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05-02-2015, 12:51 PM   #1
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K-30 AF Fine Adjustment

So I ordered a DA 55-300mm WR and just tested it out for the first time today...
I got home and noticed a lot of my shots out of focus and noisy.
I think I could have gotten away with a lower ISO (I had it set around 800 all morning)

Anyways, I went into the menu and tried playing around with the AF Fine Adjustment menu.
I set the Apply One option to -10, then -5, then 0, then +5 and +10.
I honestly can not tell the difference between any of the shots...

To test these settings I'm shooting 300mm, ISO 100, 1/125 with on-board flash triggering.
Distance of about 15ft and targeting a white piece of paper with black size 12 font on it.
Zooming to 8x in LV (roughly 100% crop)

Let me know if you guys have options or suggestions on how to fine tune AF with the K-30. As of now I cannot figure this out.
Am I missing a simple setting somewhere?
Is the onboard flash throwing off the focus?
I really just want to have this lens dialed in for tomorrow when I go back to the dunes.

Thanks for all the support!
I have many questions to come but I'll do them in separate threads...

05-02-2015, 01:03 PM   #2
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I have a K 30 but not the lens you mention ... I guess it is the HD version ? Maybe you need to up date your firmware version to the latest one (1.06) ?
05-02-2015, 01:11 PM   #3
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AF fine tuning is for fixing slight front or back focus. Usually only noticeable on fast lenses. It will not help with missed focus where the camera focuses on something just not what you want.

If you cannot see any difference it is because the dof on the slow 55-300 masks any small errors.

Put it at 0 and leave alone. Easier to mess things up than actually help unless you have a clear problem which you do not.
05-02-2015, 01:20 PM   #4
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QuoteOriginally posted by jatrax Quote
AF fine tuning is for fixing slight front or back focus. Usually only noticeable on fast lenses. It will not help with missed focus where the camera focuses on something just not what you want.

If you cannot see any difference it is because the dof on the slow 55-300 masks any small errors.

Put it at 0 and leave alone. Easier to mess things up than actually help unless you have a clear problem which you do not.
ok,
Works for me!

Thanks for the help...

05-02-2015, 02:19 PM   #5
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QuoteOriginally posted by UserAccessDenied Quote
So I ordered a DA 55-300mm WR and just tested it out for the first time today...
I got home and noticed a lot of my shots out of focus and noisy.
I think I could have gotten away with a lower ISO (I had it set around 800 all morning)
I think out of focus and soft are different beasts.
Try this, and forget about noise ("better to get the shot than not")
Stick the camera on auto ISO and set to max out at 3200
Flip to manual then open the aperture to maximum for that lens at whatever focal length your using it at.
Then adjust the shutter speed to be greater than that focal length, double if possible. (eg; 200mm = 1/250 or greater)
I mostly use spot metering unless shooting a landscape.
Now for the most important step. DISABLE SR.
SR is responsible for more blurred images than I can count. Yes I still use it when I need it and appreciate that it's there, but mostly I don't use it on my K-50 (or my K-7 before).

This works for me.. If it works for you, great - if not, oh well - at some point you'll find your own technique that works..

I honestly feel that too many people rely on SR to stabilize in every possible scenario (some even keep it enabled when mounted on a tripod!), it doesn't - all it does is help with natural hand shaking. Years ago I had a Zenit 35mm, no SR in those days (or AF)... I don't ever remember wishing for stabilization.

Now, front/back focusing is something else. My 55-300mm was spot on with the K-7 but with the K-50 I needed some + adjustment in the AF menu.
05-02-2015, 02:32 PM   #6
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QuoteOriginally posted by Steve.Ledger Quote
I think out of focus and soft are different beasts.
Try this, and forget about noise ("better to get the shot than not")
Stick the camera on auto ISO and set to max out at 3200
Flip to manual then open the aperture to maximum for that lens at whatever focal length your using it at.
Then adjust the shutter speed to be greater than that focal length, double if possible. (eg; 200mm = 1/250 or greater)
I mostly use spot metering unless shooting a landscape.
Now for the most important step. DISABLE SR.
SR is responsible for more blurred images than I can count. Yes I still use it when I need it and appreciate that it's there, but mostly I don't use it on my K-50 (or my K-7 before).

This works for me.. If it works for you, great - if not, oh well - at some point you'll find your own technique that works..

I honestly feel that too many people rely on SR to stabilize in every possible scenario (some even keep it enabled when mounted on a tripod!), it doesn't - all it does is help with natural hand shaking. Years ago I had a Zenit 35mm, no SR in those days (or AF)... I don't ever remember wishing for stabilization.

Now, front/back focusing is something else. My 55-300mm was spot on with the K-7 but with the K-50 I needed some + adjustment in the AF menu.

I never use SR unless I am shooting hand-held and I notice my hand shaking... Typically only after a few hours into a hike and I'm noticing fatigue.
Plus I was shooting from a tripod so SR would have been pointless as you mentioned.

I'll try setting ISO to auto. I've been shooting in M mode lately because I want to learn how to use this camera properly and I want to really understand the entire composition. I know a lot of my shots will suffer due to this, but I'm determined to learn it this way.

I guess shooting at F9 I'm not experiencing front or back focus issues... It's probably a matter of me being more patient and using quick focus in situations where I can't catch focus of my subject. That's why it's a feature in the lens I suppose!
05-02-2015, 03:23 PM   #7
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QuoteOriginally posted by UserAccessDenied Quote
Zooming to 8x in LV (roughly 100% crop)
AF Adjustments are only for Phase Detect focussing (Viewfinder) not Contrast Detect (Liveview). If you use liveview, no corrections are applied since focus is achieved using the actual image sensor and not the PDAF system. If your images are out of focus when focused in LV, the focussing system is probably not to blame. SR, technique and slow shutter speed are more than likely the culprits.
05-02-2015, 06:42 PM   #8
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QuoteOriginally posted by UserAccessDenied Quote
So I ordered a DA 55-300mm WR and just tested it out for the first time today...
I got home and noticed a lot of my shots out of focus and noisy.
I think I could have gotten away with a lower ISO (I had it set around 800 all morning)

...
Focus is generally much sharper when the subject is brightly lit. Try the camera lens combo in bright light. If you achieve sharp focus, you don't have a real problem :-)

05-02-2015, 08:07 PM   #9
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QuoteOriginally posted by fgaudet Quote
AF Adjustments are only for Phase Detect focussing (Viewfinder) not Contrast Detect (Liveview). If you use liveview, no corrections are applied since focus is achieved using the actual image sensor and not the PDAF system.
This is a good point, and I missed that in the OP. To the OP if you are indeed testing using the Liveview note that you are NOT testing the AF system that uses the AF fine tuning function.

Modern DSLRs have three separate focusing systems:
1) Manual focus using the focusing screen
2) Phase Detect focusing which is what you see in the viewfinder and can be fine tuned
3) Contrast Detect which is the system used by Liveview. This is supposed to be the most accurate and cannot be adjusted since it uses the sensor itself to focus.

AF fine tuning is a great feature but it can change the focusing point only a small amount. In many cases this can 'dial in' a lens that is a bit off. But if the lens is "slow" the DOF of the lens more than covers any small front/back focus error.

If you do want to test your lens read up on proper focus testing procedures. Tripod, brightly lit focus target, use a remote, repeat the test multiple times, use the lens with aperture wide open, use a testing tool or slanted ruler. And even with all of that often the margin of error in the test itself exceeds the original error. It is very easy to make things worse by running a test that is not precise and adjusting the lens based on faulty data.
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