Search results for 'back focus' - page 1125
AF Adjustment
My Pentax WR 100mm F2.8 Macro, a lens that costs £800 when new, would have had to go in the bin if I hadn't calibrated it. As I bought it second hand, I could not send it back to the shop for exchange or refund. It was useless before I adjusted the AF on all my bodies, bearing in mind this is a ma...
Posted by davidstorm on 14/02/2014 - 00:10
AF Adjustment
I have tried micro-focus adjustment several times on a number of lenses with my K30 - DA 35 f/2.4, F 35-70mm, DA 18-55mm ALII kit lens, DA 55-300mm - and cannot yet convince myself that I have discovered a method that works reliably and is repeatable. I have tried taking photos of focus charts; o...
Posted by andrewk on 14/02/2014 - 00:12
AF Adjustment
There is margin for error when adjusting and also different lighting conditions, different focal lengths, different focus distances all play a part. However, if a lens is consistently 'off' it makes sense that it needs calibrating. See above, what I've said about my Pentax DFA 100mm macro lens. I...
Posted by davidstorm on 14/02/2014 - 00:18
AF Adjustment
Can anyone tell if hearing the sound of the elements clink when the lens reaches infinity or zero when I manually focus my da"200 is normal? Re my focus adjustment. I have been using this focal length regularly for a year now and rarely have I used or felt I needed to us a tripod and I doub...
Posted by kiwao on 14/02/2014 - 00:44
AF Adjustment
I disagree John. How can it 'be calibrated at the factory' when the manufacturer cannot account for the combination of camera body and lens that we use? There are permissible tolerances that are very fine. These tolerances are designed to fall within the depth of focus. As long as they do, then all ...
Posted by johnriley on 14/02/2014 - 08:16
AF Adjustment
I disagree John. How can it 'be calibrated at the factory' when the manufacturer cannot account for the combination of camera body and lens that we use? There are permissible tolerances that are very fine. These tolerances are designed to fall within the depth of focus. As long as they do, then all ...
Posted by Smeggypants on 14/02/2014 - 09:27
AF Adjustment
I have tried micro-focus adjustment several times on a number of lenses with my K30 - DA 35 f/2.4, F 35-70mm, DA 18-55mm ALII kit lens, DA 55-300mm - and cannot yet convince myself that I have discovered a method that works reliably and is repeatable. I have tried taking photos of focus charts; o...
Posted by Smeggypants on 14/02/2014 - 09:31
AF Adjustment
Every K mount body would have to be calibrated with every inastance of every lens and store that calibration against the serial number of those lenses. There must be billions on combinations, given there's thousands of bodies and thousands of lenses. Not if you stored the lens calibration parameters...
Posted by Smeggypants on 14/02/2014 - 14:07
AF Adjustment
There are permissible tolerances that are very fine. These tolerances are designed to fall within the depth of focus. As long as they do, then all will be well. I'm talking here of Pentax cameras with Pentax lenses. The manufacturer knows how much leeway in manufacture is permissible. Now if we a...
Posted by davidstorm on 14/02/2014 - 21:06
AF Adjustment
The 'calibration' is just a fiddle factor numerical offset added to the phase detect module output to compensate for tolerances in the lens mount thickness - 'global' one for the body and a lens one for the lens flange. The two are added together. Nothing physically moves when you change it. What...
Posted by gwing on 14/02/2014 - 22:59
AF Adjustment
As an aside, was there any form of focus adjustment on the K-100d? I'm using this again whilst my K-30 is being looked at and it back focuses horribly :cry: Edit: just googled this on the bus to work. Seems a special service menu is the only way and it's a global setting for all lenses. Might ...
Posted by richandfleur on 18/02/2014 - 12:05
AF Adjustment
Reading this whole thread to date, I'm going to calibrate my primes at least, when I get my K-30 back...
Posted by richandfleur on 18/02/2014 - 12:15
AF Adjustment
The only way to do it on the K10D was in debug mode. I actually left my K10D in debug mode and changed the value when I changed lenses. yes it was a PITA, but better to have images in focus :)
Posted by Smeggypants on 18/02/2014 - 15:55
YES!!! 30MM!!!
25p! Yes, you guessed it, it's a typo. Just as a heads up. Cheapest pint around here can be had for $7 during happy hours in TAB bars (betting section). Pints in Perth are $10 to $19. Exchange rate is around .543 at the moment so the $ is down. It was much higher some months back and was even $1....
Posted by K10D on 22/02/2014 - 23:06
DA* 16-50mm F2.8 vs Sigma 17-50 F2.8
£130 sounds reasonable including the new motor. So i can put DA* lenses back on my dream list. The one i really want is the DA* 50-135 but its pie in the sky stuff for me.
Posted by Russ on 13/02/2014 - 21:40
DA* 16-50mm F2.8 vs Sigma 17-50 F2.8
£130 sounds reasonable including the new motor. So i can put DA* lenses back on my dream list. The one i really want is the DA* 50-135 but its pie in the sky stuff for me. I almost bankrupted myself to get both.....!!! :shock: The 50-135 really is worth saving for, big and heavy with a huge hood but...
Posted by Jetsam1 on 13/02/2014 - 21:52
DA* 16-50mm F2.8 vs Sigma 17-50 F2.8
I have them both. The Sigma is a great lens. I now rarely use it because the shorter 1mm focal length on the Pentax makes it more useable. I used the built in OS on the Sigma rather than the in body IS. It is fast to focus and I have had no issues with focus accuracy on it. One real quibble...
Posted by K10D on 14/02/2014 - 00:50
Interesting Mount Adapter...
There was a discussion on this a few months back. Search and you may find.
Posted by Gamka on 15/02/2014 - 09:44
Interesting Mount Adapter...
There was a discussion on this a few months back. Search and you may find. Oh thank you from the bottom of my heart for your insight Gamka, please allow me to continue living in your god like shadow...:roll:
Posted by jules on 15/02/2014 - 10:13
Examples of 10mm wide angle to 17mm
In a similar vein I posted this a while back (8-16mm)
Posted by Pentaxophile on 15/02/2014 - 23:01
