Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-02-2010, 03:40 AM   #1
Senior Member




Join Date: Dec 2009
Location: Timisoara
Photos: Albums
Posts: 119
manual focus lens into AF?

Hello!

Who can tell me please what adapter can i use to transform my smc M 50 1.7 manual focus lens into an autofocus one?

thx!

11-02-2010, 03:48 AM   #2
Veteran Member
DanielT74's Avatar

Join Date: Nov 2008
Location: Australia
Photos: Albums
Posts: 1,377
The Pentax 1.7x AF teleconverter should do a reasonable job. There's some info on it here:

About the Pentax-F 1.7X AF Adapter...: Pentax SLR Talk Forum: Digital Photography Review

There are others (Kenko?) I believe but I am not sure.
11-02-2010, 04:25 AM   #3
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
There's a way to turn almost all manual lenses into focus monsters. It's called Catch-In-Focus (CIF) aka Trap-Focus. Enable CIF by going to your Custom Menu and setting Catch-In-Focus to ON. Set the focus mode to AF.S. Use a K- or M-type lens, or an A-type with an M/A switch set to M, or a screwmount lens with a shiny base and an adapter. That's all you need.

To use CIF, aim at a subject and bring it into focus while holding the shutter down. The shutter will only SNAP when the subject comes into focus in the center of the frame. Or aim and focus at a spot where you expect the subject to be, and hold the shutter down. When the subject comes into focus, it SNAPs. Set the Drive Mode to CONTINUOUS, put the camera on a tripod, aim somewhere you expect action, use a remote to hold the shutter down, and when subjects come into focus it will SNAP and SNAP and SNAP. That's just the thing for shooting birds, bicyclists, burglars, etc.

What's nice about CIF it that it's free. No expensive adapters with IQ loss. Have fun!
11-02-2010, 10:15 AM   #4
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
RioRico,
That doesn't quite work. You need pure M manual mode. With that mode you get over and under focus with red lights in the view finder. Then a solid green hex confirmation when completely in focus. To know you have perfect focus you go one way until

11-02-2010, 10:18 AM   #5
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
the red light shows. Then go the opposite direction until the other red light shows. That's your focus area of creativity. You then Get the solid green hex. You move back and forth keeping the hex green and donLt get a red light. Then that's how you get
11-02-2010, 10:21 AM   #6
Veteran Member
paperbag846's Avatar

Join Date: Jul 2010
Photos: Gallery
Posts: 2,396
Trog: The red light only shows where the point of focus is - it does not determine critical focus. As frustrating as it can be, that red dot is plain inaccurate. You are best of looking straight at the green hexagon, and looking for a SOLID green hexagon.
11-02-2010, 10:22 AM   #7
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
sharpest picture possible. Your way will snap a picture right before the red marks which aren't optimal focus points. Not even AF will take a pic there that's why you hear screw drive go back and forth.I have 20/13 vision so I see better than the magnifier
11-02-2010, 10:26 AM   #8
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
Paperbag,
The red dot tells you your two focus points after perfect focus. Try for yourself. You will get two red confirmation beeps turning to the left and right directions after getting the green hex.

11-02-2010, 10:29 AM   #9
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
The red dot is a warning for: 'focus in the other direction you have gone too far to get the green hex confrim.' The red dot does not mean focused the green hex at the bottom does. But you still have a little play after it show to focus a little more/less
11-02-2010, 11:45 AM   #10
Senior Member




Join Date: Dec 2009
Location: Timisoara
Photos: Albums
Posts: 119
Original Poster
thx guys, i will try 1st the RioRico method.
11-02-2010, 11:58 AM   #11
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
QuoteOriginally posted by troglodyte Quote
RioRico,
That doesn't quite work. You need pure M manual mode.
CIF doesn't require M(anual). It works in any auto/manual mode. M(anual) just give you stop-down control with non-preset lenses. With a non-A-type lens mounted, the camera in any auto setting defaults to Av mode.

All CIF needs is 1) an AF lens (hold the lens-lock button down), or 2) any other PK-mount or similar lens (including some unmodified Nikons, and slightly modified NI's and OM's and C/Y's) with a conductive base, or 3) a screwmount lens (with adapter) with a base wide enough to hold a bit of metal tape to (safely) short the mount pins. Lenses with aperture presets, or those you wish to shoot wide-open, can use any mode. Lenses without aperture presets need M(anual) mode and the Green Button (or equivalent) for stop-down metering and shooting.

EDIT: Oops, I almost forgot -- using any manual lens requires that the Custom Menu setting for USING APERTURE RING must be ALLOWED. See the sticky on Using Manual Lenses that's atop the Beginner's Corner area.
11-02-2010, 12:04 PM   #12
Veteran Member




Join Date: Jun 2008
Location: NJ
Posts: 1,738
QuoteOriginally posted by RioRico Quote
CIF doesn't require M(anual). It works in any auto/manual mode. M(anual) just give you stop-down control with non-preset lenses. With a non-A-type lens mounted, the camera in any auto setting defaults to Av mode.

All CIF needs is 1) an AF lens (hold the lens-lock button down), or 2) any other PK-mount or similar lens (including some unmodified Nikons, and slightly modified NI's and OM's and C/Y's) with a conductive base, or 3) a screwmount lens (with adapter) with a base wide enough to hold a bit of metal tape to (safely) short the mount pins. Lenses with aperture presets, or those you wish to shoot wide-open, can use any mode. Lenses without aperture presets need M(anual) mode and the Green Button (or equivalent) for stop-down metering and shooting.

EDIT: Oops, I almost forgot -- using any manual lens requires that the Custom Menu setting for USING APERTURE RING must be ALLOWED. See the sticky on Using Manual Lenses that's atop the Beginner's Corner area.
RioRico: Thanks for the info. I will try it.
11-02-2010, 12:26 PM   #13
Veteran Member
jolepp's Avatar

Join Date: Oct 2010
Location: Finland
Photos: Albums
Posts: 3,196
BTW ... why this shorting contacts business for CIF? I mean, is there some rational reason, or is this just a quirk?
11-02-2010, 02:18 PM   #14
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
RioRico,
I didn't say it needed manual mode it just has three issues:
1) It will take take the picture immediately which will introduce
2) Blur from your hands shaking and turning the focus ring
3) If the person moves you can't say 'are you ready'.
11-02-2010, 02:20 PM   #15
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
Also I was talking about using AF.s and MF modes. The C mode is pure evil.
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!
focus, focus lens, k-mount, lens, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can a manual-focus lens have back focus problems? PocketPixels Pentax DSLR Discussion 33 02-13-2011 05:37 AM
Manual Focus lens Bramela Pentax SLR Lens Discussion 26 05-02-2010 05:56 PM
Front focus/ back focus on Manual lens. Possible? WangJianWei Troubleshooting and Beginner Help 6 04-20-2009 07:50 PM
manual lens focus question kjfaust Pentax DSLR Discussion 11 05-16-2008 05:20 PM
Manual focus lens Charles Pentax SLR Lens Discussion 1 01-28-2007 03:14 PM



All times are GMT -7. The time now is 09:23 PM. | 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