Hello, Found you while Googling for 20x24 pinhole camera. I have a BUNCH of Ilford RC 20x24 paper that I need to use up and I was thinking about a 20x24 pinhole camera that would use paper for the negatives. Have you found the images produced by this format to work well? How did you determine the depth of the box (based on the size of your pinhole). I'm all ears if you would care to share any specifics of what you learned building a pinhole camera of this size. Thanks in advance.
Hey, thanks for the interest in my work. Yes, this camera has produced some great images. Depending of the pinhole, subject matter, etc., you can get some really sharp images from large pinhole cameras. You can also play around with blur due to the long exposure times. The camera depth is relative to the image circle you want to produce. You want an image circle with a diameter equal to or larger than the diagonal of the film you are using. In your case, 20x24 paper has a diagonal of about 31.25". The formula to calculate focal length is: IMAGE DIAMETER = FOCAL LENGTH X 1.92 (focal length and camera depth are the same thing) So, your focal length would be about 16.3" (pinhole to paper), but I would go slightly larger just to assure full coverage. However, if you want vignetting, you can go shorter. The camera on this blog is 12" deep, so there is vignetting. I usually shoot onto 16x20 paper, though, so the vignetting is less noticeable. Two great resources are: www.mrpinhole.com - this site has great camera design calculators to assist with any formulas you need. www.pinholeresource.com - this site is run by Eric Renner who has a great book on pinhole photography. You can also buy a great set of machine drilled pinholes on the site. (But you can always just make your own with a really thin sheet of aluminum) Thanks for your interest and good luck with the camera. If you have any other questions, feel free to contact me through my website: www.matthewburris.com
Hello, Found you while Googling for 20x24 pinhole camera. I have a BUNCH of Ilford RC 20x24 paper that I need to use up and I was thinking about a 20x24 pinhole camera that would use paper for the negatives. Have you found the images produced by this format to work well? How did you determine the depth of the box (based on the size of your pinhole). I'm all ears if you would care to share any specifics of what you learned building a pinhole camera of this size. Thanks in advance.
ReplyDeleteHey, thanks for the interest in my work. Yes, this camera has produced some great images. Depending of the pinhole, subject matter, etc., you can get some really sharp images from large pinhole cameras. You can also play around with blur due to the long exposure times.
ReplyDeleteThe camera depth is relative to the image circle you want to produce. You want an image circle with a diameter equal to or larger than the diagonal of the film you are using. In your case, 20x24 paper has a diagonal of about 31.25".
The formula to calculate focal length is:
IMAGE DIAMETER = FOCAL LENGTH X 1.92
(focal length and camera depth are the same thing)
So, your focal length would be about 16.3" (pinhole to paper), but I would go slightly larger just to assure full coverage. However, if you want vignetting, you can go shorter.
The camera on this blog is 12" deep, so there is vignetting. I usually shoot onto 16x20 paper, though, so the vignetting is less noticeable.
Two great resources are:
www.mrpinhole.com - this site has great camera design calculators to assist with any formulas you need.
www.pinholeresource.com - this site is run by Eric Renner who has a great book on pinhole photography. You can also buy a great set of machine drilled pinholes on the site. (But you can always just make your own with a really thin sheet of aluminum)
Thanks for your interest and good luck with the camera.
If you have any other questions, feel free to contact me through my website: www.matthewburris.com