Inadvertent telephoto pinhole lens.

[Grandpa Ron]

After viewing several pin hole photos that other were kind enough to post, it seems that an aperture of f 250 or smaller was needed to get a fairly sharp picture. Since I had made a .5mm pinhole, I made a black tube based on Rayleigh's figures to hold the pinhole 120mm above the 35 mm film plane. This gave me a aperture of f 240, hopefully that would give me a sharper image.

What I did not consider was, by moving the pinhole 120 mm from the film plane I had created a telephoto lens. It was not until I developed the film that I finally realize the telephoto effect. You can see this in the three photos I have attached. The first is a bridge with camera's normal 50mm lens, the second is the bridge using the 120 mm tube, f 240 tube and the third is the same photo enhanced to compensate for the exposure.

Besides the obvious exposer problems and the annoying bright spot in the middle; the end result is I have not achieved the level of sharpness I was seeking. Part of the lack of sharpness may be due to the telephoto effect with the 35 mm format.

So, I have managed, after several attempts to make a .356 mm pinhole which I fit to a tube for a 77mm pinhole to film distance or an aperture of f 216. Another roll of film awaits.

 

[scheimfluger_77]

That bright spot in the middle looks like “lens” flair. Was sunlight falling on the pinhole? And for what its worth, the glories of pinhole don’t have to be sharp. LoFidelity is the name of the game.

 

[MattKing]

Warning - a little pedantry follows.
"Telephoto" actually means a lens whose focal length is longer than its physical length,
So what you put together wasn't actually a telephoto pinhole, but rather a pinhole camera whose "sensor" (the film) covers only a narrow portion of the pinhole's "angle of view".
Pedantry warning now cancelled.
There are a couple of other problems that may arise from putting a pinhole at what is essentially the end of a long tube, but the biggest problem is probably the potential for unwanted reflections and flare.

 

[ic-racer]

Pinhole can't be telephoto.

 

[Theo Sulphate]

How are you making the actual pinhole and what material is the pinhole in?

Despite the material seeming to be extremely thin, it still has a thickness and, as the hole is made, rough edges around that hole may degrade sharpness. Even though "sharpness" isn't a quality people expect or seek in pinhole photography, I think there is a minimal level of sharpness which needs to exist in order to be pleased with the results.

My ZeroImage 6x6 has always been soft, but still produces good photos.

 

[DWThomas]

There is an earlier thread where several of us have made some suggestions for Grandpa Ron. I think armed with the collected info and some experimentation he will zero in on it. I have noted in perusing the annual WPPD galleries that use of pinhole plates on 35mm and APS-C digi-cams generally turns up lackluster results in regard to sharpness.

I've not gone smaller than medium format with pinhole (in this century), but actually bought an extra body cap a few years back for my Canon crop-frame bit zapper with intent of exploring whether the problem is inherent in smaller formats (I think maybe it is, but haven't tried to wade through the math) or perhaps it's just the difficulty of the precision needed for the proportionally smaller dimensions involved with smaller formats. So far several years have gone by and I keep shooting my 8x10 and have nothing but the unadulterated EOS body cap. I guess something is sending me a message there!

"Maybe next pinhole day ..."

 

[Grandpa Ron]

Yes, I will be the the 1st to admit that was warned about the use of the use of the 35 mm format but as you can see I am still playing with exposure vs light meter readings.

Without getting into the details or semantics of the situation, what I did not realize was the 35 mm subtends only a small portion of the light field projected by the pin hole. My very first pinhole photos were shot with a cheap kid's kit and a wild guess at exposure and an f 65 aperture. I have attached two of the better photos. After looking at the results I decided to decrease the aperture by increasing the focal length. This is where I shot my self in the foot, because any gain in sharpness due to the decreased aperture was lost to the fact that image and it's lack of sharpness. was spread out over a larger area, only a portion of which was captured by the 35 mm format. For the technically minded the focal length of the kids cameras used in the attached photos was 1.75 " with a .027" pinhole punched through a piece of aluminum foil.

So why the long explanation? I am hoping this helps some other newbie learn from my errors.

Learning never stops.

 

[scheimfluger_77]

GR I think this looks great. Remember fuzziness is part of the deal with pinhole. It is the rare combination that delivers an actually sharp image.

 

[DWThomas]

Yes, those are quite nice -- like impressionist paintings.

At the moment I can't find it, but years back I posted a link to a Worldwide Pinhole Photography Day submission that described the camera used as a "Saltine 13" or some such thing. It used the perforations in one of those salty crackers, taped over a camera body, to form a multi-pinhole image! Apparently (learn something every day ...) the standard saltine has 13 holes punched in it. There were virtually no recognizable details in the shot, but I had to be impressed with the 'thinking outside the box' aspect of it.

EDIT: I found the Saltine 13

 

[LJClark]

At the moment I can't find it, but years back I posted a link to a Worldwide Pinhole Photography Day submission that described the camera used as a "Saltine 13" or some such thing. It used the perforations in one of those salty crackers, taped over a camera body, to form a multi-pinhole image! Apparently (learn something every day ...) the standard saltine has 13 holes punched in it. There were virtually no recognizable details in the shot, but I had to be impressed with the 'thinking outside the box' aspect of it.

Thinking outside the cracker box. Yer killin' me!

 

[LJClark]

Yes, I will be the the 1st to admit that was warned about the use of the use of the 35 mm format but as you can see I am still playing with exposure vs light meter readings.

Without getting into the details or semantics of the situation, what I did not realize was the 35 mm subtends only a small portion of the light field projected by the pin hole. My very first pinhole photos were shot with a cheap kid's kit and a wild guess at exposure and an f 65 aperture. I have attached two of the better photos. After looking at the results I decided to decrease the aperture by increasing the focal length. This is where I shot my self in the foot, because any gain in sharpness due to the decreased aperture was lost to the fact that image and it's lack of sharpness. was spread out over a larger area, only a portion of which was captured by the 35 mm format. For the technically minded the focal length of the kids cameras used in the attached photos was 1.75 " with a .027" pinhole punched through a piece of aluminum foil.

So why the long explanation? I am hoping this helps some other newbie learn from my errors.

Learning never stops.

You are dealing with several independent variables. One thing you might consider, just for the research value, is purchasing some pre-drilled pinholes. Even if you want to pursue making your own down the road, you would know what a controlled reference produced. James Guerin, who makes RealitySoSubtle cameras, also sells mounted laser drilled pinholes in several sizes (0.1mm , 0.15mm , 0.2mm , 0.3mm , 0.4mm , 0.5mm, and 1mm). In your testing, you wouldn't be able to blame the pinhole. And once you find a satisfactory aperture, you can still set yourself up with the challenge to make your own pinholes -- and see how close you can get to what a laser-drilled pinhole produces.

Aperture does matter. I had a ZeroImage 612. I wasn't satisfied with the results, and since I decided to concentrate on 6x9 instead of 6x12, I bought a ZeroImage 69 -- which has a smaller aperture. I prefer the results with the 69, and sold the 612.