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  1. #11
    cliveh's Avatar
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    Quote Originally Posted by jernejk View Post
    I'm printing 6-10x enlarged 35mm film, I think it's of pretty normal density. The color head has a 100w halogen lamp, but the exact specifications are not given.

    Anyway, I've been trying to figure something and it seems a layer of paper-towel tissue in the filter tray gives me an extra stop, two layers two stops...
    Need to check the heat though.
    Paper-towel tissue in the filter tray sounds like a fire starter and not ideal. Can't you use a smaller wattage bulb?

    “The contemplation of things as they are, without error or confusion, without substitution or imposture, is in itself a nobler thing than a whole harvest of invention”

    Francis Bacon

  2. #12

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    Quote Originally Posted by jernejk View Post
    I will try, but on paper I should actually open it to 5.6 it seems http://www.coinimaging.com/nikon_el50-28n.html
    Well, sure, the MTF curves show you that highest resolution of the optics is at some F value. But honestly, the optics resolution is the least of your concerns when printing on the enlarger. The biggest factors that affect print sharpness are enlarger vibrations, head alignment and negative flatness/pop and you have to deal with these before worrying about lens diffraction. At least that was my experience.

  3. #13

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    Quote Originally Posted by cliveh View Post
    Paper-towel tissue in the filter tray sounds like a fire starter and not ideal. Can't you use a smaller wattage bulb?
    It's not ideal, but I don't think it's really hazardous. The enlarger is like this one http://www.flickr.com/photos/vegaluthier/4409261714/
    The bulb is where you see the cooling slots on the head the tray is in the enlarger body. The head is actually a separate compartment and most heat stays there.

    i need to check the bulb. There are no specs really, it has 5cm diameter and uses 12V. I'll try to find something after Easter holidays (the stores are closed). It would be cool to try LED actually.

  4. #14
    Nicholas Lindan's Avatar
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    Dialing in both yellow and magenta will add density.

    You can also place an ND filter in the filter tray, above the negative or in a below-lens filter holder. The most cost-effective filters are from Rosco (or the Lee equivalent) http://www.bhphotovideo.com/c/produc...6_Neutral.html A 0.6 will add 2 stops (4x) to the exposure time, a 0.9 OD will add 3 stops (8x) and a 1.2 will add 4 stops (16x).
    DARKROOM AUTOMATION
    f-Stop Timers - Enlarging Meters
    http://www.darkroomautomation.com/da-main.htm

  5. #15

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    How LARGE are you printing?
    If you are not printing a 35mm frame at larger than 11x14, and maybe larger than 16x20, don't worry about the "optimal" aperture of the lens. The practical side is, unless you use a magnifier and look at a very detailed image up close, you likely won't see the difference anyway.

    To prove this theory, make a print at your expected print size at both the "optimal" aperture and at f/16 (the smallest aperture on the EL-Nikkor 50/2.8) and see if you can see a difference in the images. I would guess that you will not see a difference.

    Also if you are doing that detailed work, you would have to use a glass carrier to make sure that the negative is FLAT and not bowed, and you would have to make sure that your enlarger is in alignment on all 3 planes (easel, negative, lens).

    Light = heat.
    That is why negatives sometimes pop/warp when you are printing them.

  6. #16

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    how about frosted glass.

  7. #17

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    I explored my options today in a hardware shop. I came up with an idea to replace the current 12V setup with GU10 on plain 230V. This way I would get rid of the transformer which only takes space and adds complexity. It would also open a possibility to experiment with LED.

    It seems the procedure to switch to GU10 is fairly simple. The GU10 bulbs fit nicely. See LED mounted in place of the original here: https://www.dropbox.com/s/qkt04xpjge...402_194654.jpg

    All i need to do to change to Gu10 is:
    - replace current head cable with 230V + ground (easy as it's bridged to internal wires like this: https://www.dropbox.com/s/gkczjpu3v4...402_200542.jpg
    - replace existing connector in the head with GU10 one, but reuse internal cables
    - ground the head

    Any reasons why I shouldn't do it?
    Also any reasons not to use LED? It has a lag before it turns one which could make timing non-linear at short times.. but other than that?

  8. #18

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    The conversion is done :-) https://www.dropbox.com/s/a4klnvmz6x...403_121420.jpg

    Haven't tried it yet, but it seems quite ok.

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