Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: Enlarger sizing

  1. #1

    Join Date
    Dec 2012
    Location
    Up North, UK
    Posts
    202

    Enlarger sizing

    I'm going to build a 5x7 enlarger but I also want to print 5x4, 120, and possibly even 35mm.

    I have seen posts about using a LF camera in reverse as an enlarger (with a light source behind the neg).

    Light bulb moment... Does this mean I can get any 'neg to lens' and 'neg to bed' dimensions required by simply putting the relevant enlarger lens on a camera, using an appropriate film size mask on the ground glass, and paper size outlines stuck to a wall?

    That would be great - but maybe there is some other arcane magic at work with an enlarger?

    Thanks,
    Peter

  2. #2
    Tin Can's Avatar
    Join Date
    Dec 2011
    Posts
    17,733

    Re: Enlarger sizing

    More less, it is a simple thing

    Then people get nuts

    Just start and try something with 4X5

    Use 135 or 150mm lens, any lens

    The trick is getting everything aligned

    Lamp Light, Neg, Lens, Paper

    Draw it first and use cones aka triangles

  3. #3

    Join Date
    Dec 2012
    Location
    Up North, UK
    Posts
    202

    Re: Enlarger sizing

    Thanks Randy. The camera thing is just to get the relevant design parameters for the different formats.

    I've already got a 210mm enlarger lens (for 5x7), plus a 7.5" Ektanon and some very useful bits from an Omega or MPP (see What enlarger is this from).

    The idea is birch ply, homemade big square bellows, Openbuilds V-Slot rails and wheels, Acme lead screw for fine focus, and Marco's LED light unit and controller. Horizontal or vertical orientation (aka hung on the wall to get it out of the way).

    Yep, I always make full size drawings, saves lots of pain later.

  4. #4
    Tin Can's Avatar
    Join Date
    Dec 2011
    Posts
    17,733

    Re: Enlarger sizing

    All good!

    I am also working with V-Slot and wheels with Horseman parts to try and make Auto Focus Portrait camera

    The tech is ready and sold cheap from China

  5. #5

    Re: Enlarger sizing

    Sounds like a really fun project! Make sure that all surfaces between the lens and the negative are flat black. I have had an enlarger from a rather well known company (Xxxxx) that had medium gray interior paint which did cause irritation with any lens.

  6. #6

    Join Date
    Sep 2008
    Location
    Sarnia, Ontario, Canada
    Posts
    796

    Re: Enlarger sizing

    Peter,

    One can calculate the distance from the negative stage to the paper stage for various lenses to better understand maximum magnification.

    Useful when one has limited headroom to raise the enlarger head.

    Let me know if you want that spreadsheet calculation.

    Len

  7. #7

    Join Date
    Mar 2005
    Location
    Newbury, Vermont
    Posts
    1,376

    Re: Enlarger sizing

    Peter...you mentioned birch plywood, square bellows, and rails on wheels.

    Well, here is my birch ply DIY horizontal enlarger (re-crafted from an earlier DIY vertical enlarger)...with square bellows - and on wheels. But instead of rails I used the rear motorized frame (de-sprung) from an older Beseler 45M enlarger. Focus bed from an old Linhof 5x7 technical camera for focus. While this enlarger works for 8x10, I currently have it set up to accept my Heiland 5x7 LED VC head (which otherwise lives on my Zone VI series 2 enlarger).

    At any rate...the first photo is a front view, while the second is from the rear - although from a bit further away to show the rest of my "large print" (up to 40x60) setup. The easel, which is mounted to the wall, un-clips after doing test strips and is then carried (is lightweight gatorboard) to the table in the foreground, where the next length of photo-paper is rolled into it (from dowel paper-holder) and trimmed to length, prior to re-clipping onto wall (held by pre-positioned stops) for the actual exposure. Oh...and in the left(ish) background, you will see the large birch ply/epoxy processing tray, which sits on my sink in the attached darkroom (see third photo). Hope this helps...and good luck!

    Click image for larger version. 

Name:	DIY Horizontal Enlarger.jpg 
Views:	27 
Size:	54.1 KB 
ID:	220380 Click image for larger version. 

Name:	Big Print Setup.jpg 
Views:	25 
Size:	59.7 KB 
ID:	220381 Click image for larger version. 

Name:	Fill Side w:Holddowns.jpg 
Views:	24 
Size:	60.5 KB 
ID:	220382

  8. #8

    Join Date
    Dec 2012
    Location
    Up North, UK
    Posts
    202

    Re: Enlarger sizing

    Quote Originally Posted by Tin Can View Post
    All good!

    I am also working with V-Slot and wheels with Horseman parts to try and make Auto Focus Portrait camera

    The tech is ready and sold cheap from China
    That sounds interesting... How will the auto-focus work?

    (Realisation that I have no idea how auto-focus works - and I might be hijacking my own thread here )

  9. #9

    Join Date
    Dec 2012
    Location
    Up North, UK
    Posts
    202

    Re: Enlarger sizing

    Quote Originally Posted by Conrad . Marvin View Post
    Sounds like a really fun project! Make sure that all surfaces between the lens and the negative are flat black. I have had an enlarger from a rather well known company (Xxxxx) that had medium gray interior paint which did cause irritation with any lens.
    Thanks for the tip!

  10. #10

    Join Date
    Dec 2012
    Location
    Up North, UK
    Posts
    202

    Re: Enlarger sizing

    Quote Originally Posted by Len Middleton View Post
    Peter,

    One can calculate the distance from the negative stage to the paper stage for various lenses to better understand maximum magnification.

    Useful when one has limited headroom to raise the enlarger head.

    Let me know if you want that spreadsheet calculation.

    Len
    Thanks Len, yes that calculation would be really useful - if possible, could you post it here?

    (I replied here rather than by PM because it may be useful to others in the future who find this thread).

Similar Threads

  1. Need help with filter sizing.
    By Xia_Ke in forum Lenses & Lens Accessories
    Replies: 27
    Last Post: 2-Apr-2019, 00:38
  2. lensboard sizing
    By quixoticcassandra in forum Lenses & Lens Accessories
    Replies: 15
    Last Post: 14-Jan-2015, 17:10
  3. Sizing Tripod: RRS TVC 33 vs 33S
    By dodphotography in forum Gear
    Replies: 2
    Last Post: 2-May-2014, 21:14
  4. Sizing paper
    By jfert92 in forum Darkroom: Film, Processing & Printing
    Replies: 1
    Last Post: 16-Feb-2012, 19:57
  5. Sizing photos for website
    By Big Fish in forum Business
    Replies: 41
    Last Post: 14-Jan-2011, 19:50

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
  •