Search results for 'back focus' - page 1743
AF Calibration charts
None. I did try some of them but it's quite simple just to aim at an angle on the back of a corn flakes pack or something with text on at max aperture and adjust until focus is correct. :) is this wide open or shut down? Sorry but I'm still learning to lingo. Will
Posted by Whizzkiddwill on 25/04/2013 - 21:13
AF Calibration charts
The more you stop down, the more of the subject will be in focus. the object is to find the centre of the focus plane so minimum DOF is required. Wide open is best.
Posted by Mannesty on 25/04/2013 - 22:28
AF Calibration charts
None. I did try some of them but it's quite simple just to aim at an angle on the back of a corn flakes pack or something with text on at max aperture and adjust until focus is correct. :) Thought I didn't have a problem but have just tried that and ascertained my DFA 100mm macro was back focussing ...
Posted by JAK on 26/04/2013 - 11:49
AF Calibration charts
... I don't recall any talk of this issue back in the film camera days. The problem could have still been there though.
Posted by Mannesty on 26/04/2013 - 12:33
AF Calibration charts
When using these test charts do you focus from the minimum focus distance of the lens you're testing or is there a set distance for the chart being used? Or does it not matter?
Posted by DaveHolmes on 26/04/2013 - 17:27
AF Calibration charts
Thanks for that link. I'm sure there is some good info there but the rough and ready cornflake packet serves the same function - the one I have has a word search on the back and that's just great! What I am failing to grasp is how some lenses can focus OK on the viewing screen yet be out of focus...
Posted by JAK on 26/04/2013 - 17:29
AF Calibration charts
Anyone come across/use Focus Tune software?
Posted by JohnX on 26/04/2013 - 17:37
AF Calibration charts
I'll have to try it with the old lenses I was using then and see how they fare. Obviously no facility to correct them if they do need it! John K yes there is :) - just use the overall adjustment. You've just got to remember to reset it when changing back to other lenses.
Posted by Smeggypants on 26/04/2013 - 17:40
AF Calibration charts
When using these test charts do you focus from the minimum focus distance of the lens you're testing or is there a set distance for the chart being used? Or does it not matter? I check on various objects at a range of distances
Posted by Smeggypants on 26/04/2013 - 17:41
AF Calibration charts
When using these test charts do you focus from the minimum focus distance of the lens ... You now, once you download stuff, it's good to read it :D The instructions say "minimum focus distance, then back a bit".
Posted by Mannesty on 26/04/2013 - 17:42
AF Calibration charts
You now, once you download stuff, it's good to read it :D The instructions say "minimum focus distance, then back a bit". When and if I do download a test chart I certainly will but as I haven't as yet downloaded anything (and not sure where you got the idea I had?) I thought I'd just gather as m...
Posted by DaveHolmes on 27/04/2013 - 00:03
AF Calibration charts
What I am failing to grasp is how some lenses can focus OK on the viewing screen yet be out of focus on the sensor and hence need adjustment, but not others. An explanation would be interesting and useful. John K I can't find the link now but I remember reading about this a year or two back. I ...
Posted by sbrads on 27/04/2013 - 09:04
AF Calibration charts
I can't find the link now but I remember reading about this a year or two back. I think it's something to do with the focus point not necessarily being the same at different f-stops on some lenses, due to various aberrations. AF and visual focus confirmation is done with the aperture wide open, th...
Posted by JAK on 27/04/2013 - 10:47
AF Calibration charts
I can't find the link now but I remember reading about this a year or two back. I think it's something to do with the focus point not necessarily being the same at different f-stops on some lenses, due to various aberrations. residual spherical aberration, quite common on some older Nikon primes. ...
Posted by johnwhit on 27/04/2013 - 11:36
AF Calibration charts
JAK wrote: ... I don't recall any talk of this issue back in the film camera days. I remember having the lens mount shimmed on one of the film cameras I owned back in the early 70's. Amateur Photographer produced a series of test charts from which you determined the best lines/inch that could be s...
Posted by Frogherder on 27/04/2013 - 16:53
Lens calibration - Focus Tune software
Seeing the recent spate of posts regarding AF fine tuning, anyone seen/used this software? Essentially, (and this appears to be just one of it's functions), you take a series of shots of a standard test target at different AF adjustments and use the software to determine the optimum adjustment. ...
Posted by JohnX on 27/04/2013 - 09:38
Lens calibration - Focus Tune software
Seeing the recent spate of posts regarding AF fine tuning, anyone seen/used this software? Essentially, (and this appears to be just one of it's functions), you take a series of shots of a standard test target at different AF adjustments and use the software to determine the optimum adjustment. ...
Posted by giofi on 27/04/2013 - 10:07
Lens calibration - Focus Tune software
Seems a lot of work..... several shots at each ADJ value :shock: It's cheap though at £20. I wish I knew the algorithmn they are using. It could be largest file size, but unlikely and it isn't that accurate. There is a fully auto program (UK made) for Canon, been out some time. The softw...
Posted by Algernon on 27/04/2013 - 10:44
Lens calibration - Focus Tune software
Seems a lot of work..... several shots at each ADJ value :shock: It's cheap though at £20. ' Don't forget the £4 VAT they will add, but do not show a VAT number. A US company collecting VAT - I wonder how that gets to the UK Government?
Posted by Gamka on 27/04/2013 - 10:49
Lens calibration - Focus Tune software
Seeing the recent spate of posts regarding AF fine tuning, anyone seen/used this software? Essentially, (and this appears to be just one of it's functions), you take a series of shots of a standard test target at different AF adjustments and use the software to determine the optimum adjustment. ...
Posted by JohnX on 27/04/2013 - 10:58
