Page 1 of 2 12 LastLast
Results 1 to 10 of 19

Thread: Help with Speed Graphic ground glass/fresnel

  1. #1

    Join Date
    Aug 2020
    Location
    San Diego
    Posts
    8

    Help with Speed Graphic ground glass/fresnel

    Hi everyone

    Iím new to LF and the forum.
    I recently got my first LF camera, the Pacemaker Speed Graphic. Iíve strictly used the ground glass for focusing. I was pretty satisfied with my camera as it was, but the ground glass had a crack in it, so I bought a ground glass/fresnel from Global Screen on eBay. It came with no instructions. I installed it and my results were awfully out of focus. I contacted the business after reading through a mess of a website. They sent me some scrambled instructions on how to install it. The pictures are still not in focus.
    Iíve searched all over the internet and seen some forum say you need to ďraiseĒ the glass because of the thickness...?
    I was hoping someone out there had the same setup and could tell me what Iím doing wrong, cause Iím frustrated.
    Even just point me in the direction of another tradition glass/screen setup that works.

    Thank you
    -Brian

  2. #2

    Join Date
    Dec 2018
    Posts
    330

    Re: Help with Speed Graphic ground glass/fresnel

    Brian, did your camera have a fresnel installed with the screen that got cracked?
    If you're adding a fresnel, you are adding a couple mm. of thickness, which will put your film out of sync with what you see on the ground glass.
    The correct orientation (IIRC) is:
    Lens
    Fresnel (smooth side towards lens)
    Ground glass (ground side towards lens)
    Hope this helps.

  3. #3

    Join Date
    Aug 2020
    Location
    San Diego
    Posts
    8

    Re: Help with Speed Graphic ground glass/fresnel

    Hi Dugan

    Yes, the camera had a fresnel, but I removed that before installing the new one. The one I ordered has the gg and fresnel in one piece and then a protective screen on top. From the instructions given to me by the Global Screen people, the matte side of the piece should face the photographer.
    The fresnel/gg is just way thinner than the original setup and I’m wondering if that’s what’s throwing the focus off...

  4. #4

    Join Date
    Jan 2019
    Posts
    302

    Re: Help with Speed Graphic ground glass/fresnel

    The order should be from lens to eye:

    Fresnel polished side
    Fresnel corrugated side
    Ground glass ground (frosted) side
    Ground glass polished side

    This combination requires a proper placement of the GG, as the focus plane is shifted by about 1/3 of the thickness of the Fresnel lens.

    If you have an integrated version then you donít know what thickness the fresnel adds, so youíll have to try different shims until itís adjusted and the GG sits on the same plane as the film in the holder. Itís going to be painful unless others have better ideas.

  5. #5

    Join Date
    Aug 2020
    Location
    San Diego
    Posts
    8

    Re: Help with Speed Graphic ground glass/fresnel

    Thank you

    Yeah, I understand the original setup.
    When I bought this setup I thought I bought a fresnel and a ground glass, since that’s what the description indicated.
    Some forums online recommended these, but I haven’t found anyone explaining how they use it.
    It seems weird to me that a combination screen that’s half the thickness of the original fresnel would get the same results.
    The website is useless.
    I guess at this point I should start looking for a new set of ground glass and fresnel.

  6. #6

    Join Date
    Jan 2019
    Posts
    302

    Re: Help with Speed Graphic ground glass/fresnel

    Quote Originally Posted by Birthbackwards View Post
    Thank you

    Yeah, I understand the original setup.
    When I bought this setup I thought I bought a fresnel and a ground glass, since thatís what the description indicated.
    Some forums online recommended these, but I havenít found anyone explaining how they use it.
    It seems weird to me that a combination screen thatís half the thickness of the original fresnel would get the same results.
    The website is useless.
    I guess at this point I should start looking for a new set of ground glass and fresnel.
    If itís really thin, like 0.5mm and the older fresnel was like 2mm, you could try using something to temporarily shim back the fresnel by about 2/3 mm or a smidgen less (basically ignoring the new fresnel thickness). That should get you really close. In 2-3 tries you ought to be able to nail it down. That may be cheaper than buying a new one, although i understand its frustrating...
    Are you focusing and shooting with the same aperture? Just to make sure the lens is not causing a focus shift when you step down.

  7. #7

    Join Date
    Aug 2020
    Location
    San Diego
    Posts
    8

    Re: Help with Speed Graphic ground glass/fresnel

    Quote Originally Posted by Kiwi7475 View Post
    If itís really thin, like 0.5mm and the older fresnel was like 2mm, you could try using something to temporarily shim back the fresnel by about 2/3 mm or a smidgen less (basically ignoring the new fresnel thickness). That should get you really close. In 2-3 tries you ought to be able to nail it down. That may be cheaper than buying a new one, although i understand its frustrating...
    Are you focusing and shooting with the same aperture? Just to make sure the lens is not causing a focus shift when you step down.
    It IS really thin.
    Half the thickness of one of the screens I removed, which were about the same in thickness. What throws me off is that since this screen is matte on one side and fresnel groove on the other, I'm guessing it should be shimmed so that the matte is located where the matte surface were located on my old setup. Where the matte screen would meet the fresnel, to created a point of focus. Right?
    It annoys me I bought this thing. Zero help from its creators and their website looks like it was made in 95', -all the text looks like stream of consciousness, continuously jumping back to bits of info about france and how the fresnel was created there. No help whatsoever.

    To answer your other question, I've shot several lenses, different apertures. I didn't have problems focusing before, other than the screen was old, had scratches, pencil notes and cracks in it. I still have that setup and might just go back to it.
    But I'm pretty stubborn and I paid $100+ for this bright beautiful piece of frustration.

  8. #8
    Jon Shiu's Avatar
    Join Date
    Nov 2003
    Location
    Mendocino, California
    Posts
    1,286

    Re: Help with Speed Graphic ground glass/fresnel

    What you call the matte surface should face towards the lens, thus the thickness is not of consequence.
    my black and white photos of the Mendocino Coast: www.jonshiu.com

  9. #9

    Join Date
    Aug 2020
    Location
    San Diego
    Posts
    8

    Re: Help with Speed Graphic ground glass/fresnel

    Quote Originally Posted by Jon Shiu View Post
    What you call the matte surface should face towards the lens, thus the thickness is not of consequence.
    Do you have experience with the combo screen, cause that would mean the fresnel groove is pointing towards me, doing the opposite of the instructions I've gotten from the creators.
    At least that's what I understood from the email.

    "1, You must remove all the original ground glass and Fresnel lens.
    2, what you received is 2in 1 combination of ground glass and Fresnel lens. The transparent grid piece is a protective for the Fresnel/gg
    3 the combination piece should face the camera taking lens with matte side facing photographer. And the grid transparent piece put above the combination piece."

  10. #10

    Join Date
    Dec 2018
    Posts
    330

    Re: Help with Speed Graphic ground glass/fresnel

    Brian, check your PM's.

Similar Threads

  1. How to set Fresnel glass and the ground glass of Speed Graphic?
    By coko123120 in forum Cameras & Camera Accessories
    Replies: 2
    Last Post: 11-Apr-2014, 09:25
  2. Replacing Fresnel and Ground Glass on a Speed
    By rbk61 in forum LF DIY (Do It Yourself)
    Replies: 4
    Last Post: 30-Sep-2013, 13:35
  3. Speed Graphic Ground Glass (DIY Grid lines)
    By tenderobject in forum LF DIY (Do It Yourself)
    Replies: 10
    Last Post: 11-Aug-2013, 00:28
  4. Ground glass and fresnel for speed graphic?
    By mike rosenlof in forum Cameras & Camera Accessories
    Replies: 10
    Last Post: 26-May-2011, 09:23

Tags for this Thread

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
  •