woensdag 13 augustus 2014

SLR - prototype update


I have build a rotating shutter and a contraption to lift mirror into my life size wooden model camera. On the image above you can see the lens that will be mounted on its front: a lens from my Durst enlarger with an aperture of f 5,6 and a focal length of 210 mm. I put off my previews plans of making the camera usable for architecture photography as the length of the uncut mirror tile together with the back of the camera were too long to allow a short wide angle lens.


I brought the whole construction of the shutter mechanism back to its simplicity of my first cardboard model. The handle to fire the shutter I made on the right side of the camera. A pistol grip as I announced in a previews post I will make in another model. For now it is more important to concentrate on the synchronization between the mirror movement and the shutter rotation.

video

In the video above you hear a clicking sound at the end, which was made by a green pushpin that fell off from the mirror lifting mechanism. In the second video you can see how the mirror get lifted and how the shutter opens for around 1/30 of second.

video

The camera didn't got any cosmetic improvements yet. In a later state I will cover the rotating shutter with a front door that holds the lens and the ground glass will get a hood with magnifier. I am almost sure that I can post the first photo made with this camera within this month!


all images © Norman Beierle

zondag 10 augustus 2014

a lucky day


Last month I found a strip of negatives while walking the dogs. Although sandwiched between shoe soles and concrete tiles, that left heavy marks on it, the subject-matter was still strong and clear. The five photos, made with a pocket camera on 110 film, shows a special bandage in different states. 


Somehow it doesn't look like that the person with the bandage is injured. All the images together gives the impression that we look at a demonstration of this special bandage rather than a follow up of some terrible accident. 


This gives me a better feeling about posting these images and the luck of finding the negatives in time, before a heavy rain was coming in the evening that probably would have destroyed the vulnerable and already scratched gelatin layer. 


Another miracle is that these images must be at least twenty, more possibly thirty years old, as pocket film had the high days in the early 80s. I haven't seen any trace of more film material nearby, so this must have been the only strip of images that was meant to me ;-)


woensdag 6 augustus 2014

SLR - next step: the mechanism

new components for the SLR
This week I made (and collected) some new parts for the SLR camera: a wooden box that will hold the back I made earlier, a mirror tile and an improvised lens board with an old ICA lens, which I bought once on a photographica fair. The lens is far from crispy or sharp, but it has a focussing mechanism and a working iris aperture.

the inner life of the camera
In the last week I also made some new sketches on how the mechanism of the camera should work. I decided to place the lens in an already upwards shifted position on the lens board for landscape and architecture photography. I also have chosen to make this a (relatively) fast action camera with an kind of pistol grip on the bottom. This means that the camera could be used handheld with an shutter speed of 1/50 second. Perfect for bright weather conditions.

working of the mechanism
You might wonder why the mechanism for lifting the mirror is that complicated. I wanted to make the rotating shutter in the front (not seen on this post) less prone to vibration, as my original idea was a separate, spring loaded mechanism to close the shutter. I got the idea to close the shutter by rotating the front disk just a little further. The new inner mechanism should do this in an accurate way.

all images © Norman Beierle



vrijdag 1 augustus 2014

SLR - life size prototype

components of my new back for "modern" sheet film holders

Time has come to construct a first model in life size. One of the things I don't make myself are the holders for the 4x5 inch sheet films. As this part, with its specific measurement is a given fact I have to deal with, I decided to start the 1:1 version with it's back, which I made for usage in horizontal and vertical position. 

almost ready for use

This was not the first back I constructed and I already knew some of the issues that will need special attention, like: the film holder has to go in and out easily and in the same time it has to get enough pressure to hold it firmly against the opening where the image will appear. And it don't have to move while handling the camera or pulling out the dark-slide etc. In a former project I bent for instance an old spring of an alarm clock to give the right tension.

it fits like a custom made jacket: easy and smooth

My new design is even more practical, minimalistic and easy to use. Two rubber bands are strong enough to secure the holder on its position, pulling the holder in and out goes smoothly and of course without damaging the holder. At the end I will give the inside a lick of black paint.

a simple but effective design
My next step is to construct something like a box, where the back can connect to. This will be continued soon.

all images © Norman Beierle


donderdag 24 juli 2014

SLR follow up

video

This and last week I worked on the improvement of the shutter mechanism. I made several sketches with sophisticated solutions, but most of them where quite time consuming to make and allow only precision parts for a supple movement. The best way to keep this operation simple - in terms of a minimalistic, but functional design - was to make a model with a single rotating disk. 

shutter mechanism - before and after pulling the trigger
I have chosen for an oversized wooden model, which could easily placed in front of a future 8x10 inch or ultra large format (ULF) SLR. Another advantage of enlarging the shutter was that I could adjust all parts quickly and tight with just some screws. The tension of the (closing mechanism of the) shutter is regulated with an elastic band.

maandag 14 juli 2014

second project - a twin lens reflex camera

cardboard sketch of the TLR camera

Simultaneous with the start of my Single Lens Reflex camera project, I began to develop a foldable Twin Lens Reflex camera, also for large format photography. My aim is to use this camera for architecture photography, therefore it has at least to shift a wide angle lens. The other requirements were that the camera should fold up to a reasonable small package and is that it would be usable for (relatively) quick handheld photography.

folding TLR open - and with lens board

The construction of the body is light and simple and will be made from wooden multiplex plate material. By the way, the mirror is not yet attached to the body. One of the more delicate works is the design of the wide angle bellows, which have to move in different directions without blocking parts of the image area and without conflicting with the second bellows.

two different bellows designs during tests

For a quick test I made two different bag bellows. One of the bellows was an extended version of a normal wide angle bellows. The second one was a doubled bag bellows, which required some extra stabilizers. 

a more or less 'classic' bag bellows

The classic version wasn't successful enough, as the single bag stretches too much, which deforms the side and pushes cloth to the inside. The double bag bellows worked a lot better. I knew on forehand that this design will need some inner construction that it will not sag down in the middle and it will need some tension to pull each bag to its board.

double bag bellows with elastic rubber bands

The next step is a wooden model with two double bellows to have a better idea of its efficiency.

all images © Norman Beierle

zondag 13 juli 2014

Large format SLR camera

cardboard model of a simple SLR camera - front view

It is still more a rudimentary sketch rather than an advanced camera to steal the show, but its simplicity is promising for me. I found a simple mechanism to cover the lens while the mirror is moving up and release the shutter immediately afterwards. For the precise position and movement of the rotating shutter I have to develop some more tests and prototypes and I also will have a closer look for the optical devices and the focussing mechanism.

cardboard model of a simple SLR camera - back view

In the end I want to make a (very) limited series of cameras in wood for 4x5" holders and maybe some larger formats on special request. In the next couple of weeks you will see (hopefully) the expected progress in usability and another camera models, I am developing right now. Together with Alex I made a short video to attract future investors for this project.

video

all images © Norman Beierle