Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Notices

Go Back   Film and Darkroom User > Equipment > Cameras - medium format

  ***   Click here for the FADU 2015/2014 Yearbooks   ***

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 18th March 2018, 12:27 PM
EdmundH EdmundH is offline
Friend
 
Join Date: Jan 2016
Location: North Norfolk
Posts: 394
Default Mamiya 645 ProTL focusing problem

This is the newest camera in my collection by far, but a couple of weeks ago I shot a roll of film only to discover that every shot was focused in front of where I intended. Now a few months ago I did change the focusing screen for one with 35mm crop marks (it came with an alternative back for 135 film), but I'm sure I have used it successfully since then. Possibly I'd previously used smaller apertures which masked the issue.

Should I expect to adjust the focus after changing the screen? - presumably not.

There is apparently a known problem with the plastic mirror stop on this model breaking, but it looks ok.
Reply With Quote
  #2  
Old 18th March 2018, 01:26 PM
Martin Aislabie's Avatar
Martin Aislabie Martin Aislabie is offline
Friend
 
Join Date: Nov 2008
Location: Stratford-upon-Avon, England
Posts: 2,081
Default

Interchangeable focus screens are intended to be a direct swap for one another without the need for any other adjustment.

The fact that you are now focusing closer then intended indicates you have moved the ground glass away from the nodal point of the lens (and nearer to your eye)

There are 2 obvious possibilities :-

1) You have not managed to get the screen to sit down on to its correct mounting points.

2) You have put the new focus screen upside down - the focus screen has a ground glass side - and for example it should sit on the face nearest the mirror but you have inverted it so it sits against the microprism - if you follow me.

I hope this helps

Martin
Reply With Quote
  #3  
Old 18th March 2018, 03:01 PM
EdmundH EdmundH is offline
Friend
 
Join Date: Jan 2016
Location: North Norfolk
Posts: 394
Default

The screen has an offset tab which prevents putting it in the wrong way up, but I will check that it's seated properly when I get a moment.
Reply With Quote
Reply
Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Mamiya RB67 problem chriswhite Cameras - medium format 10 16th November 2017 07:03 PM
Mamiya RB67 Pro SD & 90mm K/L lens - flash sync problem. TonyMiller Cameras - medium format 7 23rd January 2016 10:27 PM
Mamiya 645 1000s, Sekor C lenses & focusing screens: AlanJones Cameras - medium format 3 9th August 2013 10:28 PM
Mamiya 645 1000s shutter problem? AlanJones Cameras - medium format 7 28th January 2013 08:23 AM
Mamiya RZ67 Pro II Query/Problem? Larry Cameras - medium format 7 5th August 2011 03:24 AM


All times are GMT. The time now is 12:43 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.