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World Pinhole Day

Discussion in 'Everything Film' started by steveandthedogs, Apr 18, 2020.

  1. gray1720

    gray1720 Well-Known Member

    Well, the damn Zoom took up a lot of the arvo, and I completely lost the thread of what I was planning to do...

    However, I did get a couple of cyanotypes in - currently flattening twixt the volumes of an 1880s Chambers Encyclopedia - and excavated the FrankenPinLeica. I really must put some effort into working out the gubbins to give me half a clue as to the exposures, though, as winging it without a clue is a recipe for disappointment. IMG_6508.jpg
     
    Zou and steveandthedogs like this.
  2. steveandthedogs

    steveandthedogs Well-Known Member

    Try :

    http://www.mrpinhole.com/calcpinh.php
     
  3. gray1720

    gray1720 Well-Known Member

    Interesting - I reckon my pinhole (just to be anal, it really was made with a pin) is about 0.2mm (see pic, measure it up yourselves if you want to check!) and according to Mr Pinhole* my sunny day exposure with ISO100 film is half a second - I'm really surprised it's that short from such a tiny opening. I've been going waaay over that. Annoyingly the FrankenPinLeica doesn't have the film plane marked on it, but I reckon I have my focal length in the right ballpark and, as far as I can see, it affects the angle of view more than exposure time.

    IMG_6512.jpg

    *I do hope Mr Pinhole is not related in anny way to Mr Pin!
     
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  4. gray1720

    gray1720 Well-Known Member

    ...and here's the cyanotypes. I did one with a geranium leaf, and one with one of my glass plate negs - that one is OK, but I really, really like the leaf.

    IMG_6510.jpg IMG_6511.jpg
     
    Zou likes this.
  5. Zou

    Zou Well-Known Member

    I found the easiest way to measure the pinhole was to scan it at very high res next to the rule; far easier to estimate than zooming in on a photo. Your 1/2s doesn't sound unreasonable to me; sunny conditions really make a difference compared to other brightish days.
     
  6. gray1720

    gray1720 Well-Known Member

    That's a good idea - now, can I unearth my scanner? It's been relegated to make space for the work computer...
     
  7. steveandthedogs

    steveandthedogs Well-Known Member

    Ain't that the truth.

    Aperture .2mm, focal length ?35mm - ish so f = 35/0.2 =175, so 1/2 -3/4 sec about right, but don't forget reciprocity add-on.

    Which film? 1/2s is spot-on for FP4+ according to PinholeDesigner. Ditto Foma 100, but more than 1/2s, Foma 100 goes berserk and needs about three weeks.

    Like the cyanotypes. Wish I could get them to work...


    S
     
  8. gray1720

    gray1720 Well-Known Member

    Neopan 100 - I can see a film order may distract me from saving for a shed, especially after buying four more box cameras, and even more especially as I am out of fixer! Thanks for the warning on Foma, it's just the stuff I'd try too.

    Any idea where I could find some red plastic to patch a missing window?
     
  9. steveandthedogs

    steveandthedogs Well-Known Member

    Don't think Neopan has any recip failure.

    Pinhole camera exposure times :

    f number: 175

    Including reciprocity failure for film: Fomapan 100

    For Fomapan 100:

    Time for f 22 Resulting time

    1/1000 1/15

    1/500 1/8

    1/250 1/4

    1/125 1/2

    1/60 2 s

    1/30 11 s

    1/15 28 s

    1/8 1 m

    1/4 2 m

    1/2 5 m

    1 s 14 m

    2 s 38 m

    4 s 2 h

    8 s 7 h

    15 s 23 h

    30 s 87 h

    1 m 341 h

    2 m 1346 h

    Created by PinholeDesigner 2.0, film database v1 (9. 6. 2003)
    Copyright © David Balihar, 2001-2003

    As for the red plastic thing, what about a bit of clear plastic stuck on the inside and painted with red glass paint? I've used this in the past :
    https://www.therange.co.uk/arts-and...ste-aquaglass-transparent-glass-paint/#463658


    S
     
  10. Zou

    Zou Well-Known Member

    IIRC Neopan is ok down to 2 minutes and thereafter rf kicks in. Take that with a huge pinch of salt though as it's about 15 years since I last used it and my memory could be foggy.

    Edit to add:

    Just checked it. Remarkably my memory was correct! :D
     
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  11. steveandthedogs

    steveandthedogs Well-Known Member

    Just a touch better than Fomapan, then.

    S
     
  12. gray1720

    gray1720 Well-Known Member

    You weren't kidding about the Fomapan! Bloomin' flip!
     

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