Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-15-2019, 08:20 PM   #1
Loyal Site Supporter
Loyal Site Supporter




Join Date: Jul 2012
Photos: Gallery | Albums
Posts: 7,842
Problem with Auto Focus Not Working, And My Camera Took The Shot Anyway.

This past Monday I went out shooting with my Pentax K-50 body and Takumar F 70~200mm, 1:4~5.6 Lens. For the first hour everything went very well. I went to another area to continue shooting and with the same set up (on a tripod,always) I suddenly noticed that when using auto focus and with the steady auto focus light on steady, the image was not in focus. I attempted to fire off a shot, and the shutter activated with the image out of focus. I checked the presets and confirmed that the shutter was set to only activate when the image was in focus. Also, on the rear LCD Panel, the image looked to be razor sharp. Well, I thought perhaps my aging eyes were once again deceiving me, however when I uploaded the images to my computer, they were out of focus. There were quite a few of these and trust me, they were not salvageable.


Okay, again that was Monday. Yesterday being Thursday, I decided to use my K-7 with the Takumar F 70~210mm 1:4~5.6 Lens. Not the same lens as was used on Monday.

After about an hour or so, the same situation occurred and I was flabbergasted at having to look at many out of focus images. By the way I should mention that I always use the self-timer and it is always set to 12s, to give it ample time to settle down prior to activation.

Any assistance with this issue will be greatly appreciated.

Tonytee

03-15-2019, 08:25 PM   #2
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 5,766
Check the diopter adjustment on the eyepiece.
03-15-2019, 09:01 PM   #3
Site Supporter
Site Supporter
ramseybuckeye's Avatar

Join Date: Apr 2009
Location: Elida, Ohio
Photos: Gallery | Albums
Posts: 9,789
I don't think focus priority works when using live view because it uses contrast autofocus. I think it only works when using the viewfinder. I like to manually fine tune focus on live view using the focus peaking and magnification.
03-16-2019, 02:32 AM   #4
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 2,682
Check the settings for SR OFF when using timer.

Check which AF point/s you were using. Depending how you are set up it can be you are presenting the camera with a choice of different focus planes.

Also post a picture on here.

ps. are you using the lens with the aperture ring on the "A" setting ?


Last edited by pschlute; 03-16-2019 at 02:47 AM.
6 Days Ago   #5
Loyal Site Supporter
Loyal Site Supporter




Join Date: Jul 2012
Photos: Gallery | Albums
Posts: 7,842
Original Poster
QuoteOriginally posted by Not a Number Quote
Check the diopter adjustment on the eyepiece.
I did check the diopter and it was in the proper position.

Thnx,

TT

---------- Post added 03-16-19 at 11:31 AM ----------

QuoteOriginally posted by ramseybuckeye Quote
I don't think focus priority works when using live view because it uses contrast autofocus. I think it only works when using the viewfinder. I like to manually fine tune focus on live view using the focus peaking and magnification.

Hi Tom. I never use LiveView. Setting the self-timer automatically cancels the Shake Reduction Feature.

Thanks,

TT

---------- Post added 03-16-19 at 11:45 AM ----------

QuoteOriginally posted by pschlute Quote
Check the settings for SR OFF when using timer.

Check which AF point/s you were using. Depending how you are set up it can be you are presenting the camera with a choice of different focus planes.

Also post a picture on here.

ps. are you using the lens with the aperture ring on the "A" setting ?

pschlute, the lens was used with the aperture ring on the "A" setting. I will have to learn how to check the AF points.

Here is the photo of a Daffodil. Thnx, Tony
6 Days Ago   #6
Pentaxian
jddwoods's Avatar

Join Date: Nov 2012
Location: Newark, Delaware
Posts: 882
QuoteOriginally posted by Tonytee Quote
This past Monday I went out shooting with my Pentax K-50 body and Takumar F 70~200mm, 1:4~5.6 Lens. For the first hour everything went very well. I went to another area to continue shooting and with the same set up (on a tripod,always) I suddenly noticed that when using auto focus and with the steady auto focus light on steady, the image was not in focus. I attempted to fire off a shot, and the shutter activated with the image out of focus. I checked the presets and confirmed that the shutter was set to only activate when the image was in focus. Also, on the rear LCD Panel, the image looked to be razor sharp. Well, I thought perhaps my aging eyes were once again deceiving me, however when I uploaded the images to my computer, they were out of focus. There were quite a few of these and trust me, they were not salvageable.


Okay, again that was Monday. Yesterday being Thursday, I decided to use my K-7 with the Takumar F 70~210mm 1:4~5.6 Lens. Not the same lens as was used on Monday.

After about an hour or so, the same situation occurred and I was flabbergasted at having to look at many out of focus images. By the way I should mention that I always use the self-timer and it is always set to 12s, to give it ample time to settle down prior to activation.

Any assistance with this issue will be greatly appreciated.

Tonytee
Do you have two Takumar F 70-200mm lenses? According to your post you used the same lens description on both the K-50 and K-7 bodies. Its odd that both camera bodies would be showing the same issue. Try a completely different lens and see if that works better. From what you posted the lens seems suspect to me. I once had a problem with a DA 17-70 zoom lens being out of focus on many shots on both my K-5 and K-3 bodies. I tried other lenses both screwdrive and in lens motor and had no problems on either camera. Long story shortened it was a failing SDM motor in the lens. A failed SDM is obviously not your issue but there could be a problem with the lens.
Also, does the autofocus work OK when not using the tripod?
6 Days Ago   #7
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 2,682
QuoteOriginally posted by Tonytee Quote
Here is the photo of a Daffodil. Thnx, Tony
You shot at 1/60th at 210 mm. On a tripod based on your previous posts. Possibly shutter shock, or perhaps wind moving the flower ? How was the wind if any ?

how much margin was there from the minimum focus distance ?
6 Days Ago   #8
Pentaxian
jddwoods's Avatar

Join Date: Nov 2012
Location: Newark, Delaware
Posts: 882
QuoteOriginally posted by Tonytee Quote
I did check the diopter and it was in the proper position.

Thnx,

TT

---------- Post added 03-16-19 at 11:31 AM ----------




Hi Tom. I never use LiveView. Setting the self-timer automatically cancels the Shake Reduction Feature.

Thanks,

TT

---------- Post added 03-16-19 at 11:45 AM ----------




pschlute, the lens was used with the aperture ring on the "A" setting. I will have to learn how to check the AF points.

Here is the photo of a Daffodil. Thnx, Tony
It looks like the entire picture is out of focus I would think the camera/lens should have got some part of the picture in focus. Maybe motion blur from either tripod shake or wind blowing the flowers around. If you shot close up at 210mm there is not much depth of field

6 Days Ago   #9
Loyal Site Supporter
Loyal Site Supporter




Join Date: Jul 2012
Photos: Gallery | Albums
Posts: 7,842
Original Poster
QuoteOriginally posted by jddwoods Quote
Do you have two Takumar F 70-200mm lenses? According to your post you used the same lens description on both the K-50 and K-7 bodies. Its odd that both camera bodies would be showing the same issue. Try a completely different lens and see if that works better. From what you posted the lens seems suspect to me. I once had a problem with a DA 17-70 zoom lens being out of focus on many shots on both my K-5 and K-3 bodies. I tried other lenses both screwdrive and in lens motor and had no problems on either camera. Long story shortened it was a failing SDM motor in the lens. A failed SDM is obviously not your issue but there could be a problem with the lens.
Also, does the autofocus work OK when not using the tripod?

On the Pentax k-50 body I used the Takumar F 70~200mm and on the Pentax k-7 I used the Takumar F 70~210mm 1:4~5.6. Actually, I am glad that you mentioned the use of a tripod. The truth is, the auto focus did work better when I handheld the camera. I thought about that, but thought there could not be a connection. Is there? If so, in all the years I have used these lenses, I have never experienced these instances. Please advise as to the tripod connection.

Thnx, Tony

---------- Post added 03-16-19 at 08:37 PM ----------

QuoteOriginally posted by pschlute Quote
You shot at 1/60th at 210 mm. On a tripod based on your previous posts. Possibly shutter shock, or perhaps wind moving the flower ? How was the wind if any ?

how much margin was there from the minimum focus distance ?

Well, I was indoors in a Garden Center in Sherwood, Oregon. There are air doors on all sides, however there was practically no wind. I would have noticed if there was a problem with the wind and would have waited until it calmed down. In fact, I had to do that a couple of times. Are you thinking that perhaps I need a steadier tripod?

Thanks again for your assistance.

TT
6 Days Ago   #10
Loyal Site Supporter
Loyal Site Supporter




Join Date: Jul 2012
Photos: Gallery | Albums
Posts: 7,842
Original Poster
A New Photo. Testing indoors with tripod.



Pentax k-7 with Takumar F 70~210mm 1:4~5.6 Lens.

1/60s, F/16, ISO 100, Manual Exposure Mode, Fired External Flash and used Multi-Segment Metering. TT

PS. Not very sharp in my opinion. Except for downsizing, this is S.O.O.C. Thnx. tt

Last edited by Tonytee; 6 Days Ago at 09:20 PM. Reason: Additional Information.
6 Days Ago   #11
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 2,682
QuoteOriginally posted by Tonytee Quote
PS. Not very sharp in my opinion. Except for downsizing, this is S.O.O.C
That image looks plenty sharp to me, but would need to see the full size image to be sure.

if you are testing for AF accuracy , dont use f16, but use wide open aperture. Also don't use flash, as that will hide any problems caused by tripod shake or shutter shock.

Best thing is to do a proper test. print the chart out from the end of this document http://www.kscameraclub.org/docs/pdfs/focus_test_chart_edited.pdf

Use centre AF point only. Camera on tripod. Widest aperture. Under natural light. Allow the AF to focus on the chart from the lenses two extremes each time (infinity/closest focus distance)

Ensure the chart is aligned squarely and at a 45 degree angle to the camera. i find it best to have the camera level and the chart at 45 degrees held securely on a recipe book stand or something similar.

Test at around 25 times the Focal length. So with your lens at 200mm you want to be 5 metres from the chart.

this last bit is important.....Do not rely one one test. Do 10 attempts , each time allowing the camera to focus from infinity/or closest focus distance. Then compare your results. Have a look at what the majority of the images look like. if there is any back/front focus issues this should be apparent. post an image on here which reflects the majority result.
6 Days Ago   #12
Pentaxian
jddwoods's Avatar

Join Date: Nov 2012
Location: Newark, Delaware
Posts: 882
QuoteOriginally posted by Tonytee Quote

Pentax k-7 with Takumar F 70~210mm 1:4~5.6 Lens.

1/60s, F/16, ISO 100, Manual Exposure Mode, Fired External Flash and used Multi-Segment Metering. TT

PS. Not very sharp in my opinion. Except for downsizing, this is S.O.O.C. Thnx. tt
This looks sharp to my 66 year old eyes. Regarding using tripods, I have one but rarely use it. I do occasionally use a monopod for outdoor shooting of distant birds. When I used my monopod or tripod I typically use a higher ISO depending on light conditions so I can use a higher shutter speed and turn the SR off. I noticed your shot of the daffodils was with a shutter speed of 1/60 which seems too slow for a telephoto lens. I tried to post some examples
of similar shots I recently took but for some reason I cannot get them to attach. You can try using higher ISO and faster shutter speed and turn SR off when you use a tripod and see if that helps.

Last edited by jddwoods; 6 Days Ago at 07:51 AM.
5 Days Ago   #13
Loyal Site Supporter
Loyal Site Supporter




Join Date: Jul 2012
Photos: Gallery | Albums
Posts: 7,842
Original Poster
QuoteOriginally posted by jddwoods Quote
This looks sharp to my 66 year old eyes. Regarding using tripods, I have one but rarely use it. I do occasionally use a monopod for outdoor shooting of distant birds. When I used my monopod or tripod I typically use a higher ISO depending on light conditions so I can use a higher shutter speed and turn the SR off. I noticed your shot of the daffodils was with a shutter speed of 1/60 which seems too slow for a telephoto lens. I tried to post some examples
of similar shots I recently took but for some reason I cannot get them to attach. You can try using higher ISO and faster shutter speed and turn SR off when you use a tripod and see if that helps.

jddwoods, I am unfortunately in a position where after five back operations, it is imperative that I use a tripod. When I set the self-timer it automatically cancels the SR. I am grateful for the suggestions regarding shutter speed, ISO and aperture settings. I will surely begin practicing in a little bit. Also, I will give a full report on the results and even post a few images here. The external flash that I used is powerful and I had to use a higher number for an aperture setting. Will get back to you soon.

Regards,

Tony
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!
aperture, auto, auto focus, camera, check, diopter, diopter adjustment, focus, hour, image, images, lens, lenses, not, pentax, pentax help, photography, problem, shot, shutter, troubleshooting, tt, view, with, working
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax K-5 Auto focus not working on Prime/Constant aperture lenses iamarunr Pentax K-5 3 07-19-2018 04:41 AM
645D Anyway to Zoom in to Focus ( MF) to make sure Image is in Focus Before taking i rollsman4 Pentax Medium Format 12 07-16-2018 04:24 PM
M42 on a K-Mount: Stop-down metering isn't the big problem (for me, anyway) taksharp Pentax SLR Lens Discussion 20 08-09-2017 04:01 PM
Mid shoot last night. Auto focus not working in viewfinder but is in live view Lurch1066 Troubleshooting and Beginner Help 17 07-31-2017 08:01 AM
Auto Chinon SMC 50mm 1.7 not working auto on K-5 IIs !? KatPal Troubleshooting and Beginner Help 13 12-22-2014 03:19 PM



All times are GMT -7. The time now is 10:21 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