Camera Obscura - take pictures with a pinhole camera? Also works with an SLR or system camera. I'll show you how this fascinating retro thing works.
I can remember the experiment so well when we, as leaders in a summer camp, built a camera obscura (pinhole camera) out of an Ovaltine can and used it to take photos in the camp. At that time we developed the picture in an improvised darkroom and converted the negative to positive with a desk lamp.
The camera obscura is the most rudimentary version of a camera: It doesn't even have a lens, just a tiny hole that bundles the light rays and can direct them onto the sensor. Extremely little light falls through the tiny opening, which means long exposure times . The tiny aperture means that the depth of field is practically infinite. In return, however, the diffraction effect reduces the image sharpness. A pinhole camera has no typical lens defects such as color fringing or distortion .
You can experience this retro feeling yourself with simple tools. I'll show you how to do it.
Material for the pinhole camera
You can order a ready-made PinCap aperture for your lens connection. The hole is drilled in stainless steel to a size of 0.2 to 0.28 mm. The PinCap costs around 20 US dollars.
If you want to build this yourself, you will need the following materials:
- System or reflex camera, analog or digital
- Camera cover
- small piece of aluminum foil or the side part of an aluminum beverage can
- Drill or awl
- Pin / nail
- waterproof, black felt pen
Instructions for the pinhole
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| PinCap aperture on a Nikon D7000 SLR camera |
Measure the center of the camera cover.
-Use a 4-5mm drill to drill a hole at this point on the camera cover. Alternatively, you can melt the hole with an awl tip heated over a candle flame.
-Clean the drilled or welded hole with a cutter and sandpaper. Make sure that no more crumbs stick to the edge. These could get on the image sensor!
-Glue a small piece of aluminum foil, which you have colored on the inside with a black, waterproof felt pen, onto the lid.
-The version with an aluminum piece from the side of a beverage can is somewhat more stable.
-Turn the lid over and place the area of the opening on one end of an eraser.
-Only poke a tiny hole in the aluminum foil with the foremost part of the point of a pin.
Your first pinhole is ready!
Handling the pinhole
-Always keep the self-made perforated panel or the PinCap in a protective cover. This keeps the perforated panel clean and the fragile aluminum foil hole intact.
-Note that your camera has a tiny opening, but through which dirt particles can get into the camera and thus to the image sensor!
-I always replace the aperture with a real camera cover during transport.
-Since you will hardly see a viewfinder image through the small aperture , you only have to work with the live view or - as in the past with the pinhole camera - the trained eye to determine the image section. Pure retro feeling!
Taking pictures with the camera obscura
If you take photos during the day - and that is a big challenge with the camera obscura - you need longer exposure times with low ISO settings and for this reason a tripod . Not for everyone, when the sun is shining with the tripod through the city. You are sure of curious looks.
The extremely small aperture ensures that you don't have to worry about focusing at all. The depth of field moves from a few centimeters to infinity. Due to the extremely strong diffraction effect , the images are never really sharp - just completely retro!
The pinhole aperture has a focal length of approx. 46 mm on a 35mm camera, due to the crop factor that makes up about 70 mm on a half-format camera like the Nikon D5300 or D7000 and a Canon about 75 mm KB equivalent.
When you buy a PinCap aperture, an exposure table with approximate guide values is included. If you have a self-made pinhole, make a note of the exposure values during the first attempts (but they are also available in the EXif file of the digital images) and create your own table for your camera obscura . The automatic exposure metering works without any problems on my cameras.
Technology and camera settings
-If you screw the pinhole cover onto your camera housing, you have to do without the cover function. With the pinhole pincap you have a fixed aperture with a value of f / 180 to f / 200. Calculation: focal length divided by the diameter of the aperture = 46 mm / 0.24 mm = f / 191.
-If possible, take pictures in RAW format . Especially with regard to further processing with Silver Efex Pro 2 (follows below) you have certain quality reserves.
-Use a tripod for the best image quality . In sunlight you need a shutter speed of 1-2s with ISO 100, and around 2 to 8s with cloudy skies, depending on the subject.
-Set the program wheel of your SLR camera to M (manual) or to aperture priority A / Av .
-The aperture priority only works up to the longest possible shutter speed, usually 30s. In my experience, that's always enough for daytime photography. I then set the ISO automatic to a range of ISO 100-6400 and the longest exposure time 10 seconds. If there is too little light for a 10-second exposure time, the camera increases the ISO value to ISO 200 or ISO 400. Maximum up to the specified maximum limit.
-Set the mirror lock-up on an SLR camera .
In the city I work with the self-timer instead of the wired one , which I set to a 2s delay.
-If you exceed the exposure time of 30s, you have to set the camera to bulb and use a cable or remote release .
-With the camera obscura you could only take tripod photos. With the high ISO settings possible with digital cameras , you can also take photos by hand: ISO 12800 results in a shutter speed of 1 / 30s on my Nikon D5300 and the PinCup . That is barely possible from the steady hand. The high image noise supports the retro effect of the pinhole camera recordings.
Camera obscura and Silver Efex Pro
Pictures that you take with the pinhole camera are very suitable for giving them the look of analog photography. Silver Efex Pro by DxO is also the perfect program to breathe the similiar life into your treasures that pictures taken with the camera obscura deserve. A brief introduction to Silver Efex Pro will help you.
More photo tips for taking pictures with the camera obscura
-Choose subjects that have high contrast. This compensates for the lack of sharpness of detail in the images.
-Motifs with signal colors look very good with the camera obscura.
-In an image editing program like Lightroom, apply a soft sepia effect to your pictures. This makes them look like they were made in the early days of photography - or even simpler: let your pictures appear in the old look with Silver Efex Pro 2 or Analog Efex Pro 2.
-Due to the extremely small aperture of approx. F / 200, the pinhole is perfect for making sensor spots visible . Ruthless! Use a tripod to photograph a light background. - And sit down before you look at the result on the PC ...
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