[Armanius]

Happy you got it resolved!

Nice setup too! Does it matter how far the camera is away from the business card?

ofer4 i just solved my problem, maybe you can follow what i did too.

inspired by lensalign (they sell a few pieces of printed cardboard for $80?? ridiculous...), i created my own.

here is the set up:



a box that i DIY for simple and small object shots,
a ruler,
a binder clip,
and a random business card with good contrast.

actually.. any white background will do, and anything that gives good contrast for the camera to focus is also good.

then place the camera on a tripod, straight and level to the business card, and start taking shots.



after messing on AF fine adjustment for a bit, a -6 value finally gives me the best result of this lens.







a few shots after the adjustment... all taken with CIF.
i would say the focus is pretty dead on now, since it gives the same sharpness as using live view focus.

also make sure you turn the focus ring very slowly when it gets near focus distance.
the slower the shutter speed is, the slower your have to turn it.

[telly0050]

Happy you got it resolved!

Nice setup too! Does it matter how far the camera is away from the business card?

I think the distance is all depends on what focal length you using.
I am testing the 50mm so it is about 1 meter away.

[Gimbal]

Also test turning the focus ring from both directions, from far to focus, and near to focus. I think that will show you how much "play" there actually is with the AF.

[Armanius]

How would you calculate the distance to determine one meter for a 50mm lens? I plan to test my 35mm lens. Thanks!

[telly0050]

gimbal:

thanks for letting me know, i'll try it out later.

Armanius:

actually i think it doesn't matter what distance you use, just try 0.5/1/2/3 meters
if you can adjust it to focus right on any distance, then your lens is done.

[Armanius]

Thank you.

[Frogfish]

Also test turning the focus ring from both directions, from far to focus, and near to focus. I think that will show you how much "play" there actually is with the AF.

This is important to note as far as using the focus confirmation hexagon is concerned. Using the hexagon all lenses have an 'in-focus range' whereby some part of that range really is in focus and of course therefore the other end is not. This will vary from lens to lens though most of my MF lenses hit real focus more often when focusing from infinity (far to near) rather than towards infinity (near to far).

[MartinDK]

After messing on AF fine adjustment for a bit, a -6 value finally gives me the best result of this lens.

Thanks for sharing your thoughts on the CIF accuracy problem.:-)

I have the same 50mm/f1.7 lens but I probably need an -11 or -12 AF adjustment to get the sharpest result. -10 is the limit on the K-5 and unfortunately this isn't enough.

Btw, f5.6 seems to be the "sweet spot"!


Regards,

Martin

[sergysergy]

MartinDK,
look for "K5 debug mode" in the forums. I have no idea of how it works but you should be able to go further than +/-10

[JohnBee]

MartinDK,
look for "K5 debug mode" in the forums. I have no idea of how it works but you should be able to go further than +/-10

There is a small software called "PK_Tether" that enables debug mode.

I tried it yesterday and successfully adjusted a backfocus on my K-5 -140um. Which in turned allow me to dial my microfocus adjustement from -8 down to 0.

PS. you have to turn debug on, then off again with the software.

[jbinpg]

Just to confirm that if your lens was backfocussed, you would need to dial in *positive* adjustment, not negative? Pentax uses the sensor plane as the zero reference rather than the lens focal point. I know Canon does it the other way around.

Jack