# What to take into account as a pinhole newbie?

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• 07-07-2010, 08:27 AM
perminna
Thanks guys for clearing up things for me! I'll take a look at the links you posted.

I have a Mac so PinholeDesigner is out of the question.
• 07-07-2010, 11:13 AM
bvy
Reciprocity (or failure thereof) basically means that the nice and neat linear relationship between EV and exposure time breaks down after a certain point. Mathematically, I wonder what a graph looks like for a given film and f-stop. That is, if you were to plot points for all exposure values and did some sort of curve fitting, what sort of function would you end up with?
• 07-07-2010, 11:30 AM
rst
Quote:

Originally Posted by bvy
... Mathematically, I wonder what a graph looks like for a given film and f-stop. That is, if you were to plot points for all exposure values and did some sort of curve fitting, what sort of function would you end up with?

Click!

Cheers
Ruediger
• 07-07-2010, 02:59 PM
grahamp
With a 6x12 format you won't be enlarging all that much, if at all, so you may as well use a faster film. The natural softness of a pinhole image will outweigh any grain issues. If you need long exposures, use slower film. I mostly use Delta 400 at EI 200 for my roll film pinholes.

Graham
• 07-07-2010, 08:53 PM
John Koehrer
I also just got into the pinhole stuff and have used HP5+ with OK results. I've just used some Acros w/o adjusting for reciprocity & it looks fine.
There are several pinhole sites out there with lots of information. f295, pinhole resource & others. F295 has an active group like APUG.

The aperture on my camera is f235 so I made a mark on my meter @ f64 & just increase the time by two stops rather than deal with multiple increases of time.
I used f64 because my calculator dial ran out of time indicators.
• 07-08-2010, 05:52 AM
perminna
Quote:

Originally Posted by grahamp
With a 6x12 format you won't be enlarging all that much, if at all, so you may as well use a faster film. The natural softness of a pinhole image will outweigh any grain issues. If you need long exposures, use slower film. I mostly use Delta 400 at EI 200 for my roll film pinholes.

I'm probably going to try faster films too. I have a few rolls of Fuji Neopan 400 which has a relatively fine grain.

Quote:

Originally Posted by John Koehrer
There are several pinhole sites out there with lots of information. f295, pinhole resource & others. F295 has an active group like APUG.

Yeah, there are lots of sites. I have still few days before my camera arrives so I'll google and do research during the weekend.
• 07-08-2010, 09:46 AM
DWThomas
In my pinhole forays, I found that fast films called for too short an exposure in bright outdoor scenes to time reliably with a human-powered shutter (a true digital shutter -- operated by thumb and forefinger :D). So I have gone toward the slower films to get exposures out towards 4 or 5 seconds with my gear. There has also been some suggestions that high reciprocity failure in some of the fast films actually results in longer exposures than some of the better behaved slower films like ACROS 100.
• 07-08-2010, 02:57 PM
grahamp
Using Delta 400 at EI 200 gives me a shortest time of two seconds in N. California (37 deg N.) with a clear sky. Long enough for manual timing, short enough to keep reciprocity under control. But a lot depends on the shutter mechanism.

Graham
• 07-08-2010, 03:28 PM
John Koehrer
Quote:

Originally Posted by DWThomas
In my pinhole forays, I found that fast films called for too short an exposure in bright outdoor scenes to time reliably with a human-powered shutter (a true digital shutter -- operated by thumb and forefinger :D). So I have gone toward the slower films to get exposures out towards 4 or 5 seconds with my gear. There has also been some suggestions that high reciprocity failure in some of the fast films actually results in longer exposures than some of the better behaved slower films like ACROS 100.

I've been fiddling with the idea of an electronically timed shutter activating a small solenoid. The difficulty seems to be availability to timers with short(1/30-1/2sec) ranges. I found one source that could provide custom timing in that range for about an extra \$100 + the timer(\$50)
The other thing is operating voltage every thing seems to be 9-12-24V
• 07-08-2010, 07:06 PM
DWThomas
Quote:

Originally Posted by John Koehrer
I've been fiddling with the idea of an electronically timed shutter activating a small solenoid. The difficulty seems to be availability to timers with short(1/30-1/2sec) ranges. I found one source that could provide custom timing in that range for about an extra \$100 + the timer(\$50)
The other thing is operating voltage every thing seems to be 9-12-24V

In theory I have some background to put a Rube Goldberg thing together with a microcontroller chip for the timing that could probably run on 6 volts, but as long as I can get exposures out toward 3 or 4 seconds or more, I figure it's not worth the effort (and I'm a slothful retired guy :p ).
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