Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-02-2009, 12:47 PM   #1
Inactive Account




Join Date: Oct 2009
Posts: 2
Concentric circles in viewfinder?

Hello all. I am new here and just purchased an old Spotmatic. In looking into the viewfinder, I notice a series of concentric circles that fill the viewfinder side to side and top to bottom. The lines are faint in some areas, bolder in others. Somewhat distracting. Is this normal? Thanks.

10-02-2009, 01:02 PM   #2
Site Supporter
Nowhere Matt's Avatar

Join Date: Nov 2007
Location: Nowhere Land
Photos: Gallery | Albums
Posts: 2,316
QuoteOriginally posted by jds Quote
Hello all. I am new here and just purchased an old Spotmatic. In looking into the viewfinder, I notice a series of concentric circles that fill the viewfinder side to side and top to bottom. The lines are faint in some areas, bolder in others. Somewhat distracting. Is this normal? Thanks.
Maybe a improperly installed focus screen. Throw it against the wall really hard and... No don't! I'm just kidding about the throwing part. But I will wager someones else mentions the focus screen and not the part about throwing it.
10-02-2009, 01:41 PM   #3
pbo
Veteran Member
pbo's Avatar

Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 891
Are you talking about fresnel? That's made to aid you in manual focusing; without them, it'll be harder to tell if the image is in focus or not - particularly in the areas outside of center microprism, where you have to judge/guess by looking at the picture of the viewfinder (as opposed to relying on split and microprism band).
10-02-2009, 03:34 PM   #4
jds
Inactive Account




Join Date: Oct 2009
Posts: 2
Original Poster
These are concentric rings that are outside of the center microprism. In reading the manual, it says " Fresnel lens consists of many concentric rings which provide the brightest possible image on the ground glass". Is that what I am seeing? Almost like a target without the center circle. Thanks.

10-02-2009, 04:03 PM   #5
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
Which camera? Using the focus screen that came with? I find I don't even notice this, unless the light is *just* right (or just wrong, depending on your perspective. As others have said, it's on purpose; without this, manual focus would be impossible. But you stop noticing it after about a day.
10-02-2009, 04:42 PM   #6
Pentaxian
Wheatfield's Avatar

Join Date: Apr 2008
Location: The wheatfields of Canada
Posts: 10,135
It's normal. They used to sandwich a fresnel lens onto the groundglass to make the screen brighter.
You might be seeing a bit of delamination of the two components with the bolder rings.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, circles, pentax help, photography, viewfinder
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Project 52, Week 40 - Concentric Circles - Winners! jezza323 Weekly Photo Challenges 5 03-29-2009 04:19 AM
Project 52, Week 40 - Concentric Circles DanLoc78 Weekly Photo Challenges 13 03-24-2009 05:43 PM
Circles & Lines shiner Post Your Photos! 1 01-23-2009 04:40 AM
Can anyone tell me what these circles are? GeneV Pentax DSLR Discussion 17 12-18-2008 02:51 PM
Color Cloth Circles Eastern Shore Charlie Monthly Photo Contests 0 04-27-2008 03:37 PM



All times are GMT -7. The time now is 07:44 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top