reciprocity failure and pinholes

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pingu666

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so ive made a recesky 3d pinhole camera, and the instructions where in chinese, but managed to find some info below

http://www.lomography.com/magazine/...esky-3d-stereo-pinhole-camera-a-winter-affair

f117 for single/stereo and f146 for panorama

the manual recommends f128 and f180

and now recipreity, have got cheap agfa poundland film, with the datasheet here
http://www.agfaphoto.com/appc/_upload/2011_30/Vista_plus_200___400.pdf (page 2 for reciprocity stuff)

which is 4 seconds, + 1/3 of a stop
16 seconds is 2/3 of a stop
64 seconds is 1 stop
(of lens opening in each case)

which is great cos i cant open my lens :(,
so should i adjust the exposure to make it longer...
so going off my digi camera, with F16 as starting point, that gives me f18,f20,f22.
now should i use them before timesing it by whatever on my conversion chart, or try and find/figure out what extra stop values would be at pinhole size :x

bit confused :(
 
I think that the best way to deal with this is to :
1. Calculate your pinhole camera's exposure factor for f22
2. Meter the scene at f22
3. Apply your exposure factor to your meter reading
4. Apply your reciprocity failure factor to the exposure time at 3. above.

There are a number of programs available on the web that will calculate pinhole camera exposure factors.

I hope that this helps.
 
Can anyone recommend a source for reciprocity failure.

Found quite a few on the web, but they seem to differ wildly with the factor to apply.
 
pingu666 said:
datasheet of the film?
Click to expand...

What's your question?

If you've got an iPhone there's an app called Pinhole Assist which pretty much does all you need when it comes to calculating pinhole exposure.
 
pingu666 said:
datasheet of the film?
Click to expand...

Doh...I'm such a dope...didn't think of checking film datasheet.

There is a remarkable amount of information on these...much of which meants little to me but yes... a nice little table with reciprocity values :)
 
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