Pinhole Photography - Page 2
PhotoCamel: Your friendly photo community, with free discussion forums, digital photography reviews, photo sharing, galleries, downloads, blogs, photography contests, and prizes.
 

Go Back   PhotoCamel - Your Friendly Photography Forum > PhotoCamel Lounge > Photography Talk

Reply
 
LinkBack Thread Tools Display Modes
Old 10-06-2010   #11
Camel Breath
 
scoundrel1728's Avatar
 
Location: Oakland, CA, USA
Posts: 10,076
CamelKarma: 1469207
Editing OK?: Ask First
Constructive Critique?: Yes
Default Re: Pinhole Photography

If you make a pinhole as described in the video, the effective "focal length" of your pinhole will be somewhere in the range of 40-48 mm, depending on the flange distance of the lens mount system for your camera model, the design of the body cap, and the details of your pinhole mount, i.e., whether you mount your pinhole on the front or rear surface of your lens cap. You can also use your extension tubes as telextenders for your pinhole, with a 25 mm tube being about the equivalent of a 1.5-1.6x extender.

The viewfinder of your dSLR will be pretty much useless with your pinhole mounted, so you may want to mount a regular lens of the same focal length to frame the shot, then mount the pinhole to actually take the picture.

If the ambient light is bright enough, you may actually have enough light to meter the shot, but don't let the light spillage around the viewfinder corrupt the reading. Otherwise, you must experiment to find the effective f-stop of your pinhole. One way to do this is to shoot a set of pictures in manual or aperture priority. Set the aperture to a convenient setting such as f/4 or f/8 (convenient because it is easy to divide by these numbers) and bracket about 1 stop in 1/3 stop increments around the target exposure with the shutter speed. Then mount your pinhole and take several pictures with exposure times one stop apart, checking the histograms to see when you have an exposure that is within one stop of being correct. For exposures taken in direct sunlight, this will probably be on the order of one second. At least that would be a good place to start looking.

Once you have your exposure information, go to the computer and use the information from your EXIF headers on your best-exposed pinhole shot and its nearest-exposed approximation from the series taken with the viewing lens. Divide the exposure time from the pinhole shot by the exposure time from the viewing lens. The result will be an exposure time multiplier. Thereafter, whenever you want to take a shot with your pinhole, you can use your viewing lens to meter as well as view your shot: set your lens to the same zoom and aperture setting as you did on the test shots, note the exposure time, and multiply by the exposure time multiplier to get the correct exposure time for your pinhole shot.

You can also use this approach to find the equivalent f-number for your pinhole and the pinhole's diameter if you want. The f-number of your pinhole will be the square root of your exposure time multiplier, times the f-number of your lens-based exposures. The approximate pinhole diameter will be this f-number times 45 mm (or whatever the actual pinhole-to-imager distance is).

If you are shooting film rather than digital, this procedure will require some adaptation. Instead of relying on the EXIF header, you must instead take careful notes of exposure times and apertures. You must also take more test shots with the pinhole to ensure getting a good shot, and you may have to correct for reciprocity failure if your exposure times become long enough. You will also need to compare the density of negatives rather than images on-screen to choose your target exposures with the lens and the pinhole. However, if your body cap fits both your film and digital cameras, you may use the same exposure multiplier for both cameras - or any other camera with the same kind of lens mount.

And if you already have one of the newer Lensbabies that doesn't require you to hold the lens in place during exposure, you can get a pinhole insert for your lens if you don't already have one. Exposure multiplier for the f/177 pinhole in this kit will be about 500x if you meter at f/8; 2000x if you meter at f/4, and 8000x if you meter with an ordinary f/2 Lensbaby lens with no aperture insert.
scoundrel1728 is offline   Reply With Quote
Old 10-06-2010   #12
F1 Camel
 
stef@apl's Avatar
 
Location: Albuquerque, NM
Posts: 3,328
CamelKarma: 783595
Editing OK?: Yes
Constructive Critique?: Yes
Default Re: Pinhole Photography

Just a quick note about the size of the pinhole. There is an optimum size, based on the focal length. For 50mm focal length (the approximate distance from sensor to the pinhole in a body cap) you want about 0.3mm diameter. This is just the very tip of a needle, just like the guy said in the video.

You can find calculators online which will give you the optimum pinhole size. An example is here.
stef@apl is offline   Reply With Quote
Old 10-06-2010   #13
PhotoCamel Supporter DONATED
Bactrian
 
Jim Jones's Avatar
 
Location: Rural Missouri
Posts: 2,338
CamelKarma: 501383
Editing OK?: Yes
Constructive Critique?: Yes
Default Re: Pinhole Photography

A site with good information and many links is Jon Grepstad - Pinhole Photography. A forum devoted to pinhole photography is Exploring 21st Century Photography — f295.org.
Jim Jones is online now   Reply With Quote
Old 06-22-2011   #14
Alpaca
 
Mark WN's Avatar
 
Location: UK
Posts: 14
CamelKarma: 10
Editing OK?: Ask first
Constructive Critique?: Yes
Default Re: Pinhole Photography

Hi

I don't know if you are interested in this at all, but I have been teaching pinhole photography within the Cambridge homeless community, using beer-cans & 3month exposures. Check this out -

Event: Pinholes and Portraits | Varsity Online

BBC News - Cambridge homeless show pinhole beer can camera pictures

YouTube - ‪The Journey of Twig's Can‬‏
__________________
Mark Woods-Nunn
Mark WN is offline   Reply With Quote
Old 07-25-2011   #15
Alpaca
 
Posts: 4
CamelKarma: 10
Editing OK?: Ask First
Constructive Critique?: Yes
Default Re: Pinhole Photography

A pinhole camera is a simple camera without a lens and with a single small aperture – effectively a light-proof box with a small hole in one side. Light from a scene passes through this single point and projects an inverted image on the opposite side of the box. The human eye in bright light acts similarly, as do cameras using small apertures.

Photography coffs harbour
simmijoe is offline   Reply With Quote
Old 11-12-2017   #16
Alpaca
 
Posts: 20
CamelKarma: 629
Editing OK?: Ask First
Constructive Critique?: Yes
Default Re: Pinhole Photography

i'm very much interested in lenseless photography , pinhole photography is something i will want to explore & i just ordered a copy of eric renners book " pinhole photography : rediscovering a historic technique " . one of the best things about pinhole photography is it's simplicity & different types of images one can take with pinhole cameras . their are your basic pinhole images , pinhole blender images , pinhole sieve images & zone plate images - these are just a few pinhole techniques that i've read about ( might be more pinhole techniques that i'm not aware of ) . using the pinhole technique is one of the most authentic ways to record photographic images , & the history of pinhole photography is fascinating ( at least to me ) & i find it simply cool that you can make these cameras from objects like soup cans , cigar boxes , paper , juice boxes , coffee cans , garbage containers , simple wooden boxes , plastic , spam cans , human skulls & rooms in houses & apartments ( it's crazy what you can build these cameras with ) i even read somewhere that a gentlemen even made a pinhole camera from a pepper if i remember correctly , lol . your only limited by your imagination i guess , you can make your own or buy one from someone who makes them commercially . i may become a pinhole devotee & just want to concentrate on that type of photography , we'll have to wait & see . just a fun fact - the largest pinhole photograph in the world is known as " the great picture " it was made with the help of the world's largest pinhole camera , building # 115 at marine corps air station el toro ( ca) , google " the great picture " wikipedia .
rwjr is offline   Reply With Quote
Old 01-12-2018   #17
Vicuna
 
Tom Moss's Avatar
 
Location: Lake Forest
Posts: 78
CamelKarma: 100643
Editing OK?: Yes
Constructive Critique?: Yes
Default Re: Pinhole Photography

Sorry, I just never understood the attraction behind pinhole photography. The only thing being introduced here is longer exposure time because the 'lens' is a tiny hole.

Just my 2 cents.


__________________
Members don't see ads in threads. Register for your free account today and become a member of PhotoCamel to open up the site's many benefits and features.
Tom Moss is offline   Reply With Quote
Reply

« PhotoCamel - Your Friendly Photography Forum > PhotoCamel Lounge > Photography Talk »


Share this topic:

Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
pinhole verdesardog Black & White 2 06-12-2009 08:52 AM
pinhole verdesardog Black & White 2 06-12-2009 08:34 AM
Pinhole Photography Day - 30th April 2006 Paul Shields Photography Talk 16 04-13-2006 05:18 PM