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07-17-2013, 08:12 AM   #1
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Manual focus on non-centre AF points

Hi there,

I love my Pentax K-30 and Pentax-A 50mm f/1.7 combo - the pictures it produces are absolutely brilliant, when I can get them in focus properly. Unfortunately, I've not figured out a way to manual focus on a point other than in the centre. I've tried the logical route of changing the AF point, but that doesn't work (probably because it's not AF). Ideally what I'd like to do is change the point in the viewfinder so that when that point is in focus, the red dot there lights up and beeps. As much as I love always having the centre focused, there are many times, such as when doing portraiture, when this hinders my ability to make a good image because the subject (such as the person's face) has to be in the centre of the image.

So, my question is - is there any way to get manual-focus confirmation on a point other than the centre of the image? I know there are 11 AF points in the camera but I can't figure out how to use any of them but the centre when doing manual focus.

Thanks!

07-17-2013, 08:35 AM   #2
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QuoteOriginally posted by jellinga Quote
Hi there,

I love my Pentax K-30 and Pentax-A 50mm f/1.7 combo - the pictures it produces are absolutely brilliant, when I can get them in focus properly. Unfortunately, I've not figured out a way to manual focus on a point other than in the centre. I've tried the logical route of changing the AF point, but that doesn't work (probably because it's not AF). Ideally what I'd like to do is change the point in the viewfinder so that when that point is in focus, the red dot there lights up and beeps. As much as I love always having the centre focused, there are many times, such as when doing portraiture, when this hinders my ability to make a good image because the subject (such as the person's face) has to be in the centre of the image.

So, my question is - is there any way to get manual-focus confirmation on a point other than the centre of the image? I know there are 11 AF points in the camera but I can't figure out how to use any of them but the centre when doing manual focus.

Thanks!
It seems to work for non-center points for me. That said, I don't think the other 10 points are quite as sensitive as the center point from a couple minutes of playing around with it.

Have you tried using Live View focus peaking for off-center portrait focusing?
07-17-2013, 08:49 AM   #3
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AFAIK on manual focus lenses, only centre point can be used for focus confirmation, but on AF lenses all 11 points can be used for both AF and MF.
(There should be a table of functions available on all lens types in the K-30 manual).
07-17-2013, 10:00 AM   #4
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Two ways in my opinions:

(1) Live view + focus peaking as IchabodCrane suggests; and
(2) Use center point to focus to obtain focus confirmation and then recompose, i.e., focus-recompose.

There is an advantage of using focus-recompose, i.e., you could lock the exposure at the same time while focusing at center point such that the object (portrait in this case) will be in the proper/desired exposure after recomposing.

There were strong debates for using either focus-recompose or focusing on non-centric points in the past, and I do not intend to get into that here. I think cognizant use of proper DOF could eliminate inaccuracy issues caused by either method. Take a look at this blog What’s the Best Method to Autofocus? Center Point or Outer?.

07-17-2013, 02:58 PM   #5
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There are a couple threads on MF focusing aides.
CiF (aka focus trapping) only works for centre point, but its a very useful tool.
Focus confirm with manual lenses, I think only works with centre point. With modern auto lenses it might work with non-centre as well (the overlay will light up and the green hexagon in viewfinder will show up, but maybe only with AF.C?)
Live view can help a lot with achieving critical focus, especially if you are using a fast prime and the focus peaking camera function.
People also add viewfinder loupes to their OVF, that way the image looks bigger and its easier to tell where the focus is. Another thing you can try is buying a different focus screen, like katzeye or one from focusingscreen.com. There are also other cheaper focusing screens with split prisms, etc. and some members report good success with them. But you install these at your own risk.

So these are your options. And of course, practice. Practice makes a big difference.
07-17-2013, 03:19 PM   #6
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Technically, the red dots flashing does not equal focus confirmation. Only the green hexagon illuminating = focus confirmation. The red dots and the green hexagon aren't always exactly in sync.
07-17-2013, 07:02 PM   #7
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I get close with focus-recompose, and take 4 or 5 shots slowly moving the focus ring, pick the best one. Electrons are close enough to free.
07-17-2013, 07:41 PM   #8
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QuoteOriginally posted by Na Horuk Quote
There are a couple threads on MF focusing aides.
CiF (aka focus trapping) only works for centre point, but its a very useful tool.
Focus confirm with manual lenses, I think only works with centre point. With modern auto lenses it might work with non-centre as well (the overlay will light up and the green hexagon in viewfinder will show up, but maybe only with AF.C?)
Live view can help a lot with achieving critical focus, especially if you are using a fast prime and the focus peaking camera function.
People also add viewfinder loupes to their OVF, that way the image looks bigger and its easier to tell where the focus is. Another thing you can try is buying a different focus screen, like katzeye or one from focusingscreen.com. There are also other cheaper focusing screens with split prisms, etc. and some members report good success with them. But you install these at your own risk.

So these are your options. And of course, practice. Practice makes a big difference.
I used my K-30 and DA 18-135 to test. Set the K-30 focus switch to MF. Set the focus system to Select and moved the focus point to one of the side dots. Rotated the focus ring on the lens while looking through the viewfinder. When in focus, the selected red focus point indicator and green hexagon would flash (beep, too, I think). I realize this is an AF lens but it's not obvious to me why that matters. As I stated earlier, the center point seems to work better than any of the other 10 points in that it gives a much more certain confirmation of focus.

07-17-2013, 11:46 PM   #9
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QuoteOriginally posted by IchabodCrane Quote
I realize this is an AF lens but it's not obvious to me why that matters.
There are some difference between the KA-mount and KAF-mount and later versions of the K-mount..
With the KAF-mount Pentax added a seventh electronic pin in the mount, which submits some extra information to the camera. It probably this that is necessary to be able to use focus confirmation on all focus points.

There is a KA2-mount that is manual focus only, and with the extra pin, but I think it's only been used on cameras not lenses.
07-19-2013, 12:14 PM   #10
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In using the available electronic focus aids for the K-30, all lenses lacking autofocus (including the A-series) are restricted to the center focus point when using the OVF. When using LV, focus peaking covers the entire frame.
07-20-2013, 02:13 PM   #11
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Thanks for the information! It seems strange to me that they would only allow centre-point focusing using older lenses - I was always under the impression that the only thing that differentiated a screw-drive AF lens and a manual focus lens was the screw drive itself. Guess I was wrong! Thanks for all your help - I'll definitely be using Live View more often now.
07-20-2013, 05:54 PM   #12
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Just remember, with manual focus lenses, the electronic focus aids are just that - aids .... nothing stops you from using your own eyes if you want to focus on an off-center subject. Generally I only use the aids as an indication to turn the focus ring slower and trust my own eyes to fine focus. And then, I try to stop down a bit to increase depth of field. I may not be as fast as an autofocus lens, but I am usually just as accurate.
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