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  1. #11

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    this thread might be helpful

    http://www.apug.org/forums/forum62/5...so-rating.html

    that same ilford emulsion might also be as fast as iso 25


    re paper speed ratings of 200&c
    that is relative to paper speed, not relative to the iso of film
    silver magnets, trickle tanks sold
    artwork often times sold for charity
    PM me for details

  2. #12
    mablo's Avatar
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    Jojje, thanks for the tip. I just reserved for me the book you mentioned above on our library website (helmet).

  3. #13
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    Well yeah, so I finally got around to trying this out.
    0.6mm hole at 200mm gives roughly f/333, near enough to 7 stops down from f/32.
    Took the digisix and the suitcase camera out at lunch today, ended up at 2 minutes with ei3, but no filter.
    Now I've got a lovely black piece of paper to hang on my wall...
    An awful lot of electrons were terribly inconvenienced in the making of this post.

  4. #14
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    Just did another test strip with a B+W 040 4x Orange filter. Same lightmeter reading, same 2 minutes, same (albeit much smaller this time) nicely black piece of paper.

    Either these times are up the creek or I've got a massive light leak somewhere...
    An awful lot of electrons were terribly inconvenienced in the making of this post.

  5. #15

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    Just to confirm that your paper is ok, try developing a piece straight from the box, without exposing it. After fixing, it should be white. If it has any tone at all then you have a problem with the paper.

    Just wondering the obvious, you do realise that the paper must be developed in darkness or with a safelight, and that you have checked your safelight is actually safe??

  6. #16
    Dr Croubie's Avatar
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    yeah, the paper and the safelight is good (as are the chems), I was enlarging stuff last weekend with the exact same paper.
    I'm pretty sure there must be a light leak somewhere in the suitcase, I'll be adding another set of baffles today to see what else I can block out...
    An awful lot of electrons were terribly inconvenienced in the making of this post.

  7. #17
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    Um this is still MGIV right? 2 minutes for 200mm "focal" length sounds pretty close to right to me. Even if your exposure was off by 1 or 2 stops whole, you'd still be able see a low contrast very dark image. I think some kind of leak is likely. A good test for light leaks is to load a little strip of paper, put the camera out in the sun, then develop!

  8. #18
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    So over the llast week I've totally attacked this thing with aquadhere, styrofoam packing, black construction-cardboard, and a can of black spraypaint.

    Last night I did 3 images:
    - a test strip with the suitcase in the sun for a full 10 minutes, lenscap-shutter on. Completely brand-new chemistry, I tipped dev/stop/fix all down the drain last weekend when my HDPP came out pink. Test strip came out totally white.

    - then another square (a 3x5" ripped in half), with an Orange 040 (4x) filter. Digisix gave me ev9 at ei6 in almost-sunset behind cloud. 8-stops below the f/32-mark (7-stops for f/ and 1-stop for ei) gave me 8 minutes at f/344 at ei3 (ie, NOT taking the filter factor into account). Test came out almost completely white again, so I started suspecting the brand new chems. Fogged a strip in front of the safelight (10cms for 10secs usually give a nice mid-grey fog) and that came out greyish so the chems were fine. When it was fixed and I turned the lights on I could just see a tiny faint of grey that would have been a bright reflection off my car in the sun.

    - So last one, the other half of the 3x5, I took the Orange filter off, got the same ev9, so did the same 8 minutes (ie, no filter factor and no filter), and got a very nice shot of a tree in front of my house. Shadows were almost white and the sky was totally burned black, lots of contrast (I haven't scanned/inverted to see how well it looks in positive).

    So today I loaded it with an 8x10 and packed it in the car, I'll see what I can take a shot of at lunchtime. As I've got the 040 Orange on again (for some reason I don't have a 52mm yellow, only orange and yellow-green) I'll take it 10-stops below the f/32 ei6 reading (7-stops for f/, 1-stop for ei3, then 2-stops for filter) and see how i go. Or should I use a different filter-factor because it's MGiv and has a weird curve?

    (if this works I've got some 11x14 MGiv and HDPP coming from B+H, this thing could turn out to be a fun suitcase)
    An awful lot of electrons were terribly inconvenienced in the making of this post.

  9. #19
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    ps, just re-reading all the posts again. So maybe I did the test last night a bit too close to sunset and there wasn't enough blue light around and the Orange filter took out what little there was. So if I do a shot today at almost exactly midday, what's a good starting point for the filter-factor? It's a bit grey and cloudy today, but it might clear up to blue skies in the next 3 hours...
    An awful lot of electrons were terribly inconvenienced in the making of this post.

  10. #20
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    My experience with orange filters is that they require a very very long exposure with paper negatives... way higher filter factor than for film. For a yellow filter I use a filter factor of 4 ( 2 full stops ). I'm not sure what it is for orange because I gave up on them early on!

    But I'm glad to hear you are starting to have success and it sounds like you will dial it in soon!

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