27

From Wikipedia's Pinhole camera article, The best pinhole is perfectly round (since irregularities cause higher-order diffraction effects), and in an extremely thin piece of material. Industrially produced pinholes benefit from laser etching, but a hobbyist can still produce pinholes of sufficiently high quality for photographic work. There is a ...


19

This is exactly what one expects from a pinhole lens. Normal lenses A normal lens has a big opening and bends all the light rays coming from a point-like object to cross in a point behind the lens. By moving the lens fore and back, one can determine the position of the point behind the lens, and when it's exactly on the sensor, it might hit a single pixel ...


19

You have vignetting. It's probably not from the pinhole failing to cover the film; more likely the pinhole is in too narrow a hole in the front panel material, and that material is blocking light from the pinhole reaching the film (or light from the scene reaching the pinhole). I base this in part on the shape of the vignette -- if it were an exposure ...


16

Even though this has been answered, I wanted to visualize this interesting problem. If we assume light travels in straight lines, then the wall thickness and hole diameter both matter. In these diagrams, the blue lines are the light rays travelling through. The yellow lines are also light rays, but they are not perfectly crossed at the center, so they add ...


15

Replace the back wall of the camera with a sheet of tracing paper, ground glass (or similar translucent material) and observe the resolved image from behind the camera. You may need a dark sheet over your head (and the rear of the camera) to allow the dim image to be visible. This should remind you of how very old cameras were operated (for exactly the ...


12

You definitely have to change the design of the camera. This HowStuffWorks page explains how instant film develops well enough. Essentially, the film cassette contains rollers that roll out the developer to begin developing your film. Until this happens, the film is still light sensitive. This is why the cassette begins with a plastic, light blocking layer ...


11

I can't summarize the whole optical physics theory behind pinhole (mostly because I don't have the proper knowledge!), but I try to explain why there are different values for constant C. One reason that there are different values for C is the fact that one parameter in the calculation of optimum diameter of hole is missing! Let us refer to the wikipedia ...


11

Regardless of the distance from the hole to the film, your camera has a maximum field of view of ~8 degrees. This is because no light ray that is off-axis by more than ~4 degrees can make it through a hole that is 3.5 mm long (thickness of the wood) and 0.24 mm in diameter. For light from larger angles, the wood shadows the back of the hole.


10

Your results are GREAT. You show exactly what one should expect using a "pinhole" lens. The reason your results are different from your Google search is because the image that you found wasn't produced by a typical pinhole lens in a single typical session without some manipulation in printing. You chose a photo from a series of creative pinhole photography "...


9

The pin-hole casts (projects) tiny image circles on the back wall of the camera. This is also the place we position photo sensitive material so that we can replica this image on film or paper or perhaps even digitize it. For the image to appear sharp, the image circles need to be so tiny that they appear as points without perceivable shape. The criteria: ½ ...


8

Make a simple, non-photographic pin-hole camera. Start with a cardboard tube. The round Quaker Oats breakfast box is perfect for this job. You can use any cardboard mailing tube. Cut off both ends, now you have a just the tube. Cover one end with a single sheet of tracing paper. In my day, we called this paper “onion skin”. Cover the other end with aluminum ...


7

If you are willing to do it the hard way, you can use standard black-and-white photographic printing paper and do a reversal processing on it. What that means is that you will be making a negative, but then making a direct positive from the negative without an additional imaging exposure (though there will be an additional exposure to light). It will ...


6

Depth of field for a pinhole camera is theoretically infinite. There is a formula to determine optimum pinhole size for any given focal length, the distance between pinhole and film. In practice we choose a hole size small enough to give good sharpness, big enough (and accurately round enough) not to produce diffraction effects.


6

Yes, that means that everything is in focus (which implies that the sensor doesn't even need to be a plane).


5

When we view a photograph made by a pin-hole camera, we are viewing an image comprised of countless circles. These are projected on film by the pin-hole. Their size is a function of the diameter of the pin-hole. The circles are called “circles of confusion” because they juxtapose each other; thus their boundaries are indistinct. It is the size of these ...


5

The earliest investigation of the right constant c that I am aware of is Petzval's 1859 On the camera obscura. The paper is predominantly about a new lens design he has created but he begins with an investigation of the optimum radius of a pinhole for resolution of the image. Resolution is defined as the ability to discern the difference of two very close ...


5

Absolutely, I've done this. The image does get dimmer though so you'll need to adjust your exposure accordingly. I've only toyed with it since much of my interest is in wide, not tele photography.


5

You can calculate an approximation of the size of the actual diffraction spot (or Airy disk) as a function of your pinhole f-number and wavelength of light: D = 2 x 1.22 x lambda x F/# Across the visible spectrum (from blue at about 400nm to red at about 600nm), you get: For the Obscura at f/290: D(blue) ~ 0.28mm to D(red) ~ 0.42mm For the Titan at f/206: ...


5

While some care is needed to avoid accidental light leaks, light-proofing a container enough to safely store film or paper is not a colossal effort. Something as simple as duct tape over a few suitably sized paper envelopes is easily more practical than lugging a Paterson tank. Black construction paper can make envelopes, or use a maker to darken a ...


4

You need a very thin wall for the pinhole, I'm not sure that it has to be smaller. The mechanism of a pin hole camera is very simple. It simply blocks light from anything other than a single point and the rays from that point get projected to the opposite side of the enclosure. If the walls of the pinhole are thick, then the light can't come from an ...


4

Yes, you can. But keep in mind that the optimal performance of a given pinhole is related to focal length used. More on the theme can be found here: How to calculate the optimal pinhole size?. Using a macro tube extender will give you suboptimal results - the longer focal length of the "camera" would ask for a bigger pinhole than your bodycap. On second ...


4

Can I combine this with a macro extension tube to adjust the focal length? Yes, you can. You can make some extension tubes with cardboard too to make some preliminary tests. P.D. Just make sure you are buying the correct extension tubes. I am assuming you have a Nikon camera, as the link you provided is for Nikon.


4

Images you see done with pinhole online may be sharper for several reasons. Size of the original... 4x5" film Quality of the pinhole.... laser cut vs drilled vs pin pushed through foil flare from light source color vs b&w, monochromatic with filtration will be sharper Otherwise you are on track. You should buy a book on pinhole photography, to ...


3

How did you look through the pinhole? If you put it far from your eye you have seen nothing. It is small hole and you have seen one "overexposed" point behind dark card. If you put the card as close to the eye as possible think of it as another lens in your eye. And the image was already inverted - it was projected on your retina and your brain ...


3

If you remove the paper from the developer after 20 seconds, the clouding could be caused by uneven development. Look at the recommended development time for the paper and the developer and adjust exposure accordingly.


3

For a really insensitive paper, try blueprint paper photography or diazo paper photography. These sheets are comparatively inexpensive and are available in large sizes. You can even make blueprint paper yourself. See this on the blueprint process. And do post your images!


3

Yes there are "super" macro lenses available. A macro lens usually provides up to 1x magnification, i.e. it can focus close enough to project an image onto the sensor that is life size. Super macro lenses go beyond 1x. The most widely available off the shelf super-marco is the Canon MP-E 65mm which offers up to 5x magnification. Using this lens on an APS-...


3

The thing that changes with pinhole camera size is the best pinhole diameter to use. The optimal pinhole diameter is such that your pinhole-to-paper distance is the "Fresnel length" (please google for definition) of the pinhole at some representative wavelength of your filter bandpass. If you don't use a filter then you can guesstimate the sensitivity of ...


3

This will work for a pinhole camera, within limitations, but zone plates actually have a certain focal length, so it won't there. (Of course, zone plates tend to have a very large depth of field, and aren't particularly sharp anyway, so in the real world you may have some latitude.) For a pinhole camera, there is an ideal pinhole size (for every wavelength ...


3

The pinhole needs to be small in order to produce a sharp image, but not so small that diffraction becomes a problem. How it works - Size of the Pinhole talks about the size of the pinhole, the diffraction limit, and provides some sample images that illustrate the point.


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