Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-30-2009, 10:28 AM   #16
Veteran Member
OregonJim's Avatar

Join Date: Mar 2009
Location: Willamette Valley, Oregon
Posts: 1,329
QuoteOriginally posted by Squier Quote
The Split image screen has made life a bit easier, especially for someone who wears Bi-focals, but i have since found that i get better pictures when i remove my glasses, and change the diopter for viewing / taking snaps without them. I can see all the metering sharply too.
I find it easier to work that way, too. Can't compose/focus worth a darn with glasses on...

And Marc - you're getting pretty good at slipping in those car analogies...

05-30-2009, 10:38 AM   #17
Ole
Administrator
Ole's Avatar

Join Date: Sep 2006
Location: Copenhagen, Denmark
Photos: Gallery | Albums
Posts: 3,792
QuoteOriginally posted by MrCynical Quote
Not my best ever thread title, but here goes... I got my K20D yesterday, have recently done the obligatory 'focus test chart', and the results look fine to me. The catch is that I know absolutely nothing about photography and have an eye condition to boot

Anyway, could some more knowledgeable folks take a look at the image and verify that it is actually OK? Cheers

IMGP0037.jpg picture by Carzor_Stelatis - Photobucket

Had to upload it to Photobucket because I know that resizing images can sometimes cause issues that aren't there, or hide ones that do exist.

PS: Apologies for the comparatively shocking lighting, and also the glitch on the right side 10mm text is my printer not the camera :P
To my eyes that looks good, nothing to worry about.

Now, let's see some photos from Scotland!
05-30-2009, 10:44 AM   #18
Veteran Member
Squier's Avatar

Join Date: Apr 2009
Location: Oxfordshire UK
Photos: Albums
Posts: 707
QuoteOriginally posted by Marc Sabatella Quote
Now, that images looks great. But again, the focus adjustment feature has *nothing whatsoever* to do with MF. It *might* (although i don't know that for sure) affect when the focus confirmation hexagon lights up. but assuming you focus by actually looking at the image, the settigns in the focus adjustment have no more affect on focus than the brand of car you drive does.



I thought the image looked good too. I degugged the software adjustments because it made no difference, either better or worse. I tried + and - 300. Thats a huge difference but there was no change what so ever. So i guess i dont need it, and as you say, because i focus the way i do, it was a waste of time

The image is fine by itself.
05-30-2009, 10:45 AM   #19
Veteran Member
Squier's Avatar

Join Date: Apr 2009
Location: Oxfordshire UK
Photos: Albums
Posts: 707
QuoteOriginally posted by OregonJim Quote
I find it easier to work that way, too. Can't compose/focus worth a darn with glasses on...

I'm going for some contact lenses next Friday - we'll see if that makes anything easier.

05-30-2009, 11:22 AM   #20
Pentaxian




Join Date: May 2007
Location: WW community of Pentax users
Photos: Gallery | Albums
Posts: 2,128
QuoteOriginally posted by Squier Quote
...I only have to put my glasses back on for reading the menu which is much smaller text...
I think the the problem is not that the text is smaller: just no diopter adjustment for the menu .

QuoteOriginally posted by Marc Sabatella Quote
...It *might* (although i don't know that for sure) affect when the focus confirmation hexagon lights up...
I certainly would expect this to be the case. After all, it lights up when the camera 'decides' the subject is in focus. This should be in sync with any AF problems or cures, shouldn't it?
05-30-2009, 12:13 PM   #21
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
QuoteOriginally posted by Bart Quote
I certainly would expect this to be the case. After all, it lights up when the camera 'decides' the subject is in focus. This should be in sync with any AF problems or cures, shouldn't it?
Not necessarily. I can't say that I've ever seen anyone give a truly definitive explanation of how focus problems happen and ho they are "fixed" in software, but there various plausible theories thrown about include quite a few different possible scenarios. Considering that some times at least, it is the *lens* and not the camera that is found (or assumed) to be at fault, that suggests the issue in those cases at least can't be an issue with *detecting* when something is in focus, but rather, an issue with how the camera communicates with the lens regarding how to focus itself. That is, camera turns screw 47.3 degree clockwise in the belief that this should move the focus point forward by 7.3 feet (completely made up numbers, of course, but that *is* more or less how phase detect AF works). If the lens is slightly off in its gear ratios or whatever, then turning the screw by that amount might result in overshooting or undershooting the mark. It's entirely possible the focus adjustment works by altering how much the screw is turned (or the SDM equivalent of this), not by changing its own opinion of whether an object is in focus or not.

BTW, if you're thinking my explanation of how the focus system works can't be right - the camera surely checks focus after turning the screw and should keep trying until it thinks focus has been achieved: yes, it does to do that to some extent, but perhaps not enough. Read on on phase detect AF systems on Wikipedia or elsewhere if you're curious (and technically minded enough to wade through the discussions).

Last edited by Marc Sabatella; 05-30-2009 at 02:17 PM.
05-30-2009, 12:35 PM   #22
Pentaxian




Join Date: May 2007
Location: WW community of Pentax users
Photos: Gallery | Albums
Posts: 2,128
QuoteOriginally posted by Marc Sabatella Quote
...BTW, if you're think my explanation of how the focus system works can't be right...
Now, why would I think that .
No, your explanation sounds quite plausible, Marc and while I am curious, I'm not exactly technical
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, focus chart, look, pentax help, photobucket, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Trying to understand front focus/back focus thing 41ants Troubleshooting and Beginner Help 16 08-31-2010 08:42 AM
The Chart graphicgr8s General Talk 50 07-18-2009 04:38 PM
Focus chart revisited... AndrewShirley Photographic Technique 6 02-08-2009 06:45 AM
My focus chart garth1948 Post Your Photos! 4 09-30-2008 03:16 AM
Little red auto-focus thing tomaplaw Pentax DSLR Discussion 3 02-03-2008 05:43 AM



All times are GMT -7. The time now is 08:17 AM. | See also: NikonForums.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