Jump to content
Greg Lytle

Focusing question from amateur with split viewfinder

Recommended Posts

Hi folks,

I own a Porst 650 XL and Porst 1500 XL Microcomputer and was wondering about the the precision of the split viewfinders on each of them. I read the instructions which instruct me to zoom in all the was, focus zoomed in, the zoom out to a desired wider angle. When I zoom in to focus, the split finder lines up, but the split finder lines do not stay aligned upon zooming out and I guess I thought the lens should be parafocal upon zooming. Does this mean my split viewfinder is not accurate? Any guidance is appreciated.


Greg Lytle

Share this post

Link to post
Share on other sites

Split-image rangefinders can be prone to error caused by the accommodation of the eye if there's no ground glass, but it's possible the lens is out of adjustment. Try a tape measure test to see if your focusing matches up with the lens scale. I would tend to trust the zoomed-in setting.

Edited by Mark Dunn

Share this post

Link to post
Share on other sites

Thanks Mark, I did just what you suggested, I think. I put the 1500 on a tripod and put a flat focus target 8 feet from the film plane. I then set the focus of the lens to 8 feet. It seemed dead-on. The focus ring does not move at all when zooming out, and it appears the rest of the field of view stays in focus, so I think that worked. I will do the same test on the 650 tonight. I appreciate your help!


Greg Lytle

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Gamma Ray Digital Inc

    G-Force Grips


    Wooden Camera


    Abel Cine

    FJS International

    Paralinx LLC

    Tai Audio

    Rig Wheels Passport

    Visual Products

    Ritter Battery

    Broadcast Solutions Inc

    The Original Slider

    Media Blackout - Custom Cables and AKS

    New Pro Video - New and Used Equipment

    Just Cinema Gear

    Metropolis Post

    Serious Gear

    Cinematography Books and Gear
  • Create New...