Page 2 of 2 FirstFirst 12
Results 11 to 16 of 16

Thread: LED Lights in an Enlarger Head

  1. #11
    umop episdn
    Join Date
    Mar 2007
    Location
    Texas
    Posts
    144

    Re: LED Lights in an Enlarger Head

    www.deadbread.com/crumbs/23c.html Hey, that's my website!

    I've just built a second LED head to improve on the original. It's white LEDs + UV LEDs combined. The head is finished and on a new enlarger. I'm currently testing the new head and until I've done some extensive printing I won't have anything concrete, but so far the UV LEDs did the trick. It's an excellent match for a 5+ filter on my condenser and cold light enlargers.

    As part of the testing process I test printed with blue only (470nm) LEDs. They didn't have near the contrast of UV (405nm) LEDs on variable contrast paper.

  2. #12

    Join Date
    Oct 2008
    Location
    Summerville, SC
    Posts
    2,016

    Re: LED Lights in an Enlarger Head

    Danny,

    We passed a couple of emails back and fourth last year when I was thinking of making an 8x10 inch version. I never really found the time! I do think it was a neat setup. Are you going to publish an article with your latest findings?

  3. #13

    Join Date
    Apr 2008
    Location
    Jamul, CA
    Posts
    100

    Re: LED Lights in an Enlarger Head

    Heiland in Germany makes a very nice split grade VC head: http://www.heilandelectronic.de/.
    It uses 100's of blue, green and red LED's and they have sizes for many enlargers. Looks pretty good but I didn't see any prices on the page I visited.

  4. #14
    the Docter is in Arne Croell's Avatar
    Join Date
    Dec 1997
    Location
    Huntsville, AL
    Posts
    1,210

    Re: LED Lights in an Enlarger Head

    Quote Originally Posted by Danny Spence View Post
    www.deadbread.com/crumbs/23c.html Hey, that's my website!

    I've just built a second LED head to improve on the original. It's white LEDs + UV LEDs combined. The head is finished and on a new enlarger. I'm currently testing the new head and until I've done some extensive printing I won't have anything concrete, but so far the UV LEDs did the trick. It's an excellent match for a 5+ filter on my condenser and cold light enlargers.

    As part of the testing process I test printed with blue only (470nm) LEDs. They didn't have near the contrast of UV (405nm) LEDs on variable contrast paper.
    You might want to check whether you're prints are fully in focus. Years ago there were reports that since enlarger lenses are not corrected for UV and VC papers were more UV sensitive one could get a significant focus shift for that part. The test and the numbers can be found in Ctein's book "Post exposure". Actually some of the "Apo"-designated lenses were worse than some others if I remember it correctly.

  5. #15

    Re: LED Lights in an Enlarger Head

    Pete, I have an LED head that Huw built. It uses blue and green LEDs and is variable contrast/constant exposure. It works great. If you are serious send Huw an email as he knows exactly how to do this.

  6. #16
    umop episdn
    Join Date
    Mar 2007
    Location
    Texas
    Posts
    144

    Re: LED Lights in an Enlarger Head

    Jon, yep!

    Arne, I've read it cover to cover several times. It's a great technical book without being overly nerdy. Ctein's work with VC paper and UV sensitivity was my influence for the new LED head. The focus shift is a twofold problem: VC papers are now UV sensitive and enlarger lenses just can't be made to correctly focus UV at the same time as visible light.

    I've got two ways to deal with possible focus shifts: I have a built in switch to turn the UV LEDs on or off when not needed. Second, I'm not having to deal with much of an enlargement factor with 4x5. Ctein's work was with enlarged 35mm; about an 8X enlargement to 8x10 prints. I'll be using the head for 4x5 enlarged to 8x10 and 11x14. Not as much of an enlargement, so the focus shift may not be as much of an issue.

Similar Threads

  1. Has Anyone Used a Zone VI LED VC 4x5 Head???
    By neil poulsen in forum Darkroom: Equipment
    Replies: 7
    Last Post: 2-Jul-2008, 17:35
  2. diffusion head for D-2 enlarger
    By d.s. in forum Darkroom: Film, Processing & Printing
    Replies: 16
    Last Post: 22-Sep-2003, 14:33

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •