Thomas Bertilsson
09-26-2008, 06:54 PM
Is the attached image what I can expect when I point a pinhole virtually directly into the sun?
Thanks,
- Thomas
Thanks,
- Thomas
| View Full Version : Pinhole into the sun? Thomas Bertilsson 09-26-2008, 06:54 PM Is the attached image what I can expect when I point a pinhole virtually directly into the sun? Thanks, - Thomas Anupam Basu 09-26-2008, 07:10 PM I'd say you're doing very well in terms of flare and have a good pinhole with even round edges. Jon Shiu 09-26-2008, 07:29 PM Here's an example of pinhole flare from 4x5 Pinhole camera. Jon Thomas Bertilsson 09-26-2008, 07:51 PM Thanks for posting guys. So, to answer my question - is it abnormal what I see? - Thomas Jon Shiu 09-26-2008, 08:04 PM You mean the dark vertical areas? It doesn't happen with my pinhole camera. Is it some type of homemade camera? Jon Thomas Bertilsson 09-26-2008, 08:09 PM Yes, exactly. That's what I'm referring to (sorry, I was in la-la land, not thinking to explain what I'm talking about). No, it's a ZeroImage2000 6x6 camera. I only get that effect when I point the camera straight into the sun. I thought I didn't have to deal with flare since there isn't a lens, but was curious if something else would show up instead... - Thomas Thomas Bertilsson 09-26-2008, 08:27 PM Here is a frame from the same roll that was pointing away from the sun. Nice, sharp, and no anomalies. - Thomas Ross Chambers 09-27-2008, 04:00 AM The area upon which the rays of the sun appear might have some influence. I've attached a Zero Image 4x5 pic which worked out not so badly. In my case probably pure luck, as so often with my pinhole pictures. It was mid morning and I was not particularly conscious of the sun's position. My point is that Zero Image's pinholes are fairly regular. Regards - Ross Joe VanCleave 09-27-2008, 12:04 PM The differences between individual pinholes show up the most when pointing the camera directly at the sun. The ideal pinhole is a two-dimensional, round aperture; practical pinholes are three-dimensional, shallow 'tunnels' and are not necessarily close to perfectly round. In addition, the material the pinhole is made from, and any coatings on the inside walls of the hole, all contribute to how much, and the quality of, light flare present in the image. I've heard that Zero Image pinholes are pretty good quality. There's also EMS electron microscope apertures, which some folks over at F295 are using in homemade cameras, and these appear to be at least as good as the Zero Image pinholes. My homemade pinholes vary widely in quality, depending on how much time I want to spend in trying to make a near-ideal pinhole. For coating the inside surface of the the pinhole tunnel, some sources recommend the ideal coating is blackening them with soot from a smokey candle, which is almost pure carbon; others use black marker pens. Of course, the fun part about pinhole is that all this doesn't have to be so technically perfect. We can get all kinds of funky light flare, and still enjoy the images the camera delivers. It's all good. :) ~Joe Andrew Moxom 09-29-2008, 04:38 PM Damn that North shore, it's claimed yet another negative! Not sure I can resolve your problem, but I wonder if there is the potential for internal reflections on anything inside that camera? Thomas Bertilsson 09-29-2008, 05:34 PM Well, I view it this way. Pointing it almost directly into the sun something is bound to happen. I'm not particularly displeased with this result, just a learning curve and how to avoid it in the future. I'm sure that there is something on the walls inside the pinhole itself that's causing reflection. I'll try the sooty candle method to improve it. - Thomas bowzart 09-29-2008, 05:46 PM It is possible to exclude the sun BARELY and if your pinhole is exceptionally well made, a knife sharp edge can separate the spectrum just as a diffraction grating. bennoj 09-29-2008, 06:41 PM My avatar image is one example of pinhole sun flare. It's from a Zero Image 6x6 camera. bowzart 09-29-2008, 08:17 PM Well, I view it this way. Pointing it almost directly into the sun something is bound to happen. I'm not particularly displeased with this result, just a learning curve and how to avoid it in the future. I'm sure that there is something on the walls inside the pinhole itself that's causing reflection. I'll try the sooty candle method to improve it. - Thomas When you do, I'd like to know what the results look like. My suspicion is that there may be an improvement in one way and a degradation in another. Soot is particulate, which accumulates on the metal and around and inside the hole. If you don't mind your images more fuzzy... The best way to blacken the hole (IMHO) is to make it in pure silver and tone it. I prefer to use selenium. However, even without toning, it will blacken over time (you know, tarnish). The black, if done this way, doesn't modify the character of the hole at all, except to kill reflections, since it is a very thin layer of silver selenide or sulphide that is made using the atoms of silver itself on the surface. Not everyone is that fussy about their pinholes, though, so you might not be as fanatical about it as I am. Thomas Bertilsson 09-30-2008, 12:58 AM Thanks. When I get around to trying soot, I'll let you know if I remember. I don't mind fuzzy. I dislike the weird reflections. Sounds like a win win to me... :) - Thomas |