Re: Re: [pinhole-discussion] exposure outdoors using meter
Thanks for that Guillermo, so as understand it it doesn't matter what the shutterspeed is for you meter reading its the f-stop that counts as it will be converted recipricly anyway. i was using paper for this exercise and thought that you set the shutter speed to the iso of the neg material used, and make a light reading from there. Thanks again for the info :) > > From: "Guillermo" > Date: Wed, 18 Jul 2001 08:23:39 -0400 > To: > Subject: Re: [pinhole-discussion] exposure outdoors using meter > > > - Original Message - > From: > > > With your info i got off your website, the sunny16 + iso exposure rule, > > when using a meter do you use the meter reading and the iso=shutterspeed to > > calculate your exposure? > > Did you mean "iso+shutterspeed"? if so, here is the answer (BTW, I may > overexplain, my excuses in advance for doing that): > > When I use a meter, I set it for the ISO of the emulsion in use, then I take > a reading and obtain a "pair of exposure values", f/stop+shutter_speed, that > is. Then I translate that pair of exposure values to an equivalent pair for > when the f/stop is the one of my pinhole camera. For instance: My pinhole > camera is f/512, a meter reading gives me f/45 @ 1/30, there are 7 stops > between f/45 and f/512 (45 -> 64,90,128,180,256,360,512), therefore the > equivalent pair of exposures values f/45@1/30 for my pinhole camera would be > f/512 @ (1/30 +7stops). 1/30 +7 stops is equal to doubling the time 7 times > 1/30 -> 1/15, 1/8, 1/4, 1/2, 1, 2, 4secs, my pinhole camera exposure should > then be f/512@4 seconds plus any reciprocity correction needed for the > emulsion in use. > > > I used it to teach a class but had varying results, although i have > > suspitions that the cameras were dodgy. > > I just need a little clarification on this. > > But the ones that did turn out on my camera and one other were as near > > perfect as i could have hoped. > > > > The only way to get consistent results from many cameras is if you have > measured the pinholes of all the cameras in a relatively accurate way, which > in turn allow you to know the f/stop of your cameras. Obviously, pinhole of > all the cameras should be clean, free of burrs and obstructions. > > > Also if you have any info on Pinhole under studio flash conditions i would > > really appretiate it, i had a formula worked out which worked well for my > > camera but had limited success with the others. > > I used > > exposure = difference of stops from meter reading to camera aperture x 1.5 > > If you have any suggestions to improve this, that would be great. > > Here is what the Laws of physics MANDATE: you should give a number of flash > "pops" equal to 2 multiplied by itself a number of times equal to the > difference of stops. For instance, stops of difference = 5, number of > "pops"= 2x2x2x2x2 = 32 pops > And then you will have to give few pops more to compensate for INTERMITTENCY > (sp) EFFECT which for the above example would state: an exposure of 32 pops > of low power flashes (flash-A) is less effective that one single pop of a > flash-B with a power equal 5 times the power of flash-A. > > If shooting negative material, you may obtain printable results for up to 4 > stops of difference when using your formula, but for the more stops of > difference the more unlikely you will. > > Hope it helps, > > Guillermo > > > ___ > Pinhole-Discussion mailing list > Pinhole-Discussion@p at ??? > unsubscribe or change your account at > http://www.???/discussion/ >
[pinhole-discussion] keeping temperatures up in tube processing
An old sage from a camera club dropped this pearl of wisdom for keeping his solution temperatures constant. He placed desk lamps with big bulbs shining onto the rotating tube of his cibachrome tubes. It seems like an excellent idea. His cibas were fantastic. eric nelson, marshfield, wi usa
[pinhole-discussion] Levi Brown, where are you
Hi Levi. I'm one of your Group 1 pinhole swappers. Someone from your Snohomish address forwarded my picture to a Rochester address. It just came today as Return to Sender. Sounds like a song I remember. If you send me your current address, I'll send the pinhole on. THANKS to all who've sent me their pictures. They adorn my walls well. Rosanne
Re: [pinhole-discussion] 4x5 processing question
That sounds like a good idea -- I'll give it a try. Thanks! --- Tom Miller wrote: > I put the sheets into an empty 3-part 4x5 film box, tape it shut and > bring it to the lab. The lab returns the processed negs in plastic > sleeves in the same box (or a different one, depending on the lab). > If the is your first box of 4x5 and you want to process only part of > it, maybe the lab or another photographer has an old box they could > give you. > > - Original Message - > From: "Derek Nielsen" > To: > Sent: Wednesday, July 18, 2001 9:02 AM > Subject: [pinhole-discussion] 4x5 processing question > > > > I am in the process of building a 4x5 pinhole camera, and was > wondering how to > > take the film from the camera to the photo lab. How do people > usually do this? > > Do you just put it in a box or a bag of some sort or do you drop of > the film > > holder? > > > > Derek Nielsen > > derekniel...@yahoo.com > > __ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail http://personal.mail.yahoo.com/
Re: [pinhole-discussion] color processing
- Original Message - From: "Mike Vande Bunt" > By the way, for the non North American audience, the 100 degrees > mentioned is in Farenheit degrees. 100 degrees Celsius is easy to > maintain, just bring the water to a boil! And watch your fish swimming backstroke style!! BTW, if 1 heater can't copy with the volume of water, nothing prevents you from having 2 heaters. Guillermo
Re: [pinhole-discussion] 4x5 processing question
I put the sheets into an empty 3-part 4x5 film box, tape it shut and bring it to the lab. The lab returns the processed negs in plastic sleeves in the same box (or a different one, depending on the lab). If the is your first box of 4x5 and you want to process only part of it, maybe the lab or another photographer has an old box they could give you. - Original Message - From: "Derek Nielsen" To: Sent: Wednesday, July 18, 2001 9:02 AM Subject: [pinhole-discussion] 4x5 processing question > I am in the process of building a 4x5 pinhole camera, and was wondering how to > take the film from the camera to the photo lab. How do people usually do this? > Do you just put it in a box or a bag of some sort or do you drop of the film > holder? > > Derek Nielsen > derekniel...@yahoo.com > > __ > Do You Yahoo!? > Get personalized email addresses from Yahoo! Mail > http://personal.mail.yahoo.com/ > > ___ > Pinhole-Discussion mailing list > Pinhole-Discussion@p at ??? > unsubscribe or change your account at > http://www.???/discussion/
Re: [pinhole-discussion] color processing
William Erickson wrote: > I'd be a little surprised if an aquarium heater can maintain 100 degrees > very reliably. Aquarium heaters are quite good a within a plus or minus one degree range. 100 degrees is on the high end for most heaters, but not outside their capability. The water must be circulating for temperature regulation to work reloably, so some sort of a pump to keep that water moving is also needed. By the way, for the non North American audience, the 100 degrees mentioned is in Farenheit degrees. 100 degrees Celsius is easy to maintain, just bring the water to a boil! Mike Vande Bunt
[pinhole-discussion] 4x5 processing question
I am in the process of building a 4x5 pinhole camera, and was wondering how to take the film from the camera to the photo lab. How do people usually do this? Do you just put it in a box or a bag of some sort or do you drop of the film holder? Derek Nielsen derekniel...@yahoo.com __ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail http://personal.mail.yahoo.com/
Re: [pinhole-discussion] exposure outdoors using meter
- Original Message - From: > With your info i got off your website, the sunny16 + iso exposure rule, when > using a meter do you use the meter reading and the iso=shutterspeed to > calculate your exposure? Did you mean "iso+shutterspeed"? if so, here is the answer (BTW, I may overexplain, my excuses in advance for doing that): When I use a meter, I set it for the ISO of the emulsion in use, then I take a reading and obtain a "pair of exposure values", f/stop+shutter_speed, that is. Then I translate that pair of exposure values to an equivalent pair for when the f/stop is the one of my pinhole camera. For instance: My pinhole camera is f/512, a meter reading gives me f/45 @ 1/30, there are 7 stops between f/45 and f/512 (45 -> 64,90,128,180,256,360,512), therefore the equivalent pair of exposures values f/45@1/30 for my pinhole camera would be f/512 @ (1/30 +7stops). 1/30 +7 stops is equal to doubling the time 7 times 1/30 -> 1/15, 1/8, 1/4, 1/2, 1, 2, 4secs, my pinhole camera exposure should then be f/512@4 seconds plus any reciprocity correction needed for the emulsion in use. > I used it to teach a class but had varying results, although i have > suspitions that the cameras were dodgy. > I just need a little clarification on this. > But the ones that did turn out on my camera and one other were as near > perfect as i could have hoped. > The only way to get consistent results from many cameras is if you have measured the pinholes of all the cameras in a relatively accurate way, which in turn allow you to know the f/stop of your cameras. Obviously, pinhole of all the cameras should be clean, free of burrs and obstructions. > Also if you have any info on Pinhole under studio flash conditions i would > really appretiate it, i had a formula worked out which worked well for my > camera but had limited success with the others. > I used > exposure = difference of stops from meter reading to camera aperture x 1.5 > If you have any suggestions to improve this, that would be great. Here is what the Laws of physics MANDATE: you should give a number of flash "pops" equal to 2 multiplied by itself a number of times equal to the difference of stops. For instance, stops of difference = 5, number of "pops"= 2x2x2x2x2 = 32 pops And then you will have to give few pops more to compensate for INTERMITTENCY (sp) EFFECT which for the above example would state: an exposure of 32 pops of low power flashes (flash-A) is less effective that one single pop of a flash-B with a power equal 5 times the power of flash-A. If shooting negative material, you may obtain printable results for up to 4 stops of difference when using your formula, but for the more stops of difference the more unlikely you will. Hope it helps, Guillermo
[pinhole-discussion] exposure outdoors using meter
Guillermo, With your info i got off your website, the sunny16 + iso exposure rule, when using a meter do you use the meter reading and the iso=shutterspeed to calculate your exposure? I used it to teach a class but had varying results, although i have suspitions that the cameras were dodgy. I just need a little clarification on this. But the ones that did turn out on my camera and one other were as near perfect as i could have hoped. Also if you have any info on Pinhole under studio flash conditions i would really appretiate it, i had a formula worked out which worked well for my camera but had limited success with the others. I used exposure = difference of stops from meter reading to camera aperture x 1.5 If you have any suggestions to improve this, that would be great. Thanks :)
Re: [pinhole-discussion] color processing
Hi: An aquarium heater may work provided the volume of water you are using is fairly large and has been stabilized over a ong period of time, adequately mixed and covered. Ie like an aquarium. Aquarium heaters don't heat water very quickly. They are designed to hold a fairly large volume of water at a stable tempurature. Auariums also have a circlulating/filtration system that keeps the water moving, without this the water would be unevenly heated. See if you could use a presure balanced faucet. These are becoming more common - used mostly for bathtubs. The tubs deliver a fixed rate of water, the valve controls the mix of hot and cold water to maintain the set temperature. Designed to prevent one from being scalded when somebody flushes the toilet while you are taking a shower. Depending on your plumbing situation you may be able to set your water at 100 dg and it may stay there. Though if someone takes a shower, flushed the toilet etc, your film could be ruined. You could try a temperature controlled water bath like this: http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1616174719 Gord On Tue, 17 Jul 2001, William Erickson wrote: > I'd be a little surprised if an aquarium heater can maintain 100 degrees > very reliably. In my experience, c-41 developing, especially 35mm, is > tedious, prone to variation in contrast, probably due to variability in > agitation rates, and no fun at all. > - Original Message - - Gordon J. Holtslander Dept. of Biology hol...@duke.usask.ca112 Science Place http://duke.usask.ca/~holtsgUniversity of Saskatchewan Tel (306) 966-4433 Saskatoon, Saskatchewan Fax (306) 966-4461 Canada S7N 5E2 -
