[DW58]

Was getting to know my new camera/lens combo. K-1 Mark II with 28-105. Results were not as sharp as I'd hoped. Thought I'd play with the AF fine tune unscientifically. Didn't seem to matter where I had the fine tune set. Wasn't much of a difference. So I tried the max both directions. Not a lot of difference between them. First image as at 0. 2nd at -10. 3rd at +10. I would think there should be more of a difference between shots. Was standing 10-12 feet away from target. Could use some feedback here. Thank you.

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[Adam]

Thought I'd play with the AF fine tune unscientifically.

Not a good idea IMO. But, if you do this, you'd need a baseline sharpness comparison image shot in live view.

The 28-105mm is sharp, but not as sharp as say a prime (especially wide-open). So, you might just be getting a little bit of that.

[BigMackCam]

As Adam says, this isn't really something to do without a proper AF adjustment target.

However...

When performing AF fine adjustment for a lens, you really need to have a focal length, aperture and distance combination that will show up minor changes in focus accuracy - because "depth of field" Since the DFA 28-105 is a variable aperture zoom lens and, therefore, relatively slow at each focal length even wide open - especially at the long end), I'd probably focus somewhat closer to the target than I might if adjusting for, say, a 50mm f/1.4 or 135mm f/2.8.

But really, you must use an appropriate target if you want to make these adjustments and get any real benefit or accuracy from them. You don't have to buy a target - you can make one easily enough.

[microlight]

Flat on at that distance wouldn’t be how I’d do it; looks to be too far away. I’m not at my PC so can’t see the exif data and can’t tell what aperture or shutter speed you’re set on.

I usually put a small object on a fine-textured surface (I use our cloth-covered spotty ironing board!), with the camera just above the board, lens at maximum aperture and not too far away from minimum focus distance. Single-point focus on the small object (usually a 5p piece), then it’s easy to see by the sharpness of the surrounding cloth texture where the lens is actually focussing so you can make adjustments if necessary.

[ProfessorBuzz]

If you want to tune it for best sharpness, you have to be scientific about it.
It has to be tripod mounted, SR off, use self timer, and wide open (f/3.5 and f/4.5 are pretty forgiving, have lots of DOF, but that's the character of that lens).

You need to look at the image at full raw resolution, zoomed in on the PC. The 3 JPGs you post are from different positions (you moved the camera), and the JPG compression gets rid of the sharpness of the text and the edges, so the target doesnt have enough detail or sharp edges to tell. So work with Raw (DNG/PEF). To cut down posting size, crop just the centre of the image, but at full resolution.


I've had good success with my K-1 and 645z with the Michael Tapes Design LensAlign tool and software. Works very well.
It takes at least 30 minutes to nail it.
Previously I used the Spyder LensCal, and I get better results with the MTD product.
LensAlign - WhiBal
and you can get it from B&H and others.

The other thing I've found is that a variation of +/- 2 is enough to make a big difference, so you need to find where it looks sharp, and shoot about 4-5 shots at each setting, and then go up and down a couple of settings, otherwise you may blow right past the in-focus sharpest point.

Another trick is get some AA batteries and line them up with each one a bit further behind the other, off on a diagonal, all with the label text visible to the camera. It makes it easier to tell when in focus precisely.

Good luck and have fun.

[johnkrumm]

Compare to a live view shot of the same, and then a manual focus live view shot on a tripod using electronic shutter. You can then start worrying about shutter shock too. : )


Seriously though, it will help you to see if the focus is working properly at all. My guess is the shot will be sharper.

[gerardbaron]

Not a good idea IMO. But, if you do this, you'd need a baseline sharpness comparison image shot in live view.

The 28-105mm is sharp, but not as sharp as say a prime (especially wide-open). So, you might just be getting a little bit of that.

Is a M lens can be fine adjusted. SMC 300mm

[DW58]

Not a good idea IMO. But, if you do this, you'd need a baseline sharpness comparison image shot in live view.

The 28-105mm is sharp, but not as sharp as say a prime (especially wide-open). So, you might just be getting a little bit of that.

As Adam says, this isn't really something to do without a proper AF adjustment target.

However...

When performing AF fine adjustment for a lens, you really need to have a focal length, aperture and distance combination that will show up minor changes in focus accuracy - because "depth of field" Since the DFA 28-105 is a variable aperture zoom lens and, therefore, relatively slow at each focal length even wide open - especially at the long end), I'd probably focus somewhat closer to the target than I might if adjusting for, say, a 50mm f/1.4 or 135mm f/2.8.

But really, you must use an appropriate target if you want to make these adjustments and get any real benefit or accuracy from them. You don't have to buy a target - you can make one easily enough.

Thanks for both of your speedy relies. Have been lucky enough to not need to fine tune a lens except for two. Neither one a zoom. And for those I did print out a target and use a tripod and remote set to 3 sec delay. Used LensAlign's website to determine distance from target. Having not much experience with AF fine tune I just thought I'd see more of a difference between minus 10 and plus 10. I am still a babe in the woods when it comes to this stuff. I guess by "fine tune" they REALLY mean "fine tune."

Again, thanks to you both.

Dave.

[DW58]

Flat on at that distance wouldn’t be how I’d do it; looks to be too far away. I’m not at my PC so can’t see the exif data and can’t tell what aperture or shutter speed you’re set on.

I usually put a small object on a fine-textured surface (I use our cloth-covered spotty ironing board!), with the camera just above the board, lens at maximum aperture and not too far away from minimum focus distance. Single-point focus on the small object (usually a 5p piece), then it’s easy to see by the sharpness of the surrounding cloth texture where the lens is actually focussing so you can make adjustments if necessary.

If you want to tune it for best sharpness, you have to be scientific about it.
It has to be tripod mounted, SR off, use self timer, and wide open (f/3.5 and f/4.5 are pretty forgiving, have lots of DOF, but that's the character of that lens).

You need to look at the image at full raw resolution, zoomed in on the PC. The 3 JPGs you post are from different positions (you moved the camera), and the JPG compression gets rid of the sharpness of the text and the edges, so the target doesnt have enough detail or sharp edges to tell. So work with Raw (DNG/PEF). To cut down posting size, crop just the centre of the image, but at full resolution.


I've had good success with my K-1 and 645z with the Michael Tapes Design LensAlign tool and software. Works very well.
It takes at least 30 minutes to nail it.
Previously I used the Spyder LensCal, and I get better results with the MTD product.
LensAlign - WhiBal
and you can get it from B&H and others.

The other thing I've found is that a variation of +/- 2 is enough to make a big difference, so you need to find where it looks sharp, and shoot about 4-5 shots at each setting, and then go up and down a couple of settings, otherwise you may blow right past the in-focus sharpest point.

Another trick is get some AA batteries and line them up with each one a bit further behind the other, off on a diagonal, all with the label text visible to the camera. It makes it easier to tell when in focus precisely.

Good luck and have fun.

Compare to a live view shot of the same, and then a manual focus live view shot on a tripod using electronic shutter. You can then start worrying about shutter shock too. : )


Seriously though, it will help you to see if the focus is working properly at all. My guess is the shot will be sharper.

Thanks to you all that replied as I was hunting and pecking at the keyboard to reply to Adam and BigMack Cam. I appreciate the input. I need all the help I can get with all this new fangled technology stuff.

[BigMackCam]

Thanks for both of your speedy relies. Have been lucky enough to not need to fine tune a lens except for two. Neither one a zoom. And for those I did print out a target and use a tripod and remote set to 3 sec delay. Used LensAlign's website to determine distance from target. Having not much experience with AF fine tune I just thought I'd see more of a difference between minus 10 and plus 10. I am still a babe in the woods when it comes to this stuff. I guess by "fine tune" they REALLY mean "fine tune."

Again, thanks to you both.

Dave.

You're very welcome, Dave I was a babe in the woods on this three or four years ago too

FYI, I use Datacolor's SpyderLENSCAL target for my own AF fine adjustment work, resting on a bench with my camera on a tripod.

One important thing with any AF adjustment target is to have a focus area that is absolutely parallel to the camera and lens, along with a sloping reference area (with graduation marks) very sightly off-set to one side, to help you identify how far in front of, or behind, the focus is. That sloping reference must be as close as possible to the centre focus point, as field curvature in some lenses means that accurate focus distance at, and away from, the centre can be different.

If you need help with this at any point, feel free to PM me. I've put every single lens I own through AF fine adjustment on several bodies, so it's something I'm very comfortable with

[DW58]

You're very welcome, Dave I was a babe in the woods on this three or four years ago too

FYI, I use Datacolor's SpyderLENSCAL target for my own AF fine adjustment work, resting on a bench with my camera on a tripod.

One important thing with any AF adjustment target is to have a focus area that is absolutely parallel to the camera and lens, along with a sloping reference area (with graduation marks) very sightly off-set to one side, to help you identify how far in front of, or behind, the focus is. That sloping reference must be as close as possible to the centre focus point, as field curvature in some lenses means that accurate focus distance at, and away from, the centre can be different.

If you need help with this at any point, feel free to PM me. I've put every single lens I own through AF fine adjustment on several bodies, so it's something I'm very comfortable with

Thanks Mike.

[rawr]

It might be useful to look at suggestions on AF fine tuning Pentax recently put out on their site:

How to optimize focusing accuracy with large-aperture lenses / Beautiful Photo-life | RICOH IMAGING

See the section titled: (2) Making minute focus adjustment in AF mode for the optimum performance of camera and lens

[jbinpg]

Dave - It has happened in the past that some people have not been following proper procedure to save the new lens adjustments. You must hit the OK button before exiting the AF tuning menu or else it will all be for naught. Maybe check to see that you are doing that.

Jack

[DW58]

It might be useful to look at suggestions on AF fine tuning Pentax recently put out on their site:

How to optimize focusing accuracy with large-aperture lenses / Beautiful Photo-life | RICOH IMAGING

See the section titled: (2) Making minute focus adjustment in AF mode for the optimum performance of camera and lens

Thanks. Some good info here. Appreciate you providing the link.

Dave - It has happened in the past that some people have not been following proper procedure to save the new lens adjustments. You must hit the OK button before exiting the AF tuning menu or else it will all be for naught. Maybe check to see that you are doing that.

Jack

Oh how I wish it were so simple. Thanks for the suggestion but as technologically challenged as I am I at least got that part right. Actually later in the day I was able to get better results with no AF fine tuning. I'm pretty sure my previous failures were due to operator error.

Thanks to all who have chimed in to help.

[ProfessorBuzz]

Glad to help... we're on this journey together. And don't stress about it.. just realize it takes time to get it right.

After all, you're only trying to adjust a lens position by a few thousands of an inch to have a few tiny photons perfectly hit a 4.86 micron pixel in a sea of 36 million pixel buddies. ;-)
But the results can be spectacular.