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  1. #1
    My Passion Is Learning
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    Unhappy Not enough exposure time

    Hello, all.
    I just got the final pieces for my darkroom today! So I've started about running tests, the first one is to find my SCT. I'm finding that I'm struggling to get gray tones. Here's my details:

    Beseler 45M enlarger w/75 watt lamp
    Schneider-Kreuznach 135mm lens
    Ilford multigrade FB classic glossy paper
    I put a 4x5 FB+F negative in the negative stage and the grade 2 filter

    My first attempt to print I did three second brackets at f8. So I had exposure times of 3-30 seconds. The entire strip was completely black.

    My second attempt I did the same but at f22 and I got two gray tones (so 3 seconds and 6 seconds) with the rest of the strip bring black.

    The enlarger head is sitting where it does for enlarging a 4x5 negative to 8x10.

    My question is why I'm having to cut down so much light to get usable exposure times? Feels like the lamp is too hot or the lens is too close. But 75w seems appropriate and the head being halfway up the height of the stand seems appropriate also. Can anyone think of what I'm missing?

    Any direction would be lovely, I can't figure out what I'm doing wrong.

  2. #2
    Jac@stafford.net's Avatar
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    Re: Not enough exposure time

    Try developing a paper with no enlarger exposure. Let us know the results.
    .

  3. #3

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    Re: Not enough exposure time

    As you (I guess) saw a non suspicious projected image... only 3 things can go wrong:


    > Developer

    > Paper

    > Safety light


    IMHO the enlarger exposurse you made (f/22, 3 seconds) should not built density with development, guessing enlargement size was something common.

    I'd do that:

    1) Take a not exposed strip of paper, develop it without exposing it. Develop 2min does it go black ??

    2) Repeat development of a new unexposed paper strip (2 min) in total darkness. If now result is white then it was safety/ambient light. It if not it is paper or developer.

    3) Mix new developer to the right concentration, better is it is from a new purchase, try again.

    4) Buy a new paper box.

  4. #4
    Pastafarian supremo Rick A's Avatar
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    Re: Not enough exposure time

    Rick Allen

    Argentum Aevum

    practicing Pastafarian

  5. #5
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    Re: Not enough exposure time

    I tested to see if it was my safelight earlier. I let a piece of paper sit exposed to the safelight for a few minutes and developed it. Pearly white!

    That tells me it's not my safelight or paper. I made a print successfully but it was 15 seconds at f32.

    The blacks seems fine so I don't think it's fogging. Im using ilford multigrade developer diluted 1+9.

  6. #6

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    Re: Not enough exposure time

    Quote Originally Posted by TroyG View Post
    I tested to see if it was my safelight earlier. I let a piece of paper sit exposed to the safelight for a few minutes and developed it. Pearly white!
    That is not how I was taught to test a safelight. What you want to do is in total darkness put something flat and opaque on the paper such as a large coin or small book. And only then turn on the safelight for a minute or two. Then turn off the safelight and develop the paper in total darkness. Once it is in the fixer, then turn on your lights. If you see nothing where the opaque object was sitting then you know for sure that your safelights are OK. What may now appear "pearly white" might not actually be so.

    The next thing to do is to expose some paper as above with extended amounts of time to where your paper finally starts to show a difference between the exposed area and where the opaque object was. Then you know the limit that you can not exceed.

    Another thing to remember is "base fog" which has to do with sensitized materials - it takes a certain amount of energy start to get them to absorb light. If your safelights are a bit too bright, they can just barely start to expose your paper but not enough to form a noticable fog. But then when you put the paper under the enlarger and expose it in the normal manner you can have inconsistent results.

    In my experience, I always wanted a B&W darkroom that was as dark as possible, not one where the safelights were bright. I had only enough safelight illumination to just barely be able to barely make out where my tools were. Of course when I was printing and developing color enlargements, the room had to be completely black so being used to working in a very dark room came in handy.
    Last edited by AtlantaTerry; 19-Aug-2017 at 02:33. Reason: Cleaning up my prose.

  7. #7

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    Re: Not enough exposure time

    Are you positive the lens is at f22, etc..? A couple of mine have levers on the back to open them up completely for focusing even when set for f16, f22, etc.. I've left them opened up a couple of times by accident.

    Other than that, your methods and settings seem fine to me.

  8. #8
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    Re: Not enough exposure time

    This lens has no such release for the aperture, but I did check just in case! Though it's very precievibly darker at f32 than it is at f4.5. My question I guess would be, how dark should it be? My only logical conclusion is that my lamp is too bright. But I inspected it and it says it's only 75 watts. With the lens stopped down to f32, I can still see it quite easily under the safelight. Here's a photo of the circle of light (through the grade 2 filter) with the lens opened to f4.5 but with the regular lights on. I use three 500 lumen LED bulbs in this hybrid bathroom/darkroom, so it's not dim by any means! However the light from the enlarger is still very clearly visible. Click image for larger version. 

Name:	IMG_8136.jpg 
Views:	30 
Size:	47.1 KB 
ID:	168626

  9. #9

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    Re: Not enough exposure time

    Quote Originally Posted by TroyG View Post
    This lens has no such release for the aperture, but I did check just in case! Though it's very precievibly darker at f32 than it is at f4.5. My question I guess would be, how dark should it be? My only logical conclusion is that my lamp is too bright. But I inspected it and it says it's only 75 watts. With the lens stopped down to f32, I can still see it quite easily under the safelight. Here's a photo of the circle of light (through the grade 2 filter) with the lens opened to f4.5 but with the regular lights on. I use three 500 lumen LED bulbs in this hybrid bathroom/darkroom, so it's not dim by any means! However the light from the enlarger is still very clearly visible. Click image for larger version. 

Name:	IMG_8136.jpg 
Views:	30 
Size:	47.1 KB 
ID:	168626

    75w from a LED bulb throws x5 to x7 more light than a 75w from an incandescent lamp. For this reason you where needing x7 less exposure time, I guess.

    Please post what brightness has the image projected by enlarger, you can obtain the level in different ways:

    > A lux meter, like the (Amazon) Leaton Digital Luxmeter, 0.1Lux capable, $16 (interesting to hace something like that in the darkroom)

    > Use a Lux Meter app for the smartphone, it uses a sensor that's near screen for screen autobrigth feature. It gives too high readings with directonal light, but still a reference.

    > Use DSLR/SLR photometer and say the f/, shutter speed and iso

  10. #10

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    Re: Not enough exposure time

    Quote Originally Posted by TroyG View Post
    This lens has no such release for the aperture, but I did check just in case! Though it's very precievibly darker at f32 than it is at f4.5. My question I guess would be, how dark should it be? My only logical conclusion is that my lamp is too bright. But I inspected it and it says it's only 75 watts. With the lens stopped down to f32, I can still see it quite easily under the safelight. Here's a photo of the circle of light (through the grade 2 filter) with the lens opened to f4.5 but with the regular lights on. I use three 500 lumen LED bulbs in this hybrid bathroom/darkroom, so it's not dim by any means! However the light from the enlarger is still very clearly visible. Click image for larger version. 

Name:	IMG_8136.jpg 
Views:	30 
Size:	47.1 KB 
ID:	168626

    Please post what brightness has the image projected by enlarger, you can obtain the level in different ways:

    > A lux meter, like the (Amazon) "Leaton Digital Luxmeter" , 0.1Lux capable, $16 (interesting to hace something like that in the darkroom)

    > Use a Lux Meter app for the smartphone, it uses a sensor that's near screen for screen autobrigth feature. It gives too high readings with perpendicular directional light, but still a reference.

    > Use DSLR/SLR photometer and say the f/, shutter speed and iso

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