Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-06-2010, 11:29 AM   #1
Banned




Join Date: Jun 2010
Photos: Gallery | Albums
Posts: 190
Difficulty in focusing with manual lens on k-x

Hello,

I asked again this last week, but the server went down after that.

Basically I recently bought a manual 50mm lens for my k-x. However almost half of the pics I take are out of focus. How would I be able to understand where and when the k-x focuses?
When I initially bought the k-x I thought that I wouldn't care so much about focus points in viewfinder, however now I just wished they existed!

Would you have any tips for me, in order to understand better and easier onto which items is the lens focusing on?

Thanks in advance

12-06-2010, 11:57 AM   #2
hcc
Pentaxian
hcc's Avatar

Join Date: Nov 2009
Location: Brisbane, Australia
Photos: Gallery | Albums
Posts: 3,533
I do not have the K-x but the K-7. From my own (and limited) experience with MF, I suggest a few tricks:

- set the camera to centre focus; in absence of focus points, you know that always where the picture centre is;

- use the focus confirmation to have some idea of the typical MF setting; eventually adjust the MF ring slightly if you feel it is needed;

- in doubt, I take 2-3 identical shots, but from very slightly different positions; I often take the 2nd shot slightly forward (~5-10 cm) from my initial position and another slightly behind (~ 5-10 cm) from the initial shot; for example, by leaning slightly forward then slightly backward.

Hope that the comment will help...
12-06-2010, 12:24 PM   #3
Veteran Member
paperbag846's Avatar

Join Date: Jul 2010
Photos: Gallery
Posts: 2,396
It's hard with lenses faster than 2.8, because the screen increases the DOF visible in the viewfinder.

There are 2 tricks:

1) Learn to look for the image "pop" on the screen, and develop the reflexes to shoot right at that point.

2) Use catch-in-focus.
12-06-2010, 12:39 PM   #4
Pentaxian
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,864
The camera will only use the center focus point for lenses without an A position on the aperture ring, even with the 11-point viewfinder-visible system. I thought you needed at least a KA-mount lens to use multiple focus points, but with the camera and lenses in my lap, I can't get anything except the center to work. So don't worry much about what your camera doesn't have.

The first step is to set the viewfinder diopter. You can also take some test shots to confirm that what you see in the VF is what the sensor sees too. Put a newspaper on the floor in some bright light or daylight. Set your lens wide open. Use a distance close to the minimum focus distance on the lens. Focus on a particular line of text in the middle of a paragraph and shoot. Look at the photo and make sure the same line you chose is in perfect focus. If not, that needs to be fixed.

MF is not quite so easy as it sounds. Practice will help a lot. This can be formal and rigid, like setting up a static scene with objects at varying distances, shooting and keeping score. Or just do it, pay more attention to what you see in the viewfinder and how precise you need to be. I had a split prism screen for 3+ years and it was great. Now I find that I can mostly get by without it, using practice instead. I also do "focus-bracketing" as described above.

12-06-2010, 12:53 PM   #5
Site Supporter
Nowhere Matt's Avatar

Join Date: Nov 2007
Location: Nowhere Land
Photos: Gallery | Albums
Posts: 2,318
I agree with most of what Dave said. Check your diopter and then a few simple focus tests to help see where your issue lies. And shooting at shallow depths of field does take a good, steady handle on focusing.

Waiting for trap focus to come to you would not teach you much.
12-06-2010, 01:00 PM   #6
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,271
+1 for Dave and MAtt

I would add that a new focus screen would make life a lot simpler
there are numerous ones out there, they all kill the Spot metering on the camera but don't affect aqnything else and make focussing far easier (at least for me)

a site with a good selection of screens and good samples of the differences in the screens is

Focusing Screen
12-06-2010, 01:40 PM   #7
Ira
Inactive Account




Join Date: Mar 2009
Location: Coral Springs, FL
Photos: Gallery | Albums
Posts: 5,216
It's not easy, but people have focus problems with auto F lenses also.

I shoot strictly manual lenses (see my signature), and it's still a challenge.

And that's what makes it fun.

I was never interested in catch-in focus, because I don't want the shutter to fire unless I tell it to. But a lot of people love catch-in, so maybe I'll try it one day.

Gotta buy the aluminum tape though for my M42s.

Last edited by Ira; 12-06-2010 at 01:47 PM.
12-06-2010, 01:53 PM   #8
Veteran Member
paperbag846's Avatar

Join Date: Jul 2010
Photos: Gallery
Posts: 2,396
It's also an issue of what you are shooting. I love the feel of manual focus, it's just fun. But when a person runs by, or a "moment" happens, or an animal leaps out of the bushes, or my convoy is attacked by insurgents, I don't want ANYTHING to get in the way of an in focus shot when I only have 1/2 a second to prepare myself.

AF.C + an AF lens is one solution, and catch-in focus is another.

For calmer scenes, though, manual focus is "where it's at"... it's just more fun.

12-06-2010, 01:54 PM   #9
Veteran Member
Coeurdechene's Avatar

Join Date: Oct 2010
Location: madrid
Photos: Albums
Posts: 833
If you keep the button that lets you select between auto and manual focus on the camera body on autofocus the camera will beep when it's focused...(when the camera identifies that the place where your autofocus is pointed is in focus...)...
The beep is really helpfull when starting..later on you'll get used to it and start doing it better...
12-06-2010, 01:55 PM   #10
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
one thing you may find, related to Ira's comment is that the focus throw of many manual focus lenses is longer than the focus throw of the corresponding AF lenses. as a simple generalization (although I am sure there are contradictory examples out there) it is easier to manually focus a MF lens than an AF lens only because the focus throw is longer and hence more precise.
12-06-2010, 02:00 PM   #11
Site Supporter
grhazelton's Avatar

Join Date: Jul 2007
Location: Jonesboro, GA
Photos: Albums
Posts: 1,829
The focus confirmation beep and catch focus are handy, but the best deal for manual focus is a proper replacement screen. I bought a KatzEye for my K10 and find that it makes focusing my 50mm f1.2 feasible; before it was really a matter of luck. Losing the spot function - I think it might be compensated for with an exposure adjustment - is something I haven't missed since I got used to center weighted exposure on my LX and MX. YMMV, of course!
12-06-2010, 02:27 PM   #12
Veteran Member
paperbag846's Avatar

Join Date: Jul 2010
Photos: Gallery
Posts: 2,396
QuoteOriginally posted by Lowell Goudge Quote
it is easier to manually focus a MF lens than an AF lens only because the focus throw is longer and hence more precise.
My experience with the K55 (which has a very long throw) is hit or miss. When I'm shooting a still scene, it is absolutely more accurate... much more so than my 50 1.7.

However for action, the throw actually get in the way, because if I have to go too far, the moment dissolves into the 4th dimension...

Last edited by paperbag846; 12-06-2010 at 03:29 PM.
12-06-2010, 02:39 PM   #13
Veteran Member
jolepp's Avatar

Join Date: Oct 2010
Location: Finland
Photos: Albums
Posts: 3,196
With the k-x (standard focusing screen,) and manual lenses I obtain a rough focus by eye and use the focus confirmation hexagon in the viewfinder to tune in with (a part of) the target in the center ring of the viewfinder. The idea is turning back and forth slowly while keeping the shutter half-pressed to find the spot where the hexagon becomes solid. When so, I can recompose (if needed) and push the shutter fully. I have been setting focus point to center, but as mentioned above this might in fact not be necessary. Also, using a smaller aperture (higher numerical value) should help too as the focus setting doesn't have to be spot on for the snap to turn out ok.
12-06-2010, 02:50 PM   #14
tux
Forum Member




Join Date: Dec 2009
Posts: 82
I have a 50 f1.2 & the only way I can nail focus is to go to liveview mode on my k-x. Then hit the info button & magnify the LCD screen to about 6-10*

then focus/shoot. Nails focus even with the razor thing dof at f1.2
12-06-2010, 03:24 PM   #15
Ira
Inactive Account




Join Date: Mar 2009
Location: Coral Springs, FL
Photos: Gallery | Albums
Posts: 5,216
QuoteOriginally posted by tux Quote
I have a 50 f1.2 & the only way I can nail focus is to go to liveview mode on my k-x. Then hit the info button & magnify the LCD screen to about 6-10*

then focus/shoot. Nails focus even with the razor thing dof at f1.2
I have to start playing with this technique for static objects, if you say it works for you. It makes total sense.

The only thing is I'm usually shooting in mega-bright sun, and don't know if I'll be able to read the LCD correctly.

But I'm gonna try, and thanks for reminding me about it.
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, k-x, lens, pentax help, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Focusing technique with fast manual lens Corvairfan Troubleshooting and Beginner Help 14 10-28-2010 09:09 PM
Focusing manual lens with OEM focusing screen, is a split screen really needed? skid2964 Pentax Camera and Field Accessories 16 09-17-2010 02:54 PM
Manual lens focusing: what is causing this? kerey Pentax SLR Lens Discussion 10 11-17-2007 02:51 PM
Focusing and manual lens... schmikey Pentax DSLR Discussion 22 08-24-2007 06:13 AM
12-24 manual focusing taveren Pentax SLR Lens Discussion 1 06-29-2007 05:31 PM



All times are GMT -7. The time now is 08:18 AM. | 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