K-x misfocusing

jessray · 01-26-2013, 07:02 AM

Hey Gang,

I was volunteering at my local animal shelter, taking pictures of the new critters needing to be posted on Petfinder and was having issues with my lens not focusing on the right spot.

I am using a 50mm 1.4 AF lens and I have the focus set to the center in the camera.

I was shooting away, checking sharpness quickly on my LCD and all looked fine. But when I loaded the pics on my computer to edit I was very disappointed. I've attached a couple of images to show what I am talking about...

Forgive my ignorance as I primarily shoot with an old Hasselblad 500c/m and Pentax k1000. Film and film cameras I understand. The world of DSLR's is still new to me. I'm not used to all the technology involved...

So, is there a setting within the camera I am missing? Is that what they call "back focusing"? Do I need to calibrate the lens? If so, how is this done? I'd like to get this resolved sooner than later as I plan to visit the shelter once a week to help out with web listings and such.

Thanks in advance for the help.

Attached Images

aleonx3 · 01-26-2013, 07:37 AM

Looks like you have a BF issue with the lens as it seems to be focused on the base of the wall. Also, if you increase the DOF a bit by stopping down the aperture, it may help there. I am not sure if there is AF fine adjustment option on the k-x though.

GibbyTheMole · 01-26-2013, 10:40 AM

Originally posted by aleonx3

I am not sure if there is AF fine adjustment option on the k-x though.

It is, but unfortunately not on a per-lens basis. Here's how.

excanonfd · 01-26-2013, 11:22 AM

I don't think this is BF/FF issue, the in camera focus adjustment is meant for adjusting differences measured in millimetres not a foot. OP simply mis-focused. The centre focus point (more like centre focus circle) is obscenely large, and from within that focus circle the camera looks for the most contrasty area to focus on. The cat's head is not very contrasty (most animal fur don't vary very much in contrast), on the other hand the concrete foundation pockmarked with dark shadow points is quite contrasty.

You can either try composing tighter to the animal's face (not always possible if the intention is to show the whole animal not just it's mug) or if the camera has face recognition, try forcing the camera to focus on the eyes with it. The standard focus screen is a poor choice for fine focus adjustment through the viewfinder, there are better screens available but at a cost. If you can pose the animals, try selecting backgrounds that has little contrast so that the camera is forced to focus on the animal.

01-26-2013, 07:02 AM	#1
jessray New Member Join Date: Apr 2010 Location: Upstate NY Posts: 7	K-x misfocusing Hey Gang, I was volunteering at my local animal shelter, taking pictures of the new critters needing to be posted on Petfinder and was having issues with my lens not focusing on the right spot. I am using a 50mm 1.4 AF lens and I have the focus set to the center in the camera. I was shooting away, checking sharpness quickly on my LCD and all looked fine. But when I loaded the pics on my computer to edit I was very disappointed. I've attached a couple of images to show what I am talking about... Forgive my ignorance as I primarily shoot with an old Hasselblad 500c/m and Pentax k1000. Film and film cameras I understand. The world of DSLR's is still new to me. I'm not used to all the technology involved... So, is there a setting within the camera I am missing? Is that what they call "back focusing"? Do I need to calibrate the lens? If so, how is this done? I'd like to get this resolved sooner than later as I plan to visit the shelter once a week to help out with web listings and such. Thanks in advance for the help. Attached Images

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01-26-2013, 07:37 AM	#2
aleonx3 Veteran Member Join Date: Jul 2007 Location: Brampton, Ontario Photos: Gallery \| Albums Posts: 3,996	Looks like you have a BF issue with the lens as it seems to be focused on the base of the wall. Also, if you increase the DOF a bit by stopping down the aperture, it may help there. I am not sure if there is AF fine adjustment option on the k-x though.

01-26-2013, 10:40 AM	#3
GibbyTheMole Veteran Member Join Date: Nov 2009 Location: Iowa Photos: Albums Posts: 2,275	Originally posted by aleonx3 I am not sure if there is AF fine adjustment option on the k-x though. It is, but unfortunately not on a per-lens basis. Here's how.

01-26-2013, 11:22 AM	#4
excanonfd Veteran Member Join Date: Jan 2010 Location: Vancouver, BC Posts: 1,421	I don't think this is BF/FF issue, the in camera focus adjustment is meant for adjusting differences measured in millimetres not a foot. OP simply mis-focused. The centre focus point (more like centre focus circle) is obscenely large, and from within that focus circle the camera looks for the most contrasty area to focus on. The cat's head is not very contrasty (most animal fur don't vary very much in contrast), on the other hand the concrete foundation pockmarked with dark shadow points is quite contrasty. You can either try composing tighter to the animal's face (not always possible if the intention is to show the whole animal not just it's mug) or if the camera has face recognition, try forcing the camera to focus on the eyes with it. The standard focus screen is a poor choice for fine focus adjustment through the viewfinder, there are better screens available but at a cost. If you can pose the animals, try selecting backgrounds that has little contrast so that the camera is forced to focus on the animal.