Possible Dumb Question About Pentax 645n Auto Focusing

topaz · 10-05-2015, 11:58 AM

If my auto focus Pentax 645n camera indicates that my subject is in focus, is that true and reliable? The reason I ask is when the camera indicates I'm in focus, it sometimes looks a little off to me and my 60 year old eyes. I want the best results I can get from the camera, so should I just trust that the auto focus is accurate and my eyes are just too old to know it?

Compounding the question a little more...If the diopter adjustment in the eyepiece isn't adjusted right for what I see, is the camera still giving me the optimum focus regardless? I'm guessing the diopter and the cameras auto focus are unrelated. In other words, the camera will always be right...no matter how I see it. Correct?

max_pyne · 10-05-2015, 12:12 PM

Originally posted by topaz

If my auto focus Pentax 645n camera indicates that my subject is in focus, is that true and reliable? The reason I ask is when the camera indicates I'm in focus, it sometimes looks a little off to me and my 60 year old eyes. I want the best results I can get from the camera, so should I just trust that the auto focus is accurate and my eyes are just too old to know it?

Compounding the question a little more...If the diopter adjustment in the eyepiece isn't adjusted right for what I see, is the camera still giving me the optimum focus regardless? I'm guessing the diopter and the cameras auto focus are unrelated. In other words, the camera will always be right...no matter how I see it. Correct?

i don't know the 645n (thats why i cant answer your first part) but on every camera I've seen so far the auto focusing is not related in any way to the diopter correction. So if you set the diopter to you requirements there is no way that this is influencing the AF.

**blackcloudbrew** · 10-05-2015, 12:15 PM

The 645n will give proper AF indication when it thinks either the spot focus or grid focus (which you select) when it thinks the image is in focus. Generally it's pretty good but you can confuse it. Personally, I trust the focus on my 645n a lot.

topaz · 10-05-2015, 04:29 PM

Thanks for all of your replies...It's what I expected, but wanted to be sure.

10-05-2015, 11:58 AM	#1
topaz Inactive Account Join Date: Jan 2011 Location: Midwest Posts: 106	Possible Dumb Question About Pentax 645n Auto Focusing If my auto focus Pentax 645n camera indicates that my subject is in focus, is that true and reliable? The reason I ask is when the camera indicates I'm in focus, it sometimes looks a little off to me and my 60 year old eyes. I want the best results I can get from the camera, so should I just trust that the auto focus is accurate and my eyes are just too old to know it? Compounding the question a little more...If the diopter adjustment in the eyepiece isn't adjusted right for what I see, is the camera still giving me the optimum focus regardless? I'm guessing the diopter and the cameras auto focus are unrelated. In other words, the camera will always be right...no matter how I see it. Correct?

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10-05-2015, 12:12 PM	#2
max_pyne Pentaxian Join Date: Aug 2010 Location: zurich Photos: Gallery \| Albums Posts: 409	Originally posted by topaz If my auto focus Pentax 645n camera indicates that my subject is in focus, is that true and reliable? The reason I ask is when the camera indicates I'm in focus, it sometimes looks a little off to me and my 60 year old eyes. I want the best results I can get from the camera, so should I just trust that the auto focus is accurate and my eyes are just too old to know it? Compounding the question a little more...If the diopter adjustment in the eyepiece isn't adjusted right for what I see, is the camera still giving me the optimum focus regardless? I'm guessing the diopter and the cameras auto focus are unrelated. In other words, the camera will always be right...no matter how I see it. Correct? i don't know the 645n (thats why i cant answer your first part) but on every camera I've seen so far the auto focusing is not related in any way to the diopter correction. So if you set the diopter to you requirements there is no way that this is influencing the AF.

10-05-2015, 12:15 PM	#3
blackcloudbrew Loyal Site Supporter Join Date: Mar 2009 Location: Cotati, California USA Photos: Gallery \| Albums Posts: 4,460	The 645n will give proper AF indication when it thinks either the spot focus or grid focus (which you select) when it thinks the image is in focus. Generally it's pretty good but you can confuse it. Personally, I trust the focus on my 645n a lot.

10-05-2015, 04:29 PM	#4
topaz Inactive Account Join Date: Jan 2011 Location: Midwest Posts: 106 Original Poster	Thanks for all of your replies...It's what I expected, but wanted to be sure.