Search results for 'back focus' - page 1640
How much focus adjustment?
I've had a read and this proves that some are being misled into thinking they have a fault. http://www.dofmaster.com/doftable.html I put in 300mm at F5.6 for my KR in the table and got 1.5 nearest 1.5 furthest at 1.5 metres, in other words correct focus at that distance with no latitude in depth ...
Posted by wvbarnes on 17/10/2011 - 16:28
How much focus adjustment?
Thanks to Amin for his suggestion. On the K-5 it seems it goes up to +/- 10. I've done it a bit more carefully now, and I'm quite troubled. Here it is, pre-adjustment: Here it is again, +10 dialled in and saved: Both of these are the whole width of the frame. Notice anyth...
Posted by ChrisA on 17/10/2011 - 16:40
How much focus adjustment?
Notice anything funny? Um, the sensor isn't absolutely square to the chart. Very hard to achieve without lots of fiddling about.
Posted by karma mechanic on 17/10/2011 - 16:48
How much focus adjustment?
Notice anything funny? Um, the sensor isn't absolutely square to the chart. Very hard to achieve without lots of fiddling about. Well, I've been doing a lot of fiddling about :) And I thought I had it pretty close. There are a couple of bobbles in the paper where it didn't stick to the card I've ...
Posted by ChrisA on 17/10/2011 - 16:51
How much focus adjustment?
Some lenses can be very slightly off-centre as well, or it could even be a combination of that and the physical adjustment of the sensor inside the body. The sensor assembly is held by the anti-shake, and the whole enclosing assembly is on three adjusting screws. Out of the three K20D's I've conver...
Posted by karma mechanic on 17/10/2011 - 16:59
How much focus adjustment?
For comparison, here's the same lens on the K10D: If there's a difference between left and right, it's clearly a lot less pronounced.
Posted by ChrisA on 17/10/2011 - 17:09
How much focus adjustment?
It looks to me like the K10D one is showing the same general effect though, albeit a little bit back-focussed compared to the K5 one. That would implicate the lens - or the alignment of the chart :) Edited to add - try moving the tripod a centimetre or so to the right, centre the image and sho...
Posted by karma mechanic on 17/10/2011 - 17:12
How much focus adjustment?
It looks to me like the K10D one is showing the same general effect though, albeit a little bit back-focussed compared to the K5 one. That would implicate the lens - or the alignment of the chart :) Edited to add - try moving the tripod a centimetre or so to the right, centre the image and sho...
Posted by ChrisA on 17/10/2011 - 17:17
How much focus adjustment?
I'm just thinking that the difference between sides is only a few mm, so it might be instructive to deliberately skew the alignment to see what happens. If it changes a lot then it suggests the alignment is very sensitive.
Posted by karma mechanic on 17/10/2011 - 17:19
How much focus adjustment?
I'm just thinking that the difference between sides is only a few mm, so it might be instructive to deliberately skew the alignment to see what happens. If it changes a lot then it suggests the alignment is very sensitive. Mmmm. I must admit, I would have thought that any back- or front-focus woul...
Posted by ChrisA on 17/10/2011 - 17:32
How much focus adjustment?
What I meant was whether the lens axis was truly perpendicular to the chart. The plane of sharp focus is only a few mm out across the chart, which could be accounted for by the lens being a few mm off the correct axis. The idea of adding a little bit of error is to see what the effect is - maybe it...
Posted by karma mechanic on 17/10/2011 - 17:43
How much focus adjustment?
What I meant was whether the lens axis was truly perpendicular to the chart. The plane of sharp focus is only a few mm out across the chart, which could be accounted for by the lens being a few mm off the correct axis. The idea of adding a little bit of error is to see what the effect is - maybe it...
Posted by ChrisA on 17/10/2011 - 17:48
How much focus adjustment?
hi as a matter of interest where did you get the chart from and how did you set it up neil
Posted by gtis on 17/10/2011 - 18:48
How much focus adjustment?
where did you get the chart from and how did you set it up http://focustestchart.com/ Printed it out (just the page with the A4 chart on), stuck it on a piece of A4 card, put it on the floor. Camera on a tripod, pointing at the chart. Ages and ages trying to get it lined up straight, possibly...
Posted by ChrisA on 17/10/2011 - 19:25
How much focus adjustment?
where did you get the chart from and how did you set it up http://focustestchart.com/ Printed it out (just the page with the A4 chart on), stuck it on a piece of A4 card, put it on the floor. Camera on a tripod, pointing at the chart. Ages and ages trying to get it lined up straight, possibly...
Posted by gtis on 17/10/2011 - 19:30
How much focus adjustment?
Chris I actually fiddled with micro adjustment quite recently and mine goes up to + and -20 and let me tell you, got so fed up that I ended up leaving it to 0 again. To begin with what seemed like off focus wasn't really much, and most probably was because of the angle etc. What took me to embark o...
Posted by aminstar on 17/10/2011 - 19:58
How much focus adjustment?
You get the green hexagon to confirm where the camera thinks it's focused. Then you take the shot with the lens wide open, and see where it was actually in focus. Sorry to be pedantic, but the green hexagon tells you you're in focus, not what you're focussed on. It's the focus points that do that, ...
Posted by JohnX on 17/10/2011 - 20:24
How much focus adjustment?
You get the green hexagon to confirm where the camera thinks it's focused. Then you take the shot with the lens wide open, and see where it was actually in focus. Sorry to be pedantic, but the green hexagon tells you you're in focus, not what you're focussed on. It's the focus points that do that, ...
Posted by ChrisA on 17/10/2011 - 23:01
How much focus adjustment?
Chris, I wish you hadn't started this thread as it's got me on one of my hobby horses again. I have no idea why some lenses (and cameras) back or front focus, but I was on the point of returning my DA L 55-300 to the supplier as I could not get sharp pics with it and thought the lens was faulty. T...
Posted by davidstorm on 17/10/2011 - 23:52
How much focus adjustment?
At least on the K-5 and K-r it is more accessible. Regards David A mixed blessing though - debug mode isn't yet available on the K-5 and K-r, and you'd never get an adjustment of +70 via the normal adjustment menu.
Posted by karma mechanic on 18/10/2011 - 10:37
