"Sharpist" Pinhole Image

[wildbillbugman]

Hello to all,
I have not stuck my head into this Forum for a long time. My question is: For as close as is possible to a "Perfectly"round hole, I have read that acid etched holes are superior to laser holes. I am also in possesion of some holes that were micro-filed under magnification and are claimed to be superior to laser drilled holes. My goal here may be in conflict with some people's Philosophy. But I want to get the sharpest image that I can, using no lense.. I found a company website that claims superior holes via acid etching. The cost is high, but not discouragingly so.
Bill

 

[cliveh]

An interesting question and I wonder if a scene illuminated by laser light would produce a sharper image in a pinhole camera than one illuminated by diffuse light?

 

[DWThomas]

I can believe it could be possible that etched is best. At the microscopic level etching tends to leave a conical hole where I suspect a laser might create a more cylindrical one. But I admit to not knowing much about the state of the art in either technology. Decades back I did some etching of printed circuit boards using photo resist and ferric chloride. There is a tendency for the substrate to etch back under the edge of the resist, but it's a time function so the walls/edges become sloped, thus for a hole it might appear like a knife edge (albeit maybe a dull one!) which is desirable.

But personally, I try not to obsess quite that much!

 

[SMBooth]

Think you need to buy and test. The best way to get the cleanest image from pinhole is bigger formats. Really don't think you will get a visual difference between laser or acid etched.

 

[gzinsel]

it also might advantageous to think more in contrast than sharp. greater contrast "seems" sharper than a lens that is sharp yet not good contrast. Also I agree, the larger the neg. the better the print. I suggest 16x20 or 20x24 full neg with contact on slow chloride paper. you can still get an order in for ilford for ultra large format sheet sizes S.O. go for it!!!!!!!!!!!!!

 

[jeffreyg]

I profess no knowledge about making the pinhole (I bought an Ilford Titan) but would think that the quality of the hole would be dependent on the materials used and the skill of the technician. With a lens you are generally focusing on a particular spot that would be the most critical point of focus and the depth of field would depend on the length of the lens and f stop. I suppose you could figure out that spot for a pinhole but I don't think most people approach pinhole photography that way.

http://www.jeffreyglasser.com/

 

[bvy]

I think it's diminishing returns after a certain point. I did this with pie tin, a sewing needle from my mother-in-law, and clear coat sandpaper. It's 5x7 paper in an oatmeal box.

 

[Mainecoonmaniac]

I can't believe it's a pinhole

I think it's diminishing returns after a certain point. I did this with pie tin, a sewing needle from my mother-in-law, and clear coat sandpaper. It's 5x7 paper in an oatmeal box.

And you made the lens and camera? Wow. Great job. So how did you calculate the aperture?

 

[Jim Jones]

Jeffrey is right in suspecting that there is an ideal focal length for each pinhole diameter. This chart shows the effect of pinhole diameter on resolution, both on-axis and up to 60 degrees off-axis. If on-axis resolution is most important, a user constant of maybe 1.5 in PinholeDesigner might give near optimum pinhole diameter. A slightly larger pinhole favors off-axis sharpness. Deviating by 10% from the optimum diameter causes a measureable loss in resolution. For photographers who prefer making photographs over measuring resolution, a pinhole that is larger or smaller than the calculated optimum diameter may provide the most pleasing photographs. Sharpness is academic: photography should be art.

 

[RalphLambrecht]

lighting has a strong impact on apparent sharpness, whatever that may be, but flat frontal lightingis not as sharp asharsh side lighting.

 

[RalphLambrecht]

a couple of things before you go ottwith pin hole sharpness:
1. the 'beauty of pinhole images lies inthe fact that they are not perfectly sharp, don't ruin that.
2.there are two different 'optimal pinhole diameters; one one for maxresolution and one for max contrast(sharpness)
good luck.

 

[wildbillbugman]

Thanks everyone,
I see some etched pinholes in my near future! But I will compare to laser and EXPERTLY filed holes.
Why,some may ask, do I wanna make sharp looking pinholes. At this time I make everything that is used producing my final image, EXCEPT the lense. I make all my emulsions and everything else that goes into, or is used producing, my final piece of work, EXCEPT the lens. Call me a narcisistc egomaniac if you so choose. But my goal is to make Everything that goes into my final images. I don't think that I could ever produce quality lenses. Since my final images are Pt/Pd/Au/Pigment based color separation work, I usualy strive for only one image per year. That is working everyday.:alien: High production ain't my bag.

 

[bvy]

And you made the lens and camera? Wow. Great job. So how did you calculate the aperture?

Thanks. I think I scanned it at high res and did some mesaurements and calculations. ~f/226 is what I came up with.

I've got to go back to a point Ralph just made. Maybe I got lucky crafting such a sharp pinhole -- I did a lot of research at the time and was pretty meticulous. But I remember being initially disappointed with the super sharp images I was getting. In some cases (like what I posted) it worked well, but I was after something softer and not so perfect, like many of the great pinhole images I had seen in books and online.

 

[NedL]

Thanks everyone,
I see some etched pinholes in my near future! But I will compare to laser and EXPERTLY filed holes.
Why,some may ask, do I wanna make sharp looking pinholes. At this time I make everything that is used producing my final image, EXCEPT the lense. I make all my emulsions and everything else that goes into, or is used producing, my final piece of work, EXCEPT the lens. Call me a narcisistc egomaniac if you so choose. But my goal is to make Everything that goes into my final images. I don't think that I could ever produce quality lenses. Since my final images are Pt/Pd/Au/Pigment based color separation work, I usualy strive for only one image per year. That is working everyday.:alien: High production ain't my bag.

Given all of this, you could try making some pinholes. You have more than enough patience. A needle, some emery paper and patience is all that it takes.

 

[TheToadMen]

Hello to all,
I have not stuck my head into this Forum for a long time. My question is: For as close as is possible to a "Perfectly"round hole, I have read that acid etched holes are superior to laser holes. I am also in possesion of some holes that were micro-filed under magnification and are claimed to be superior to laser drilled holes. My goal here may be in conflict with some people's Philosophy. But I want to get the sharpest image that I can, using no lense.. I found a company website that claims superior holes via acid etching. The cost is high, but not discouragingly so.
Bill

Hi Bill,
I was wondering what kind of camera you use and what your focal length is? I recently got me some "perfect pinholes" normally used for elektron microscopes. If I have the right size for you, I'm willing to mail you one so you can experiment with it before buying an "expensive" pinhole? In return you can send me a nice print made with the pinhole.
Send me a PM with your address if interested.

"Have fun and catch that light beam!"
Bert from Holland
my blog: http://thetoadmen.blogspot.nl
Linkedin pinhole group: http://tinyurl.com/pinholegroup

 

[wildbillbugman]

Hi Toadmen,
I have sent to you a private message with all info. I am getting a bit excited about this. I hope that you are not repulsed by insects. Macro "Portraits" of bugs, magnified to the extream , is my specialty.

 

[NedL]

I think if you are planning to use this for macro, the calculations for your optimal pinhole might be different. I seem to remember reading that the pinhole can be smaller for macro work. Haven't tried it myself but I think there are people here who will know. You might want to check this before deciding on a size.

Edit: (there was a url link here which no longer exists) has a link.

 

[Mark Fisher]

If you are going acid etched (or laser) you can probably get a bunch of them made for nearly the price of one if you are going to an etching or laser cutting place.

 

[RalphLambrecht]

a pin hole can easily produce 7 lp/mm,and consequently is as 'sharp' as it gets or needs to be. your eyes cannot resolve more than that anyway, but i agree with the comment about contrast vsresolution'sharpness is more about contrast than resolution!

 

[Mike Walker]

Hi Wild Bill
Mike Walker here I make the Harman Titan pinhole cameras, acid etched holes are superior to laser holes, and if done the right way they very very round, I am going to upset some here, put round does not matter that much, it is more the sharpness of the inside edge of the hole.
I can back this up, as Schneider once had a play with this, and by taking 3 scalpel blades interlocking they and blacking with candle smoke made what they said, was as sharp a pinhole as it was possible to make.
Hope this helps.
Mike

 

[Maris]

The best holes I've ever seen are the single hole electron microscope grids I used in a variety of transmission electron microscopes. These apertures are made by etching and are close to perfect at a molecular level.

The sharpest looking pinhole pictures tend to exploit high contrast high frequency detail that is just coarser than the limiting resolution of the pinhole itself.

 

[Jim Jones]

Hi Wild Bill
Mike Walker here I make the Harman Titan pinhole cameras, acid etched holes are superior to laser holes, and if done the right way they very very round, I am going to upset some here, put round does not matter that much, it is more the sharpness of the inside edge of the hole.
I can back this up, as Schneider once had a play with this, and by taking 3 scalpel blades interlocking they and blacking with candle smoke made what they said, was as sharp a pinhole as it was possible to make.
Hope this helps.
Mike

Sharpness in pinhole images is limited by diffraction at the edges of the pinhole. The triangular pinhole has greater edge length in relation to the opening area than does a circular pinhole. However, there is one advantage to a triangular pinhole; by moving only one blade the aperture can be varied. With more care, a four-sided variable pinhole can also be constructed.

 

[blockend]

I'm no expert, but I was talking to a man recently who made large format pinhole chromes, and he used acupuncture needles of hair thickness. IIRC he used taught metal foil.