied a thousand times. Black and white pictures are printed on PE color paper.
And every minor unwanted detail can, -and will be – erased by the easy power of the clone-stamp. I didn’t believed the digital photo anymore. It even looked like people didn’t believed photography anymore.

Once there was a time, people believed photography, you could see that it was real, because it was on the picture itself, that was the proof, and otherwise it could not have been made. Now the time had come for me to decide to continue analogue photography.

Also the fact that analogue had been replaced by digital, didn’t meant that photography was explored in every way. Actually there was, -and still is- a lot of unexplored areas in photography.

I started to combine several processes. Common processes, but just combined in a different way, so new possibility’s announced.

The day the umigraphy was born. Named after a huge repro-camera, the “umigraff” (Actually I “invented” it a long time ago, but back than I didn’t felt the need to use it right away because of an overdoses of other techniques). But now It gave me the back possibilities to create valuable photo’s . The pictures became little objects again, precious, and because of the absence of a negative, they are uniques.

The beautiful silver soaked paper, that is in the camera (mainly 8 x 10″ ) during the exposure, is also the final print. Touched by the light that was there during the photo-moment, as if the paper is a silent whiteness. The photo, as if it has stolen a little of the light, and a little of the soul, of the one who is portrayed. Just like in the old times, when the Indians were afraid of being portrayed, afraid to loose their souls.

On the other hand, it gives me as a mortal, the opportunity to get a kind of grip at life, by collecting all these small pieces of soul. As if the models, the young women, kind of trust me with a piece of them. It gives me an affirmation of my existence.

* * *

An other project I have been working on is a “pinhole polaroid porn project”. As there is a lot of disciplines in photography, pinhole is one that has my interest as well. It’s a magical thing, to catch light. Perhaps even more because the instruments being used are primitive, self build and understandable. A perfect tool for light catchers in the purest form. Funny thing though, is the fact that porn is an underexposed subject for pinhole users. So I decided to explore the possibility’s of it.

I realized the ‘inconvenient’ side-effects of the camera obscura. Extremely long exposure times, a blur because of a lack of lens, and unsharpness because of movement. On the other hand, I was happy to see the first results. because its dimness. Its that effect that makes it more comfortable to look at the pictures. They became a kind of paintings. Man can say the project is a “failure” cause no matter how hard I try, the important ingredients for porn are missing.

Because of the exposure times, face expressions, become less intense, and the razer sharp pink colored skin has turned soft and greenish, by the behavior of long exposure on Polaroid. In order to get a little sharpness, I desired to use flash now and then, when I thought it was needed.

The profit in use of Polaroid, man can immediately see the results. And still there is a lot of unexpected coincidences and surprises involved with this material. But also the uniqueness of Polaroid and the light-catch story as told above are important for me.

As has been written in my photobook “Atropa bella donna”¹ “Arnoud Bakker is an alchemist who wants to create golden girls on paper”.

I try to combine a ‘perfect’ woman, and by collecting all kind of different aspects of women, I catch their light, their soul, their sexuality, their forms, in a stereographic way, their moves in small pieces of 8 mm film.

I will try to get it all, with one camera, with two camera’s, with big camera’s with small camera’s. I want their winks, their moments, their eyes, their light, mouths, tooth, their scars, their skin. I want their braveness, and their naivety. I try to order them in rows, as if I make an archive. A collection. And how things can be overwhelming like in a museum for example.

Once there was a time, I was not aware of what I was looking for, I was fascinated and restless, but couldn’t explain what I was searching for. Actually that was a good condition to be in.

The more I try to explained what I’m doing, the more it looses it’s magic, the search for a destiny, is as important for me as reaching the destiny itself. I think this , “the-Frankenstein-put-everything-together-project” as you might call it, will be a lifelong project.

Might be a bit strange for one, but I think it’s just too beautiful.

For more photography please visit Arnoud Bakker website.

Atropa bella donna, Arnoud Bakker, published by Noorderlicht, isbn 978-9076703-39-8.

Topography, by Daniel Tubío

Daniel Tubío — Fri, 25 Dec 2009 16:30:08 +0000

Pinhole self-portrait
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

Text and photos by Daniel Tubío.

A methodical search

This series consists of a work on Buenos Aires city, which was conceived and carried out during 2003/2004. The whole work included designing and building the pinhole camera for the creation of these photographies, and with them I try to reflect about some aspects of the way we relate ourselves with urban spaces, specially about all those itineraries in which chance –or protocolar decision, as it was the case– breaks monotony and leads us to areas which we perceive as strange territories, even when they are not so distant from the places where our day-to-day life belongs. One route, any corner… a quotidian spot (a commonplace) for some of the city inhabitants, an unknown world for some others. This work also means a reflection about the photographic medium and the available possibilities in pinhole technics, as when we build up our own tools, one advantage is that cameras have no secrets for the builder and setting them up is directly conected with the type of images we are trying to obtain.

O'Higgins and Pico
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

The series genesis

This photographic adventure began some time before the actual materialization of the series, by means of a present from a friend that turned into a challenge: she gave me a triangular tin and told me: “I’m sure you are going to do something good with it”. Since then, trying not to dissapoint her, I started thinking what kind of camera could I build with that container and what kind of photographic series should I create from it.

It came gradually to my mind the idea -obviously an arbitrary idea– that a triangular camera should only be used to shoot corners. To complete this notion and make it more consistent with the urban modern development concepts, I designed a chamfer-shaped negative mounting to support a film strip –an inverted chamfer corner, because its goal is obtaining a negative, an inversed view in relation to the so-called “reality”.

Triangular camera
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

Once the camera was finished, I went through two processes which usually appear simoultaneusly in all my series: searching for optimal technical parameters based upon the kind of pictures I wanted to obtain, on one hand, –this search is described at the end of this text-, and on the other hand, taking conceptual decisions about the images: which specific corners should I shoot, where should I take the photos, and the reason of the choice itself.

Searching for corners

So, while tunning the camera, I began to think about some basis to select the corners. The general location was solved in advance, as one of the recurring topics in my work is my hometown Buenos Aires, a city I really love. It is big enough to display a surpassing cultural life, and gentle enough to house neighborhoods —as “Saavedra” my own neighborhood— where people takes their chairs out to the sidewalks in summer evening and sit to share some “mate”¹.

Lujan and Sta Elena
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

From the very beginning I rejected the idea of looking for “traditional” corners, famous spots or any kind of tourist cliché. And suddenly, by linking schemes, the answer appeared. What was interesting about it is the fact that the clue was “suggested” by the camera itself, specifically by its shape: being a triangle, it reminded me those movies where detectives and cops map out triangles just to locate areas where the suspicious guys would eventually make their moves, and then, inmediatly, my modus operandi came clear to my mind: to delineate triangles on a Buenos Aires map by copying the camera shape, and then, allow chance (random ensuing from the method itself) decide which corners should be shot.

So I bought the biggest available city map and embarked myself upon the task. My first dilemma was about the initial point in order to design the triangulation protocol. I decided it should be at Av. Rivadavia & Biedma St. crossing, because it is the location where it used to be the clinic where I was born. Now, at the same place, there is a high complexity medical institute. I could justify my choice arguing that this corner is only some 700 meters from the geographical city center, but this choice is in fact as arbitrary as any other else, and it proposes a subjective departing point for a later development which just kids about those typical “objectivity” claims of the photographic medium.

Rivadavia and Biedma
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

Once found the initial corner at the center of the city, the rest was just a systematic work: I placed one of the triangle camera vertex on that corner and mapped out a northwards triangle. Then, I repeated the proceedment by resetting the camera on each obtained vertex until touching the city limits. This operation was repeated three more times: eastwards, westwards and southwards. This way, the city map ended up covered by triangles with 22 marked intersections, which turned out to be the sites I should shot during my work.

Buenos Aires Map
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

All these triangles created a net on the map, and this net coincided with one of the possible routes between the corners. But this itinerary was in fact unapproachable in the actual space of the city, except for urban explorers²), as it crosses blocks diagonally and does not obbeys to transit defined spaces.

Taking the photos

After solving camera technical aspects and defining routes, the rest was just to take the photos. I decided that each shot should be made with the camera in the same position, it is: set parallel in relation to the ground, at a height equivalent to that of my eyes, which means around 1,65m. from the floor. Once again, subjectivity apears here applied to the work.

Cochabamba and Salta
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

A previous investigation about the routes was made, as I had to obbey not my web on the map but the usual roads and streets in the city. This investigation was aimed to find the proper way of reaching each one of those assigned places by means of public transport, and I also made an informal inquiry among my friends and close people about features of those neighborhoods which were unknown to me, to prevent eventual security, access or circulation problems, on one hand, and to plan which day in the week or which time in the day would be more accurate to accomplish my expedition on the other hand. All this research was carefully put into paper and it is summarized in four A4 sheets, which turned to be the “roadmaps” I used for the task. These documents show selected corners and the way to reach them, references about the different areas (only in those cases I managed to get references before going there), dates and times when the shots were taken and additional observations about pre and post-production of the work.

We should bear in mind that due to the camera technical parameters, only one shot was possible at a time, so it was necessary to make an accurate plan in order to take profit of each trip. Let’s say that Buenos Aires is so big that sometimes it can take almost two hours to cross it from one limit to the other.

Roadmaps
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

I took four photos at the starting intersection, facing the camera towards a different cardinal point each time, in order to register the whole surrounding space and to “echo” the gesture I had accomplished on the map: a circling movement towards the four cardinal points. As for the rest of the registered corners, the view was choosen by me among the possible ones –usually there were four possibilites, but some streets intersections in the city are formed by 3 or 5 corners. Once again, at this point, “subjectivity” was the leading idea.

There were 25 final photographies, shot approximately in the term of two and a half months (may/july, 2004). Only once it was necessary to return to the corner to take back an incorrectly exposed shot; for the rest of the images, only one trip was enough.

Av. Casares and B. Roldan
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

About the show

The complete series comprises not only 25 images of the 22 street crossings, but it incorporates the original map were the triangulated web was designed (1,25mts x 1 mt) and the “route maps” used for the work as well.

The whole photographic series was showed for the first time in August, 2004, at the Museo Histórico Saavedra (Saavedra History Museum) in Buenos Aires City, and then, in 2007, it was exhibited again at the Palermo University Photogallery (may) and at the Architecture Faculty Exhibitions Rooms in the University of Buenos Aires (november). There were different audiences in each of the three exhibitions, as they came from widely different backgrounds and that meant a variation in individual profiles. However, one of the most interesting aspects regarding public reaction was the fact that people came to me to express similar concerns. On one side, they showed themselves surprised to see in the photos some places they could hardly recognize as belonging to the City, as it is the case of the photo taken in Castañares St. & Goleta Julia St.

Castañares and Goleta Julia
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

On the other hand, in an opposite direction, everybody discovered some places that were well-known for them, because locations were close to their homes or to their jobs. Some of them, indeed, found an image (surprise!) of their own homes in the photos.

This made me think that this series, which had began as a challenging game, had somehow turned into an interesting and peculiar documental land registry -even being partial and limited- and it was working well regarding one of the most relevant aspects still valid in a photographic image: its relationship with the referent, its “documentary” status and the audience interpretacion -better, the audience assumption– of photography medium as a reflection of their own experiences.

Camino del Medio and Laguna de los Patos
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

Technical aspects of the work: fitting the camera

The inverted chamfer shape of the film inside the camera was supposed to be an interesting technical challenge. Film setting plus distance from the pinhole to the imaging plane in the camera generates an angle of view of around 160º, which makes it possible, if standing on one of the streets crossings, to include the other three corners in the same image. But this shape brings rigged several problems to solve.

Light breaking through the pinhole travels along dissimilar distances to reach different areas throughout the film, which has a size of more or less 6x22cms. Because of this, it was necessary to find out an average among all these distances in order to calculate the appropiate pinhole to obtain an optimized sharpness. I arrived to the conclusion that best pinhole diameter was 0,25mm, which provides the camera with a 360 f number. This size of apertures needs quite long exposure times, and here I run into another problem: long exposure times combined with a chamfer shaped negative –where the film reflects some light onto its others own surface areas– produced low contrast negatives. I started to test different films, exposures and developers until finding the ideal combination: Ilford HP5 plus 120 roll-film, ISO 400, pushed up to ISO 1600 and developed with D76 stock in 11½ minutes at 22ºC. It took me around six months to test camera and film until I reached to the results I was looking for.

Matanza and Itaqui
© Daniel Tubío
Please visit Topography, by Daniel Tubío for the full size image.

Final prints were copied by me on FB black & white paper by means of an AGFA Repromaster 1300 used as negatives enlarger. The Repromaster is a reproduction camera which makes it possible to enlarge or reduce transparent or opaque originals. Some years ago it used to be an essential device in graphic industries, but today it has turned into another example of technological garbage due to the outcoming of digital printing systems.

To see more about this traditional Argentine drink, read the Wikipedia article
There are some gangs whose members take “impossible” routes or explorations into urban geography: they are called “urban explorers” and their adventures include entering forbidden buildings, exploring sewers and storm drains, crossing blocks through roofs and so on. Usually, they register these activities in videos or photos and upload them to the web

Pinhole Self-Portraits, by Alyson Belcher

Alyson Belcher — Sun, 07 Jun 2009 08:27:57 +0000

Following text and photos by Alyson Belcher.

For the past 10 years I have been making self-portraits that combine pinhole photography and improvisational performance. When I began this series, I was looking for a way to photograph the human body that went beyond an objective rendering of the external form. The body is a vessel that contains and channels all of our experiences, thoughts and feelings. My photographic process (the use of movement and long exposure times) has allowed me to access and give visual form to what lies beneath the surface of the skin.

During the early part of my life, athletic activities were my primary focus. I was a competitive springboard diver from the age of 6 until about 25. My family has been very involved in dance as well, so I have always been surrounded by people who are interested in movement. I was never a dancer, but I have been strongly influenced by all kinds of dance. I began to seriously take photographs when I was a teenager, and since I was always at the pool, I photographed other divers. At first, I was interested in capturing the strength and grace of the body in flight. Over the years, I realized that I was trying to convey something more subjective: the experience of diving, of being in that body flying through the air. This is what eventually led me into the studio to make self-portraits. I didn’t think I could actually make photographs that conveyed what it felt like to dive. But I might be able to convey the experience of simply being present in my body.

My first self-portraits were made in an empty studio using only natural light—nothing but me and my pinhole camera. I wanted to create an environment that was free of distractions: no props, no lights, nothing that would interfere with my experience while I was in front of the camera. This quiet, empty space was a place where I could focus inward and be fully present in each moment. I didn’t even use a timer; I counted out the seconds of each exposure. While my studio has become a bit more cluttered over the years, I still keep my shooting space very spare and empty. I use a 4 x 5 pinhole camera and Polaroid T-55 positive/negative film. I still use primarily natural light, but I sometimes have to add a little extra fill light on dark days. My exposure times range from 30 seconds to 2 minutes. And I still count the seconds rather than using a timer.

The Polaroid T-55 film has been a key element in this work. It is extremely helpful for me to see each image immediately after it’s made so that I can check composition and exposure. I have developed a system of working from one image to the next, of creating a storyboard for each day of shooting. I don’t usually have a clear idea of what I want to do when I enter the studio each day. I might have a glimpse of an idea, so that’s where I begin. It might be a gesture or a movement I want to explore, or it may be a feeling I want to convey. But wherever I begin, the work each day always unfolds in an unexpected and organic way. I make the first picture (which is often not very interesting) and I look for something that I like—it could be the way a certain movement leaves traces of the body on the film, or it could be a gesture. In the next picture, I begin with that element and build on it. And I continue that way for several hours, until I have a series of about 20 pictures that illustrate my process of unfolding and discovery for that day.

Making self-portraits with a pinhole camera is a relatively blind process. I am both the photographer and the subject. There is no viewfinder or ground glass in the camera through which I can preview the image. There are a lot of variables, but that’s what I love about working this way. I have drawn some lessons from my diving days that have allowed me to embrace the element of uncertainty. In diving you have to learn how to balance relaxation and control. You have to be relaxed enough to let your body do the dive, yet you also have to maintain control to execute the dive correctly. You have to totally trust your body and you have to have a keen sense of kinesthetic awareness—knowing where you are in time and space. These things have become key factors in the creation of my self-portraits. The pinhole camera has allowed me to incorporate the element of improvisational movement as a way of exploring both physical space and inner experience simultaneously. Combining the long exposure times with movement reduces my ability to predict how an image will turn out, and often I am pleasantly surprised. The image making process takes on a life of its own.

This work has benefited from my willingness to put myself in emotionally and physically challenging situations. I am drawn to things that challenge me, to things that put me off balance. Initially, there was a fear in exposing myself. Like most people, I am uncomfortable in front of the camera. When I began this work, I wanted to see what would happen if I allowed myself to fully experience that discomfort, how it might shift and change over time. I have also been known to create physical situations for myself that are very difficult, if not impossible, to hold for the entire two minute exposure time. As I count out the time and my body strains to hold a position, unexpected movements are recorded on the film. These images are some of my favorites, for they surprise me the most when I peel apart the film.

One of the themes that has emerged in my self-portraits is the relationship between stillness and movement. Where does a movement or a gesture originate internally? Is it possible to ever be completely still? I have attempted to remain completely still for an entire exposure, but it’s really not possible. Even if I am just standing in front of the camera, I’m breathing and my heart is beating. Those subtle movements are recorded in the image.

Another theme in my work is the presence of multiple figures in a single image. These figures contribute a narrative quality to the work. In some photographs I appear to be interacting with myself, or there appears to be another person in the frame. Some viewers think that there are several different people in these photographs, but the figures are all me. The presence of multiple figures can represent the duality of the self, or different parts of myself interacting with one another.

When I’m moving in front of the camera, I have to move very slowly in order for any image to show up on the film. I have to remain still for about 10 seconds if I want the film to record any trace of my body. If I want my body to leave a more solid impression on the film then I may have to remain still for 30-45 seconds. So in the images where there are multiple figures, I held each one of those positions for at least 30 seconds. The movement is a slow, moving meditation in which I remain acutely aware of my body and my position in front of the camera. I do not mark out my positioning ahead of time. Rather, I trust my instincts to tell me when, how, and where to move.

This series of pinhole self-portraits began as an experiment and it has evolved into an ongoing visual journal. The focus for me has always been more on the process than the product. If I focus too much on getting a “good picture”, nothing works. When I am able to let go of expectations and leave room for the unexpected, the results are filled with mystery and magic. The best photographs have been the result of spontaneity and improvisation.

Pinholeswap 2008: pinhole cards exchange

Fabiano Busdraghi — Fri, 18 Jan 2008 15:28:41 +0000

Some of the envelopes received during the annual exchange of pinhole pictures.

Since 2001 some pinhole photography lovers created the Pinhole Cards Exchange, which means exchanging pinhole pictures or more generally pictures realized without any lens (that is zone plate, pinhole slits, multi-holes, etc…) in occasion of the new year. In practical terms, the members add their address to a list, they can send one or a dozen of pictures, for free and without any specific rule, apart that the picture must be obtained without the use of a lens. Christmas and wishes are not my problem, but I gladly participated, and I must say that I was pleased to receive almost a letter per day, when everything arrives on the net and spot or bank bills are the only thing inside the mailbox. No way to explain the pleasure to see different envelopes, letter or print paper.

I sent a picture shot in 2005, a self-portrait made with a cardboard box, hole done by a pin in a beer tin can, negative on 13×18 cm ilford paper. I photographed with backlighting because I don’t have a good scanner, I create a digital negative and printed a cyanotype on 9x11cm Bristol Paper, followed by tea toning. 25 exemplars editions and two artist-test, signed and numbered. The toning part is one of the most excellent of the last times; I had deep black, almost black, and not the classical cyanotype blues. The high lights have been tainted by tea in warm reddish yellow that I find very nice.

I will post here some of the pictures I received, my favorite ones. The first place goes to the Eric Mitchell’s, fine subject and amazing print on Foma FB basic paper. The best print is the Ingo Guenther’s, an amazing photogravure on a beautiful textured paper, with wonderful deep blacks and classic ink aspect, with lovely grain. Earl Johnson’smust be mentioned among the particular cyanotypes, perfectly realized and by the interesting matter and grain; shame for the stain in the sky. I find Adrien Arles’ double exposition perfectly fulfilled, as the two images totally blend to each other, as they’d be one. Moreover, I do appreciate panoramic pictures right now; therefore I’m happy to have received many of them. Finally, I do appreciate the particular soft and delicate view of the pastel colors in the curious rounded pic by Matt Neima.

[See image gallery at www.co-mag.net]

Mounting pinhole diaphragms on support slides

Fabiano Busdraghi — Sat, 15 Dec 2007 22:45:53 +0000

Instruments needed to mount a pinhole diaphragm on a support slide.

The electronic microscope diaphragms are splendid pinhole of perfectly known and regular diameter, but they are small (circular 3mm slides) and they have to be mounted on bigger support slide not to ruin them and to use them more easily. This article will expose some suggestions that will let you mount them in an easy and efficient way. The holes are not sold mounted as the exigencies of every photographer could vary.

The necessary currency material: an aluminum tin can, some black adhesive tape (the one used by electricians) and an instrument to make 2mm holes. If you got a drill and a 2mm drill bit, well you got the whole! But unfortunately not everyone has a little workshop in its house. I procured a 2mm punch, which is 1,50 euros in any ironmonger’s. I think that everyone has a hammer in its house, as well as a piece of compact cardboard that will be your pad, therefore the expense to get everything you need is quite contained.

Let’s start cutting a piece of aluminum from the tin can. It must be of the desired dimensions, let’s say up from a cm2. Let’s cut a couple of centimeters of tape or put the aluminum slide at the center of it. It is not necessary that they fast completely to each other, the tape will be taken apart during next step. Lay everything on your paper pad, the tape looking on top, put the punch in the center and beat with your hammer, so that you contemporary create a hole in the tape and in the aluminum.

At this point you can detach the tape and put it within reach, for example fasten at the border of your table. If you used the punch, the slide will be bended on one side and will present a little cone on the opposite side. Therefore you must turn it and give a couple of hits with your hammer to flatten it. It could be necessary to turn the slide again and give some little smacks to both sides. If there’s some smears, it could be useful some sandpaper, but it is usually easy to form clean and faultless holes. If the slide is big and is not covered entirely by tape, for example in the case the slide will be an entire wall of the pinhole camera, it is the moment when you must paint it black. Black opaque spray painting is not expensive and will dry in a short time.

At this point it is necessary to work with precision. The idea is to put the electronic microscope diaphragm on the table you’re working on. The pierced tape must adhere with the diaphragm, in a way that the diaphragm hole will be exactly centered with the hole of the tape. Thanks to the tape glue, the diaphragm will be stuck. Then you put the tape on the surface, with the glue and the diaphragm side looking to the top; you make the aluminum slide adhere to the tape, in a way that all the holes will be superimposed. This way, the microscope diaphragm is free at the center of the sandwich, between adhesive tape and one-millimeter aluminum all around its border.

I personally find tables a little bit uncomfortable, as there’s no space for fingers to work. So I put the microscope diaphragm on a one-centimeter-diameter cylinder, some centimeters long. I use a lipstick case, but just because it was the first thing that came into my mind with that precise shape. This trick helps me put my wrists on the table and lets my fingers come closer the diaphragm. It is easy to put the holes together looking through the tape hole before and through the aluminum after.

That’s all, folks. You just need to control the tape is perfectly stuck and the slide perfectly mounted in the center. Easier said than done. I mounted tenth diaphragms for now, and no one was wrong, therefore the procedure I explained shouldn’t be so hard.

At this point you can paint the inside of the diaphragms with a black felt-tip if you want, but I strongly suggest to do this only in case of real need, since you could damage the hole. Reflection problems could bear only with lots of sun and with backlight pictures; the majority of the pictures and cloudy days don’t require painted holes.

The dimensions of the support slide depend on the thickness of the material on which the rest of the box was made of. The more it is thick the bigger the support slide must be, to move away widths that could project shadows, limiting the effective dimension of the image recorded on sensitive supports. To the limit, one wall of the box can be built with the aluminum of a tin can. If you’re using a tin box, the metal is thin enough to allow 2mm-holes directly in the cover of the box.

Microscope diaphragms as perfects pinholes

Fabiano Busdraghi — Fri, 30 Nov 2007 17:55:57 +0000

The diaphragm of an electronic microscope is a perfectly circular pinhole with a precise diameter. Picture under microscope of a 0,8 mm hole.

Best quality pinhole I could find was the diaphragm of electronic microscope.

The apertures are perfectly circular, as you can notice from the microscope pictures attached with the article. The apertures are even more precise than the ones obtained with the laser. This is because, except you’re one of the few person that switched on a rapid impulses laser, in the exact moment a laser beam digs the hole in the metallic slide, it creates local micro-explosions due to the thermal diffusion. The result is that the hole is partially fringed. In the case of electronic microscope diaphragms, the hole is perfectly clean and circular.

Attempt with 0.3mm pinhole, 60mm focal length, image size 12cm x 15cm. The image is clearer than the ones shot with those kind of aperture obtained with perforation.

Holes have a perfectly known diameter. I bought 150µm, 300µm, 400µm, 600µm and 800µm. Therefore, there’s no waste of time in measuring the hole with the negative method, and the incertitude it bring within. This way, you can build multi-holes pinhole cameras, being sure that the exposition will be the same for each hole. It was a huge problem in the past, when the holes were handcrafted. The diameters I chose allow the construction of pinhole cameras with focal length between 15mm (f/100) and 45 cm (f/556), following the classical tables of optimal pinholes diameters. Higher focal lengths can be achieved using diameters larger than 0,8 mm. It is easy to make round and clean holes such as the ones of the electronic microscopes diaphragms using a simple precise perforator.

Detail of the attempt reported on top. The area is not larger than a couple of centimeters per side. The noise is due to the scanner. I unfortunately own only an old scanner that does not allow decent enlargement.

The thickness of the laminate is very thin, limiting the tunnel reflections inside the hole on a thick slide. Although this could be useful, it could be necessary to blacken the inside of the hole. A suggestion, that I didn’t tried, is using a bath of selenium toner. Passing delicately a felt-tip all around the hole, a thin one, similar to those used to write on CD’s, is another solution. This is my method and the results are more than satisfying. In any case, the holes I used are probably the less affected from reflection. Before blacken the hole, I suggest some shots of attempt, not to damage the hole. If you do not need to eliminate eventual reflections, the microscope diaphragm can be used as they are.

The hole of the microscope diaphragm is at the center of a circular 3mm thick slide in copper. The most simple way to use it is mounting it on a support slide. It is fragile and precise material therefore you must be careful. Once you mounted the material on a support slide, it becomes practical and resistant.

I had to buy lots of holes, so I sell some. The price is 10 euros per hole and 1 euro for an ordinary sending in Italy. There’s the possibility of a discount for the purchase of many holes, anyway the sending price is fixed in 1 euro.

pinholes from microscope diaphragms

The following galleries shows some pictures took from the microscope of the pinholes this article talks about, obtained using electronic microscope diaphragms.

[See image gallery at www.co-mag.net]

Just take a look to the holes; they’re perfectly circular and their borders are absolutely clean or faultless.

Thanks to Adrien Arles who realized those pictures of the pinholes with the microscope.

pinholes realized with a laser

The following gallery shows picture of pinholes obtained through laser perforation.

[See image gallery at www.co-mag.net]

It is possible only an indicative confrontation with the microscope diaphragms, as it should be necessary to take pictures using the same focal length and the same hole diameter of both for the system. Although those details, it is clear that the laser holes are less rounded and uniform compared to the electronic microscope diaphragms. Most of all, the laser holes has a lot of faults on the borders, and this could cause diffraction problems.

Thanks to Ruscello Claudio who realized the laser holes and the images here attached.

Conclusions

The microscope diaphragms described in this article seem to be the most precise obtainable pinhole. Compared to the renowned laser holes, diaphragms are more rounded and precise; they do not have any irregular or smeared border that could cause diffraction problems, decreasing the quality of the image. The diaphragms also have a known and constant diameter, and this simplifies the realization of multi-pinholes cameras.