Search results for 'back focus' - page 1134
Lens calibration shop
I've always wonder how lenses are calibrated. I've taken some apart to fix them and there doesn't appear to be any adjustments to alignment of lenses. It's all in software* - they just rewrite the look-up tables :) You can of course physically adjust the AF module ( with s screw underneath the bott...
Posted by Smeggypants on 29/05/2014 - 07:25
Lens calibration shop
all my other lenses are fine but its been a while since i checked them with the focus chart. which number do you see in focus on the picture in the right?because for me both 0 and the 8 above it seem ok whereas 16 isnt (referring to 2nd column fm right again)
Posted by schnitzer79 on 29/05/2014 - 08:03
Lens calibration shop
all my other lenses are fine but its been a while since i checked them with the focus chart. which number do you see in focus on the picture in the right?because for me both 0 and the 8 above it seem ok whereas 16 isnt (referring to 2nd column fm right again) -8 looks sharper than +8 here so it's st...
Posted by Smeggypants on 29/05/2014 - 09:10
Lens calibration shop
all my other lenses are fine but its been a while since i checked them with the focus chart. which number do you see in focus on the picture in the right?because for me both 0 and the 8 above it seem ok whereas 16 isnt (referring to 2nd column fm right again) -8 looks sharper than +8 here so it's st...
Posted by schnitzer79 on 29/05/2014 - 09:51
Lens calibration shop
[quote:3496ace15f="schnitzer79"]all my other lenses are fine but its been a while since i checked them with the focus chart. which number do you see in focus on the picture in the right?because for me both 0 and the 8 above it seem ok whereas 16 isnt (referring to 2nd column fm right again) -8 looks...
Posted by Smeggypants on 29/05/2014 - 10:06
Lens calibration shop
Given it's phase detect I would have thought some kind of comparator circuit would be used to detect Focus. Something like that. With a bit more maths :) And the output of the correlator also gives you the amount and direction in which to go to focus. Back to the OP : How does this lens behave...
Posted by kh1234567890 on 29/05/2014 - 16:09
Lens calibration shop
The only lenses I've found that lie outside the +/-10 range is some old manual focus lenses. What is the point of adjusting the phase detect AF correction for manual focus lenses ?
Posted by kh1234567890 on 29/05/2014 - 16:12
Lens calibration shop
The only lenses I've found that lie outside the +/-10 range is some old manual focus lenses. What is the point of adjusting the phase detect AF correction for manual focus lenses ? "Capture in focus" - press the shutter release then slowly alter focus and when focus is detected the shutter will rele...
Posted by Gamka on 29/05/2014 - 16:47
Lens calibration shop
[quote:3496ace15f="Smeggypants"] How does this lens behave at infinity (how much correction does it need) ? after ive adjusted it to +10 ive tried it at infinity with f/8 and f/11 and its sharp and everything is in focus.
Posted by schnitzer79 on 29/05/2014 - 17:05
Lens calibration shop
If you want the ultimate in focus peaking and the most accurate focusing possible..... see this software.... http://lensvid.com/gear/kuuvik-capture-tethered-shooting-the-next-stage/ No Pentax version though! Big Boys Don't Cry! :shock: :mrgreen: --
Posted by Algernon on 29/05/2014 - 18:55
Lens calibration shop
[quote:3496ace15f="Smeggypants"]The only lenses I've found that lie outside the +/-10 range is some old manual focus lenses. What is the point of adjusting the phase detect AF correction for manual focus lenses ? "Capture in focus" - press the shutter release then slowly alter focus and when focus i...
Posted by kh1234567890 on 29/05/2014 - 20:29
Lens calibration shop
The only lenses I've found that lie outside the +/-10 range is some old manual focus lenses. What is the point of adjusting the phase detect AF correction for manual focus lenses ? Focus confirmation. .
Posted by Smeggypants on 29/05/2014 - 20:45
Lens calibration shop
Hi everyone, Wanted to know if there is a reputable shop that calibrates lenses for back focus issues (+10 on fine tune wont quite cut it). Thanks Schnitzer, I think I may have found the answer to your problem. Back in the day on the K-10D the only way to adjust AF was in Debug mode. This invo...
Posted by Smeggypants on 29/05/2014 - 22:58
Lens calibration shop
[quote:3496ace15f="kh1234567890"][quote:3496ace15f="Smeggypants"]The only lenses I've found that lie outside the +/-10 range is some old manual focus lenses. What is the point of adjusting the phase detect AF correction for manual focus lenses ? "Capture in focus" - press the shutter release then sl...
Posted by Algernon on 30/05/2014 - 08:51
Lens calibration shop
Post a spoiler you mean :shock: With CiF what do you do when the bit of the image that you want in focus is not at your chosen focus point ?
Posted by kh1234567890 on 30/05/2014 - 11:26
Lens calibration shop
Press shutter half-way. Move in until you get a beep and CiF lit. Re compose. Shoot. :mrgreen: If you look at the video you will see that there is a CiF range just like a DOF range. I set mine up with an adjustment value so that as I move in on a bug the shutter trips at the beginning of t...
Posted by Algernon on 30/05/2014 - 12:06
Lens calibration shop
Press shutter half-way. Move in until you get a beep and CiF lit. Re compose. Shoot. :mrgreen: That is not CiF, where the shutter fires automatically when focus is detected :(
Posted by kh1234567890 on 30/05/2014 - 12:20
Lens calibration shop
Well after some tests it seems that +10 is not consistent throughout all the apertures or focal distance. For instance at a close distance and F/4 the setting needs to be at +10 whereas at focus to infinity and F/11, i get better results with +4 than with +10. Is this common?
Posted by schnitzer79 on 02/06/2014 - 15:02
Lens calibration shop
Well after some tests it seems that +10 is not consistent throughout all the apertures or focal distance. For instance at a close distance and F/4 the setting needs to be at +10 whereas at focus to infinity and F/11, i get better results with +4 than with +10. Is this common? You'll find various r...
Posted by JohnX on 02/06/2014 - 16:58
Lens calibration shop
I still can't understand why people get obsessed with 'calibration'. With DA lenses all the relevant focusing parameters are in the lens EEPROM - read the patents - and so far no-one had figured out what they mean. All that the menu 'calibration' tweak does is correct for tolerances in flange dis...
Posted by davidstorm on 03/06/2014 - 00:26
