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  1. #71
    RalphLambrecht's Avatar
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    Quote Originally Posted by Sirius Glass View Post
    More more for the list.

    If the number of rods and cones were increased in our eyes, we would not see any better because the evolution of the resolution of the eye stopped when the evolution got to the diffraction limit of the eye.

    Steve
    Not sure about that.

    More cones might help. I don't think my eyes are diffraction limited at f/2.

    Not that I'm complaining or arguing with my maker, but...
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  2. #72
    keithwms's Avatar
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    I don't see what diffraction limit has to do with light sensitivity nor the number of receptors. the receptors aren't close-packed in a Bayer grid or something, they have an unusual distribution (hence blind spots). What we see and how sensitively we see it depends very much on the angle at which we look. E.g. optimal scotopic sensitivity is not head-on, this is well known to observational astronomers.

    Now, there is a correlation between the diffraction limit and the size of the photoreceptors in the eye: different animals have different sized receptors. But the spectral sensitivity of the individual receptors... the quantum efficiency, if you will.... is a different topic.
    "Only dead fish follow the stream"

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  3. #73
    fotch's Avatar
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    If Black is perfect, why accept less?

    I can understand that some situations are near impossible to solve however, in that case, a person has to accept the fact that it may or may not be a problem is some or all cases.

    But, if its something a person and control, why not see the light and block it out? To me, this is part of the fun of making ones darkroom, a challenge to my ability.
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  4. #74

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    It should be just as dark as the deleted post has been deleted.
    I brake for fixer!

  5. #75
    Ian Grant's Avatar
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    Don't waste too much time the OP decided APUG's answer's weren't good enough and is now looking elsewhere

    Ian

  6. #76
    keithwms's Avatar
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    Quote Originally Posted by fotch View Post
    If Black is perfect, why accept less?
    Because unless you live in a cave there is no perfect black? And because a lot of folks don't have access to a perfect darkroom anymore? There are a lot of dual-purpose rooms being used these days, it's not like everyone can dedicate a perfect, windowless room. Newcomers should not be given the false impression that they can't make do with a room that isn't textbook perfect.

    Also there are many ways to get a little extra base fog in a neg, not just some stray light in an imperfectly dark room that isn't hermetically sealed.

    People speak of base fog like it's an intestinal polyp or something. I am still using 40 year old panatomic x that wasn't cold stored and yeah there is all kinds of base fog and it's doesn't amount to a hill of beans. I do have benzotriazole on my shelf and I have yet to use it. Seriously, if base fog is cutting into my contrast, then I guess I am lucky because I am still printing just about everything at grade 2 or 3. And in my darkroom I see my hands, I see my feet, I have two timers with bright glowing faces, a leaky safelight and a leaky enlarger bellows.... not to mention my discovery that residual wd2d+ glows when you transfer the film into the stop bath. So many things I *thought* were big crises.

    If someone is having a really hard time lightproofing a room and is working with fast films then my advice is just to invest in a big film changing tent e.g. 11x14, put a big kitty litter tray in that, and load up all your chems in that. Short of dev'ing HIE in high noon sun, you can use a Harrison tent just about everywhere.

    Again, as has been said many times, people simply need to test. We can't conduct exposure checks over the internet so none of us knows who does or does not have a problem. Test and all will be clear.
    "Only dead fish follow the stream"

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  7. #77
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    Quote Originally Posted by Mahler_one View Post
    ... IF the light is coming in from the bottom of the door, and is rather faint....since light travels in a straight line, if the light is not bouncing off of anything bright, how can such light affect film on a table some feet above and to the side of the bottom of the door?
    I always find these "since light travels in a straight line" assertions very interesting. Light does travel in a straight line IF.... (insert the many ideal state conditions here). The key point is light coming in under a door is getting scattered by many things like the uneven surface of the floor and even dust in the air. If it were not, then how could you see it when your eyes are 5 feet above the floor?

    I used to not worry about this stuff too until I attended one of John Sexton's Expressive Print workshops and saw the lengths he went to insuring that no white light hit his paper unless it passed through the negative. He devoted a fair amount of time to this subject during the workshop.

  8. #78

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    My "darkroom" ia a laundry room. It has ventilated folding doors and a window whose only covering is a blind. The door itself is made of nothing but slanted wood strips. Light tight? Not in a million years. Add to that the furnace, right there inthe room, and the hot water heater, gas-burning, light emitting beasts - plus white walls and 3 large white appliances - and I have no hope of darkness. I can only work in it at night. During the Winter it works out ok but by summer I have to stay up way past my bedtime to print. My prints don't seem to be affected by it, or I'm just used to the results as I have nothing else to compare to.
    In life you only get one great dog, one great car, and one great woman. Pet the dog. Drive the car. Make love to the woman. Don't mix them up.

  9. #79

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    Simple solution for light coming under the door.....find one or two of those bean bags that one can use to put by the door in winter time to prevent drafts from entering the house. Close the darkroom door, put down the bags, forget about it....end of problem...low tech solution, and you can still use the bags to prevent the drafts....of course, one can always train the dog to stretch out in front of the bottom of the door as well...:{

  10. #80
    RalphLambrecht's Avatar
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    Quote Originally Posted by Wolfeye View Post
    My "darkroom" ia a laundry room. It has ventilated folding doors and a window whose only covering is a blind. The door itself is made of nothing but slanted wood strips. Light tight? Not in a million years. Add to that the furnace, right there inthe room, and the hot water heater, gas-burning, light emitting beasts - plus white walls and 3 large white appliances - and I have no hope of darkness. I can only work in it at night. During the Winter it works out ok but by summer I have to stay up way past my bedtime to print. My prints don't seem to be affected by it, or I'm just used to the results as I have nothing else to compare to.
    Well put. Much better than the folks who claim never to have had a problem with a little light leak. They don't know what they are missing.

    John Sexton knows what he's doing!
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

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