Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-02-2019, 12:46 PM   #1
Site Supporter
Site Supporter




Join Date: Mar 2015
Location: Chicago
Posts: 20
K1 and Sigma EX 24-70 out of focus shots

I recently got this Sigma EX 24-70 from Ebay to use with my K1. I sent it to Sigma before use to get the mount switched to the one that doesn't scratch the K1 body. I took it out for the first time today and ended up with a bunch of out of focus shots. I don't have any experience with lens calibration, does this look like something that can be fixed using that? FWIW, I didn't notice any issues taking similar shots with an SMC 35-70 on the same camera.

Here is my picture. Any advice appreciated!

Attached Images
View Picture EXIF
PENTAX K-1  Photo 
06-02-2019, 12:55 PM   #2
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 3,198
QuoteOriginally posted by jtk Quote
I recently got this Sigma EX 24-70 from Ebay to use with my K1. I sent it to Sigma before use to get the mount switched to the one that doesn't scratch the K1 body. I took it out for the first time today and ended up with a bunch of out of focus shots. I don't have any experience with lens calibration, does this look like something that can be fixed using that? FWIW, I didn't notice any issues taking similar shots with an SMC 35-70 on the same camera.

Here is my picture. Any advice appreciated!
You need to link to a 100% image to get any advice, and tell us what you actually focussed on.
06-02-2019, 12:59 PM   #3
Pentaxian




Join Date: Sep 2012
Location: NY
Photos: Gallery | Albums
Posts: 3,576
I do not know what type of luck you have been having shooting at F4 for a landscape picture, but I myself would have been shooting that type of shot at something similar to F10 or more to obtain depth of field and detail. If you try something like F10 or more with both the 24-70 and 35-70 and find there is a vast difference between them, you may have an issue, but otherwise I would not expect a vast amount of detail from a landscape shot taken at F4. Also, you may want to focus on more of a single object (like a flower), instead of a mass, to see if the focus is obtaining detail in that way.
06-02-2019, 01:03 PM   #4
jtk
Site Supporter
Site Supporter




Join Date: Mar 2015
Location: Chicago
Posts: 20
Original Poster
I'm still getting used to the camera, so that's entirely on me. I will try again with the correct settings and see if there is a difference.

Also, based on the images I got at F4, I would say my luck has been bad.

06-02-2019, 01:04 PM   #5
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 11,831
Sorry, but nothing can be determined from that type of image. We have no idea what you were focusing on and its just trees and grass which might be moving. And as noted above landscapes at f/4 are going to have significant areas out of focus anyway.

If you have access to a focus test chart use that. Otherwise locate a brick building (or something with lots of details and lines) and shoot some shots from a tripod precisely aligned in plane with the wall. Then post a link to full size images so they can be zoomed in.
06-02-2019, 01:11 PM   #6
jtk
Site Supporter
Site Supporter




Join Date: Mar 2015
Location: Chicago
Posts: 20
Original Poster
Sorry for wasting everyone's time. I'll try to do better. Thanks for looking.
06-02-2019, 01:12 PM   #7
Pentaxian




Join Date: Sep 2012
Location: NY
Photos: Gallery | Albums
Posts: 3,576
You may want to set your AF mode to C (continuous), AF Area mode to Spot (center point), aperture to F10, shutter speed to at least 1/125, and take some shots of single objects that have obvious details (as was mentioned already by jatrax).

If you want to use slower shutter speeds, a tripod may come in handy to hold your camera still for the shots.

Please note that you do not have to use 1/4000 as a shutter speed for a shot as you did in the sample you posted. A slower speed can be used for a shot of that type (landscape).

Good luck.

Last edited by C_Jones; 06-02-2019 at 01:21 PM.
06-02-2019, 02:54 PM   #8
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 11,831
QuoteOriginally posted by jtk Quote
Sorry for wasting everyone's time. I'll try to do better. Thanks for looking.
You are NOT wasting anyone's time. We would be delighted to help you. Just help us help you. Fixing / testing for focus is a quite common question on this forum. And having done that dozens (personally) hundreds (forum as a whole) of times, there are things we have learned. First among those is that testing for focus requires some specific controlled parameters. You cannot reliably judge focus on the tiny size image that can be posted here. A full size image uploaded to a photo share site (such as Flickr) and then linked here allows anyone to zoom in 2x, 4x and really see what is going on.

06-03-2019, 11:06 AM   #9
Pentaxian




Join Date: Dec 2016
Posts: 1,738
Also, it is important in testing to use the camera set to center-point spot focus only, and then focus on a single solid object having good edges and good contrasting detail. Use the half-press or the rear AF button to achieve focus before firing the shutter.

As to front or back focusing problems, one of my first tests with a new lens is to set up several small objects close together and at very close distances from each other, then focus on the central one, then the others one at a time. I shoot wide open aperture, and using spot focus. If the one I select is in good focus compared with the other objects in every instance, I then feel confident in my lens's AF accuracy without needing fine tuning adjustment.
06-04-2019, 12:22 AM   #10
jtk
Site Supporter
Site Supporter




Join Date: Mar 2015
Location: Chicago
Posts: 20
Original Poster
You know, in thinking about this more, I'm quite sure I was changing the aperture as I shot (F4 and 1/4000 is not a setting I would ever use for landscape shots) and every picture I took that day was shot at F4. In test shots after that I've been able to get the aperture to change but now I'm wondering how everything would've ended up at F4. I'll have to play with it more to see if I can figure out what happened.
06-05-2019, 06:51 AM   #11
Forum Member




Join Date: Jun 2018
Posts: 70
Is the in body shake reduction off while it's on a tripod?
06-05-2019, 02:40 PM - 1 Like   #12
jtk
Site Supporter
Site Supporter




Join Date: Mar 2015
Location: Chicago
Posts: 20
Original Poster
OK, in case you're still interested, I took some better pictures and now think the only problem was me. Here's a link to my Flickr, the latest 3 were taken with the Sigma.

Justin DeAre | Flickr
06-06-2019, 04:46 PM - 1 Like   #13
Pentaxian




Join Date: Dec 2016
Posts: 1,738
Those results look very fine indeed! Glad there is no actual problem.
06-07-2019, 02:06 PM - 1 Like   #14
Pentaxian




Join Date: Sep 2012
Location: NY
Photos: Gallery | Albums
Posts: 3,576
You can tell the detail is showing up, even at F8.

Nice shots.
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, k1, k1 and sigma, pentax help, photography, shots, sigma, troubleshooting
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: SOLD - Pentax K1, 15-30, 24-70; Sigma 35mm Art; Tamron 70-200 turff Sold Items 3 02-21-2019 10:17 PM
K1 Freezes with Sigma 24-70 EX DG HSM JENSEN7474 Pentax K-1 13 03-17-2018 07:21 AM
For Sale - Sold: Sigma 24-70 DG EX 2.8 Macro / Pentax k-s2 / Sigma 30mm 1.4 DC EX/ Sigma 10-20 4-5.6 closhlab Sold Items 15 05-04-2016 10:41 PM
Sigma 24-70mm F2.8 IF EX DG HSM - VS - Sigma 24-70mm F2.8 EX DG Macro Braciola Pentax SLR Lens Discussion 2 10-15-2010 04:54 AM



All times are GMT -7. The time now is 07:06 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